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Intellectual disability

MedGen UID:
334384
Concept ID:
C1843367
Finding
Synonyms: Dull intelligence; Low intelligence; Mental deficiency; Mental retardation, nonspecific; Mental-retardation; Nonprogressive intellectual disability; Nonprogressive mental retardation; Poor school performance
 
HPO: HP:0001249

Conditions with this feature

Acrocephalosyndactyly type I
MedGen UID:
7858
Concept ID:
C0001193
Congenital Abnormality
The eight disorders comprising the FGFR-related craniosynostosis spectrum are Pfeiffer syndrome, Apert syndrome, Crouzon syndrome, Beare-Stevenson syndrome, FGFR2-related isolated coronal synostosis, Jackson-Weiss syndrome, Crouzon syndrome with acanthosis nigricans (AN), and Muenke syndrome (isolated coronal synostosis caused by the p.Pro250Arg pathogenic variant in FGFR3). Muenke syndrome and FGFR2-related isolated coronal synostosis are characterized only by uni- or bicoronal craniosynostosis; the remainder are characterized by bicoronal craniosynostosis or cloverleaf skull, distinctive facial features, and variable hand and foot findings.
Autistic disorder of childhood onset
MedGen UID:
13966
Concept ID:
C0004352
Mental or Behavioral Dysfunction
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypic, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). Levy et al. (2009) provided a general review of autism and autism spectrum disorder, including epidemiology, characteristics of the disorder, diagnosis, neurobiologic hypotheses for the etiology, genetics, and treatment options. Genetic Heterogeneity of Autism Autism is considered to be a complex multifactorial disorder involving many genes. Accordingly, several loci have been identified, some or all of which may contribute to the phenotype. Included in this entry is AUTS1, which has been mapped to chromosome 7q22. Other susceptibility loci include AUTS3 (608049), which maps to chromosome 13q14; AUTS4 (608636), which maps to chromosome 15q11; AUTS6 (609378), which maps to chromosome 17q11; AUTS7 (610676), which maps to chromosome 17q21; AUTS8 (607373), which maps to chromosome 3q25-q27; AUTS9 (611015), which maps to chromosome 7q31; AUTS10 (611016), which maps to chromosome 7q36; AUTS11 (610836), which maps to chromosome 1q41; AUTS12 (610838), which maps to chromosome 21p13-q11; AUTS13 (610908), which maps to chromosome 12q14; AUTS14A (611913), which has been found in patients with a deletion of a region of 16p11.2; AUTS14B (614671), which has been found in patients with a duplication of a region of 16p11.2; AUTS15 (612100), associated with mutation in the CNTNAP2 gene (604569) on chromosome 7q35-q36; AUTS16 (613410), associated with mutation in the SLC9A9 gene (608396) on chromosome 3q24; AUTS17 (613436), associated with mutation in the SHANK2 gene (603290) on chromosome 11q13; AUTS18 (615032), associated with mutation in the CHD8 gene (610528) on chromosome 14q11; and AUTS19, associated with mutation in the EIF4E gene (133440) on chromosome 4q23. (NOTE: the symbol 'AUTS2' has been used to refer to a gene on chromosome 7q11 (KIAA0442; 607270) and therefore is not used as a part of this autism locus series.) There are several X-linked forms of autism susceptibility: AUTSX1 (300425), associated with mutations in the NLGN3 gene (300336); AUTSX2 (300495), associated with mutations in NLGN4 (300427); AUTSX3 (300496), associated with mutations in MECP2 (300005); AUTSX4 (300830), associated with variation in the region on chromosome Xp22.11 containing the PTCHD1 gene (300828); AUTSX5 (300847), associated with mutations in the RPL10 gene (312173); and AUTSX6 (300872), associated with mutation in the TMLHE gene (300777). A locus on chromosome 2q (606053) associated with a phenotype including intellectual disability and speech deficits was formerly designated AUTS5. Folstein and Rosen-Sheidley (2001) reviewed the genetics of autism.
Gorlin syndrome
MedGen UID:
2554
Concept ID:
C0004779
Neoplastic Process
Nevoid basal cell carcinoma syndrome (NBCCS) is characterized by the development of multiple jaw keratocysts, frequently beginning in the second decade of life, and/or basal cell carcinomas (BCCs) usually from the third decade onward. Approximately 60% of individuals have a recognizable appearance with macrocephaly, frontal bossing, coarse facial features, and facial milia. Most individuals have skeletal anomalies (e.g., bifid ribs, wedge-shaped vertebrae). Ectopic calcification, particularly in the falx, is present in more than 90% of affected individuals by age 20 years. Cardiac and ovarian fibromas occur in approximately 2% and 20% of individuals respectively. Approximately 5% of all children with NBCCS develop medulloblastoma (primitive neuroectodermal tumor), generally the desmoplastic subtype. The risk of developing medulloblastoma is substantially higher in individuals with an SUFU pathogenic variant (33%) than in those with a PTCH1 pathogenic variant (<2%). Peak incidence is at age one to two years. Life expectancy in NBCCS is not significantly different from average.
Chédiak-Higashi syndrome
MedGen UID:
3347
Concept ID:
C0007965
Disease or Syndrome
Chediak-Higashi syndrome (CHS) is characterized by partial oculocutaneous albinism, immunodeficiency, and a mild bleeding tendency. Approximately 85% of affected individuals develop the accelerated phase, or hemophagocytic lymphohistiocytosis, a life-threatening, hyperinflammatory condition. All affected individuals including adolescents and adults with atypical CHS and children with classic CHS who have successfully undergone allogenic hematopoietic stem cell transplantation (HSCT) develop neurologic findings during early adulthood.
Crouzon syndrome
MedGen UID:
1162
Concept ID:
C0010273
Disease or Syndrome
Crouzon syndrome is a genetic disorder characterized by the premature fusion of certain skull bones (craniosynostosis). This early fusion prevents the skull from growing normally and affects the shape of the head and face.Many features of Crouzon syndrome result from the premature fusion of the skull bones. Abnormal growth of these bones leads to wide-set, bulging eyes and vision problems caused by shallow eye sockets; eyes that do not point in the same direction (strabismus); a beaked nose; and an underdeveloped upper jaw. In addition, people with Crouzon syndrome may have dental problems and hearing loss, which is sometimes accompanied by narrow ear canals. A few people with Crouzon syndrome have an opening in the lip and the roof of the mouth (cleft lip and palate). The severity of these signs and symptoms varies among affected people. People with Crouzon syndrome are usually of normal intelligence.
5p partial monosomy syndrome
MedGen UID:
41345
Concept ID:
C0010314
Disease or Syndrome
Cri-du-chat syndrome was first described by Lejeune et al. (1963) as a hereditary congenital syndrome associated with deletion of part of the short arm of chromosome 5. The deletions can vary in size from extremely small and involving only band 5p15.2 to the entire short arm. Although the majority of deletions arise as new mutations, approximately 12% result from unbalanced segregation of translocations or recombination involving a pericentric inversion in one of the parents.
Complete trisomy 21 syndrome
MedGen UID:
4385
Concept ID:
C0013080
Disease or Syndrome
Down syndrome, the most frequent form of mental retardation caused by a microscopically demonstrable chromosomal aberration, is characterized by well-defined and distinctive phenotypic features and natural history. It is caused by triplicate state (trisomy) of all or a critical portion of chromosome 21.
Chondroectodermal dysplasia
MedGen UID:
8584
Concept ID:
C0013903
Disease or Syndrome
Ellis-van Creveld syndrome is an autosomal recessive skeletal dysplasia characterized by short limbs, short ribs, postaxial polydactyly, and dysplastic nails and teeth. Congenital cardiac defects, most commonly a defect of primary atrial septation producing a common atrium, occur in 60% of affected individuals (summary by Ruiz-Perez et al., 2000). The clinical features of the Ellis-van Creveld syndrome appear to be identical regardless of whether the disorder is caused by mutation in the EVC gene (604831) or in the EVC2 gene (607261) (Ruiz-Perez et al., 2003, Galdzicka et al., 2002).
Progressive myositis ossificans
MedGen UID:
4698
Concept ID:
C0016037
Disease or Syndrome
Fibrodysplasia ossificans progressiva is a rare autosomal dominant disease with complete penetrance involving progressive ossification of skeletal muscle, fascia, tendons, and ligaments. FOP has a prevalence of approximately 1 in 2 million worldwide, and shows no geographic, ethnic, racial, or gender preference. Individuals with FOP appear normal at birth except for great toe abnormalities: the great toes are short, deviated, and monophalangic. Ossification occurs progressively over the course of a lifetime in an inevitable and unpredictable episodic manner, with most patients being confined to a wheelchair by the third decade of life and requiring lifelong care (summary by Petrie et al., 2009).
Focal dermal hypoplasia
MedGen UID:
42055
Concept ID:
C0016395
Disease or Syndrome
Focal dermal hypoplasia is a multisystem disorder characterized primarily by involvement of the skin, skeletal system, eyes, and face. Skin manifestations present at birth include atrophic and hypoplastic areas of skin; cutis aplasia; fat nodules in the dermis manifesting as soft, yellow-pink cutaneous nodules; and pigmentary changes. Verrucoid papillomas of the skin and mucous membranes may appear later. The nails can be ridged, dysplastic, or hypoplastic; hair can be sparse or absent. Limb malformations include oligo-/syndactyly and split hand/foot. Developmental abnormalities of the eye can include anophthalmia/microphthalmia, iris and chorioretinal coloboma, and lacrimal duct abnormalities. Craniofacial findings can include facial asymmetry, notched alae nasi, cleft lip and palate, and pointed chin. Occasional findings include dental anomalies, abdominal wall defects, diaphragmatic hernia, and renal anomalies. Psychomotor development is usually normal; some individuals have cognitive impairment.
Hereditary fructosuria
MedGen UID:
42105
Concept ID:
C0016751
Disease or Syndrome
Following dietary exposure to fructose, sucrose, or sorbitol, untreated hereditary fructose intolerance (HFI) is characterized by metabolic disturbances (hypoglycemia, lactic acidemia, hypophosphatemia, hyperuricemia, hypermagnesemia, hyperalaninemia) and clinical findings (nausea, vomiting, and abdominal distress; chronic growth restriction/failure to thrive). Untreated HFI typically first manifests when fructose- and sucrose-containing foods are introduced in the course of weaning young infants from breast milk. If large quantities of fructose are ingested, the infant may acutely develop lethargy, seizures, and/or progressive coma. Untreated HFI may result in renal and hepatic failure. If identified and treated before permanent organ injury occurs, individuals with HFI can experience a normal quality of life and life expectancy.
Fucosidosis
MedGen UID:
5288
Concept ID:
C0016788
Disease or Syndrome
Fucosidosis is an autosomal recessive lysosomal storage disease caused by defective alpha-L-fucosidase with accumulation of fucose in the tissues. Clinical features include angiokeratoma, progressive psychomotor retardation, neurologic signs, coarse facial features, and dysostosis multiplex. Fucosidosis has been classified into 2 major types. Type 1 is characterized by rapid psychomotor regression and severe neurologic deterioration beginning at about 6 months of age, elevated sweat sodium chloride, and death within the first decade of life. Type 2 is characterized by milder psychomotor retardation and neurologic signs, the development of angiokeratoma corporis diffusum, normal sweat salinity, and longer survival (Kousseff et al., 1976).
Hallermann-Streiff syndrome
MedGen UID:
5414
Concept ID:
C0018522
Disease or Syndrome
Hallermann-Streiff syndrome is characterized by a typical skull shape (brachycephaly with frontal bossing), hypotrichosis, microphthalmia, cataracts, beaked nose, micrognathia, skin atrophy, dental anomalies, and proportionate short stature (Hallermann, 1948; Streiff, 1950; Francois, 1958). Mental retardation is present in a minority of cases (Gorlin et al., 1990).
Hereditary insensitivity to pain with anhidrosis
MedGen UID:
6915
Concept ID:
C0020074
Disease or Syndrome
Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV (HSAN IV), is characterized by insensitivity to pain, anhidrosis (the inability to sweat), and intellectual disability. The ability to sense all pain (including visceral pain) is absent, resulting in repeated injuries including: oral self-mutilation (biting of tongue, lips, and buccal mucosa); biting of fingertips; bruising, scarring, and infection of the skin; multiple bone fractures (many of which fail to heal properly); and recurrent joint dislocations resulting in joint deformity. Sense of touch, vibration, and position are normal. Anhidrosis predisposes to recurrent febrile episodes that are often the initial manifestation of CIPA. Hypothermia in cold environments also occurs. Intellectual disability of varying degree is observed in most affected individuals; hyperactivity and emotional lability are common.
Incontinentia pigmenti syndrome
MedGen UID:
7049
Concept ID:
C0021171
Disease or Syndrome
Incontinentia pigmenti (IP) is a disorder that affects the skin, hair, teeth, nails, eyes, and central nervous system; it occurs primarily in females and on occasion in males. Characteristic skin lesions evolve through four stages: I. Blistering (birth to age ~4 months). II. Wart-like rash (for several months). III. Swirling macular hyperpigmentation (age ~6 months into adulthood). IV. Linear hypopigmentation. Alopecia, hypodontia, abnormal tooth shape, and dystrophic nails are observed. Neovascularization of the retina, present in some individuals, predisposes to retinal detachment. Neurologic findings including seizures, intellectual disability, and developmental delays are occasionally seen.
Hypomelanosis of Ito
MedGen UID:
5920
Concept ID:
C0022283
Congenital Abnormality
A large brown, blue, or gray hamartoma of dermal melanocytes, usually on the shoulder and upper arm that is most commonly found in Asian populations and in females. It is sometimes associated with sensory changes in the involved skin area, but very rarely becomes cancerous.
Menkes kinky-hair syndrome
MedGen UID:
44030
Concept ID:
C0022716
Disease or Syndrome
Menkes disease is an X-linked recessive disorder characterized by generalized copper deficiency. The clinical features result from the dysfunction of several copper-dependent enzymes. De Bie et al. (2007) provided a detailed review of the molecular pathogenesis of Menkes disease.
Klippel Trenaunay syndrome
MedGen UID:
9646
Concept ID:
C0022739
Disease or Syndrome
Klippel-Trenaunay syndrome is a condition that affects the development of blood vessels, soft tissues (such as skin and muscles), and bones. The disorder has three characteristic features: a red birthmark called a port-wine stain, abnormal overgrowth of soft tissues and bones, and vein malformations.Most people with Klippel-Trenaunay syndrome are born with a port-wine stain. This type of birthmark is caused by swelling of small blood vessels near the surface of the skin. Port-wine stains are typically flat and can vary from pale pink to deep maroon in color. In people with Klippel-Trenaunay syndrome, the port-wine stain usually covers part of one limb. The affected area may become lighter or darker with age. Occasionally, port-wine stains develop small red blisters that break open and bleed easily.Klippel-Trenaunay syndrome is also associated with overgrowth of bones and soft tissues beginning in infancy. Usually this abnormal growth is limited to one limb, most often one leg. However, overgrowth can also affect the arms or, rarely, the torso. The abnormal growth can cause pain, a feeling of heaviness, and reduced movement in the affected area. If the overgrowth causes one leg to be longer than the other, it can also lead to problems with walking.Malformations of veins are the third major feature of Klippel-Trenaunay syndrome. These abnormalities include varicose veins, which are swollen and twisted veins near the surface of the skin that often cause pain. Varicose veins usually occur on the sides of the upper legs and calves. Veins deep in the limbs can also be abnormal in people with Klippel-Trenaunay syndrome. Malformations of deep veins increase the risk of a type of blood clot called a deep vein thrombosis (DVT). If a DVT travels through the bloodstream and lodges in the lungs, it can cause a life-threatening blood clot known as a pulmonary embolism (PE).Other complications of Klippel-Trenaunay syndrome can include a type of skin infection called cellulitis, swelling caused by a buildup of fluid (lymphedema), and internal bleeding from abnormal blood vessels. Less commonly, this condition is also associated with fusion of certain fingers or toes (syndactyly) or the presence of extra digits (polydactyly).
Langer-Giedion syndrome
MedGen UID:
6009
Concept ID:
C0023003
Disease or Syndrome
Trichorhinophalangeal syndrome (TRPS) comprises TRPS I (caused by a heterozygous pathogenic variant in TRPS1) and TRPS II (caused by contiguous gene deletion of TRPS1, RAD21, and EXT1). Both types of TRPS are characterized by distinctive facial features; ectodermal features (fine, sparse, depigmented, and slow growing hair; dystrophic nails; and small breasts); and skeletal findings (short stature; short feet; brachydactyly with ulnar or radial deviation of the fingers; and early, marked hip dysplasia). TRPS II is characterized by multiple osteochondromas (typically first observed clinically on the scapulae and around the elbows and knees between ages 1 month and 6 years) and an increased risk of mild-to-moderate intellectual disability.
Laurence-Moon syndrome
MedGen UID:
44078
Concept ID:
C0023138
Disease or Syndrome
PNPLA6-related disorders span a phenotypic continuum characterized by variable combinations of cerebellar ataxia, upper motor neuron involvement manifesting as spasticity and/or brisk reflexes, chorioretinal dystrophy associated with variable degrees of reduced visual function, and hypogonadotropic hypogonadism (delayed puberty and lack of secondary sex characteristics), either in isolation or as part of anterior hypopituitarism (growth hormone, thyroid hormone, or gonadotropin deficiencies). Common but less frequent features are peripheral neuropathy (usually of axonal type manifesting as reduced distal reflexes, diminished vibratory sensation, and/or distal muscle wasting), hair anomalies (long eyelashes, bushy eyebrows, or scalp alopecia), short stature, and impaired cognitive functioning (learning disabilities in children and deficits in attention, visuospatial abilities, and recall in adults). Some of these features can occur in distinct clusters on the phenotypic continuum: Boucher-Neuhäuser syndrome (cerebellar ataxia, chorioretinal dystrophy, and hypogonadotropic hypogonadism); Gordon Holmes syndrome (cerebellar ataxia, hypogonadotropic hypogonadism, and – to a variable degree – brisk reflexes); Oliver-McFarlane syndrome (trichomegaly, chorioretinal dystrophy, short stature, intellectual disability, and hypopituitarism); Laurence-Moon syndrome; and spastic paraplegia type 39 (SPG39) (upper motor neuron involvement, peripheral neuropathy, and sometimes reduced cognitive functioning and/or cerebellar ataxia).
Leigh syndrome
MedGen UID:
44095
Concept ID:
C0023264
Disease or Syndrome
Leigh syndrome is a clinically and genetically heterogeneous disorder resulting from defective mitochondrial energy generation. It most commonly presents as a progressive and severe neurodegenerative disorder with onset within the first months or years of life, and may result in early death. Affected individuals usually show global developmental delay or developmental regression, hypotonia, ataxia, dystonia, and ophthalmologic abnormalities, such as nystagmus or optic atrophy. The neurologic features are associated with the classic findings of T2-weighted hyperintensities in the basal ganglia and/or brainstem on brain imaging. Leigh syndrome can also have detrimental multisystemic affects on the cardiac, hepatic, gastrointestinal, and renal organs. Biochemical studies in patients with Leigh syndrome tend to show increased lactate and abnormalities of mitochondrial oxidative phosphorylation. Thus, Leigh syndrome may be a clinical feature of a primary deficiency of any of the mitochondrial respiratory chain complexes: complex I deficiency (see 252010), complex II deficiency (see 252011), complex III deficiency (see 124000), complex IV deficiency (cytochrome c oxidase; see 220110), or complex V deficiency (see 604273) (summary by Lake et al., 2015). Genetic Heterogeneity of Leigh Syndrome Mutations in complex I genes include mitochondrial-encoded MTND2 (516001), MTND3 (516002), MTND5 (516005), and MTND6 (516006), the nuclear-encoded NDUFS1 (157655), NDUFS3 (603846), NDUFS4 (602694), NDUFS7 (601825), NDUFS8 (602141), NDUFA2 (602137), NDUFA9 (603834), NDUFA10 (603835), NDUFA12 (614530), NDUFAF6 (612392), and NDUFAF5 (612360). Mutation in the MTFMT gene (611766), which is involved in mitochondrial translation, has also been reported with complex I deficiency. A mutation has been found in a complex III gene: BCS1L (603647), which is involved in the assembly of complex III. Mutations in complex IV genes include mitochondrial-encoded MTCO3 (516050) and nuclear-encoded COX10 (602125), COX15 (603646), SCO2 (604272), SURF1 (185620), which is involved in the assembly of complex IV, TACO1 (612958), and PET100 (614770). A mutation has been found in a complex V gene: the mitochondrial-encoded MTATP6 (516060). Mutations in genes encoding mitochondrial tRNA proteins have also been identified in patients with Leigh syndrome: see MTTV (590105), MTTK (590060), MTTW (590095), and MTTL1 (590050). Leigh syndrome may also be caused by mutations in components of the pyruvate dehydrogenase complex (e.g., DLD, 238331 and PDHA1, 300502). The French Canadian (or Saguenay-Lac-Saint-Jean) type of Leigh syndrome with COX deficiency (LSFC; 220111) is caused by mutation in the LRPPRC gene (607544). Deficiency of coenzyme Q10 (607426) can present as Leigh syndrome.
Lesch-Nyhan syndrome
MedGen UID:
9721
Concept ID:
C0023374
Disease or Syndrome
Lesch-Nyhan syndrome is characterized by motor dysfunction that resembles cerebral palsy, cognitive and behavioral disturbances, and uric acid overproduction (hyperuricemia). The most common presenting features, hypotonia and developmental delay, are evident by age three to six months. Affected children are delayed in sitting and most never walk. Within the first few years, extrapyramidal involvement (e.g., dystonia, choreoathetosis, opisthotonos) and pyramidal involvement (e.g., spasticity, hyperreflexia, extensor plantar reflexes) become evident. Cognitive impairment and behavioral disturbances emerge between ages two and three years. Persistent self-injurious behavior (biting the fingers, hands, lips, and cheeks; banging the head or limbs) is a hallmark of the disease. Overproduction of uric acid may lead to deposition of uric acid crystals or calculi in the kidneys, ureters, or bladder. Gouty arthritis may occur later in the disease. Related disorders with less severe manifestations include hyperuricemia with neurologic dysfunction but no self-injurious behavior and hyperuricemia alone, sometimes with acute renal failure.
Metachromatic leukodystrophy
MedGen UID:
6071
Concept ID:
C0023522
Disease or Syndrome
Arylsulfatase A deficiency (also known as metachromatic leukodystrophy or MLD) is characterized by three clinical subtypes: late-infantile MLD, juvenile MLD, and adult MLD. Age of onset within a family is usually similar. The disease course may be from several years in the late-infantile-onset form to decades in the juvenile- and adult-onset forms. Late-infantile MLD. Onset is before age 30 months. Typical presenting findings include weakness, hypotonia, clumsiness, frequent falls, toe walking, and dysarthria. As the disease progresses, language, cognitive, and gross and fine motor skills regress. Later signs include spasticity, pain, seizures, and compromised vision and hearing. In the final stages, children have tonic spasms, decerebrate posturing, and general unawareness of their surroundings. Juvenile MLD. Onset is between age 30 months and 16 years. Initial manifestations include decline in school performance and emergence of behavioral problems, followed by gait disturbances. Progression is similar to but slower than in the late-infantile form. Adult MLD. Onset occurs after age 16 years, sometimes not until the fourth or fifth decade. Initial signs can include problems in school or job performance, personality changes, emotional lability, or psychosis; in others, neurologic symptoms (weakness and loss of coordination progressing to spasticity and incontinence) or seizures initially predominate. Peripheral neuropathy is common. Disease course is variable – with periods of stability interspersed with periods of decline – and may extend over two to three decades. The final stage is similar to earlier-onset forms.
Deficiency of alpha-mannosidase
MedGen UID:
7467
Concept ID:
C0024748
Disease or Syndrome
Alpha-mannosidosis encompasses a continuum of clinical findings from mild to severe. Three major clinical subtypes have been suggested: A mild form recognized after age ten years with absence of skeletal abnormalities, myopathy, and slow progression (type 1). A moderate form recognized before age ten years with presence of skeletal abnormalities, myopathy, and slow progression (type 2). A severe form manifested as prenatal loss or early death from progressive central nervous system involvement or infection (type 3). Individuals with a milder phenotype have mild-to-moderate intellectual disability, impaired hearing, characteristic coarse features, clinical or radiographic skeletal abnormalities, immunodeficiency, and primary central nervous system disease – mainly cerebellar involvement causing ataxia. Periods of psychiatric symptoms are common. Associated medical problems can include corneal opacities, hepatosplenomegaly, aseptic destructive arthritis, and metabolic myopathy. Alpha-mannosidosis is insidiously progressive; some individuals may live into the sixth decade.
Maple syrup urine disease
MedGen UID:
6217
Concept ID:
C0024776
Disease or Syndrome
Maple syrup urine disease (MSUD) is classified as classic or intermediate. Twelve hours after birth, untreated neonates with classic MSUD have a maple syrup odor in cerumen; by 12-24 hours, elevated plasma concentrations of branched-chain amino acids (BCAAs) (leucine, isoleucine, and valine) and allo-isoleucine, as well as a generalized disturbance of plasma amino acid concentration ratios; by age two to three days, ketonuria, irritability, and poor feeding; by age four to five days, deepening encephalopathy manifesting as lethargy, intermittent apnea, opisthotonus, and stereotyped movements such as "fencing" and "bicycling." By age seven to ten days, coma and central respiratory failure may supervene. Individuals with intermediate MSUD have partial BCKAD enzyme deficiency that only manifests intermittently or responds to dietary thiamine therapy; these individuals can experience severe metabolic intoxication and encephalopathy during sufficient catabolic stress.
Marinesco-Sjögren syndrome
MedGen UID:
6222
Concept ID:
C0024814
Disease or Syndrome
Marinesco-Sjögren syndrome (MSS) is characterized by cerebellar ataxia with cerebellar atrophy, dysarthria, nystagmus, early-onset (not necessarily congenital) cataracts, myopathy, muscle weakness, and hypotonia. Additional features may include psychomotor delay, hypergonadotropic hypogonadism, short stature, and various skeletal abnormalities. Children with MSS usually present with muscular hypotonia in early infancy; distal and proximal muscular weakness is noticed during the first decade of life. Later, cerebellar findings of truncal ataxia, dysdiadochokinesia, nystagmus, and dysarthria become apparent. Motor function worsens progressively for some years, then stabilizes at an unpredictable age and degree of severity. Cataracts can develop rapidly and typically require lens extraction in the first decade of life. Although many adults have severe disabilities, life span in MSS appears to be near normal.
Lowe syndrome
MedGen UID:
18145
Concept ID:
C0028860
Disease or Syndrome
Lowe syndrome (oculocerebrorenal syndrome) is characterized by involvement of the eyes, central nervous system, and kidneys. Dense congenital cataracts are found in all affected boys and infantile glaucoma in approximately 50%. All boys have impaired vision; corrected acuity is rarely better than 20/100. Generalized hypotonia is noted at birth and is of central (brain) origin. Deep tendon reflexes are usually absent. Hypotonia may slowly improve with age, but normal motor tone and strength are never achieved. Motor milestones are delayed. Almost all affected males have some degree of intellectual disability; 10%-25% function in the low-normal or borderline range, approximately 25% in the mild-to-moderate range, and 50%-65% in the severe-to-profound range of intellectual disability. Affected males have varying degrees of proximal renal tubular dysfunction of the Fanconi type, including low molecular-weight (LMW) proteinuria, aminoaciduria, bicarbonate wasting and renal tubular acidosis, phosphaturia with hypophosphatemia and renal rickets, hypercalciuria, sodium and potassium wasting, and polyuria. The features of symptomatic Fanconi syndrome do not usually become manifest until after the first few months of life, except for LMW proteinuria. Glomerulosclerosis associated with chronic tubular injury usually results in slowly progressive chronic renal failure and end-stage renal disease between the second and fourth decades of life.
Pelger-Huët anomaly
MedGen UID:
10617
Concept ID:
C0030779
Disease or Syndrome
An autosomal dominant inherited condition caused by mutations in the lamin B receptor gene. It is characterized by defects in the neutrophil lobulation, resulting in the presence of dumbbell-shaped neutrophils with bilobed nuclei in the peripheral blood smear.
Phenylketonuria
MedGen UID:
19244
Concept ID:
C0031485
Disease or Syndrome
Phenylketonuria (PKU) is the most common inborn error of amino acid metabolism and is characterized by mild to severe mental disability in untreated patients.
Rothmund-Thomson syndrome
MedGen UID:
10819
Concept ID:
C0032339
Disease or Syndrome
Rothmund-Thomson syndrome (RTS) is characterized by a rash that progresses to poikiloderma; sparse hair, eyelashes, and/or eyebrows; small size; skeletal and dental abnormalities; cataracts; and an increased risk for cancer, especially osteosarcoma. The skin is typically normal at birth; the rash of RTS develops between ages three and six months as erythema, swelling, and blistering on the face, subsequently spreading to the buttocks and extremities. The rash evolves over months to years into the chronic pattern of reticulated hypo- and hyperpigmentation, punctate atrophy, and telangiectasias, collectively known as poikiloderma. Hyperkeratotic lesions occur in approximately one third of individuals. Skeletal abnormalities include radial ray defects, ulnar defects, absent or hypoplastic patella, and osteopenia.
Pseudo-Hurler polydystrophy
MedGen UID:
10988
Concept ID:
C0033788
Disease or Syndrome
Mucolipidosis alpha/beta (ML III alpha/beta; pseudo-Hurler polydystrophy), a slowly progressive disorder with clinical onset at approximately age three years, is characterized by slow growth rate and subnormal stature; radiographic evidence of mild to moderate dysostosis multiplex; joint stiffness and pain initially in the shoulders, hips, and fingers; gradual mild coarsening of facial features; and normal to mildly impaired cognitive development. If present, organomegaly is mild. Pain from osteoporosis that is clinically and radiologically apparent in childhood becomes more severe from adolescence. Cardiorespiratory complications (restrictive lung disease, thickening and insufficiency of the mitral and aortic valves, left and/or right ventricular hypertrophy) are common causes of death, typically in early to middle adulthood.
Pseudohypoparathyroidism
MedGen UID:
46178
Concept ID:
C0033806
Disease or Syndrome
A condition characterized by resistance to the action of parathyroid hormone, in which there is hypocalcemia, hyperphosphatemia, and (appropriately) high levels of parathyroid hormone.
Pseudopseudohypoparathyroidism
MedGen UID:
10995
Concept ID:
C0033835
Disease or Syndrome
Disorders of GNAS inactivation include the phenotypes pseudohypoparathyroidism Ia, Ib, and Ic (PHP-Ia, -Ib, -Ic), pseudopseudohypoparathyroidism (PPHP), progressive osseous heteroplasia (POH), and osteoma cutis (OC). PHP-Ia and PHP-Ic are characterized by: End-organ resistance to endocrine hormones including parathyroid hormone (PTH), thyroid-stimulating hormone (TSH), gonadotropins (LH and FSH), growth hormone-releasing hormone (GHRH), and CNS neurotransmitters (leading to obesity and variable degrees of intellectual disability and developmental delay); and The Albright hereditary osteodystrophy (AHO) phenotype (short stature, round facies, and subcutaneous ossifications) and brachydactyly type E (shortening mainly of the 4th and/or 5th metacarpals and metatarsals and distal phalanx of the thumb). Although PHP-Ib is characterized principally by PTH resistance, some individuals also have partial TSH resistance and mild features of AHO (e.g., brachydactyly). PPHP, a more limited form of PHP-Ia, is characterized by various manifestations of the AHO phenotype without the hormone resistance or obesity. POH and OC are even more restricted variants of PPHP: POH consists of dermal ossification beginning in infancy, followed by increasing and extensive bone formation in deep muscle and fascia. OC consists of extra-skeletal ossification that is limited to the dermis and subcutaneous tissues.
Pyruvate carboxylase deficiency
MedGen UID:
18801
Concept ID:
C0034341
Disease or Syndrome
Pyruvate carboxylase (PC) deficiency is characterized in most affected individuals by failure to thrive, developmental delay, recurrent seizures, and metabolic acidosis. Three clinical types are recognized: Type A (infantile form), in which most affected children die in infancy or early childhood. Type B (severe neonatal form), in which affected infants have hepatomegaly, pyramidal tract signs, and abnormal movement and die within the first three months of life. Type C (intermittent/benign form), in which affected individuals have normal or mildly delayed neurologic development and episodic metabolic acidosis.
Pyruvate dehydrogenase complex deficiency
MedGen UID:
19610
Concept ID:
C0034345
Disease or Syndrome
A genetic disorder caused by mutations in the genes that are responsible for production of protein components of the pyruvate dehydrogenase complex. It may present with lactic acidosis. Signs and symptoms include developmental delays, seizures and hypotonia.
Rubinstein-Taybi syndrome
MedGen UID:
48517
Concept ID:
C0035934
Disease or Syndrome
A chromosomal disorder characterized by MENTAL RETARDATION, broad thumbs, webbing of fingers and toes, beaked nose, short upper lip, pouting lower lip, agenesis of corpus callosum, large foramen magnum, keloid formation, pulmonary stenosis, vertebral anomalies, chest wall anomalies, sleep apnea, and megacolon. The disease has an autosomal dominant pattern of inheritance and is associated with deletions of the short arm of chromosome 16 (16p13.3).
Schwartz-Jampel syndrome
MedGen UID:
19892
Concept ID:
C0036391
Disease or Syndrome
A classification for rare genetic syndromes with an autosomal recessive pattern of inheritance. Clinical features include muscle stiffness and weakness, facial and skeletal abnormalities with joint contractures and short stature. Two types have been characterized: Schwartz-Jampel Syndrome type I (SJSI) and Schwartz-Jampel Syndrome type II (SJSII). SJSI is associated with a mutation of the HSPG2 gene on chromosome 1 and has been further characterized into two subtypes IA and IB. SJSIA is more common, less severe in presentation and is seen later in childhood than SJSIB. For both SJSI subtypes, prognosis is favorable as the main feature of muscle stiffness is slowly progressive, if at all, and is compatible with a normal life span. SJSII is apparent at birth, shares the same clinical profile and mutation in the LIFR gene noted in Stuve-Wiedemann Syndrome and is thus presumed to be the same disorder. In contrast to SJSI, its presentation is more severe and likelihood of survivability is much lower.
Sjögren-Larsson syndrome
MedGen UID:
11443
Concept ID:
C0037231
Disease or Syndrome
Sjogren-Larsson syndrome is an autosomal recessive, early childhood-onset disorder characterized by ichthyosis, mental retardation, spastic paraparesis, macular dystrophy, and leukoencephalopathy. It is caused by deficiency of fatty aldehyde dehydrogenase (summary by Lossos et al., 2006).
Sturge-Weber syndrome
MedGen UID:
21361
Concept ID:
C0038505
Congenital Abnormality
Sturge-Weber syndrome is characterized by an intracranial vascular anomaly, leptomeningeal angiomatosis, most often involving the occipital and posterior parietal lobes. The most common symptoms and signs are facial cutaneous vascular malformations (port-wine stains), seizures, and glaucoma. Stasis results in ischemia underlying the leptomeningeal angiomatosis, leading to calcification and laminar cortical necrosis. The clinical course is highly variable and some children experience intractable seizures, mental retardation, and recurrent stroke-like episodes (review by Thomas-Sohl et al., 2004).
Male Turner Syndrome
MedGen UID:
22527
Concept ID:
C0041409
Disease or Syndrome
Wolfram syndrome
MedGen UID:
21923
Concept ID:
C0043207
Disease or Syndrome
WFS1-related disorders range from Wolfram syndrome (WFS) to WFS1-related low-frequency sensory hearing loss (also known as DFNA6/14/38 low-frequency sensorineural hearing loss [LFSNHL]). WFS is a progressive neurodegenerative disorder characterized by onset of diabetes mellitus and optic atrophy before age 16 years, and typically associated with sensorineural hearing loss, progressive neurologic abnormalities (cerebellar ataxia, peripheral neuropathy, dementia, psychiatric illness, and urinary tract atony), and other endocrine abnormalities. Median age at death is 30 years. WFS-like disease is characterized by sensorineural hearing loss, diabetes mellitus, psychiatric illness, and variable optic atrophy. WFS1-related LFSNHL is characterized by congenital, nonsyndromic, slowly progressive, low-frequency (<2000 Hz) sensorineural hearing loss.
Holoprosencephaly sequence
MedGen UID:
38214
Concept ID:
C0079541
Congenital Abnormality
Holoprosencephaly (HPE) is a structural anomaly of the brain in which there is failed or incomplete separation of the forebrain early in gestation. Classic HPE encompasses a continuum of brain malformations including (in order of decreasing severity): alobar, semilobar, lobar, and middle interhemispheric variant (MIHV) type HPE; a septopreoptic type has also been described. Other CNS abnormalities not specific to HPE may also occur. HPE is accompanied by a spectrum of characteristic craniofacial anomalies in approximately 80% of individuals with HPE. Developmental delay is present in virtually all individuals with the HPE spectrum of CNS anomalies. Seizures and pituitary dysfunction are common. Most affected fetuses do not survive; severely affected children typically do not survive beyond early infancy, while a significant proportion of more mildly affected children survive past 12 months. Mildly manifesting individuals without appreciable brain anomalies on conventional neuroimaging may be described as having "microform" HPE.
Mucopolysaccharidosis type VII
MedGen UID:
43108
Concept ID:
C0085132
Disease or Syndrome
Mucopolysaccharidosis type VII is an autosomal recessive lysosomal storage disease characterized by the inability to degrade glucuronic acid-containing glycosaminoglycans. The phenotype is highly variable, ranging from severe lethal hydrops fetalis to mild forms with survival into adulthood. Most patients with the intermediate phenotype show hepatomegaly, skeletal anomalies, coarse facies, and variable degrees of mental impairment (Shipley et al., 1993). MPS VII was the first autosomal mucopolysaccharidosis for which chromosomal assignment was achieved.
Mucopolysaccharidosis, MPS-III-A
MedGen UID:
39264
Concept ID:
C0086647
Disease or Syndrome
The Sanfilippo syndrome, or mucopolysaccharidosis III, is an autosomal recessive lysosomal storage disease due to impaired degradation of heparan sulfate (Esposito et al., 2000). The disorder is characterized by severe central nervous system degeneration, but only mild somatic disease. Onset of clinical features usually occurs between 2 and 6 years; severe neurologic degeneration occurs in most patients between 6 and 10 years of age, and death occurs typically during the second or third decade of life. Type A has been reported (van de Kamp et al., 1981) to be the most severe, with earlier onset and rapid progression of symptoms and shorter survival. Genetic Heterogeneity of Mucopolysaccharidosis Type III MPS III includes 4 types, each due to the deficiency of a different enzyme: heparan N-sulfatase (type A); alpha-N-acetylglucosaminidase (type B; 252920); acetyl CoA:alpha-glucosaminide acetyltransferase (type C; 252930); and N-acetylglucosamine 6-sulfatase (type D; 252940).
Mucopolysaccharidosis, MPS-III-B
MedGen UID:
88601
Concept ID:
C0086648
Disease or Syndrome
Sanfilippo syndrome B is an autosomal recessive lysosomal storage disorder characterized by the accumulation of heparan sulfate. Clinically, patients have progressive neurodegeneration, behavioral problems, mild skeletal changes, and shortened life span. The clinical severity ranges from mild to severe (Chinen et al., 2005). For a phenotypic description and a discussion of genetic heterogeneity of Sanfilippo syndrome, or mucopolysaccharidosis III, see MPS IIIA (252900).
Mucopolysaccharidosis, MPS-III-C
MedGen UID:
39477
Concept ID:
C0086649
Disease or Syndrome
Sanfilippo syndrome comprises several forms of lysosomal storage diseases due to impaired degradation of heparan sulfate. The deficient enzyme in Sanfilippo syndrome C, or MPS IIIC, is an acetyltransferase that catalyzes the conversion of alpha-glucosaminide residues to N-acetylglucosaminide in the presence of acetyl-CoA. For a general phenotypic description and a discussion of genetic heterogeneity of Sanfilippo syndrome, see MPS IIIA (252900).
Mucopolysaccharidosis, MPS-III-D
MedGen UID:
88602
Concept ID:
C0086650
Disease or Syndrome
The mucopolysaccharidoses are a family of lysosomal storage diseases caused by deficiencies of enzymes required for the catabolism of glycosaminoglycans. The defects result in accumulation of excessive intralysosomal glycosoaminoglycans (mucopolysaccharides) in various tissues, causing distended lysosomes to accumulate in the cell and interfere with cell function. Multiple types have been described (Mok et al., 2003).
Dysostosis multiplex
MedGen UID:
39698
Concept ID:
C0086795
Disease or Syndrome
Mucopolysaccharidosis type I (MPS I) is a progressive multisystem disorder with features ranging over a continuum of severity. While affected individuals have traditionally been classified as having one of three MPS I syndromes (Hurler syndrome, Hurler-Scheie syndrome, or Scheie syndrome), no easily measurable biochemical differences have been identified and the clinical findings overlap; thus, affected individuals are best described as having either severe or attenuated MPS I, a distinction that influences therapeutic options. Severe MPS I. Infants appear normal at birth. Typical early manifestations are nonspecific (e.g., umbilical or inguinal hernia, frequent upper respiratory-tract infections before age 1 year). Coarsening of the facial features may not become apparent until after age one year. Gibbus deformity of the lower spine is common and often noted within the first year. Progressive skeletal dysplasia (dysostosis multiplex) involving all bones is universal. By age three years, linear growth decreases. Intellectual disability is progressive and profound. Hearing loss is common. Death, typically caused by cardiorespiratory failure, usually occurs within the first ten years of life. Attenuated MPS I. The severity and rate of disease progression range from serious life-threatening complications leading to death in the second to third decades to a normal life span complicated by significant disability from progressive joint manifestations and cardiorespiratory disease. While some individuals have no neurologic involvement and psychomotor development may be normal in early childhood, learning disabilities can be present. Clinical onset is usually between ages three and ten years. Hearing loss and cardiac valvular disease are common.
Cyclical vomiting syndrome
MedGen UID:
57509
Concept ID:
C0152164
Disease or Syndrome
Cyclic vomiting syndrome is a disorder that causes recurrent episodes of nausea, vomiting, and tiredness (lethargy). This condition is diagnosed most often in young children, but it can affect people of any age.The episodes of nausea, vomiting, and lethargy last anywhere from an hour to 10 days. An affected person may vomit several times per hour, potentially leading to a dangerous loss of fluids (dehydration). Additional symptoms can include unusually pale skin (pallor), abdominal pain, diarrhea, headache, fever, and an increased sensitivity to light (photophobia) or to sound (phonophobia). In most affected people, the signs and symptoms of each attack are quite similar. These attacks can be debilitating, making it difficult for an affected person to go to work or school.Episodes of nausea, vomiting, and lethargy can occur regularly or apparently at random, or can be triggered by a variety of factors. The most common triggers are emotional excitement and infections. Other triggers can include periods without eating (fasting), temperature extremes, lack of sleep, overexertion, allergies, ingesting certain foods or alcohol, and menstruation.If the condition is not treated, episodes usually occur four to 12 times per year. Between attacks, vomiting is absent, and nausea is either absent or much reduced. However, many affected people experience other symptoms during and between episodes, including pain, lethargy, digestive disorders such as gastroesophageal reflux and irritable bowel syndrome, and fainting spells (syncope). People with cyclic vomiting syndrome are also more likely than people without the disorder to experience depression, anxiety, and panic disorder. It is unclear whether these health conditions are directly related to nausea and vomiting.Cyclic vomiting syndrome is often considered to be a variant of migraines, which are severe headaches often associated with pain, nausea, vomiting, and extreme sensitivity to light and sound. Cyclic vomiting syndrome is likely the same as or closely related to a condition called abdominal migraine, which is characterized by attacks of stomach pain and cramping. Attacks of nausea, vomiting, or abdominal pain in childhood may be replaced by migraine headaches as an affected person gets older. Many people with cyclic vomiting syndrome or abdominal migraine have a family history of migraines.Most people with cyclic vomiting syndrome have normal intelligence, although some affected people have developmental delay or intellectual disability. Autism spectrum disorder, which affects communication and social interaction, have also been associated with cyclic vomiting syndrome. Additionally, muscle weakness (myopathy) and seizures are possible. People with any of these additional features are said to have cyclic vomiting syndrome plus.
Deficiency of argininosuccinate synthase
MedGen UID:
104491
Concept ID:
C0175683
Disease or Syndrome
A group of diseases related to a deficiency of the enzyme ARGININOSUCCINATE SYNTHASE which causes an elevation of serum levels of CITRULLINE. In neonates, clinical manifestations include lethargy, hypotonia, and SEIZURES. Milder forms also occur. Childhood and adult forms may present with recurrent episodes of intermittent weakness, lethargy, ATAXIA, behavioral changes, and DYSARTHRIA. (From Menkes, Textbook of Child Neurology, 5th ed, p49)
Dubowitz syndrome
MedGen UID:
59797
Concept ID:
C0175691
Disease or Syndrome
A rare, autosomal recessive inherited syndrome characterized by microcephaly, growth retardation, and a small, round, triangular shaped face with a pointed, receding chin, a broad, wide-tipped nose, and wide-set eyes with drooping eyelids.
Johanson-Blizzard syndrome
MedGen UID:
59798
Concept ID:
C0175692
Disease or Syndrome
Pancreatitis is inflammation of the pancreas that progresses from acute (sudden onset; duration <6 months) to recurrent acute (>1 episode of acute pancreatitis) to chronic (duration >6 months). The range of symptoms and disease course vary from person to person. Familial pancreatitis, defined as pancreatitis from any cause that occurs in a family with an incidence that is greater than would be expected by chance alone, can be non-genetic or genetic, the latter including autosomal dominant hereditary pancreatitis and pancreatitis syndromes characterized by pancreatitis or pancreatic insufficiency. The majority of familial pancreatitis appears to have a complex, multigenic, or gene-environmental etiology with a variable number of germline pathogenic variants in genes that affect trypsin regulation, including CASR, CTRC, and CLDN2. Hereditary pancreatitis (HP) is defined as either two or more individuals with pancreatitis in two or more generations of a family (i.e., an autosomal dominant pattern of inheritance) or pancreatitis associated with a germline PRSS1 disease-causing gain-of-function variant. The phenotype of hereditary pancreatitis is increased susceptibility to acute pancreatitis, with complications such as chronic inflammation, fibrosis, and chronic pain in some affected individuals. Heterozygous pathogenic variants in PRSS1 are found in 60%-100% of families with hereditary pancreatitis, and most large families with pancreatitis spanning multiple generations; biallelic pathogenic variants in SPINK1 or biallelic pathogenic variants in CFTR result in autosomal recessive pancreatitis. Syndromes in which pancreatitis is a finding include: Pearson marrow pancreas syndrome, CEL maturity-onset diabetes of the young (CEL-MODY), and Johanson-Blizzard syndrome. Shwachman-Diamond syndrome, an autosomal recessive disorder, includes pancreatic exocrine insufficiency as well as other features. Idiopathic sporadic pancreatitis is a single occurrence of pancreatitis in a family for which no etiology is identified.
Smith-Lemli-Opitz syndrome
MedGen UID:
61231
Concept ID:
C0175694
Disease or Syndrome
Smith-Lemli-Opitz syndrome (SLOS) is a congenital multiple anomaly syndrome caused by an abnormality in cholesterol metabolism resulting from deficiency of the enzyme 7-dehydrocholesterol (7-DHC) reductase. It is characterized by prenatal and postnatal growth retardation, microcephaly, moderate to severe intellectual disability, and multiple major and minor malformations. The malformations include distinctive facial features, cleft palate, cardiac defects, underdeveloped external genitalia in males, postaxial polydactyly, and 2-3 syndactyly of the toes. The clinical spectrum is wide and individuals have been described with normal development and only minor malformations.
Sotos syndrome
MedGen UID:
61232
Concept ID:
C0175695
Disease or Syndrome
Sotos syndrome is a disorder characterized by a distinctive facial appearance, overgrowth in childhood, and learning disabilities or delayed development of mental and movement abilities. Characteristic facial features include a long, narrow face; a high forehead; flushed (reddened) cheeks; and a small, pointed chin. In addition, the outside corners of the eyes may point downward (down-slanting palpebral fissures). This facial appearance is most notable in early childhood. Affected infants and children tend to grow quickly; they are significantly taller than their siblings and peers and have an unusually large head. However, adult height is usually in the normal range.People with Sotos syndrome often have intellectual disability, and most also have behavioral problems. Frequent behavioral issues include attention deficit hyperactivity disorder (ADHD), phobias, obsessions and compulsions, tantrums, and impulsive behaviors. Problems with speech and language are also common. Affected individuals often have a stutter, a monotone voice, and problems with sound production. Additionally, weak muscle tone (hypotonia) may delay other aspects of early development, particularly motor skills such as sitting and crawling.Other signs and symptoms of Sotos syndrome can include an abnormal side-to-side curvature of the spine (scoliosis), seizures, heart or kidney defects, hearing loss, and problems with vision. Some infants with this disorder experience yellowing of the skin and whites of the eyes (jaundice) and poor feeding.A small percentage of people with Sotos syndrome have developed cancer, most often in childhood, but no single form of cancer occurs most frequently with this condition. It remains uncertain whether Sotos syndrome increases the risk of specific types of cancer. If people with this disorder have an increased cancer risk, it is only slightly greater than that of the general population.
Saethre-Chotzen syndrome
MedGen UID:
64221
Concept ID:
C0175699
Disease or Syndrome
Classic Saethre-Chotzen syndrome (SCS) is characterized by coronal synostosis (unilateral or bilateral), facial asymmetry (particularly in individuals with unicoronal synostosis), strabismus, ptosis, and characteristic appearance of the ear (small pinna with a prominent superior and/or inferior crus). Syndactyly of digits two and three of the hand is variably present. Cognitive development is usually normal, although those with a large genomic deletion are at an increased risk for intellectual challenges. Less common manifestations of SCS include other skeletal findings (parietal foramina, vertebral segmentation defects, radioulnar synostosis, maxillary hypoplasia, ocular hypertelorism, hallux valgus, duplicated or curved distal hallux), hypertelorism, palatal anomalies, obstructive sleep apnea, increased intracranial pressure, short stature, and congenital heart malformations.
Aarskog syndrome
MedGen UID:
61234
Concept ID:
C0175701
Disease or Syndrome
Aarskog-Scott syndrome, also known as faciogenital dysplasia, is an X-linked disorder characterized by short stature, hypertelorism, shawl scrotum, and brachydactyly, although there is wide phenotypic variability and other features, such as joint hyperextensibility, short nose, widow's peak, and inguinal hernia, may also occur. Most patients do not have mental retardation, but some may have neurobehavioral features. Carrier females may present with subtle features, such as widow's peak or short stature (summary by Orrico et al., 2010).
Williams syndrome
MedGen UID:
59799
Concept ID:
C0175702
Disease or Syndrome
Williams syndrome (WS) is characterized by cardiovascular disease (elastin arteriopathy, peripheral pulmonary stenosis, supravalvar aortic stenosis, hypertension), distinctive facies, connective tissue abnormalities, intellectual disability (usually mild), a specific cognitive profile, unique personality characteristics, growth abnormalities, and endocrine abnormalities (hypercalcemia, hypercalciuria, hypothyroidism, and early puberty). Feeding difficulties often lead to poor weight gain in infancy. Hypotonia and hyperextensible joints can result in delayed attainment of motor milestones.
Radial aplasia-thrombocytopenia syndrome
MedGen UID:
61235
Concept ID:
C0175703
Congenital Abnormality
Thrombocytopenia absent radius (TAR) syndrome is characterized by bilateral absence of the radii with the presence of both thumbs and thrombocytopenia (<50 platelets/nL) that is generally transient. Thrombocytopenia may be congenital or may develop within the first few weeks to months of life; in general, thrombocytopenic episodes decrease with age. Cow's milk allergy is common and can be associated with exacerbation of thrombocytopenia. Other anomalies of the skeleton (upper and lower limbs, ribs, and vertebrae), heart, and genitourinary system (renal anomalies and agenesis of uterus, cervix, and upper part of the vagina) can occur.
Corpus callosum agenesis
MedGen UID:
104498
Concept ID:
C0175754
Congenital Abnormality
The corpus callosum is the largest fiber tract in the central nervous system and the major interhemispheric fiber bundle in the brain. Formation of the corpus callosum begins as early as 6 weeks' gestation, with the first fibers crossing the midline at 11 to 12 weeks' gestation, and completion of the basic shape by age 18 to 20 weeks (Schell-Apacik et al., 2008). Agenesis of the corpus callosum (ACC) is one of the most frequent malformations in brain with a reported incidence ranging between 0.5 and 70 in 10,000 births. ACC is a clinically and genetically heterogeneous condition, which can be observed either as an isolated condition or as a manifestation in the context of a congenital syndrome (see MOLECULAR GENETICS and Dobyns, 1996). Also see mirror movements-1 and/or agenesis of the corpus callosum (MRMV1; 157600). Schell-Apacik et al. (2008) noted that there is confusion in the literature regarding radiologic terminology concerning partial absence of the corpus callosum, where various designations have been used, including hypogenesis, hypoplasia, partial agenesis, or dysgenesis.
Pelizaeus-Merzbacher disease
MedGen UID:
61440
Concept ID:
C0205711
Disease or Syndrome
PLP1-related disorders of central nervous system myelin formation include a range of phenotypes from Pelizaeus-Merzbacher disease (PMD) to spastic paraplegia 2 (SPG2). PMD typically manifests in infancy or early childhood with nystagmus, hypotonia, and cognitive impairment; the findings progress to severe spasticity and ataxia. Life span is shortened. SPG2 manifests as spastic paraparesis with or without CNS involvement and usually normal life span. Intrafamilial variation of phenotypes can be observed, but the signs are usually fairly consistent within families. Female carriers may manifest mild to moderate signs of the disease.
Wilms tumor, aniridia, genitourinary anomalies, and mental retardation syndrome
MedGen UID:
64512
Concept ID:
C0206115
Disease or Syndrome
PAX6-related aniridia occurs either as an isolated ocular abnormality or as part of the Wilms tumor-aniridia-genital anomalies-retardation (WAGR) syndrome. Aniridia is a pan ocular disorder affecting the cornea, iris, intraocular pressure (resulting in glaucoma), lens (cataract and lens subluxation), fovea (foveal hypoplasia), and optic nerve (optic nerve coloboma and hypoplasia). Individuals with aniridia characteristically show nystagmus and impaired visual acuity (usually 20/100 - 20/200); however, milder forms of aniridia with subtle iris architecture changes, good vision, and normal foveal structure do occur. Other ocular involvement may include strabismus and occasionally microphthalmia. Although the severity of aniridia can vary between and within families, little variability is usually observed in the two eyes of an affected individual. WAGR syndrome. The risk for Wilms tumor is 42.5%-77%; of those who develop Wilms tumor, 90% do so by age four years and 98% by age seven years. Genital anomalies in males can include cryptorchidism and hypospadias (sometimes resulting in ambiguous genitalia), urethral strictures, ureteric abnormalities, and gonadoblastoma. While females typically have normal external genitalia, they may have uterine abnormalities and streak ovaries. Intellectual disability (defined as IQ <74) is observed in 70%; behavioral abnormalities include attention deficit hyperactivity disorder (ADHD), autism spectrum disorder, anxiety, depression, and obsessive-compulsive disorder. Other individuals with WAGR syndrome can have normal intellect without behavioral problems.
KBG syndrome
MedGen UID:
66317
Concept ID:
C0220687
Disease or Syndrome
KBG syndrome is typically characterized by macrodontia (especially of the upper central incisors), characteristic facial features (triangular face, brachycephaly, synophrys, widely spaced eyes, broad or bushy eyebrows, prominent ears, prominent nasal bridge, bulbous nose, anteverted nares, long philtrum, and thin vermilion of the upper lip), short stature, developmental delay / intellectual disability, and behavioral issues. Affected individuals may have feeding difficulties (particularly in infancy), skeletal anomalies (brachydactyly, large anterior fontanelle with delayed closure, scoliosis), hearing loss (conductive, mixed, and sensorineural), seizure disorder, and brain malformations. There is significant variability in the clinical findings, even between affected members of the same family.
Shprintzen syndrome
MedGen UID:
65085
Concept ID:
C0220704
Disease or Syndrome
Individuals with 22q11.2 deletion syndrome (22q11.2DS) have a range of findings including the following: Congenital heart disease (74% of individuals), particularly conotruncal malformations (tetralogy of Fallot, interrupted aortic arch, ventricular septal defect, and truncus arteriosus). Palatal abnormalities (69%), particularly velopharyngeal incompetence, submucosal cleft palate, bifid uvula, and cleft palate. Characteristic facial features (present in the majority of individuals of northern European heritage). Learning difficulties (70%-90%). An immune deficiency (regardless of the clinical presentation) (77%). Additional findings include the following: Hypocalcemia (50%). Significant feeding and swallowing problems; constipation with or without structural gastrointestinal anomalies (intestinal malrotation, imperforate anus, and Hirschsprung disease). Renal anomalies (31%). Hearing loss (both conductive and sensorineural). Laryngotracheoesophageal anomalies. Growth hormone deficiency. Autoimmune disorders. Seizures (idiopathic or associated with hypocalcemia). CNS anomalies including tethered cord. Skeletal abnormalities (scoliosis with or without vertebral anomalies, clubbed feet, polydactyly, and craniosynostosis). Ophthalmologic abnormalities (strabismus, posterior embryotoxon, tortuous retinal vessels, scleracornea, and anophthalmia). Enamel hypoplasia. Malignancies (rare). Developmental delay (in particular delays in emergence of language), intellectual disability, and learning differences (non-verbal learning disability where the verbal IQ is significantly greater than the performance IQ) are common. Autism or autistic spectrum disorder is found in approximately 20% of children and psychiatric illness (specifically schizophrenia) is present in 25% of adults; however, attention deficit disorder, anxiety, perseveration, and difficulty with social interactions are also common.
Cerebro-oculo-facio-skeletal syndrome
MedGen UID:
66320
Concept ID:
C0220722
Congenital Abnormality
Cerebrooculofacioskeletal syndrome is an autosomal recessive progressive neurodegenerative disorder characterized by microcephaly, congenital cataracts, severe mental retardation, facial dysmorphism, and arthrogryposis (summary by Jaakkola et al., 2010). Genetic Heterogeneity of Cerebrooculofacioskeletal Syndrome See also COFS2 (610756), caused by mutation in the ERCC2 gene (126340); COFS3 (616570), caused by mutation in the ERCC5 gene (133530); and COFS4 (610758), caused by mutation in the ERCC1 gene (126380).
Fryns syndrome
MedGen UID:
65088
Concept ID:
C0220730
Disease or Syndrome
Fryns syndrome is characterized by diaphragmatic defects (diaphragmatic hernia, eventration, hypoplasia or agenesis); characteristic facial appearance (coarse facies, ocular hypertelorism, broad and flat nasal bridge, thick nasal tip, long philtrum, low-set and poorly formed ears, tented upper lip, macrostomia, micrognathia); distal digital hypoplasia (nails, terminal phalanges); pulmonary hypoplasia; and associated anomalies (polyhydramnios, cloudy corneas and/or microphthalmia, orofacial clefting, renal dysplasia / renal cortical cysts, and/or malformations involving the brain, cardiovascular system, gastrointestinal system, genitalia). Survival beyond the neonatal period has been rare. Data on postnatal growth and psychomotor development are limited; however, severe developmental delay and intellectual disability are common.
FG syndrome
MedGen UID:
113106
Concept ID:
C0220769
Disease or Syndrome
The phenotypic spectrum of MED12-related disorders, which is still being defined, includes at a minimum the phenotypes of FG syndrome type 1 (FGS1), Lujan syndrome (LS), and X-linked Ohdo syndrome. FGS1 and LS share the clinical findings of cognitive impairment, hypotonia, and abnormalities of the corpus callosum. FGS1 is further characterized by absolute or relative macrocephaly, tall forehead, downslanted palpebral fissures, small and simple ears, constipation and/or anal anomalies, broad thumbs and halluces, and characteristic behavior. LS is further characterized by large head, tall thin body habitus, long thin face, prominent nasal bridge, high narrow palate, and short philtrum. Carrier females in families with FGS1 and LS are typically unaffected. X-linked Ohdo syndrome (referred to as XLOS in this GeneReview) is characterized by intellectual disability, blepharophimosis, and facial coarsening. A number of individuals with nonsyndromic intellectual disability – including some affected females – have been described.
Histidinemia
MedGen UID:
113135
Concept ID:
C0220992
Disease or Syndrome
Histidinemia is a metabolic disorder characterized by increased levels of histidine in blood, urine, and cerebrospinal fluid, and decreased levels of the metabolite urocanic acid in blood, urine, and skin cells. Although histidinemia was originally associated with mental retardation and speech defects, it is generally considered to be a benign disorder (Levy et al., 2001). However, it is possible that histidinemia may be a risk factor for developmental disorders in certain individuals under specific circumstances, such as perinatal events (Ishikawa, 1987).
Hypothalamic hypothyroidism
MedGen UID:
113137
Concept ID:
C0220998
Disease or Syndrome
A type of hypothyroidism that results from a defect in thyrotropin-releasing hormone activity.
Abortive cerebellar ataxia
MedGen UID:
66358
Concept ID:
C0221061
Disease or Syndrome
'Behr syndrome' is a clinical term that refers to the constellation of early-onset optic atrophy accompanied by neurologic features, including ataxia, pyramidal signs, spasticity, and mental retardation (Behr, 1909; Thomas et al., 1984). Patients with mutations in genes other than OPA1 can present with clinical features reminiscent of Behr syndrome. Mutations in one of these genes, OPA3 (606580), result in type III 3-methylglutaconic aciduria (MGCA3; 258501). Lerman-Sagie (1995) noted that the abnormal urinary pattern in MGCA3 may not be picked up by routine organic acid analysis, suggesting that early reports of Behr syndrome with normal metabolic features may actually have been 3-methylglutaconic aciduria type III.
Cholestanol storage disease
MedGen UID:
116041
Concept ID:
C0238052
Disease or Syndrome
Cerebrotendinous xanthomatosis (CTX) is a lipid storage disease characterized by infantile-onset diarrhea, childhood-onset cataract, adolescent- to young adult-onset tendon xanthomas, and adult-onset progressive neurologic dysfunction (dementia, psychiatric disturbances, pyramidal and/or cerebellar signs, dystonia, atypical parkinsonism, peripheral neuropathy, and seizures). Chronic diarrhea from infancy may be the earliest clinical manifestation. In approximately 75% of affected individuals, cataracts are the first finding, often appearing in the first decade of life. Xanthomas appear in the second or third decade; they occur on the Achilles tendon, the extensor tendons of the elbow and hand, the patellar tendon, and the neck tendons. Xanthomas have been reported in the lung, bones, and central nervous system. Some individuals show cognitive impairment from early infancy, whereas the majority have normal or only slightly impaired intellectual function until puberty; dementia with slow deterioration in intellectual abilities occurs in the 20s in more than 50% of individuals. Neuropsychiatric symptoms such as behavioral changes, hallucinations, agitation, aggression, depression, and suicide attempts may be prominent. Pyramidal signs (i.e., spasticity) and/or cerebellar signs almost invariably become evident between ages 20 and 30 years. The biochemical abnormalities that distinguish CTX from other conditions with xanthomas include high plasma and tissue cholestanol concentration, normal-to-low plasma cholesterol concentration, decreased chenodeoxycholic acid, increased concentration of bile alcohols and their glyconjugates, and increased concentrations of cholestanol and apolipoprotein B in cerebrospinal fluid.
Mucolipidosis type IV
MedGen UID:
68663
Concept ID:
C0238286
Disease or Syndrome
Mucolipidosis IV is characterized by severe psychomotor delay evident by the end of the first year of life and slowly progressive visual impairment during the first decade as a result of a combination of corneal clouding and retinal degeneration. By the end of the first decade of life and certainly by their early teens, all individuals with typical mucolipidosis IV have severe visual impairment as a result of retinal degeneration. Neurodegeneration is thought to occur in no more than 15% of individuals. About 5% of individuals have atypical mucolipidosis IV, often manifest as less severe psychomotor retardation and/or eye findings. Although in the past, mucolipidosis IV was considered an Ashkenazi Jewish disease, currently most affected individuals are non-Ashkenazi Jewish.
Facioscapulohumeral muscular dystrophy
MedGen UID:
65956
Concept ID:
C0238288
Disease or Syndrome
An autosomal dominant degenerative muscle disease characterized by slowly progressive weakness of the muscles of the face, upper-arm, and shoulder girdle. The onset of symptoms usually occurs in the first or second decade of life. Affected individuals usually present with impairment of upper extremity elevation. This tends to be followed by facial weakness, primarily involving the orbicularis oris and orbicularis oculi muscles. (Neuromuscul Disord 1997;7(1):55-62; Adams et al., Principles of Neurology, 6th ed, p1420)
Treacher Collins syndrome
MedGen UID:
66078
Concept ID:
C0242387
Disease or Syndrome
Treacher Collins syndrome (TCS) is characterized by bilateral and symmetric downslanting palpebral fissures, malar hypoplasia, micrognathia, and external ear abnormalities. Hypoplasia of the zygomatic bones and mandible can cause significant feeding and respiratory difficulties. About 40%-50% of individuals have conductive hearing loss attributed most commonly to malformation of the ossicles and hypoplasia of the middle ear cavities. Inner ear structures tend to be normal. Other, less common abnormalities include cleft palate and unilateral or bilateral choanal stenosis or atresia. Typically intellect is normal.
DE SANCTIS-CACCHIONE SYNDROME
MedGen UID:
75550
Concept ID:
C0265201
Disease or Syndrome
A rare autosomal recessive inherited syndrome. It is characterized by xeroderma pigmentosum, mental retardation, dwarfism, hypogonadism, and neurologic abnormalities.
Seckel syndrome
MedGen UID:
78534
Concept ID:
C0265202
Disease or Syndrome
A rare autosomal recessive inherited syndrome caused by mutations in the ATR gene, RBBP8 gene, CENPJ gene, CEP152 gene, CEP63 gene, NIN gene, DNA2 gene, or TRAIP gene. It is characterized by intrauterine growth retardation, dwarfism, microcephaly, mental retardation, and a "bird-headed" facial appearance.
Robinow syndrome
MedGen UID:
78535
Concept ID:
C0265205
Disease or Syndrome
A rare autosomal recessive or dominant inherited disorder. The autosomal recessive form is caused by mutations in the ROR2 gene. There is no causative mutation identified for the autosomal dominant form. It is manifested with short limbs, abnormal facial features, underdeveloped genitalia, and wedge-shaped vertebrae.
Weaver syndrome
MedGen UID:
120511
Concept ID:
C0265210
Disease or Syndrome
EZH2-related overgrowth includes EZH2-related Weaver syndrome at one end of the spectrum and tall stature at the other. Although most individuals diagnosed with a heterozygous EZH2 pathogenic variant have been identified because of a clinical suspicion of Weaver syndrome, a minority have been identified through molecular genetic testing of family members of probands or individuals with overgrowth who did not have a clinical diagnosis of Weaver syndrome. Thus, the extent of the phenotypic spectrum associated with a heterozygous EZH2 pathogenic variant is not yet known. Weaver syndrome is characterized by tall stature, variable intellect (ranging from normal intellect to severe intellectual disability), characteristic facial appearance, and a range of associated clinical features including advanced bone age, poor coordination, soft doughy skin, camptodactyly of the fingers and/or toes, umbilical hernia, abnormal tone, and hoarse low cry in infancy. Brain MRI has identified abnormalities in a few individuals with EZH2-related overgrowth. Neuroblastoma occurs at a slightly increased frequency in individuals with a heterozygous EZH2 pathogenic variant but data are insufficient to determine absolute risk. There is currently no evidence that additional malignancies (including hematologic malignancies) occur with increased frequency.
Marshall-Smith syndrome
MedGen UID:
75551
Concept ID:
C0265211
Disease or Syndrome
The Marshall-Smith syndrome is a malformation syndrome characterized by accelerated skeletal maturation, relative failure to thrive, respiratory difficulties, mental retardation, and unusual facies, including prominent forehead, shallow orbits, blue sclerae, depressed nasal bridge, and micrognathia (Adam et al., 2005).
X-linked hydrocephalus syndrome
MedGen UID:
75552
Concept ID:
C0265216
Disease or Syndrome
The phenotypic spectrum of L1 syndrome includes: X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS); MASA syndrome (mental retardation [intellectual disability], aphasia [delayed speech], spastic paraplegia [shuffling gait], adducted thumbs); SPG1 (X-linked complicated hereditary spastic paraplegia type 1); and X-linked complicated corpus callosum agenesis. Males with HSAS are born with severe hydrocephalus, adducted thumbs, and spasticity; intellectual disability is severe. In less severely affected males, hydrocephalus may be subclinically present and documented only because of developmental delay; intellectual disability ranges from mild (IQ: 50-70) to moderate (IQ: 30-50).
Miller Dieker syndrome
MedGen UID:
78538
Concept ID:
C0265219
Disease or Syndrome
PAFAH1B1-associated lissencephaly includes Miller-Dieker syndrome (MDS), isolated lissencephaly sequence (ILS), and (rarely) subcortical band heterotopia (SBH). Lissencephaly and SBH are cortical malformations caused by deficient neuronal migration during embryogenesis. Lissencephaly refers to a "smooth brain" with absent gyri (agyria) or abnormally wide gyri (pachygyria). SBH refers to a band of heterotopic gray matter located just beneath the cortex and separated from it by a thin zone of normal white matter. MDS is characterized by lissencephaly, typical facial features, and severe neurologic abnormalities. ILS is characterized by lissencephaly and its direct sequelae: developmental delay, intellectual disability, and seizures.
Cohen syndrome
MedGen UID:
78539
Concept ID:
C0265223
Congenital Abnormality
Cohen syndrome is characterized by failure to thrive in infancy and childhood; truncal obesity in the teen years; early-onset hypotonia and developmental delays; microcephaly developing during the first year of life; moderate to profound psychomotor retardation; progressive retinochoroidal dystrophy and high myopia; neutropenia in many with recurrent infections and aphthous ulcers in some; a cheerful disposition; joint hypermobility; and characteristic facial features.
Freeman-Sheldon syndrome
MedGen UID:
120516
Concept ID:
C0265224
Disease or Syndrome
Freeman-Sheldon syndrome (FSS), or DA2A, is phenotypically similar to DA1. In addition to contractures of the hands and feet, FSS is characterized by oropharyngeal abnormalities, scoliosis, and a distinctive face that includes a very small oral orifice (often only a few millimeters in diameter at birth), puckered lips, and an H-shaped dimple of the chin; hence, FSS has been called 'whistling face syndrome.' The limb phenotypes of DA1 and FSS may be so similar that they can only be distinguished by the differences in facial morphology (summary by Bamshad et al., 2009). For a general phenotypic description and a discussion of genetic heterogeneity of distal arthrogryposis, see DA1 (108120).
Schinzel-Giedion syndrome
MedGen UID:
120517
Concept ID:
C0265227
Disease or Syndrome
Schinzel-Giedion syndrome is a highly recognizable syndrome characterized by severe mental retardation, distinctive facial features, and multiple congenital malformations including skeletal abnormalities, genitourinary and renal malformations, and cardiac defects, as well as a higher-than-normal prevalence of tumors, notably neuroepithelial neoplasia (summary by Hoischen et al., 2010).
Cryptophthalmos syndrome
MedGen UID:
82692
Concept ID:
C0265233
Disease or Syndrome
A rare, autosomal recessive inherited disorder caused by mutations in the FRAS1, FREM2, or GRIP1 genes. It is characterized by the presence of cryptophthalmos, cutaneous syndactyly, and genitourinary abnormalities.
Goldenhar syndrome
MedGen UID:
75554
Concept ID:
C0265240
Disease or Syndrome
A congenital birth defect characterized by incomplete development or absence of face structures, usually affecting one side of the face. The defects include partially formed or absent ear, nose, lip, mandible, and/or soft palate.
Ruvalcaba syndrome
MedGen UID:
120520
Concept ID:
C0265248
Disease or Syndrome
A dysmorphic syndrome characterized by short stature, microcephaly, mental deficiency, peculiar facies, hypoplastic genitalia, and skeletal anomalies.
Mietens syndrome
MedGen UID:
82695
Concept ID:
C0265249
Disease or Syndrome
Mild mental deficiency with growth retardation, ocular defects, and limb abnormalities.
Coffin-Lowry syndrome
MedGen UID:
75556
Concept ID:
C0265252
Disease or Syndrome
Coffin-Lowry syndrome (CLS) is usually characterized by severe-to-profound intellectual disability in males; less severely impaired individuals have been reported. Neuropsychiatric concerns can include behavioral problems, loss of strength, progressive spasticity or paraplegia, sleep apnea, or stroke. Stimulus-induced drop attacks (SIDAs) in which unexpected tactile or auditory stimuli or excitement triggers a brief collapse but no loss of consciousness are present in approximately 20% of affected individuals. Typically SIDAs begin between mid-childhood and the teens. Characteristic facial features may be more apparent with age. Upper-extremity differences may be subtle and include short, soft, fleshy hands with tapered fingers as well as fleshy forearms. Progressive kyphoscoliosis is one of the most difficult aspects of long-term care. Affected females tend to have intellectual disability in the mild to moderate range and may also have the typical facial, hand, and skeletal findings noted in males.
Adams-Oliver syndrome
MedGen UID:
78544
Concept ID:
C0265268
Disease or Syndrome
Adams-Oliver syndrome (AOS) is characterized by aplasia cutis congenita (ACC) of the scalp and terminal transverse limb defects (TTLD). ACC lesions usually occur in the midline of the parietal or occipital regions, but can also occur on the abdomen or limbs. At birth, an ACC lesion may already have the appearance of a healed scar. ACC lesions less than 5 cm often involve only the skin and almost always heal over a period of months; larger lesions are more likely to involve the skull and possibly the dura, and are at greater risk for complications, which can include infection, hemorrhage, or thrombosis, and can result in death. The limb defects range from mild (unilateral or bilateral short distal phalanges) to severe (complete absence of all toes or fingers, feet or hands, or more, often resembling an amputation). The lower extremities are almost always more severely affected than the upper extremities. Additional major features frequently include cardiovascular malformations/dysfunction (23%), brain anomalies, and less frequently renal, liver, and eye anomalies.
Frontometaphyseal dysplasia
MedGen UID:
82703
Concept ID:
C0265293
Congenital Abnormality
Baller-Gerold syndrome
MedGen UID:
120532
Concept ID:
C0265308
Disease or Syndrome
Baller-Gerold syndrome (BGS) can be suspected at birth in an infant with craniosynostosis and upper limb abnormality. The coronal suture is most commonly affected; the metopic, lambdoid, and sagittal sutures may also be involved alone or in combination. Upper limb abnormality can include a combination of thumb hypo- or aplasia and radial hypo- or aplasia and may be asymmetric. Malformation or absence of carpal or metacarpal bones has also been described. Skin lesions may appear anytime within the first few years after birth, typically beginning with erythema of the face and extremities and evolving into poikiloderma. Slow growth is apparent in infancy with eventual height and length typically at 4 SD below the mean.
Bannayan-Riley-Ruvalcaba syndrome
MedGen UID:
78554
Concept ID:
C0265326
Disease or Syndrome
The PTEN hamartoma tumor syndrome (PHTS) includes Cowden syndrome (CS), Bannayan-Riley-Ruvalcaba syndrome (BRRS), PTEN-related Proteus syndrome (PS), and Proteus-like syndrome. CS is a multiple hamartoma syndrome with a high risk for benign and malignant tumors of the thyroid, breast, and endometrium. Affected individuals usually have macrocephaly, trichilemmomas, and papillomatous papules, and present by the late 20s. The lifetime risk of developing breast cancer is 85%, with an average age of diagnosis between 38 and 46 years. The lifetime risk for thyroid cancer (usually follicular, rarely papillary, but never medullary thyroid cancer) is approximately 35%. The risk for endometrial cancer may approach 28%. BRRS is a congenital disorder characterized by macrocephaly, intestinal hamartomatous polyposis, lipomas, and pigmented macules of the glans penis. PS is a complex, highly variable disorder involving congenital malformations and hamartomatous overgrowth of multiple tissues, as well as connective tissue nevi, epidermal nevi, and hyperostoses. Proteus-like syndrome is undefined but refers to individuals with significant clinical features of PS who do not meet the diagnostic criteria for PS.
Moynahan syndrome
MedGen UID:
120535
Concept ID:
C0265328
Congenital Abnormality
Alopecia or hypotrichosis, microcephaly, seizures, and mental retardation. A suggested classification groups this syndrome into three types: Type I. Total alopecia and mental retardation, the main features, in association with microcephaly. Type II. Subtotal alopecia and mental retardation with or without epilepsy. Type III. Subtotal alopecia and psychomotor retardation with microcephaly and epilepsy.
Cerebro-costo-mandibular syndrome
MedGen UID:
120537
Concept ID:
C0265342
Disease or Syndrome
Cerebrocostomandibular syndrome (CCMS) is characterized mainly by severe micrognathia, rib defects, and mental retardation. A spectrum of rib gap defects have been reported ranging from a few dorsal rib segments to complete absence of ossification. In about half of the 65 reported cases to date, there is cerebral involvement including mental retardation, microcephaly, and histologic anomalies. Both autosomal dominant and autosomal recessive forms of the disorder have been described (Zeevaert et al., 2009). See CDG2G (611209) for a cerebrocostomandibular-like syndrome.
CHARGE association
MedGen UID:
75567
Concept ID:
C0265354
Disease or Syndrome
CHARGE is a mnemonic for coloboma, heart defects, choanal atresia, retarded growth and development, genital abnormalities, and ear anomalies. CHARGE syndrome is characterized by the following: Unilateral or bilateral coloboma of the iris, retina-choroid, and/or disc with or without microphthalmos (80%-90% of individuals). Unilateral or bilateral choanal atresia or stenosis (50%-60%). Cranial nerve dysfunction resulting in hyposmia or anosmia, unilateral or bilateral facial palsy (40%), impaired hearing, and/or swallowing problems (70%-90%). Abnormal outer ears, ossicular malformations, Mondini defect of the cochlea and absent or hypoplastic semicircular canals (>90%). Cryptorchidism in males and hypogonadotropic hypogonadism in both males and females. Developmental delay. Cardiovascular malformations (75%-85%). Growth deficiency (70%-80%). Orofacial clefts (15%-20%). Tracheoesophageal fistula (15%-20%). Neonates with CHARGE syndrome often have multiple life-threatening medical conditions. Feeding difficulties are a major cause of morbidity in all age groups.
13q partial monosomy syndrome
MedGen UID:
120541
Concept ID:
C0265451
Disease or Syndrome
A rare syndrome that is characterized by the partial deletion of the long arm of chromosome 13. Signs and symptoms include low birth weight, craniofacial malformations, hands and feet malformations, and mental and psychomotor retardation.
Pili torti-deafness syndrome
MedGen UID:
82728
Concept ID:
C0266006
Disease or Syndrome
Bjornstad syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss and pili torti. The hearing loss is congenital and of variable severity. Pili torti (twisted hairs), a condition in which the hair shafts are flattened at irregular intervals and twisted 180 degrees from the normal axis, making the hair very brittle, is usually recognized early in childhood (Selvaag, 2000).
Idiopathic hypercalcemia of infancy
MedGen UID:
120608
Concept ID:
C0268080
Disease or Syndrome
Combined molybdoflavoprotein enzyme deficiency
MedGen UID:
75652
Concept ID:
C0268119
Disease or Syndrome
Molybdenum cofactor deficiency (MOCOD) is a rare autosomal recessive metabolic disorder characterized by onset in infancy of poor feeding, intractable seizures, and severe psychomotor retardation. Characteristic biochemical abnormalities include decreased serum uric acid and increased urine sulfite levels due to the combined enzymatic deficiency of xanthine dehydrogenase (XDH; 607633) and sulfite oxidase (SUOX; 606887), both of which use molybdenum as a cofactor. Most affected individuals die in early childhood (summary by Reiss, 2000; Reiss et al., 2011). Genetic Heterogeneity of Molybdenum Cofactor Deficiency See also MOCOD, complementation group B (MOCODB; 252160), caused by mutation in the MOCS2 gene (602708) on chromosome 5q11; and MOCOD, complementation group C (MOCODC; 615501), caused by mutation in the GPHN gene (603930) on chromosome 14q24.
Purine-nucleoside phosphorylase deficiency
MedGen UID:
75653
Concept ID:
C0268125
Disease or Syndrome
Purine nucleoside phosphorylase deficiency is a rare autosomal recessive immunodeficiency disorder characterized mainly by decreased T-cell function. Some patients also have neurologic impairment (review by Aust et al., 1992).
Adenylosuccinate lyase deficiency
MedGen UID:
78641
Concept ID:
C0268126
Disease or Syndrome
Adenylosuccinase deficiency is an autosomal recessive inborn error of metabolism caused by an enzymatic defect in de novo purine synthesis (DNPS) pathway. ADSL deficiency leads to the accumulation of toxic intermediates, including succinyladenosine (S-Ado) and succinylaminoimidazole carboxamide riboside (SAICAr) in body fluids. There are 3 major phenotypic forms of the disorder that correlate with different values of the S-Ado and SAICAr concentration ratios (S-Ado/SAICAr) in the cerebrospinal fluid. These include the most severe fatal neonatal encephalopathy (S-Ado/SAICAr ratio less than 1); childhood form (type I) with severe psychomotor retardation (S-Ado/SAICAr ratio close to 1), and a milder form (type II) with psychomotor retardation or hypotonia (S-Ado/SAICAr ratio greater than 2) (summary by Baresova et al., 2012).
Xeroderma pigmentosum, type 1
MedGen UID:
82775
Concept ID:
C0268135
Disease or Syndrome
Xeroderma pigmentosum (XP) is characterized by: Sun sensitivity (severe sunburn with blistering, persistent erythema on minimal sun exposure in ~60% of affected individuals), with marked freckle-like pigmentation of the face before age two years in most affected individuals; Sunlight-induced ocular involvement (photophobia, keratitis, atrophy of the skin of the lids); Greatly increased risk of sunlight-induced cutaneous neoplasms (basal cell carcinoma, squamous cell carcinoma, melanoma). Approximately 25% of affected individuals have neurologic manifestations (acquired microcephaly, diminished or absent deep tendon stretch reflexes, progressive sensorineural hearing loss, and progressive cognitive impairment). The most common causes of death are skin cancer, neurologic degeneration, and internal cancer. The median age at death in persons with XP with neurodegeneration (29 years) was found to be younger than that in persons with XP without neurodegeneration (37 years).
Xeroderma pigmentosum, group D
MedGen UID:
75656
Concept ID:
C0268138
Disease or Syndrome
Xeroderma pigmentosum (XP) is characterized by: Sun sensitivity (severe sunburn with blistering, persistent erythema on minimal sun exposure in ~60% of affected individuals), with marked freckle-like pigmentation of the face before age two years in most affected individuals; Sunlight-induced ocular involvement (photophobia, keratitis, atrophy of the skin of the lids); Greatly increased risk of sunlight-induced cutaneous neoplasms (basal cell carcinoma, squamous cell carcinoma, melanoma). Approximately 25% of affected individuals have neurologic manifestations (acquired microcephaly, diminished or absent deep tendon stretch reflexes, progressive sensorineural hearing loss, and progressive cognitive impairment). The most common causes of death are skin cancer, neurologic degeneration, and internal cancer. The median age at death in persons with XP with neurodegeneration (29 years) was found to be younger than that in persons with XP without neurodegeneration (37 years).
Xeroderma pigmentosum, group F
MedGen UID:
120612
Concept ID:
C0268140
Congenital Abnormality
Xeroderma pigmentosum (XP) is characterized by: Sun sensitivity (severe sunburn with blistering, persistent erythema on minimal sun exposure in ~60% of affected individuals), with marked freckle-like pigmentation of the face before age two years in most affected individuals; Sunlight-induced ocular involvement (photophobia, keratitis, atrophy of the skin of the lids); Greatly increased risk of sunlight-induced cutaneous neoplasms (basal cell carcinoma, squamous cell carcinoma, melanoma). Approximately 25% of affected individuals have neurologic manifestations (acquired microcephaly, diminished or absent deep tendon stretch reflexes, progressive sensorineural hearing loss, and progressive cognitive impairment). The most common causes of death are skin cancer, neurologic degeneration, and internal cancer. The median age at death in persons with XP with neurodegeneration (29 years) was found to be younger than that in persons with XP without neurodegeneration (37 years).
Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase
MedGen UID:
82777
Concept ID:
C0268151
Disease or Syndrome
The term galactosemia refers to disorders of galactose metabolism that include classic galactosemia, clinical variant galactosemia, and biochemical variant galactosemia. This GeneReview focuses on: Classic galactosemia, which can result in life-threatening complications including feeding problems, failure to thrive, hepatocellular damage, bleeding, and E. coli sepsis in untreated infants. If a lactose-restricted diet is provided during the first ten days of life, the neonatal signs usually quickly resolve and the complications of liver failure, sepsis, and neonatal death are prevented; however, despite adequate treatment from an early age, children with classic galactosemia remain at increased risk for developmental delays, speech problems (termed childhood apraxia of speech and dysarthria), and abnormalities of motor function. Almost all females with classic galactosemia manifest premature ovarian insufficiency (POI). Clinical variant galactosemia, which can result in life-threatening complications including feeding problems, failure to thrive, hepatocellular damage including cirrhosis and bleeding in untreated infants. This is exemplified by the disease that occurs in African Americans and native Africans in South Africa. Persons with clinical variant galactosemia may be missed with newborn screening (NBS) as the hypergalactosemia is not as marked as in classic galactosemia and breath testing is normal. If a lactose-restricted diet is provided during the first ten days of life, the severe acute neonatal complications are usually prevented. African Americans with clinical variant galactosemia and adequate early treatment do not appear to be at risk for long-term complications including POI.
Deficiency of cytochrome-b5 reductase
MedGen UID:
75661
Concept ID:
C0268193
Disease or Syndrome
Methemoglobinemia due to NADH-cytochrome b5 reductase deficiency is an autosomal recessive disorder characterized clinically by decreased oxygen carrying capacity of the blood, with resultant cyanosis and hypoxia (review by Percy and Lappin, 2008). There are 2 types of methemoglobin reductase deficiency. In type I, the defect affects the soluble form of the enzyme, is restricted to red blood cells, and causes well-tolerated methemoglobinemia. In type II, the defect affects both the soluble and microsomal forms of the enzyme and is thus generalized, affecting red cells, leukocytes, and all body tissues. Type II methemoglobinemia is associated with mental deficiency and other neurologic symptoms. The neurologic symptoms may be related to the major role played by the cytochrome b5 system in the desaturation of fatty acids (Vives-Corrons et al., 1978; Kaplan et al., 1979).
Aspartylglucosaminuria
MedGen UID:
78649
Concept ID:
C0268225
Disease or Syndrome
Aspartylglucosaminuria is a severe autosomal recessive lysosomal storage disorder that involves the central nervous system and causes skeletal abnormalities as well as connective tissue lesions. The most characteristic feature is progressive mental retardation. The disorder is caused by deficient activity of the lysosomal enzyme glycosylasparaginase, which results in body fluid and tissue accumulation of a series of glycoasparagines, i.e., glycoconjugates with an aspartylglucosamine moiety at the reducing end. AGU belongs to the group of disorders commonly referred to as the Finnish disease heritage (summary by Mononen et al., 1993 and Arvio and Arvio, 2002).
Sialidosis
MedGen UID:
120621
Concept ID:
C0268226
Disease or Syndrome
An autosomal recessive inherited lysosomal storage disease characterized by excessive intracellular accumulation and urinary excretion of sialic acid associated with neuraminidase deficiency.
Combined deficiency of sialidase AND beta galactosidase
MedGen UID:
82779
Concept ID:
C0268233
Disease or Syndrome
Galactosialidosis is a lysosomal storage disease associated with a combined deficiency of beta-galactosidase (611458) and neuraminidase (608272), secondary to a defect in protective protein/cathepsin A (PPCA). All patients have clinical manifestations typical of a lysosomal disorder, such as coarse facies, cherry red spots, vertebral changes, foam cells in the bone marrow, and vacuolated lymphocytes. Three phenotypic subtypes are recognized. The early infantile form is associated with fetal hydrops, edema, ascites, visceromegaly, skeletal dysplasia, and early death. The late infantile type is characterized by hepatosplenomegaly, growth retardation, cardiac involvement, and rare occurrence of neurologic signs. The juvenile/adult form is characterized by myoclonus, ataxia, angiokeratoma, mental retardation, neurologic deterioration, absence of visceromegaly, and long survival. The majority of reported patients belong to the juvenile/adult group and are mainly of Japanese origin (summary by d'Azzo et al., 2001).
Hepatic failure, early-onset, and neurologic disorder due to cytochrome C oxidase deficiency
MedGen UID:
75662
Concept ID:
C0268237
Congenital Abnormality
Leigh syndrome (or subacute necrotizing encephalomyelopathy) is characterized by decompensation (often with elevated lactate levels in blood and/or CSF) during an intercurrent illness. It is typically associated with psychomotor retardation or regression, often followed by transient or prolonged stabilization or even improvement, but inevitably resulting in eventual progressive neurologic decline, typically occurring in stepwise decrements. Neurologic manifestations include hypotonia, spasticity, movement disorders (including chorea), cerebellar ataxia, and peripheral neuropathy. Extraneurologic manifestations may include hypertrophic cardiomyopathy, hypertrichosis, anemia, renal tubulopathy, liver involvement, ptosis, and muscle weakness. Onset is typically between ages three and 12 months; about 50% of affected individuals die by age three years, most often as a result of respiratory or cardiac failure. Later onset (including in adulthood) and long-term survival may occasionally occur.
Triglyceride storage disease with ichthyosis
MedGen UID:
82780
Concept ID:
C0268238
Disease or Syndrome
Chanarin-Dorfman syndrome is a condition in which fats (lipids) are stored abnormally in the body. Affected individuals cannot break down certain fats called triglycerides, and these fats accumulate in organs and tissues, including skin, liver, muscles, intestine, eyes, and ears. People with this condition also have dry, scaly skin (ichthyosis), which is usually present at birth. Additional features of this condition include an enlarged liver (hepatomegaly), clouding of the lens of the eyes (cataracts), difficulty with coordinating movements (ataxia), hearing loss, short stature, muscle weakness (myopathy), involuntary movement of the eyes (nystagmus), and mild intellectual disability.The signs and symptoms vary greatly among individuals with Chanarin-Dorfman syndrome. Some people may have ichthyosis only, while others may have problems affecting many areas of the body.
Niemann-Pick disease, type A
MedGen UID:
78650
Concept ID:
C0268242
Disease or Syndrome
Acid sphingomyelinase (ASM) deficiency has been categorized in the past as either neuronopathic (Niemann-Pick disease type A [NPD-A]), with death in early childhood, or non-neuronopathic (Niemann-Pick disease type B [NPD-B]). While forms intermediate to these two extremes occur, all ASM deficiency that is not NPD-A is designated in this review as NPD-B, despite its wide range of manifestations and severity. The first symptom in NPD-A is hepatosplenomegaly, usually noted by age three months; over time the liver and spleen become massive. Psychomotor development progresses no further than the 12-month level, after which neurologic deterioration is relentless. A classic cherry-red spot of the macula of the retina, which may not be present in the first few months, is eventually present in all affected children. Interstitial lung disease caused by storage of sphingomyelin in pulmonary macrophages results in frequent respiratory infections and often respiratory failure. Most children succumb before the third year. NPD type B, later in onset and milder in manifestations than NPD type A, is characterized by hepatosplenomegaly with progressive hypersplenism and stable liver dysfunction, gradual deterioration in pulmonary function, osteopenia, and atherogenic lipid profile. Progressive and/or clinically significant neurologic manifestations occur infrequently. Survival to adulthood can occur.
Farber disease
MedGen UID:
78654
Concept ID:
C0268255
Disease or Syndrome
The spectrum of ASAH1-related disorders ranges from Farber disease (FD) to spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME). Classic FD is characterized by onset in the first weeks of life of painful, progressive deformity of the major joints; palpable subcutaneous nodules of joints and mechanical pressure points; and a hoarse cry resulting from granulomas of the larynx and epiglottis. Life expectancy is usually less than two years. In the other less common types of FD, onset, severity, and primary manifestations vary. SMA-PME is characterized by early-childhood-onset progressive lower motor neuron disease manifest typically between ages three and seven years as proximal lower-extremity weakness, followed by progressive myoclonic and atonic seizures, tremulousness/tremor, and sensorineural hearing loss. Myoclonic epilepsy typically begins in late childhood after the onset of weakness and can include jerking of the upper limbs, action myoclonus, myoclonic status, and eyelid myoclonus. Other findings include generalized tremor, and cognitive decline. The time from disease onset to death from respiratory complications is usually five to 15 years.
Multiple sulfatase deficiency
MedGen UID:
75664
Concept ID:
C0268263
Disease or Syndrome
Initial symptoms of multiple sulfatase deficiency (MSD) can develop from infancy through early childhood, and presentation is widely variable. Some individuals display the multisystemic features characteristic of mucopolysaccharidosis disorders (e.g., developmental regression, organomegaly, skeletal deformities) while other individuals present primarily with neurologic regression (associated with leukodystrophy). Based on age of onset, rate of progression, and disease severity, several different clinical subtypes of MSD have been described: Neonatal MSD is the most severe with presentation in the prenatal period or at birth with rapid progression and death occurring within the first two years of life. Infantile MSD is the most common variant and may be characterized as attenuated (slower clinical course with cognitive disability and neurodegeneration identified in the 2nd year of life) or severe (loss of the majority of developmental milestones by age 5 years). Juvenile MSD is the rarest subtype with later onset of symptoms and subacute clinical presentation. Many of the features found in MSD are progressive, including neurologic deterioration, heart disease, hearing loss, and airway compromise.
Infantile GM1 gangliosidosis
MedGen UID:
75665
Concept ID:
C0268271
Disease or Syndrome
GLB1-related disorders comprise two phenotypically distinct lysosomal storage disorders: GM1 gangliosidosis and mucopolysaccharidosis type IVB (MPS IVB). GM1 gangliosidosis includes phenotypes that range from severe to mild. Type I (infantile) begins before age one year; progressive central nervous system dysfunction leads to spasticity, deafness, blindness, and decerebrate rigidity. Life expectancy is two to three years. Type II can be subdivided into the late-infantile form and juvenile form. Type II, late-infantile form begins between ages one and three years; life expectancy is five to ten years. Type II, juvenile form begins between ages three and ten years with insidious plateauing of motor and cognitive development followed by slow regression. Type II may or may not include skeletal dysplasia. Type III begins in the second to third decade with extrapyramidal signs, gait disturbance, and cardiomyopathy; and can be misidentified as Parkinson disease. Intellectual impairment is common late in the disease; skeletal involvement includes short stature, kyphosis, and scoliosis of varying severity. MPS IVB is characterized by skeletal changes, including short stature and skeletal dysplasia. Affected children have no distinctive clinical findings at birth. The severe form is usually apparent between ages one and three years, and the attenuated form in late childhood or adolescence. In addition to skeletal involvement, significant morbidity can result from respiratory compromise, obstructive sleep apnea, valvular heart disease, hearing impairment, corneal clouding, and spinal cord compression. Intellect is normal unless spinal cord compression leads to central nervous system compromise.
Cutis laxa-corneal clouding-oligophrenia syndrome
MedGen UID:
82794
Concept ID:
C0268354
Disease or Syndrome
De Barsy syndrome, or autosomal recessive cutis laxa type III (ARCL3), is characterized by cutis laxa, a progeria-like appearance, and ophthalmologic abnormalities (summary by Kivuva et al., 2008). For a phenotypic description and a discussion of genetic heterogeneity of autosomal recessive cutis laxa, see 219100. Genetic Heterogeneity of de Barsy Syndrome Also see ARCL3B (614438), caused by mutation in the PYCR1 gene (179035) on chromosome 17q25.
Cutis laxa with osteodystrophy
MedGen UID:
82795
Concept ID:
C0268355
Disease or Syndrome
ATP6V0A2-related cutis laxa, also known as autosomal recessive cutis laxa type 2A (ARCL2A), spans a phenotypic spectrum that includes Debré-type cutis laxa at the severe end and wrinkly skin syndrome at the mild end. Affected individuals have furrowing of the skin of the whole body that improves with time. They may have other evidence of a generalized connective disorder, including enlarged anterior fontanelle in infancy, congenital dislocation of the hips, inguinal hernias, and high myopia. In most (not all) affected individuals, cortical and cerebellar malformations are present and are associated with severe developmental delays, seizures, and neurologic regression.
Deficiency of glycerol kinase
MedGen UID:
82803
Concept ID:
C0268418
Disease or Syndrome
NR0B1-related adrenal hypoplasia congenita includes both X-linked adrenal hypoplasia congenita (X-linked AHC) and Xp21 deletion (previously called complex glycerol kinase deficiency). X-linked AHC is characterized by primary adrenal insufficiency and/or hypogonadotropic hypogonadism (HH). Adrenal insufficiency is acute infantile onset (average age 3 weeks) in approximately 60% of affected males and childhood onset (ages 1-9 years) in approximately 40%. HH typically manifests in a male with adrenal insufficiency as delayed puberty (i.e., onset age >14 years) and less commonly as arrested puberty at about Tanner Stage 3. Rarely, X-linked AHC manifests initially in early adulthood as delayed-onset adrenal insufficiency, partial HH, and/or infertility. Heterozygous females very occasionally have manifestations of adrenal insufficiency or hypogonadotropic hypogonadism. Xp21 deletion includes deletion of NR0B1 (causing X-linked AHC) and GK (causing glycerol kinase deficiency), and in some cases deletion of DMD (causing Duchenne muscular dystrophy). Developmental delay has been reported in males with Xp21 deletion when the deletion extends proximally to include DMD or when larger deletions extend distally to include IL1RAPL1 and DMD.
Dihydropteridine reductase deficiency
MedGen UID:
75682
Concept ID:
C0268465
Disease or Syndrome
Tetrahydrobiopterin deficiency is a rare disorder characterized by a shortage (deficiency) of a molecule called tetrahydrobiopterin or BH4. This condition alters the levels of several substances in the body, including phenylalanine. Phenylalanine is a building block of proteins (an amino acid) that is obtained through the diet. It is found in foods that contain protein and in some artificial sweeteners. High levels of phenylalanine are present from early infancy in people with untreated tetrahydrobiopterin deficiency. This condition also alters the levels of chemicals called neurotransmitters, which transmit signals between nerve cells in the brain.Infants with tetrahydrobiopterin deficiency appear normal at birth, but medical problems ranging from mild to severe become apparent over time. Signs and symptoms of this condition can include intellectual disability, progressive problems with development, movement disorders, difficulty swallowing, seizures, behavioral problems, and an inability to control body temperature.
Sepiapterin reductase deficiency
MedGen UID:
120642
Concept ID:
C0268468
Disease or Syndrome
The phenotypic spectrum of sepiapterin reductase deficiency (SRD), which ranges from significant motor and cognitive deficits to only minimal findings, has not been completely elucidated. Clinical features in the majority of affected individuals include motor and speech delay, axial hypotonia, dystonia, weakness, and oculogyric crises; symptoms show diurnal fluctuation and sleep benefit. Other common features include parkinsonian signs (tremor, bradykinesia, masked facies, rigidity), limb hypertonia, hyperreflexia, intellectual disability, psychiatric and/or behavioral abnormalities, autonomic dysfunction, and sleep disturbances (hypersomnolence, difficulty initiating or maintaining sleep, and drowsiness). Most affected individuals have nonspecific features in infancy including developmental delays and axial hypotonia; other features develop over time.
Tryptophanuria with dwarfism
MedGen UID:
78680
Concept ID:
C0268473
Disease or Syndrome
Hydroxykynureninuria
MedGen UID:
78681
Concept ID:
C0268474
Disease or Syndrome
Hooft syndrome
MedGen UID:
75686
Concept ID:
C0268479
Disease or Syndrome
Tyrosinemia type 2
MedGen UID:
75687
Concept ID:
C0268487
Disease or Syndrome
Tyrosinemia type II is an autosomal recessive disorder characterized by keratitis, painful palmoplantar hyperkeratosis, mental retardation, and elevated serum tyrosine levels. The disorder is caused by deficiency of hepatic tyrosine aminotransferase (Natt et al., 1992).
Cross syndrome
MedGen UID:
82811
Concept ID:
C0268496
Disease or Syndrome
gamma-Glutamyltransferase deficiency
MedGen UID:
82813
Concept ID:
C0268524
Disease or Syndrome
Proline dehydrogenase deficiency
MedGen UID:
120645
Concept ID:
C0268529
Disease or Syndrome
Phang et al. (2001) noted that prospective studies of HPI probands identified through newborn screening as well as reports of several families have suggested that it is a metabolic disorder not clearly associated with clinical manifestations. Phang et al. (2001) concluded that HPI is a relatively benign condition in most individuals under most circumstances. However, other reports have suggested that some patients have a severe phenotype with neurologic manifestations, including epilepsy and mental retardation (Jacquet et al., 2003). Genetic Heterogeneity of Hyperprolinemia See also hyperprolinemia type II (HYRPRO2; 239510), which is caused by mutation in the gene encoding pyrroline-5-carboxylate dehydrogenase (P5CDH, ALDH4A1; 606811) on chromosome 1p36.
Hyperhydroxyprolinemia
MedGen UID:
75691
Concept ID:
C0268531
Disease or Syndrome
Hydroxyproline is an imino acid normally present in human plasma. It is derived primarily from endogenous collagen turnover and the breakdown of dietary collagen. The finding of elevated (5- to 10-fold increase from the normal of less than 50 micromoles) serum hydroxyproline is thought to be an inherited defect in the catabolism of hydroxyproline.
Hyperornithinemia-hyperammonemia-homocitrullinuria syndrome
MedGen UID:
82815
Concept ID:
C0268540
Disease or Syndrome
Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is characterized by variable clinical presentation and age of onset. Neonatal onset (~12% of affected individuals). Infants are normal for the first 24-48 hours followed by onset of symptoms related to hyperammonemia (poor feeding, vomiting, lethargy, low temperature, rapid breathing). Information on long-term outcome is limited. Infancy, childhood, and adult presentation (~88%). Affected individuals may present with: Chronic neurocognitive deficits (including developmental delay, ataxia, spasticity, learning disabilities, cognitive deficits and/or unexplained seizures); Acute encephalopathy secondary to hyperammonemic crisis precipitated by a variety of factors; and Chronic liver dysfunction (unexplained elevation of liver transaminases with or without mild coagulopathy, with or without mild hyperammonemia and protein intolerance). Neurologic findings and cognitive abilities can continue to deteriorate despite early metabolic control that prevents hyperammonemia.
Ornithine carbamoyltransferase deficiency
MedGen UID:
75692
Concept ID:
C0268542
Disease or Syndrome
Ornithine transcarbamylase (OTC) deficiency can occur as a severe neonatal-onset disease in males (but rarely in females) and as a post-neonatal-onset (partial deficiency) disease in males and females. Males with severe neonatal-onset OTC deficiency are typically normal at birth but become symptomatic from hyperammonemia on day two to three of life and are usually catastrophically ill by the time they come to medical attention. After successful treatment of neonatal hyperammonemic coma these infants can easily become hyperammonemic again despite appropriate treatment; they typically require liver transplant by age six months to improve quality of life. Males and heterozygous females with post-neonatal-onset (partial) OTC deficiency can present from infancy to later childhood, adolescence, or adulthood. No matter how mild the disease, a hyperammonemic crisis can be precipitated by stressors and become a life-threatening event at any age and in any situation in life. For all individuals with OTC deficiency, typical neuropsychological complications include developmental delay, learning disabilities, intellectual disability, attention deficit hyperactivity disorder (ADHD), and executive function deficits.
Argininosuccinate lyase deficiency
MedGen UID:
78687
Concept ID:
C0268547
Disease or Syndrome
Deficiency of argininosuccinate lyase (ASL), the enzyme that cleaves argininosuccinic acid to produce arginine and fumarate in the fourth step of the urea cycle, may present as a severe neonatal-onset form and a late-onset form: The severe neonatal-onset form is characterized by hyperammonemia within the first few days after birth that can manifest as increasing lethargy, somnolence, refusal to feed, vomiting, tachypnea, and respiratory alkalosis. Absence of treatment leads to worsening lethargy, seizures, coma, and even death. In contrast, the manifestations of late-onset form range from episodic hyperammonemia triggered by acute infection or stress to cognitive impairment, behavioral abnormalities, and/or learning disabilities in the absence of any documented episodes of hyperammonemia. Manifestations of ASL deficiency (ASLD) that appear to be unrelated to the severity or duration of hyperammonemic episodes: Neurocognitive deficiencies (attention-deficit/hyperactivity disorder, developmental delay, seizures, and learning disability). Liver disease (hepatitis, cirrhosis). Trichorrhexis nodosa (coarse brittle hair that breaks easily). Systemic hypertension.
Arginase deficiency
MedGen UID:
78688
Concept ID:
C0268548
Disease or Syndrome
Arginase deficiency in untreated individuals is characterized by episodic hyperammonemia of variable degree that is infrequently severe enough to be life threatening or to cause death. Most commonly, birth and early childhood are normal. Untreated individuals have slowing of linear growth at age one to three years, followed by development of spasticity, plateauing of cognitive development, and subsequent loss of developmental milestones. If untreated, arginase deficiency usually progresses to severe spasticity, loss of ambulation, complete loss of bowel and bladder control, and severe intellectual disability. Seizures are common and are usually controlled easily.
Hyperlysinemia
MedGen UID:
82816
Concept ID:
C0268553
Disease or Syndrome
An increased concentration of lysine in the blood.
Hyperlysinuria with hyperammonemia
MedGen UID:
120650
Concept ID:
C0268555
Disease or Syndrome
Saccharopinuria
MedGen UID:
75693
Concept ID:
C0268556
Disease or Syndrome
Saccharopinuria, also known as hyperlysinemia type II, is an autosomal recessive metabolic condition with few, if any, clinical manifestations. Hyperlysinemia type II and hyperlysinemia type I (238700) both result from deficiency of the bifunctional enzyme AASS (605113) on chromosome 7q31. The AASS gene encodes lysine alpha-ketoglutarate reductase and saccharopine dehydrogenase, which catalyze, respectively, the sequential conversion of lysine to saccharopine and saccharopine to alpha-aminoadipic semialdehyde and glutamate (summary by Tondo et al., 2013). In hyperlysinemia type I, both enzymatic functions of AASS are defective and patients have increased serum lysine and possibly increased saccharopine; in hyperlysinemia type II, most of the first enzymatic function is retained, and patients tend to have isolated saccharopine increase (Cox, 1985; Cox et al., 1985).
Hyperleucine-isoleucinemia
MedGen UID:
82821
Concept ID:
C0268574
Disease or Syndrome
3-MCC Deficiency
MedGen UID:
78691
Concept ID:
C0268600
Disease or Syndrome
3-methylcrotonyl-CoA carboxylase deficiency (also known as 3-MCC deficiency) is an inherited disorder in which the body is unable to process certain proteins properly. People with this disorder have a shortage of an enzyme that helps break down proteins containing a particular building block (amino acid) called leucine.Infants with 3-MCC deficiency appear normal at birth but usually develop signs and symptoms in infancy or early childhood. The characteristic features of this condition, which can range from mild to life-threatening, include feeding difficulties, recurrent episodes of vomiting and diarrhea, excessive tiredness (lethargy), and weak muscle tone (hypotonia). If untreated, this disorder can lead to delayed development, seizures, and coma. Many of these complications can be prevented with early detection and lifelong management with a low-protein diet and appropriate supplements. Some people with gene mutations that cause 3-MCC deficiency never experience any signs or symptoms of the condition.The characteristic features of 3-MCC deficiency are similar to those of Reye syndrome, a severe disorder that develops in children while they appear to be recovering from viral infections such as chicken pox or flu. Most cases of Reye syndrome are associated with the use of aspirin during these viral infections.
GLUTAMATE FORMIMINOTRANSFERASE DEFICIENCY
MedGen UID:
82823
Concept ID:
C0268609
Disease or Syndrome
Glutamate formiminotransferase deficiency is an autosomal recessive disorder and the second most common inborn error of folate metabolism. Features of a severe phenotype include elevated levels of formiminoglutamate (FIGLU) in the urine in response to histidine administration, megaloblastic anemia, and mental retardation. Features of a mild phenotype include high urinary excretion of FIGLU in the absence of histidine administration, mild developmental delay, and no hematologic abnormalities (summary by Hilton et al., 2003).
Hepatic methionine adenosyltransferase deficiency
MedGen UID:
75700
Concept ID:
C0268621
Disease or Syndrome
Methionine adenosyltransferase deficiency is an inborn error of metabolism resulting in isolated hypermethioninemia. Most patients have no clinical abnormalities, although some with the autosomal recessive form have have neurologic abnormalities (Mudd et al., 2003; Kim et al., 2016).
Familial methionine malabsorption
MedGen UID:
78693
Concept ID:
C0268622
Disease or Syndrome
Succinate-semialdehyde dehydrogenase deficiency
MedGen UID:
124340
Concept ID:
C0268631
Disease or Syndrome
Succinic semialdehyde dehydrogenase (SSADH) deficiency is characterized by infantile-onset hypotonia, developmental delay, cognitive impairment, expressive language deficit, and mild ataxia. Epilepsy is present in about half of affected individuals and is more common in adults. Hyperkinetic behavior, aggression, self-injurious behaviors, hallucinations, and sleep disturbances have been reported in nearly half of all affected individuals, more commonly in those who are older. Basal ganglia signs including choreoathetosis, dystonia, and myoclonus have been reported in a few individuals with earlier-onset, more severe disease. Involvement beyond the central nervous system has not been described. Individuals with SSADH deficiency typically have 4-hydroxybutyric aciduria present on urine organic acid analysis. Head MRI reveals T2 hyperintensities in multiple regions, involving the globus pallidi, cerebellar dentate nuclei, subthalamic nuclei, subcortical white matter, and brain stem, as well as cerebral and sometimes cerebellar atrophy. EEG findings include background slowing and spike discharges that are usually generalized.
Homocarnosinosis
MedGen UID:
75703
Concept ID:
C0268632
Disease or Syndrome
Histidine transport defect
MedGen UID:
82825
Concept ID:
C0268642
Disease or Syndrome
An increased concentration of histidine in the urine.
Iminoglycinuria
MedGen UID:
124342
Concept ID:
C0268654
Disease or Syndrome
The imino acids, proline and hydroxyproline, share a renal tubular reabsorptive mechanism with glycine. Iminoglycinuria (IG), a benign inborn error of amino acid transport, is also a normal finding in neonates and infants under 6 months of age (Chesney, 2001). Early studies of families with iminoglycinuria suggested genetic complexity, with homozygotes developing IG and heterozygotes manifesting only hyperglycinuria (HG; 138500) (summary by Broer et al., 2008). Iminoglycinuria may be more frequent in Ashkenazim than in others (Tancredi et al., 1970). Iminoglycinuria also occurs as part of the generalized amino aciduria of the Fanconi renotubular syndrome (134600).
Infantile neuroaxonal dystrophy
MedGen UID:
82852
Concept ID:
C0270724
Disease or Syndrome
PLA2G6-associated neurodegeneration (PLAN) comprises a continuum of three phenotypes with overlapping clinical and radiologic features: Infantile neuroaxonal dystrophy (INAD). Atypical neuroaxonal dystrophy (atypical NAD). PLA2G6-related dystonia-parkinsonism. INAD usually begins between ages six months and three years with psychomotor regression or delay, hypotonia, and progressive spastic tetraparesis. Many affected children never learn to walk or lose the ability shortly after attaining it. Strabismus, nystagmus, and optic atrophy are common. Disease progression is rapid, resulting in severe spasticity, progressive cognitive decline, and visual impairment. Many affected children do not survive beyond their first decade. Atypical NAD shows more phenotypic variability than INAD. In general, onset is in early childhood but can be as late as the end of the second decade. The presenting signs may be gait instability, ataxia, or speech delay and autistic features, which are sometimes the only evidence of disease for a year or more. Strabismus, nystagmus, and optic atrophy are common. Neuropsychiatric disturbances including impulsivity, poor attention span, hyperactivity, and emotional lability are also common. The course is fairly stable during early childhood and resembles static encephalopathy but is followed by neurologic deterioration between ages seven and 12 years. PLA2G6-related dystonia-parkinsonism has a variable age of onset, but most individuals present in early adulthood with gait disturbance or neuropsychiatric changes. Affected individuals consistently develop dystonia and parkinsonism (which may be accompanied by rapid cognitive decline) in their late teens to early twenties. Dystonia is most common in the hands and feet but may be more generalized. The most common features of parkinsonism in these individuals are bradykinesia, resting tremor, rigidity, and postural instability.
De Lange syndrome
MedGen UID:
78752
Concept ID:
C0270972
Disease or Syndrome
Classic Cornelia de Lange syndrome (CdLS) is characterized by distinctive facial features, growth retardation (prenatal onset; <5th centile throughout life), hirsutism, and upper-limb reduction defects that range from subtle phalangeal abnormalities to oligodactyly (missing digits). Craniofacial features include synophrys, highly arched eyebrows, long eyelashes, short nose with anteverted nares, small widely spaced teeth, and microcephaly. IQ ranges from below 30 to 102 (mean: 53). Many individuals demonstrate autistic and self-destructive tendencies. Frequent findings include cardiac septal defects, gastrointestinal dysfunction, hearing loss, myopia, and cryptorchidism or hypoplastic genitalia. Individuals with a milder phenotype have less severe growth, cognitive, and limb involvement, but often have facial features consistent with CdLS.
Leucine-induced hypoglycemia
MedGen UID:
82888
Concept ID:
C0271714
Disease or Syndrome
Glucocorticoid deficiency with achalasia
MedGen UID:
82889
Concept ID:
C0271742
Disease or Syndrome
Triple A syndrome is an inherited condition characterized by three specific features: achalasia, Addison disease, and alacrima. Achalasia is a disorder that affects the ability to move food through the esophagus, the tube that carries food from the throat to the stomach. It can lead to severe feeding difficulties and low blood sugar (hypoglycemia). Addison disease, also known as primary adrenal insufficiency, is caused by abnormal function of the small hormone-producing glands on top of each kidney (adrenal glands). The main features of Addison disease include fatigue, loss of appetite, weight loss, low blood pressure, and darkening of the skin. The third major feature of triple A syndrome is a reduced or absent ability to secrete tears (alacrima). Most people with triple A syndrome have all three of these features, although some have only two.Many of the features of triple A syndrome are caused by dysfunction of the autonomic nervous system. This part of the nervous system controls involuntary body processes such as digestion, blood pressure, and body temperature. People with triple A syndrome often experience abnormal sweating, difficulty regulating blood pressure, unequal pupil size (anisocoria), and other signs and symptoms of autonomic nervous system dysfunction (dysautonomia).People with this condition may have other neurological abnormalities, such as developmental delay, intellectual disability, speech problems (dysarthria), and a small head size (microcephaly). In addition, affected individuals commonly experience muscle weakness, movement problems, and nerve abnormalities in their extremities (peripheral neuropathy). Some develop optic atrophy, which is the degeneration (atrophy) of the nerves that carry information from the eyes to the brain. Many of the neurological symptoms of triple A syndrome worsen over time.People with triple A syndrome frequently develop a thickening of the outer layer of skin (hyperkeratosis) on the palms of their hands and the soles of their feet. Other skin abnormalities may also be present in people with this condition.Alacrima is usually the first noticeable sign of triple A syndrome, as it becomes apparent early in life that affected children produce little or no tears while crying. They develop Addison disease and achalasia during childhood or adolescence, and most of the neurologic features of triple A syndrome begin during adulthood. The signs and symptoms of this condition vary among affected individuals, even among members of the same family.
Pendred syndrome
MedGen UID:
82890
Concept ID:
C0271829
Disease or Syndrome
Pendred syndrome/nonsyndromic enlarged vestibular aqueduct (PDS/NSEVA) comprises a phenotypic spectrum of sensorineural hearing loss (SNHL) that is usually congenital and often severe to profound (although mild-to-moderate progressive hearing impairment also occurs), vestibular dysfunction, and temporal bone abnormalities (bilateral enlarged vestibular aqueduct with or without cochlear hypoplasia). PDS also includes development of euthyroid goiter in late childhood to early adulthood whereas NSEVA does not.
HNSHA due to aldolase A deficiency
MedGen UID:
82895
Concept ID:
C0272066
Disease or Syndrome
Aldolase A deficiency is an autosomal recessive disorder associated with hereditary hemolytic anemia (Kishi et al., 1987).
Neonatal adrenoleucodystrophy
MedGen UID:
129184
Concept ID:
C0282525
Disease or Syndrome
A rare metabolic disorder that affects neonates. It is characterized by damage of the white matter in the brain and degeneration of the adrenal glands. It manifests with hyperactivity, paralysis, muscular weakness, crossed eyes, hearing loss, seizures, and coma.
Peroxisome biogenesis disorder 1B
MedGen UID:
79470
Concept ID:
C0282527
Disease or Syndrome
Zellweger spectrum disorder (ZSD) is a phenotypic continuum ranging from severe to mild. While individual phenotypes (e.g., Zellweger syndrome [ZS], neonatal adrenoleukodystrophy [NALD], and infantile Refsum disease [IRD]) were described in the past before the biochemical and molecular bases of this spectrum were fully determined, the term "ZSD" is now used to refer to all individuals with a PEX gene defect regardless of phenotype. Individuals with ZSD usually come to clinical attention in the newborn period or later in childhood. Affected newborns are hypotonic and feed poorly. They have distinctive facies, congenital malformations (neuronal migration defects associated with neonatal-onset seizures, renal cysts, and bony stippling [chondrodysplasia punctata] of the patella[e] and other long bones), and liver disease that can be severe. Infants with severe ZSD are significantly impaired and typically die during the first year of life, usually having made no developmental progress. Individuals with intermediate/milder ZSD do not have congenital malformations, but rather progressive peroxisome dysfunction variably manifest as sensory loss (secondary to retinal dystrophy and sensorineural hearing loss); neurologic involvement (ataxia, polyneuropathy, and leukodystrophy); liver dysfunction; adrenal insufficiency; and renal oxalate stones. While hypotonia and developmental delays are typical, intellect can be normal. Some have osteopenia; almost all have ameleogenesis imperfecta in the secondary teeth.
Hennekam lymphangiectasia-lymphedema syndrome
MedGen UID:
137946
Concept ID:
C0340834
Disease or Syndrome
Iodotyrosyl coupling defect
MedGen UID:
90976
Concept ID:
C0342194
Disease or Syndrome
Kanou et al. (2007) reviewed characteristics of thyroid dyshormonogenesis caused by mutations in the thyroglobulin (TG) gene. This form of thyroid dyshormonogenesis has an estimated prevalence of one in 100,000 newborns. Inherited in an autosomal recessive manner, the disorder in the majority of patients causes large goiters of elastic and soft consistency. Although the degree of thyroid dysfunction varies considerably among patients with defective TG synthesis, patients usually have a relatively high serum free T3 concentration with disproportionately low free T4 level. The maintenance of relatively high FT3 levels prevents profound tissue hypothyroidism except in brain and pituitary, which are dependent on T4 supply, resulting in neurologic and intellectual defects in some cases.
Iodotyrosine deiodination defect
MedGen UID:
87429
Concept ID:
C0342195
Disease or Syndrome
Presumed loss-of-function mutation(s) in the IYD gene, resulting in reduced activity of the enzyme iodotyrosine deiodinase.
Thyroglobulin synthesis defect
MedGen UID:
87430
Concept ID:
C0342196
Disease or Syndrome
Congenital hypothyroidism is a partial or complete loss of function of the thyroid gland (hypothyroidism) that affects infants from birth (congenital). The thyroid gland is a butterfly-shaped tissue in the lower neck. It makes iodine-containing hormones that play an important role in regulating growth, brain development, and the rate of chemical reactions in the body (metabolism). People with congenital hypothyroidism have lower-than-normal levels of these important hormones.Congenital hypothyroidism occurs when the thyroid gland fails to develop or function properly. In 80 to 85 percent of cases, the thyroid gland is absent, severely reduced in size (hypoplastic), or abnormally located. These cases are classified as thyroid dysgenesis. In the remainder of cases, a normal-sized or enlarged thyroid gland (goiter) is present, but production of thyroid hormones is decreased or absent. Most of these cases occur when one of several steps in the hormone synthesis process is impaired; these cases are classified as thyroid dyshormonogenesis. Less commonly, reduction or absence of thyroid hormone production is caused by impaired stimulation of the production process (which is normally done by a structure at the base of the brain called the pituitary gland), even though the process itself is unimpaired. These cases are classified as central (or pituitary) hypothyroidism.Signs and symptoms of congenital hypothyroidism result from the shortage of thyroid hormones. Affected babies may show no features of the condition, although some babies with congenital hypothyroidism are less active and sleep more than normal. They may have difficulty feeding and experience constipation. If untreated, congenital hypothyroidism can lead to intellectual disability and slow growth. In the United States and many other countries, all hospitals test newborns for congenital hypothyroidism. If treatment begins in the first two weeks after birth, infants usually develop normally.Congenital hypothyroidism can also occur as part of syndromes that affect other organs and tissues in the body. These forms of the condition are described as syndromic. Some common forms of syndromic hypothyroidism include Pendred syndrome, Bamforth-Lazarus syndrome, and brain-lung-thyroid syndrome.
Fetal iodine deficiency disorder
MedGen UID:
83336
Concept ID:
C0342200
Disease or Syndrome
Severely reduced physical and mental growth associated with pyramidal and extrapyramidal signs and symptoms, due to dietary iodine deficiency.
Bird-headed dwarfism with progressive ataxia, insulin-resistant diabetes, goiter, and primary gonadal insufficiency
MedGen UID:
90978
Concept ID:
C0342284
Disease or Syndrome
Hypogonadism, diabetes mellitus, alopecia, mental retardation and electrocardiographic abnormalities
MedGen UID:
83337
Concept ID:
C0342286
Disease or Syndrome
Neurodegeneration with brain iron accumulation (NBIA) is a group of inherited neurologic disorders in which iron accumulates in the basal ganglia resulting in progressive dystonia, spasticity, parkinsonism, neuropsychiatric abnormalities, and optic atrophy or retinal degeneration. Ten types and their associated genes are recognized. The age of onset ranges from infancy to late adulthood; the rate of progression varies. Cognitive decline occurs in some subtypes, but more often cognition is relatively spared. Cerebellar atrophy is a frequent finding in some subtypes.
Klein-Waardenberg syndrome
MedGen UID:
449531
Concept ID:
C0342680
Disease or Syndrome
Transcobalamin II deficiency
MedGen UID:
137976
Concept ID:
C0342701
Disease or Syndrome
Transcobalamin II deficiency is an autosomal recessive disorder with onset in early infancy characterized by failure to thrive, megaloblastic anemia, and pancytopenia. Other features include methylmalonic aciduria, recurrent infections, and vomiting and diarrhea. Treatment with cobalamin results in clinical improvement, but the untreated disorder may result in mental retardation and neurologic abnormalities (summary by Haberle et al., 2009). Hall (1981) gave a clinically oriented review of congenital defects of vitamin B12 transport, and Frater-Schroder (1983) gave a genetically oriented review.
Congenital defect of folate absorption
MedGen UID:
83348
Concept ID:
C0342705
Disease or Syndrome
Hereditary folate malabsorption (HFM) is characterized by folate deficiency with impaired intestinal folate absorption and impaired folate transport into the central nervous system. Findings include poor feeding, failure to thrive, and anemia. There can be leukopenia and thrombocytopenia, diarrhea and/or oral mucositis, hypoimmunoglobulinemia, and other immunologic dysfunction resulting in infections, most often Pneumocystis jerovicii pneumonia. Neurologic manifestations include developmental delays, cognitive and motor impairment, behavioral disorders and, frequently, seizures.
Dihydropyrimidinase deficiency
MedGen UID:
83353
Concept ID:
C0342803
Disease or Syndrome
DPYS deficiency is an autosomal recessive disease characterized by the presence of dihydropyrimidinuria. The clinical phenotype is highly variable, ranging from early infantile onset of severe neurologic involvement, dysmorphic features, and feeding problems to late onset of mild intellectual disability and even asymptomatic individuals. Patients with a complete or partial deficiency have an increased risk of developing severe toxicity after administration of the anticancer drug 5-fluorouracil (5-FU) (summary by Nakajima et al., 2017). See also dihydropyrimidine dehydrogenase deficiency (274270), a similar disorder.
Osteopetrosis with renal tubular acidosis
MedGen UID:
91042
Concept ID:
C0345407
Disease or Syndrome
Osteopetrosis is a bone disease that makes bones abnormally dense and prone to breakage (fracture). Researchers have described several major types of osteopetrosis, which are usually distinguished by their pattern of inheritance: autosomal dominant, autosomal recessive, or X-linked. The different types of the disorder can also be distinguished by the severity of their signs and symptoms.Autosomal dominant osteopetrosis (ADO), which is also called Albers-Schönberg disease, is typically the mildest type of the disorder. Some affected individuals have no symptoms. In these people, the unusually dense bones may be discovered by accident when an x-ray is done for another reason. In affected individuals who develop signs and symptoms, the major features of the condition include multiple bone fractures, abnormal side-to-side curvature of the spine (scoliosis) or other spinal abnormalities, arthritis in the hips, and a bone infection called osteomyelitis. These problems usually become apparent in late childhood or adolescence.Autosomal recessive osteopetrosis (ARO) is a more severe form of the disorder that becomes apparent in early infancy. Affected individuals have a high risk of bone fracture resulting from seemingly minor bumps and falls. Their abnormally dense skull bones pinch nerves in the head and face (cranial nerves), often resulting in vision loss, hearing loss, and paralysis of facial muscles. Dense bones can also impair the function of bone marrow, preventing it from producing new blood cells and immune system cells. As a result, people with severe osteopetrosis are at risk of abnormal bleeding, a shortage of red blood cells (anemia), and recurrent infections. In the most severe cases, these bone marrow abnormalities can be life-threatening in infancy or early childhood.Other features of autosomal recessive osteopetrosis can include slow growth and short stature, dental abnormalities, and an enlarged liver and spleen (hepatosplenomegaly). Depending on the genetic changes involved, people with severe osteopetrosis can also have brain abnormalities, intellectual disability, or recurrent seizures (epilepsy).A few individuals have been diagnosed with intermediate autosomal osteopetrosis (IAO), a form of the disorder that can have either an autosomal dominant or an autosomal recessive pattern of inheritance. The signs and symptoms of this condition become noticeable in childhood and include an increased risk of bone fracture and anemia. People with this form of the disorder typically do not have life-threatening bone marrow abnormalities. However, some affected individuals have had abnormal calcium deposits (calcifications) in the brain, intellectual disability, and a form of kidney disease called renal tubular acidosis.Rarely, osteopetrosis can have an X-linked pattern of inheritance. In addition to abnormally dense bones, the X-linked form of the disorder is characterized by abnormal swelling caused by a buildup of fluid (lymphedema) and a condition called anhydrotic ectodermal dysplasia that affects the skin, hair, teeth, and sweat glands. Affected individuals also have a malfunctioning immune system (immunodeficiency), which allows severe, recurrent infections to develop. Researchers often refer to this condition as OL-EDA-ID, an acronym derived from each of the major features of the disorder.
Roberts-SC phocomelia syndrome
MedGen UID:
95931
Concept ID:
C0392475
Disease or Syndrome
Roberts syndrome (RBS) is characterized by prenatal growth retardation (ranging from mild to severe), craniofacial findings (including microcephaly and cleft lip and/or palate) and limb malformations (including bilateral symmetric tetraphocomelia or hypomelia caused by mesomelic shortening). Upper limbs are more severely affected than lower limbs. Other limb malformations include oligodactyly with thumb aplasia or hypoplasia, syndactyly, clinodactyly, and elbow and knee flexion contractures. Craniofacial abnormalities include cleft lip and/or cleft palate, premaxillary prominence, micrognathia, microbrachycephaly, malar flattening, downslanted palpebral fissures, widely spaced eyes, exophthalmos resulting from shallow orbits, corneal clouding, underdeveloped ala nasi, beaked nose, and ear malformations. Intellectual disability is reported in the majority of affected individuals. Mortality is high among severely affected pregnancies and newborns. Mildly affected individuals may survive to adulthood.
Dysequilibrium syndrome
MedGen UID:
98295
Concept ID:
C0394006
Disease or Syndrome
VLDLR-associated cerebellar hypoplasia is an inherited condition that affects the development of the brain. People with this condition have an unusually small and underdeveloped cerebellum, which is the part of the brain that coordinates movement. This brain malformation leads to problems with balance and coordination (ataxia) that become apparent in infancy and remain stable over time. Children with VLDLR-associated cerebellar hypoplasia may learn to walk later in childhood, usually after the age of 6, although some are never able to walk independently. In one Turkish family, affected people walk on their hands and feet (quadrupedal locomotion).Additional features of VLDLR-associated cerebellar hypoplasia include moderate to profound intellectual disability, impaired speech (dysarthria) or a lack of speech, and eyes that do not look in the same direction (strabismus). Some affected individuals have also had flat feet (pes planus), seizures, and short stature. Studies suggest that VLDLR-associated cerebellar hypoplasia does not significantly affect a person's life expectancy.
Congenital laryngeal abductor palsy
MedGen UID:
96004
Concept ID:
C0396059
Congenital Abnormality
Laryngeal abductor paralysis is an autosomal dominant condition characterized by variable penetrance and expressivity ranging from mild symptoms to neonatal asphyxia. (summary by Morelli et al., 1982; Manaligod and Smith, 1998).
Gluthathione synthetase deficiency
MedGen UID:
97988
Concept ID:
C0398746
Disease or Syndrome
Glutathione synthetase deficiency, or 5-oxoprolinuria, is an autosomal recessive disorder characterized, in its severe form, by massive urinary excretion of 5-oxoproline, metabolic acidosis, hemolytic anemia, and central nervous system damage. The metabolic defect results in decreased levels of cellular glutathione, which overstimulates the synthesis of gamma-glutamylcysteine and its subsequent conversion to 5-oxoproline (Larsson and Anderson, 2001).
Centromeric instability of chromosomes 1,9 and 16 and immunodeficiency
MedGen UID:
140770
Concept ID:
C0398788
Disease or Syndrome
Variable immunodeficiency with centromeric instability of chromosomes 1, 9, 16 and, less frequently, chromosome 2. Manifestations vary and most common symptoms include facial dysmorphism, mental retardation and prolonged respiratory, cutaneous, and gastrointestinal infections.
Microcephaly, normal intelligence and immunodeficiency
MedGen UID:
140771
Concept ID:
C0398791
Disease or Syndrome
Nijmegen breakage syndrome (NBS) is characterized by progressive microcephaly, intrauterine growth retardation and short stature, recurrent sinopulmonary infections, an increased risk for cancer, and premature ovarian failure in females. Developmental milestones are attained at the usual time during the first year; however, borderline delays in development and hyperactivity may be observed in early childhood. Intellectual abilities tend to decline over time and most children tested after age seven years have mild to moderate intellectual disability. Recurrent pneumonia and bronchitis may result in respiratory failure and early death. Approximately 40% of affected individuals have developed malignancies before age 20 years, with the risk being highest for T-cell (55%) and B-cell lymphomas (45%). Other tumors include solid tumors (e.g., medulloblastoma, glioma, and rhabdomyosarcoma). Note, however, that much of what is reported about NBS is based on individuals who are homozygous for the single most common Eastern European pathogenic variant, c.657_661del5.
Prune belly syndrome with pulmonic stenosis, mental retardation and deafness
MedGen UID:
96043
Concept ID:
C0403551
Disease or Syndrome
Neonatal pseudo-hydrocephalic progeroid syndrome
MedGen UID:
140806
Concept ID:
C0406586
Disease or Syndrome
Wiedemann-Rautenstrauch syndrome (WDRTS) is a rare autosomal recessive neonatal progeroid disorder characterized by intrauterine growth retardation, failure to thrive, short stature, a progeroid appearance, hypotonia, and variable mental impairment (summary by Toriello, 1990). Average survival in WDRTS is 7 months, although survival into the third decade of life has been reported (Akawi et al., 2013).
Wrinkly skin syndrome
MedGen UID:
98030
Concept ID:
C0406587
Disease or Syndrome
ATP6V0A2-related cutis laxa, also known as autosomal recessive cutis laxa type 2A (ARCL2A), spans a phenotypic spectrum that includes Debré-type cutis laxa at the severe end and wrinkly skin syndrome at the mild end. Affected individuals have furrowing of the skin of the whole body that improves with time. They may have other evidence of a generalized connective disorder, including enlarged anterior fontanelle in infancy, congenital dislocation of the hips, inguinal hernias, and high myopia. In most (not all) affected individuals, cortical and cerebellar malformations are present and are associated with severe developmental delays, seizures, and neurologic regression.
Odontotrichomelic syndrome
MedGen UID:
98034
Concept ID:
C0406723
Disease or Syndrome
GAPO syndrome is the acronymic designation for a complex of growth retardation, alopecia, pseudoanodontia (failure of tooth eruption), and progressive optic atrophy (Tipton and Gorlin, 1984). Ilker et al. (1999) and Bayram et al. (2014) noted that optic atrophy is not a consistent feature of the disorder.
Orofacial-digital syndrome III
MedGen UID:
96069
Concept ID:
C0406726
Disease or Syndrome
Oral-facial-digital syndrome is actually a group of related conditions that affect the development of the oral cavity (the mouth and teeth), facial features, and digits (fingers and toes).Researchers have identified at least 13 potential forms of oral-facial-digital syndrome. The different types are classified by their patterns of signs and symptoms. However, the features of the various types overlap significantly, and some types are not well defined. The classification system for oral-facial-digital syndrome continues to evolve as researchers find more affected individuals and learn more about this disorder.The signs and symptoms of oral-facial-digital syndrome vary widely. However, most forms of this disorder involve problems with development of the oral cavity, facial features, and digits. Most forms are also associated with brain abnormalities and some degree of intellectual disability.Abnormalities of the oral cavity that occur in many types of oral-facial-digital syndrome include a split (cleft) in the tongue, a tongue with an unusual lobed shape, and the growth of noncancerous tumors or nodules on the tongue. Affected individuals may also have extra, missing, or defective teeth. Another common feature is an opening in the roof of the mouth (a cleft palate). Some people with oral-facial-digital syndrome have bands of extra tissue (called hyperplastic frenula) that abnormally attach the lip to the gums.Distinctive facial features often associated with oral-facial-digital syndrome include a split in the lip (a cleft lip); a wide nose with a broad, flat nasal bridge; and widely spaced eyes (hypertelorism).Abnormalities of the digits can affect both the fingers and the toes in people with oral-facial-digital syndrome. These abnormalities include fusion of certain fingers or toes (syndactyly), digits that are shorter than usual (brachydactyly), or digits that are unusually curved (clinodactyly). The presence of extra digits (polydactyly) is also seen in most forms of oral-facial-digital syndrome.Other features occur in only one or a few types of oral-facial digital syndrome. These features help distinguish the different forms of the disorder. For example, the most common form of oral-facial-digital syndrome, type I, is associated with polycystic kidney disease. This kidney disease is characterized by the growth of fluid-filled sacs (cysts) that interfere with the kidneys' ability to filter waste products from the blood. Other forms of oral-facial-digital syndrome are characterized by neurological problems, particular changes in the structure of the brain, bone abnormalities, vision loss, and heart defects.
Kohlschutter syndrome
MedGen UID:
98036
Concept ID:
C0406740
Disease or Syndrome
Kohlschutter-Tonz syndrome is an autosomal recessive disorder characterized by severe global developmental delay, early-onset intractable seizures, spasticity, and amelogenesis imperfecta affecting both primary and secondary teeth and causing yellow or brown discoloration of the teeth. Although the phenotype is consistent, there is variability. Intellectual disability is related to the severity of seizures, and the disorder can thus be considered an epileptic encephalopathy. Some infants show normal development until seizure onset, whereas others are delayed from birth. The most severely affected individuals have profound mental retardation, never acquire speech, and become bedridden early in life (summary by Schossig et al., 2012 and Mory et al., 2012).
Fukuyama congenital muscular dystrophy
MedGen UID:
140820
Concept ID:
C0410174
Disease or Syndrome
Fukuyama congenital muscular dystrophy (FCMD) is characterized by hypotonia, symmetric generalized muscle weakness, and CNS migration disturbances that result in changes consistent with cobblestone (previously type II) lissencephaly with cerebral and cerebellar cortical dysplasia. Mild, typical, and severe phenotypes are recognized. Onset typically occurs in early infancy, with a poor suck, weak cry, and floppiness. Affected individuals have contractures of the hips, knees, and interphalangeal joints. Later features include myopathic facial appearance, pseudohypertrophy of the calves and forearms, motor and speech retardation, intellectual disability, seizures, ophthalmologic abnormalities including visual impairment and retinal dysplasia, and progressive cardiac involvement in individuals older than age ten years. Swallowing disturbance occurs in individuals with severe FCMD and in individuals older than age ten years, leading to recurrent aspiration pneumonia and death.
Hypochondroplasia
MedGen UID:
98376
Concept ID:
C0410529
Congenital Abnormality
Hypochondroplasia is a skeletal dysplasia characterized by short stature; stocky build; disproportionately short arms and legs; broad, short hands and feet; mild joint laxity; and macrocephaly. Radiologic features include shortening of long bones with mild metaphyseal flare; narrowing of the inferior lumbar interpedicular distances; short, broad femoral neck; and squared, shortened ilia. The skeletal features are very similar to those seen in achondroplasia but tend to be milder. Medical complications common to achondroplasia (e.g., spinal stenosis, tibial bowing, obstructive apnea) occur less frequently in hypochondroplasia but intellectual disability and epilepsy may be more prevalent. Children usually present as toddlers or school-age children with decreased growth velocity leading to short stature and limb disproportion. Other features also become more prominent over time.
Craniodiaphyseal dysplasia
MedGen UID:
96080
Concept ID:
C0410539
Disease or Syndrome
An autosomal dominant or recessive form of craniotubular hyperostosis due to mutation(s) in the SOST gene, encoding sclerostin. This condition is characterized by massive generalized hyperostosis and sclerosis, especially involving the skull and facial bones, which is so severe that the resulting facial distortion is referred to as 'leontiasis ossea'; the bone deposition results in progressive stenosis of craniofacial foramina and can lead to severe neurologic impairment in childhood.
Telecanthus
MedGen UID:
140836
Concept ID:
C0423113
Finding
Distance between the inner canthi more than two standard deviations above the mean (objective); or, apparently increased distance between the inner canthi.
Lissencephaly 1
MedGen UID:
98463
Concept ID:
C0431375
Disease or Syndrome
PAFAH1B1-associated lissencephaly includes Miller-Dieker syndrome (MDS), isolated lissencephaly sequence (ILS), and (rarely) subcortical band heterotopia (SBH). Lissencephaly and SBH are cortical malformations caused by deficient neuronal migration during embryogenesis. Lissencephaly refers to a "smooth brain" with absent gyri (agyria) or abnormally wide gyri (pachygyria). SBH refers to a band of heterotopic gray matter located just beneath the cortex and separated from it by a thin zone of normal white matter. MDS is characterized by lissencephaly, typical facial features, and severe neurologic abnormalities. ILS is characterized by lissencephaly and its direct sequelae: developmental delay, intellectual disability, and seizures.
Joubert syndrome
MedGen UID:
98464
Concept ID:
C0431399
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Gillespie syndrome
MedGen UID:
96563
Concept ID:
C0431401
Disease or Syndrome
Gillespie syndrome is usually diagnosed in the first year of life by the presence of fixed dilated pupils in a hypotonic infant. Affected individuals have a characteristic form of iris hypoplasia in which the pupillary border of the iris exhibits a scalloped or 'festooned' edge, with iris strands extending onto the anterior lens surface at regular intervals. The key extraocular features of Gillespie syndrome are congenital hypotonia, progressive cerebellar hypoplasia, and ataxia, as well as variable cognitive impairment that is usually mild (summary by Gerber et al., 2016 and McEntagart et al., 2016).
Microcephalic osteodysplastic primordial dwarfism type 2
MedGen UID:
96587
Concept ID:
C0432246
Congenital Abnormality
Microcephalic osteodysplastic primordial dwarfism type II is characterized by intrauterine growth retardation, severe proportionate short stature, and microcephaly. It is distinct from Seckel syndrome (see 210600) by more severe growth retardation, radiologic abnormalities, and absent or mild mental retardation (summary by Willems et al., 2010).
Geroderma osteodysplastica
MedGen UID:
98149
Concept ID:
C0432255
Disease or Syndrome
Dysosteosclerosis
MedGen UID:
98150
Concept ID:
C0432262
Disease or Syndrome
Dysosteosclerosis is a rare bone dysplasia associated with neurodevelopmental deterioration. There is sclerosis and platyspondyly with progressive metaphyseal expansion and alteration of bone density. The early craniotubular bone modeling and clinical presentation resemble osteopetrosis (summary by Elcioglu et al., 2002).
Lenz-Majewski hyperostosis syndrome
MedGen UID:
98483
Concept ID:
C0432269
Congenital Abnormality
Lenz-Majewski hyperostotic dwarfism is a rare condition characterized by intellectual disability, sclerosing bone dysplasia, distinct craniofacial and dental anomalies, loose skin, and distal limb anomalies, particularly brachydactyly and symphalangism. Patients have multiple radiographic abnormalities due to progressive generalized hyperostosis that affects the cranium, vertebrae, and diaphyses of tubular bones, leading to severe growth retardation (summary by Sousa et al., 2014).
Deletion of short arm of chromosome 18
MedGen UID:
96604
Concept ID:
C0432442
Disease or Syndrome
A rare genetic syndrome characterized by the deletion of the short arm of chromosome 18. It is associated with mental and growth retardation, prominent ears and ptosis.
Deletion of long arm of chromosome 18
MedGen UID:
96605
Concept ID:
C0432443
Disease or Syndrome
A condition in which some or all of the cells of the body contain extra genetic material from chromosome 18. Clinical features of this condition may include the following: spina bifida, hearing loss, cleft lip, cleft palate, undescended testes, rocker bottom feet, micrognathia, low set ears, cardiac anomalies (ventricular septal defect, atrial septal defect, patent ductus arteriosus, tetralogy of Fallot), intellectual disability, holoprosencephaly, pituitary dysplasia, seizures, autoimmune disorders, hip dysplasia, and/or congenital cataracts.
Michelin-tire baby
MedGen UID:
96881
Concept ID:
C0473586
Disease or Syndrome
Symmetric ringed creases around the extremities which disappear later in life. They are reminiscent of these of the mascot of the tire manufacturer, Michelin, hence the name of the syndrome. Associated abnormalities vary and may include facial dysmorphism, upslanting palpebral fissures, hypertelorism, cleft palate, genital anomalies, mild developmental delay, ureterocele, smooth muscle hamartoma, nevus lipomatosus, Laron syndrome (dwarfism and high growth hormone and low somatomedin activity), and other defects.
Deficiency of guanidinoacetate methyltransferase
MedGen UID:
154356
Concept ID:
C0574080
Disease or Syndrome
The cerebral creatine deficiency syndromes (CCDS), inborn errors of creatine metabolism, include the two creatine biosynthesis disorders, guanidinoacetate methyltransferase (GAMT) deficiency and L-arginine:glycine amidinotransferase (AGAT) deficiency, and the creatine transporter (CRTR) deficiency. Intellectual disability and seizures are common to all three CCDS. The majority of individuals with GAMT deficiency have a behavior disorder that can include autistic behaviors and self-mutilation; about 40% have movement disorder. Onset is between ages three months and three years. Only 14 individuals with AGAT deficiency have been reported. The phenotype of CRTR deficiency in affected males ranges from mild intellectual disability and speech delay to severe intellectual disability, seizures, movement disorder and behavior disorder; age at diagnosis ranges from two to 66 years. Clinical phenotype of females heterozygous for CRTR deficiency ranges from asymptomatic to severe phenotype resembling male phenotype.
Costello syndrome
MedGen UID:
108454
Concept ID:
C0587248
Disease or Syndrome
Costello syndrome is characterized by failure to thrive in infancy as a result of severe postnatal feeding difficulties; short stature; developmental delay or intellectual disability; coarse facial features (full lips, large mouth, full nasal tip); curly or sparse, fine hair; loose, soft skin with deep palmar and plantar creases; papillomata of the face and perianal region; diffuse hypotonia and joint laxity with ulnar deviation of the wrists and fingers; tight Achilles tendons; and cardiac involvement including: cardiac hypertrophy (usually typical hypertrophic cardiomyopathy [HCM]), congenital heart defect (usually valvar pulmonic stenosis), and arrhythmia (usually supraventricular tachycardia, especially chaotic atrial rhythm/multifocal atrial tachycardia or ectopic atrial tachycardia). Relative or absolute macrocephaly is typical, and postnatal cerebellar overgrowth can result in the development of a Chiari I malformation with associated anomalies including hydrocephalus or syringomyelia. Individuals with Costello syndrome have an approximately 15% lifetime risk for malignant tumors including rhabdomyosarcoma and neuroblastoma in young children and transitional cell carcinoma of the bladder in adolescents and young adults.
Anophthalmos with limb anomalies
MedGen UID:
154638
Concept ID:
C0599973
Disease or Syndrome
Microphthalmia, anophthalmia, and coloboma comprise the MAC spectrum of ocular malformations. Microphthalmia refers to a globe with a total axial length that is at least two standard deviations below the mean for age. Anophthalmia refers to complete absence of the globe in the presence of ocular adnexa (eyelids, conjunctiva, and lacrimal apparatus). Coloboma refers to the ocular malformations that result from failure of closure of the optic fissure. Chorioretinal coloboma refers to coloboma of the retina and choroid. Iris coloboma causes the iris to appear keyhole-shaped. Microphthalmia, anophthalmia, and coloboma may be unilateral or bilateral; when bilateral they may occur in any combination.
Cockayne syndrome B
MedGen UID:
155487
Concept ID:
C0751038
Disease or Syndrome
Cockayne syndrome (referred to as CS in this GeneReview) spans a phenotypic spectrum that includes: CS type I, the "classic" or "moderate" form; CS type II, a more severe form with symptoms present at birth; this form overlaps with cerebrooculofacioskeletal syndrome (COFS) or Pena-Shokeir syndrome type II; CS type III, a milder form; Xeroderma pigmentosum-Cockayne syndrome (XP-CS). CS type I (moderate CS) is characterized by normal prenatal growth with the onset of growth and developmental abnormalities in the first two years. By the time the disease has become fully manifest, height, weight, and head circumference are far below the fifth percentile. Progressive impairment of vision, hearing, and central and peripheral nervous system function leads to severe disability; death typically occurs in the first or second decade. CS type II (severe CS or early-onset CS) is characterized by growth failure at birth, with little or no postnatal neurologic development. Congenital cataracts or other structural anomalies of the eye may be present. Affected children have early postnatal contractures of the spine (kyphosis, scoliosis) and joints. Death usually occurs by age seven years. CS type III (mild CS or late-onset CS) is characterized by essentially normal growth and cognitive development or by late onset. Xeroderma pigmentosum-Cockayne syndrome (XP-CS) includes facial freckling and early skin cancers typical of XP and some features typical of CS, including intellectual disability, spasticity, short stature, and hypogonadism. XP-CS does not include skeletal involvement, the facial phenotype of CS, or CNS dysmyelination and calcifications.
Cockayne syndrome type A
MedGen UID:
155488
Concept ID:
C0751039
Disease or Syndrome
Cockayne syndrome (referred to as CS in this GeneReview) spans a phenotypic spectrum that includes: CS type I, the "classic" or "moderate" form; CS type II, a more severe form with symptoms present at birth; this form overlaps with cerebrooculofacioskeletal syndrome (COFS) or Pena-Shokeir syndrome type II; CS type III, a milder form; Xeroderma pigmentosum-Cockayne syndrome (XP-CS). CS type I (moderate CS) is characterized by normal prenatal growth with the onset of growth and developmental abnormalities in the first two years. By the time the disease has become fully manifest, height, weight, and head circumference are far below the fifth percentile. Progressive impairment of vision, hearing, and central and peripheral nervous system function leads to severe disability; death typically occurs in the first or second decade. CS type II (severe CS or early-onset CS) is characterized by growth failure at birth, with little or no postnatal neurologic development. Congenital cataracts or other structural anomalies of the eye may be present. Affected children have early postnatal contractures of the spine (kyphosis, scoliosis) and joints. Death usually occurs by age seven years. CS type III (mild CS or late-onset CS) is characterized by essentially normal growth and cognitive development or by late onset. Xeroderma pigmentosum-Cockayne syndrome (XP-CS) includes facial freckling and early skin cancers typical of XP and some features typical of CS, including intellectual disability, spasticity, short stature, and hypogonadism. XP-CS does not include skeletal involvement, the facial phenotype of CS, or CNS dysmyelination and calcifications.
FRAXE
MedGen UID:
155512
Concept ID:
C0751157
Disease or Syndrome
FRAXE mental retardation is a form of mild to moderate mental retardation associated with learning difficulties, communication deficits, attention problems, hyperactivity, and autistic behavior (summary by Bensaid et al., 2009). FRAXE is associated with a fragile site on chromosome Xq28 and is the cause of nonsyndromic X-linked mental retardation in 1 of 50,000 newborn males. The disorder can be caused either by silencing of the FMR2 gene as a consequence of a CCG expansion located upstream of this gene or by deletion within the gene (Stettner et al., 2011).
UDPglucose-4-epimerase deficiency
MedGen UID:
199598
Concept ID:
C0751161
Disease or Syndrome
Epimerase deficiency galactosemia (GALE deficiency galactosemia) is a continuum comprising three forms: Generalized. Enzyme activity is profoundly decreased in all tissues tested. Peripheral. Enzyme activity is deficient in red blood cells (RBC) and circulating white blood cells, but normal or near normal in all other tissues. Intermediate. Enzyme activity is deficient in red blood cells and circulating white blood cells and less than 50% of normal levels in other cells tested. Infants with generalized epimerase deficiency galactosemia develop clinical findings on a regular milk diet (which contains lactose, a disaccharide of galactose and glucose); manifestations include hypotonia, poor feeding, vomiting, weight loss, jaundice, hepatomegaly, liver dysfunction, aminoaciduria, and cataracts. Prompt removal of galactose/lactose from their diet resolves or prevents these acute symptoms. In contrast, neonates with the peripheral or intermediate form generally remain clinically well even on a regular milk diet and are usually only identified by biochemical testing, often in newborn screening programs.
Juvenile neuronal ceroid lipofuscinosis
MedGen UID:
155549
Concept ID:
C0751383
Disease or Syndrome
The neuronal ceroid lipofuscinoses (NCL; CLN) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by the intracellular accumulation of autofluorescent lipopigment storage material in different patterns ultrastructurally. The clinical course includes progressive dementia, seizures, and progressive visual failure (Mole et al., 2005). The hallmark of CLN3 is the ultrastructural pattern of lipopigment with a 'fingerprint' profile, which can have 3 different appearances: pure within a lysosomal residual body; in conjunction with curvilinear or rectilinear profiles; and as a small component within large membrane-bound lysosomal vacuoles. The combination of fingerprint profiles within lysosomal vacuoles is a regular feature of blood lymphocytes from patients with CLN3 (Mole et al., 2005). For a general phenotypic description and a discussion of genetic heterogeneity of CLN, see CLN1 (256730).
Arachnoid cysts, intracranial
MedGen UID:
148353
Concept ID:
C0751615
Disease or Syndrome
Arachnoid cysts are extraparenchymal, nonneoplastic accumulations of fluid with density similar to that of cerebrospinal fluid. They account for approximately 1% of intracranial space-occupying lesions, although studies since the advent of CT scanning suggest a higher percentage. A striking male preponderance has been observed (summary by Wilson et al., 1988).
Non-ketotic hyperglycinemia
MedGen UID:
155625
Concept ID:
C0751748
Disease or Syndrome
Nonketotic hyperglycinemia (NKH) is the inborn error of glycine metabolism defined by deficient activity of the glycine cleavage enzyme system (GCS), which results in accumulation of large quantities of glycine in all body tissues including the brain. Based on ultimate outcome NKH is categorized into severe NKH (no developmental progress and intractable epilepsy) and attenuated NKH (variable developmental progress and treatable or no epilepsy). The majority of children with NKH have onset in the neonatal period manifest as progressive lethargy evolving into profound coma and marked hypotonia; 85% have severe NKH and 15% attenuated NKH. Those with onset between two weeks and three months typically present with hypotonia; 50% have severe NKH and 50% attenuated NKH. Those with onset after age three months have attenuated NKH. Severe versus attenuated NKH is consistent within families, but the degree of developmental progress in those with attenuated NKH can vary.
Carbamoyl-phosphate synthetase 1 deficiency
MedGen UID:
199727
Concept ID:
C0751753
Disease or Syndrome
A rare and severe disorder of urea cycle metabolism most commonly characterised by either a neonatal-onset of severe hyperammonaemia that occurs few days after birth and manifests with lethargy, vomiting, hypothermia, seizures, coma and death or a presentation outside the newborn period at any age with (sometimes) milder symptoms of hyperammonaemia. The disease is due to mutations in the CPS1 gene (2p) that encodes carbamoyl-phosphate synthetase I (CPS1), an enzyme located in the mitochondrial matrix of hepatocytes and epithelial cells of intestinal mucosa that controls the first step of the urea cycle where ammonia is converted into carbamoyl-phosphate. Mutations in this gene lead to an interruption in the urea cycle and excess nitrogen is not converted to urea for excretion by the kidneys, leading to hyperammonemia. Inherited in an autosomal recessive manner.
Bardet-Biedl syndrome
MedGen UID:
156019
Concept ID:
C0752166
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Recombinant chromosome 8 syndrome
MedGen UID:
167070
Concept ID:
C0795822
Disease or Syndrome
Recombinant 8 syndrome is a condition that involves heart and urinary tract abnormalities, moderate to severe intellectual disability, and a distinctive facial appearance. The characteristic facial features include a wide, square face; a thin upper lip; a downturned mouth; a small chin (micrognathia); wide-set eyes (hypertelorism); and low-set or unusually shaped ears. People with recombinant 8 syndrome may have overgrowth of the gums (gingival hyperplasia) and abnormal tooth development. Males with this condition frequently have undescended testes (cryptorchidism). Some affected individuals have recurrent ear infections (otitis media) or hearing loss. Many children with recombinant 8 syndrome do not survive past early childhood, usually due to complications related to their heart abnormalities.
Chromosome 9, monosomy 9p
MedGen UID:
167073
Concept ID:
C0795830
Disease or Syndrome
Partial deletion of the short arm of chromosome 9 with mental retardation, craniofacial anomalies, abnormal dermatoglyphics, short and webbed neck, heart murmurs, square nails, and other defects.
11q partial monosomy syndrome
MedGen UID:
162878
Concept ID:
C0795841
Disease or Syndrome
Jacobsen syndrome is a condition caused by a loss of genetic material from chromosome 11. Because this deletion occurs at the end (terminus) of the long (q) arm of chromosome 11, Jacobsen syndrome is also known as 11q terminal deletion disorder.The signs and symptoms of Jacobsen syndrome vary considerably. Most affected individuals have delayed development, including the development of speech and motor skills (such as sitting, standing, and walking). Most also have cognitive impairment and learning difficulties. Behavioral problems have been reported, including compulsive behavior (such as shredding paper), a short attention span, and easy distractibility. Many people with Jacobsen syndrome have been diagnosed with attention deficit-hyperactivity disorder (ADHD). Jacobsen syndrome is also associated with an increased likelihood of autism spectrum disorders, which are characterized by impaired communication and socialization skills.Jacobsen syndrome is also characterized by distinctive facial features. These include small and low-set ears, widely set eyes (hypertelorism) with droopy eyelids (ptosis), skin folds covering the inner corner of the eyes (epicanthal folds), a broad nasal bridge, downturned corners of the mouth, a thin upper lip, and a small lower jaw. Affected individuals often have a large head size (macrocephaly) and a skull abnormality called trigonocephaly, which gives the forehead a pointed appearance.More than 90 percent of people with Jacobsen syndrome have a bleeding disorder called Paris-Trousseau syndrome. This condition causes a lifelong risk of abnormal bleeding and easy bruising. Paris-Trousseau syndrome is a disorder of platelets, which are blood cell fragments that are necessary for blood clotting.Other features of Jacobsen syndrome can include heart defects, feeding difficulties in infancy, short stature, frequent ear and sinus infections, and skeletal abnormalities. The disorder can also affect the digestive system, kidneys, and genitalia. The life expectancy of people with Jacobsen syndrome is unknown, although affected individuals have lived into adulthood.
Cutis verticis gyrata, thyroid aplasia, and mental retardation
MedGen UID:
162779
Concept ID:
C0795848
Disease or Syndrome
Cutis verticis gyrata, hypoplastic thyroid disease and mental retardation.
Smith-Magenis syndrome
MedGen UID:
162881
Concept ID:
C0795864
Disease or Syndrome
Smith-Magenis syndrome (SMS) is characterized by distinctive physical features (particularly facial features that progress with age), developmental delay, cognitive impairment, and behavioral abnormalities. Infants have feeding difficulties, failure to thrive, hypotonia, hyporeflexia, prolonged napping or need to be awakened for feeds, and generalized lethargy. The majority of individuals function in the mild-to-moderate range of intellectual disability. The behavioral phenotype, including significant sleep disturbance, stereotypies, and maladaptive and self-injurious behaviors, is generally not recognized until age 18 months or older and continues to change until adulthood. Sensory integration issues are frequently noted. Children and adults typically have inattention, distractibility, hyperactivity, impulsivity, maladaptive behaviors including frequent outbursts/temper tantrums, attention seeking, disobedience, aggression, toileting difficulties, and self-injurious behaviors (SIB) including self-hitting, self-biting, and/or skin picking, inserting foreign objects into body orifices (polyembolokoilamania), and yanking fingernails and/or toenails (onychotillomania). Among the stereotypic behaviors described, the spasmodic upper-body squeeze or "self-hug" seems to be highly associated with SMS. The finger lick and page flipping ("lick and flip") behavior may be less prevalent than initially reported. An underlying developmental asynchrony, specifically between intellectual functioning and emotional maturity, may also contribute to maladaptive behaviors in people with SMS.
Autism, susceptibility to, X-linked 4
MedGen UID:
162886
Concept ID:
C0795888
Finding
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypical, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). Levy et al. (2009) provided a general review of autism and autism spectrum disorder, including epidemiology, characteristics of the disorder, diagnosis, neurobiologic hypotheses for the etiology, genetics, and treatment options.
Cowchock syndrome
MedGen UID:
162891
Concept ID:
C0795910
Disease or Syndrome
Cowchock syndrome (COWCK) is an X-linked recessive neuromuscular disorder characterized by early childhood onset of a slowly progressive axonal sensorimotor neuropathy associated in some patients with sensorineural deafness and cognitive impairment (summary by Rinaldi et al., 2012).
Crome syndrome
MedGen UID:
167082
Concept ID:
C0795914
Disease or Syndrome
A lethal combination of manifestations including short stature, congenital cataracts, encephalopathy with epileptic fits and postmortem confirmation of nephropathy (renal tubular necrosis). The combination has been described in 2 female infant children of first cousin parents. The infants did not survive beyond 4 and 8 months respectively. There have been no further descriptions in the literature since 1963.
Chromosome 16-related alpha-thalassemia/mental retardation syndrome
MedGen UID:
162892
Concept ID:
C0795917
Disease or Syndrome
Alpha-thalassemia X-linked intellectual disability (ATRX) syndrome is characterized by distinctive craniofacial features, genital anomalies, severe developmental delays, hypotonia, intellectual disability, and mild-to-moderate anemia secondary to alpha-thalassemia. Craniofacial abnormalities include small head circumference, telecanthus or widely spaced eyes, short nose, tented vermilion of the upper lip, and thick or everted vermilion of the lower lip with coarsening of the facial features over time. Although all affected individuals have a normal 46,XY karyotype, genital anomalies range from hypospadias and undescended testicles to severe hypospadias and ambiguous genitalia, to normal-appearing female external genitalia. Global developmental delays are evident in infancy and some affected individuals never walk independently or develop significant speech.
Edinburgh malformation syndrome
MedGen UID:
167084
Concept ID:
C0795933
Disease or Syndrome
A syndrome reported in an Edinburgh family in which five infants (four female and one male) were found to have a characteristic facial appearance, hydrocephalus, and psychomotor retardation. Some characteristics of this syndrome are similar to those of the de Lange syndrome 1.
Filippi syndrome
MedGen UID:
163197
Concept ID:
C0795940
Disease or Syndrome
Filippi syndrome is characterized by short stature, microcephaly, syndactyly, intellectual disability, and facial dysmorphism consisting of bulging forehead, broad and prominent nasal bridge, and diminished alar flare. Common features include cryptorchidism, speech impairment, and clinodactyly of the fifth finger, Some patients exhibit visual disturbances, polydactyly, seizures, and/or ectodermal abnormalities, such as nail hypoplasia, long eyelashes, hirsutism, and microdontia (summary by Hussain et al., 2014).
Fine-Lubinsky syndrome
MedGen UID:
163198
Concept ID:
C0795941
Disease or Syndrome
Syndrome with characteristics of psychomotor delay, brachycephaly with flat face, small nose, microstomia, cleft palate, cataract, hearing loss, hypoplastic scrotum and digital anomalies. Less than 10 patients have been described in the literature so far. Although the majority of reported cases were sporadic, the syndrome has been reported in one pair of siblings (a brother and sister) with an apparently autosomal recessive inheritance pattern.
Fitzsimmons syndrome
MedGen UID:
163199
Concept ID:
C0795942
Disease or Syndrome
Fountain syndrome
MedGen UID:
208650
Concept ID:
C0795944
Disease or Syndrome
An extremely rare multi-systemic genetic disorder with characteristics of intellectual disability, deafness, skeletal abnormalities and coarse facial features.The syndrome is exceedingly rare and has been reported in only a few patients to date. Male and female patients have been described. The main clinical features include moderate to severe intellectual deficit, congenital sensorineural hearing impairment and broad, stubby hands and feet. A coarse face with full lips and cheeks is also found. These signs are reported to become more prominent with age. The pattern of inheritance appears to be autosomal recessive.
Subaortic stenosis short stature syndrome
MedGen UID:
167085
Concept ID:
C0795947
Disease or Syndrome
Mental and somatic retardation with Peters anomaly (defect of the Descemet membrane and deep stromal layers of the cornea), corneal clouding, hypoplastic facies, subvalvular aortic stenosis, and skeletal abnormalities.
Galloway-Mowat syndrome
MedGen UID:
167086
Concept ID:
C0795949
Disease or Syndrome
Galloway-Mowat syndrome is a rare autosomal recessive neurodegenerative disorder characterized by infantile onset of microcephaly and central nervous system abnormalities resulting in severely delayed psychomotor development. Brain imaging shows cerebellar atrophy and sometimes cerebral atrophy. More variable features include optic atrophy, movement disorders, seizures, and nephrotic syndrome (summary by Vodopiutz et al., 2015). Genetic Heterogeneity of Galloway-Mowat Syndrome See also GAMOS2 (301006), caused by mutation in the LAGE3 gene (300060) on chromosome Xq28; GAMOS3 (617729), caused by mutation in the OSGEP gene (610107) on chromosome 14q11; GAMOS4 (617730), caused by mutation in the TP53RK gene (608679) on chromosome 20q13; GAMOS5 (617731), caused by mutation in the TPRKB gene (608680) on chromosome 2p13; GAMOS6 (618347), caused by mutation in the WDR4 gene (605924) on chromosome 21q22; GAMOS7 (618348), caused by mutation in the NUP107 gene (607617) on chromosome 12q15; and GAMOS8 (618349), caused by mutation in the NUP133 gene (607613) on chromosome 1q42.
Andermann syndrome
MedGen UID:
162893
Concept ID:
C0795950
Disease or Syndrome
Hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC), a neurodevelopmental and neurodegenerative disorder, is characterized by severe progressive sensorimotor neuropathy with resulting hypotonia, areflexia, and amyotrophy and variable degrees of dysgenesis of the corpus callosum. Mild-to-severe intellectual disability and "psychotic episodes" during adolescence are observed. Sensory modalities are moderately to severely affected beginning in infancy. The average age of onset of walking is 3.8 years; the average age of loss of walking is 13.8 years; the average age of death is 33 years.
Spastic paraplegia 1
MedGen UID:
162894
Concept ID:
C0795953
Disease or Syndrome
The phenotypic spectrum of L1 syndrome includes: X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS); MASA syndrome (mental retardation [intellectual disability], aphasia [delayed speech], spastic paraplegia [shuffling gait], adducted thumbs); SPG1 (X-linked complicated hereditary spastic paraplegia type 1); and X-linked complicated corpus callosum agenesis. Males with HSAS are born with severe hydrocephalus, adducted thumbs, and spasticity; intellectual disability is severe. In less severely affected males, hydrocephalus may be subclinically present and documented only because of developmental delay; intellectual disability ranges from mild (IQ: 50-70) to moderate (IQ: 30-50).
Chylomicron retention disease
MedGen UID:
208651
Concept ID:
C0795956
Disease or Syndrome
Chylomicron retention disease is an autosomal recessive disorder of severe fat malabsorption associated with failure to thrive in infancy (Dannoura et al., 1999).
Mental retardation Gustavson type, X-linked
MedGen UID:
167088
Concept ID:
C0795965
Disease or Syndrome
Mental retardation syndrome with microcephaly, severely impaired vision, hearing defect, epileptic seizures, restricted movement, and early death.
Harrod Doman Keele syndrome
MedGen UID:
162895
Concept ID:
C0795970
Disease or Syndrome
The association of intellectual deficit, facial dysmorphism (a highly arched palate, pointed chin, and small mouth, hypotelorism, a long nose and large protruding ears), arachnodactyly, hypogenitalism (undescended testes and hypospadias) and failure to thrive. So far, it has been described in three males (including two brothers). An autosomal recessive mode of transmission has been suggested.
Bullous dystrophy hereditary macular type
MedGen UID:
167089
Concept ID:
C0795974
Disease or Syndrome
A skin disease characterized by formation of bullae without evidence of trauma, hyperpigmentation or hypopigmentation and acrocyanosis in association with microcephaly, subnormal growth and mental development, short tapering fingers, and occasionally deformed nails.
Wiedemann Oldigs Oppermann syndrome
MedGen UID:
163202
Concept ID:
C0795976
Disease or Syndrome
A combination of congenital anomalies consisting of hirsutism, brachycephaly, abnormal position of thumbs, pedes excavatio with claw-toes, facial abnormalities, and mental deficiency.
Hypospadias mental retardation Goldblatt type
MedGen UID:
162896
Concept ID:
C0795989
Disease or Syndrome
Hypospadias, retarded mental development, microcephaly, craniofacial dysmorphism, joint laxity, and beaked nails.
Striatonigral degeneration infantile
MedGen UID:
167090
Concept ID:
C0795996
Disease or Syndrome
Bilateral striatal necrosis (BSN) encompasses a heterogeneous group of neurologic disorders with different causation. Familial infantile striatal degeneration is rare and can be inherited as an autosomal recessive or mitochondrial (see 500003) disorder. The familial form has an insidious onset and a slowly progressive course; the sporadic form is associated with acute systemic illness. Many features of BSN overlap with Leigh syndrome (256000) and certain metabolic disorders, including glutaric acidemia I (231670) and methylmalonic aciduria (251000). See also Aicardi-Goutieres syndrome (225750) (Mito et al., 1986; De Meirleir et al., 1995). Genetic Heterogeneity of Stiatonigral Degeneration Childhood-onset striatonigral degeneration (617054) is caused by mutation in the VAC14 gene (604632) on chromosome 16q22. See also adult-onset autosomal dominant striatal degeneration (ADSD; 609161), caused by mutation in the PDE8B gene (603390) on chromosome 5q13.
Johnson neuroectodermal syndrome
MedGen UID:
167092
Concept ID:
C0796002
Disease or Syndrome
Johnson neuroectodermal syndrome has characteristics of alopecia, anosmia or hyposmia, conductive deafness with malformed ears and microtia and/or atresia of the external auditory canal and hypogonadotropic hypogonadism. So far, less than 30 cases have been described in the literature. Other variable features include a congenital heart defect, facial asymmetry, intellectual deficit, cleft palate, choanal stenosis and an increased tendency for dental caries. The syndrome is transmitted as an autosomal dominant trait. The combination of developmental anomalies present in patients with this syndrome is suggestive of an embryological defect in the formation of the neuroectodermal derivatives of cephalic neural crest.
Kabuki syndrome
MedGen UID:
162897
Concept ID:
C0796004
Congenital Abnormality
Kabuki syndrome is a disorder that affects many parts of the body. It is characterized by distinctive facial features including arched eyebrows; long eyelashes; long openings of the eyelids (long palpebral fissures) with the lower lids turned out (everted) at the outside edges; a flat, broadened tip of the nose; and large protruding earlobes. The name of this disorder comes from the resemblance of its characteristic facial appearance to stage makeup used in traditional Japanese Kabuki theater.People with Kabuki syndrome have mild to severe developmental delay and intellectual disability. Affected individuals may also have seizures, an unusually small head size (microcephaly), or weak muscle tone (hypotonia). Some have eye problems such as rapid, involuntary eye movements (nystagmus) or eyes that do not look in the same direction (strabismus).Other characteristic features of Kabuki syndrome include short stature and skeletal abnormalities such as abnormal side-to-side curvature of the spine (scoliosis), short fifth (pinky) fingers, or problems with the hip and knee joints. The roof of the mouth may have an abnormal opening (cleft palate) or be high and arched, and dental problems are common in affected individuals. People with Kabuki syndrome may also have fingerprints with unusual features and fleshy pads at the tips of the fingers. These prominent finger pads are called fetal finger pads because they normally occur in human fetuses; in most people they disappear before birth.A wide variety of other health problems occur in some people with Kabuki syndrome. Among the most commonly reported are heart abnormalities, frequent ear infections (otitis media), hearing loss, and early puberty.
Kifafa seizure disorder
MedGen UID:
208655
Concept ID:
C0796010
Disease or Syndrome
A convulsive seizure disorder observed in an isolated tribe in the interior of Tanzania. It is a chronic degenerative disorder of the central nervous system associated with seizures and other neurological complications, characteristic facies, psychomotor retardation, and pachyderma. Kifafa is a Swahili word meaning "being half-dead and rigid."
Lenz microphthalmia syndrome
MedGen UID:
162898
Concept ID:
C0796016
Congenital Abnormality
Lenz microphthalmia syndrome (LMS) is characterized by unilateral or bilateral microphthalmia and/or clinical anophthalmia with malformations of the ears, teeth, fingers, skeleton, and/or genitourinary system. Microphthalmia is often accompanied by microcornea and glaucoma. Coloboma is present in approximately 60% of microphthalmic eyes with severity ranging from isolated iris coloboma to coloboma of the ciliary body, choroid, and optic disk. Ears may be low set, anteverted, posteriorly rotated, simple, cup shaped, or abnormally modeled. Hearing loss has been observed. Dental findings include irregularly shaped, missing, or widely spaced teeth. Duplicated thumbs, syndactyly, clinodactyly, camptodactyly, and microcephaly are common, as are narrow/sloping shoulders, underdeveloped clavicles, kyphoscoliosis, exaggerated lumbar lordosis, long cylindric thorax, and webbed neck. Genitourinary anomalies include hypospadias, cryptorchidism, renal hypoplasia/aplasia, and hydroureter. Approximately 60% of affected males have mild-to-severe intellectual disability or developmental delay.
Lowry Maclean syndrome
MedGen UID:
167095
Concept ID:
C0796020
Disease or Syndrome
A very rare syndrome with characteristics of microcephaly, craniosynostosis, glaucoma, growth failure and visceral malformations. Only three cases have been reported in the literature in three unrelated families. Dysmorphic features include trigonocephaly, exotropia, cleft palate, beaked nose and low-set ears. All the affected patients have associated congenital visceral malformations including congenital heart defects, diaphragmatic hernia, genital or cerebral abnormalities. The demonstration of congenital glaucoma, hallmark of the syndrome, in the father of an affected patient, supports autosomal dominant inheritance. Prognosis is poor.
X-linked mental retardation with marfanoid habitus syndrome
MedGen UID:
167096
Concept ID:
C0796022
Disease or Syndrome
The phenotypic spectrum of MED12-related disorders, which is still being defined, includes at a minimum the phenotypes of FG syndrome type 1 (FGS1), Lujan syndrome (LS), and X-linked Ohdo syndrome. FGS1 and LS share the clinical findings of cognitive impairment, hypotonia, and abnormalities of the corpus callosum. FGS1 is further characterized by absolute or relative macrocephaly, tall forehead, downslanted palpebral fissures, small and simple ears, constipation and/or anal anomalies, broad thumbs and halluces, and characteristic behavior. LS is further characterized by large head, tall thin body habitus, long thin face, prominent nasal bridge, high narrow palate, and short philtrum. Carrier females in families with FGS1 and LS are typically unaffected. X-linked Ohdo syndrome (referred to as XLOS in this GeneReview) is characterized by intellectual disability, blepharophimosis, and facial coarsening. A number of individuals with nonsyndromic intellectual disability – including some affected females – have been described.
Lysine malabsorption syndrome
MedGen UID:
167097
Concept ID:
C0796023
Disease or Syndrome
Lysine malabsorption with severe malnourishment, extreme flaccidity, and psychomotor retardation.
Arts syndrome
MedGen UID:
163205
Concept ID:
C0796028
Disease or Syndrome
Arts syndrome, which is part of the spectrum of PRPS1-related disorders, is characterized by profound congenital sensorineural hearing impairment, early-onset hypotonia, delayed motor development, mild to moderate intellectual disability, ataxia, and increased risk of infection, all of which – with the exception of optic atrophy – present before age two years. Signs of peripheral neuropathy develop during early childhood. Twelve of 15 boys from the two Dutch families reported with Arts syndrome died before age six years of complications of infection. Carrier females can show late-onset (age >20 years) hearing impairment and other findings.
Dilated cardiomyopathy-hypergonadotropic hypogonadism syndrome
MedGen UID:
162901
Concept ID:
C0796031
Disease or Syndrome
Mental retardation, ovarian dysgenesis, congestive cardiomyopathy, broad nasal base, blepharoptosis, and bone abnormalities. The phenotype varies and not all features are present in individual cases. Occasional marfanoid habitus (tall stature with long and thin limbs, little subcutaneous fat, arachnodactyly, joint hyperextensibility, narrow face, small chin, large testes, and hypotonia).
Malpuech facial clefting syndrome
MedGen UID:
208657
Concept ID:
C0796032
Disease or Syndrome
The term '3MC syndrome' encompasses 4 rare autosomal recessive disorders that were previously designated the Carnevale, Mingarelli, Malpuech, and Michels syndromes, respectively. The main features of these syndromes are facial dysmorphism that includes hypertelorism, blepharophimosis, blepharoptosis, and highly arched eyebrows, which are present in 70 to 95% of cases. Cleft lip and palate, postnatal growth deficiency, cognitive impairment, and hearing loss are also consistent findings, occurring in 40 to 68% of cases. Craniosynostosis, radioulnar synostosis, and genital and vesicorenal anomalies occur in 20 to 30% of cases. Rare features include anterior chamber defects, cardiac anomalies, caudal appendage, umbilical hernia (omphalocele), and diastasis recti (summary by Rooryck et al., 2011). For a discussion of genetic heterogeneity of 3MC syndrome, see 3MC1 (257920).
Marden-Walker syndrome
MedGen UID:
163206
Concept ID:
C0796033
Disease or Syndrome
Marden-Walker syndrome is characterized by psychomotor retardation, a mask-like face with blepharophimosis, micrognathia and a high-arched or cleft palate, low-set ears, kyphoscoliosis, and joint contractures. Other features may include Dandy-Walker malformation with hydrocephalus and vertebral abnormalities (summary by Schrander-Stumpel et al., 1993). There are 2 distal arthrogryposis syndromes with features overlapping those of Marden-Walker syndrome that are also caused by heterozygous mutation in PIEZO2: distal arthrogryposis type 3 (DA3, or Gordon syndrome; 114300) and distal arthrogryposis type 5 (DA5; 108145), which are distinguished by the presence of cleft palate and ocular abnormalities, respectively. McMillin et al. (2014) suggested that the 3 disorders may represent variable expressivity of the same condition.
McDonough syndrome
MedGen UID:
162902
Concept ID:
C0796038
Disease or Syndrome
Belongs to the group of multiple congenital anomalies/mental retardation syndromes with intellectual deficit, distinctive facies (upward slanting palpebral fissures, squint), kyphoscoliosis, diastasis recti, cryptorchidism, and a congenital heart defect. Autosomal recessive inheritance suggested.
Reardon Wilson Cavanagh syndrome
MedGen UID:
208659
Concept ID:
C0796045
Disease or Syndrome
Ataxia, deafness, mental retardation, and upper and lower neuron disease are the principal symptoms.
Gurrieri syndrome
MedGen UID:
208660
Concept ID:
C0796046
Disease or Syndrome
Moderate to severe intellectual deficit, seizures, short stature, and skeletal dysplasia. Other manifestations can be associated (retinal abnormalities, brachydactyly, prognathism, dental malocclusion). It is transmitted as an autosomal recessive trait.
Mercaptolactate-cysteine disulfiduria
MedGen UID:
208661
Concept ID:
C0796055
Disease or Syndrome
Mercaptolactate-cysteine disulfiduria with mental retardation, seizures, flat nasal bridge, and highly arched palate.
Ataxia-microcephaly-cataract syndrome
MedGen UID:
167098
Concept ID:
C0796056
Disease or Syndrome
Ataxia, microcephaly, hypotonia, cataracts, and nystagmus.
Microcephaly deafness syndrome
MedGen UID:
163208
Concept ID:
C0796062
Disease or Syndrome
This syndrome has manifestations of microcephaly, deafness, intellectual deficit and facial dysmorphism (facial asymmetry, prominent glabella, low-set and cup-shaped ears, protruding lower lip, micrognathia). It has been described in a mother and her son. The mode of inheritance is probably autosomal dominant.
Microcephaly with mental retardation and digital anomalies
MedGen UID:
810673
Concept ID:
C0796063
Disease or Syndrome
A craniodigital syndrome marked by characteristic facies, microcephaly, retrognathia, symmetrical digital defects, and retarded mental development.
Microcephaly cervical spine fusion anomalies
MedGen UID:
208663
Concept ID:
C0796066
Disease or Syndrome
A very rare disorder, features include microcephaly, facial dysmorphism (beaked nose, low-set ears, downslanting palpebral fissures, micrognathia), mild intellectual deficit, short stature, and cervical spine fusion anomalies producing spinal cord compression.
Feingold syndrome
MedGen UID:
163209
Concept ID:
C0796068
Disease or Syndrome
Feingold syndrome is a disorder that affects many parts of the body. There are two types of Feingold syndrome, distinguished by their genetic cause; both types have similar features that can vary among affected individuals.Individuals with Feingold syndrome type 1 or type 2 have characteristic abnormalities of their fingers and toes. Almost all people with this condition have a specific hand abnormality called brachymesophalangy, which refers to shortening of the second and fifth fingers. Other common abnormalities include fifth fingers that curve inward (clinodactyly), underdeveloped thumbs (thumb hypoplasia), and fusion (syndactyly) of the second and third toes or the fourth and fifth toes.Additional common features of both types of Feingold syndrome include an unusually small head size (microcephaly), a small jaw (micrognathia), a narrow opening of the eyelids (short palpebral fissures), and mild to moderate learning disabilities. Less often, affected individuals have hearing loss, short stature, or kidney or heart abnormalities.People with Feingold syndrome type 1 are frequently born with a blockage in part of their digestive system called gastrointestinal atresia. In most cases, the blockage occurs in the esophagus (esophageal atresia) or in part of the small intestine (duodenal atresia). Individuals with type 2 do not have gastrointestinal atresias.
Dwarfism, mental retardation and eye abnormality
MedGen UID:
208664
Concept ID:
C0796076
Disease or Syndrome
Delayed growth and mental development with ocular disorders.
Intellectual deficit Buenos-Aires type
MedGen UID:
167102
Concept ID:
C0796080
Disease or Syndrome
A rare intellectual disability syndrome with characteristics of growth retardation, microcephaly, characteristic facial features (including narrow forehead, bushy eyebrows, hypertelorism, small, downward-slanting palpebral fissures with blepharoptosis, malformed and low-set ears, broad straight nose, thin upper lip and a wide, tented mouth), developmental delay, intellectual disability, speech disorder, and multiple organ malformations (e.g. ventricular septal defect, megaloureter, dilated renal pelvis). Additional manifestations reported include neurocutaneous lesions (including palmoplantar hyperkeratosis), internal hydrocephalus, and bilateral partial soft-tissue syndactyly of second and third toe.
Myhre syndrome
MedGen UID:
167103
Concept ID:
C0796081
Disease or Syndrome
Myhre syndrome is a connective tissue disorder with multisystem involvement, progressive and proliferative fibrosis that may occur spontaneously or following trauma or surgery, mild-to-moderate intellectual disability, and in some instances, autistic-like behaviors. Organ systems primarily involved include: cardiovascular (congenital heart defects, long- and short-segment stenosis of the aorta and peripheral arteries, pericardial effusion, constrictive pericarditis, restrictive cardiomyopathy, and hypertension); respiratory (choanal stenosis, laryngotracheal narrowing, obstructive airway disease, or restrictive pulmonary disease), gastrointestinal (pyloric stenosis, duodenal strictures, severe constipation); and skin (thickened particularly on the hands and extensor surfaces). Additional findings include distinctive craniofacial features and skeletal involvement (intrauterine growth restriction, short stature, limited joint range of motion). To date, 55 individuals with molecularly confirmed Myhre syndrome have been reported.
Megalocornea mental retardation syndrome
MedGen UID:
162904
Concept ID:
C0796086
Disease or Syndrome
A rare intellectual disability syndrome with most common characteristics of megalocornea, congenital hypotonia, varying degrees of intellectual disability, psychomotor/developmental delay, seizures, and mild facial dysmorphism (including round face, frontal bossing, antimongoloid slant of the eyes, epicanthal folds, large low set ears, broad nasal base, anteverted nostrils, and long upper lip). Interfamilial and intrafamilial clinical variability has been reported.
Neurofaciodigitorenal syndrome
MedGen UID:
163212
Concept ID:
C0796088
Disease or Syndrome
A multiple developmental anomalies syndrome with characteristics of neurological abnormalities (including megalencephaly, hypotonia, intellectual disability, abnormal EEG), dysmorphic facial features (high prominent forehead, grooved nasal tip, ptosis, ear anomalies) and acrorenal defects (such as triphalangism, broad halluces, unilateral renal agenesis). Additionally, intrauterine growth restriction, short stature and congenital heart defects may be associated. There have been no further descriptions in the literature since 1997.
Oculocerebrocutaneous syndrome
MedGen UID:
163214
Concept ID:
C0796092
Disease or Syndrome
Orbital cysts and other eye defects, multiple cerebral anomalies, and focal dermal defects are the principal characteristics of this syndrome.
Mental retardation, congenital heart disease, blepharophimosis, blepharoptosis and hypoplastic teeth
MedGen UID:
162905
Concept ID:
C0796094
Disease or Syndrome
A syndrome of delayed development, blepharophimosis, blepharoptosis, dental hypoplasia, deafness, heart defect, cryptorchidism and scrotal hypoplasia in males, and other abnormalities.
Cleft lip/palate with abnormal thumbs and microcephaly
MedGen UID:
162906
Concept ID:
C0796099
Disease or Syndrome
A polymalformation syndrome that associates multiple skeletal anomalies with microcephaly, facial dysmorphism, urogenital anomalies and intellectual deficit.
Pallister W syndrome
MedGen UID:
163215
Concept ID:
C0796110
Disease or Syndrome
W syndrome has characteristics of intellectual deficit, epileptic seizures and facial dysmorphism. Skeletal anomalies are also often present. To date, it has been described in six male patients. The mode of transmission appears to be X-linked dominant.
Primrose syndrome
MedGen UID:
162911
Concept ID:
C0796121
Disease or Syndrome
Primrose syndrome consists of recognizable facial features, macrocephaly, mental retardation, enlarged and calcified external ears, sparse body hair, and distal muscle wasting (summary by Carvalho and Speck-Martins, 2011). Patients with a deletion syndrome involving 3q13.31 (615433) exhibit features overlapping those of Primrose syndrome.
Pseudoprogeria syndrome
MedGen UID:
163218
Concept ID:
C0796125
Disease or Syndrome
Syndrome with characteristics of intellectual deficit associated with progressive spastic quadriplegia, microcephaly, and glaucoma, absence of the eyebrows and eyelashes, and a malformation of the nose. It has been described in two brothers.
Ramon Syndrome
MedGen UID:
208669
Concept ID:
C0796133
Disease or Syndrome
A slowly progressive syndrome of cherubic facies (fullness of the cheeks, producing a typical chubby face suggestive of a cherub) maxillary fibrous dysplasia, gingival enlargement, radiolucent lesions of the jaws, seizures, delayed mental development, stunted growth, and other defects. Insulin dependent diabetes mellitus and vascular skin lesions may occur.
Renpenning syndrome 1
MedGen UID:
208670
Concept ID:
C0796135
Disease or Syndrome
Renpenning syndrome is an X-linked mental retardation syndrome with clinically recognizable features. Affected individuals have microcephaly, short stature, small testes, and dysmorphic facies, including tall narrow face, upslanting palpebral fissures, abnormal nasal configuration, cupped ears, and short philtrum. The nose may appear long or bulbous, with overhanging columella. Less consistent manifestations include ocular colobomas, cardiac malformations, cleft palate, and anal anomalies. Stevenson et al. (2005) proposed that the various X-linked mental retardation syndromes due to PQBP1 mutations be combined under the name of Renpenning syndrome.
Richards-Rundle syndrome
MedGen UID:
163219
Concept ID:
C0796136
Disease or Syndrome
An extremely rare neurodegenerative disorder characterised by progressive spinocerebellar ataxia, sensorineural hearing loss, and hypergonadotropic hypogonadism associated with additional neurological manifestations (such as peripheral muscle wasting, nystagmus, intellectual disability or dementia) and ketoaciduria.
Richieri-costa/guion-almeida syndrome
MedGen UID:
162914
Concept ID:
C0796142
Disease or Syndrome
The Richieri-Costa/Guion-Almeida syndrome is characterized by mild mental retardation, short stature, microbrachycephaly, ptosis, esotropia, cleft lip/palate (Richieri-Costa and Guion-Almeida, 1992).
Acrocallosal syndrome, Schinzel type
MedGen UID:
162915
Concept ID:
C0796147
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Snyder Robinson syndrome
MedGen UID:
162918
Concept ID:
C0796160
Disease or Syndrome
Snyder-Robinson syndrome (SRS) is an X-linked intellectual disability syndrome characterized by asthenic build, facial dysmorphism with a prominent lower lip, kyphoscoliosis, osteoporosis, and speech abnormalities. Developmental delay usually presents as failure to meet early developmental milestones and then evolves to moderate to profound global intellectual disability (which appears to remain stable over time) and variable motor disability. Asthenic habitus and low muscle mass usually develop during the first year, even in males who are ambulatory. During the first decade, males with SRS develop osteoporosis, resulting in fractures in the absence of trauma.
Sonoda syndrome
MedGen UID:
167108
Concept ID:
C0796162
Disease or Syndrome
A very rare syndrome described in three siblings of one Japanese family with main features of congenital heart disease, round face with depressed nasal bridge, small mouth, short stature, and relatively dark skin and typical dermatoglyphic anomalies, and intellectual deficit.
Toriello Carey syndrome
MedGen UID:
163225
Concept ID:
C0796184
Disease or Syndrome
Toriello-Carey syndrome is a multiple congenital anomaly disorder with variable systemic manifestations, most commonly including mental retardation, agenesis of the corpus callosum, postnatal growth delay, cardiac defects, usually septal defects, distal limb defects, and urogenital anomalies in affected males. Patients have facial dysmorphic features, micrognathia, including full cheeks, hypertelorism, flattened nasal bridge, anteverted nares, and short neck. Not all features are found in all patients and some patients may have additional features such as anal anomalies or hernias (summary by Toriello et al., 2003). In a review of the Toriello-Carey syndrome, Toriello et al. (2016) stated that while corpus callosum abnormalities and micrognathia with highly arched or cleft palate are seen in most patients, other manifestations are widely variable. They noted that etiologic heterogeneity has been observed in reported patients, with at least 20% of patients having chromosome anomalies, and that no good candidate genes have been identified by exome sequencing. The authors commented that this condition might not be a unitary diagnostic entity. They recommended chromosome microarray for any child suspected of having the condition, followed by standard of care by genetic testing.
Prader-Willi habitus, osteopenia, and camptodactyly
MedGen UID:
162919
Concept ID:
C0796189
Disease or Syndrome
This syndrome has characteristics of intellectual deficit, short stature, obesity, genital abnormalities, and hand and/or toe contractures. It has been described in two brothers and in one isolated case. This syndrome is similar to Prader-Willi syndrome, but the hand contractures and osteoporosis, together with the lack of hypotonia, indicate this is a different entity.
Van Den Bosch syndrome
MedGen UID:
162920
Concept ID:
C0796192
Disease or Syndrome
Syndrome that is characterised by intellectual deficit, choroideraemia, acrokeratosis verruciformis, anhidrosis, and skeletal deformities. It has been observed in a single kindred. The syndrome is transmitted as an X-linked recessive trait and may be caused by a small X-chromosome deletion.
Parkinsonism, early onset with mental retardation
MedGen UID:
208674
Concept ID:
C0796195
Disease or Syndrome
Waisman syndrome is an X-linked neurologic disorder characterized by delayed psychomotor development, intellectual disability, and early-onset Parkinson disease (summary by Wilson et al., 2014).
Pashayan syndrome
MedGen UID:
163226
Concept ID:
C0796197
Disease or Syndrome
A rare otorhinolaryngological malformation syndrome with characteristics of a distinctive mask-like facial dysmorphism, lacrimal duct obstruction, extrapyramidal features, digital malformations and intellectual disability. Reported in 3 families to date. The facies has a mask-like appearance due to weakness of facial muscles and lacrimal duct obstruction is characteristic. Clinical features also include telecanthus, bulky nose, broad nasal bridge, sometimes a hypoplastic midface, longitudinal cheek furrows, trapezoidal upper lip and malformation of the ears. Intellectual disability, cutaneous syndactyly, torsion dystonia, increased deep tendon reflexes; Babinski sign, poor coordination and joint laxity are also observed.
Woods syndrome
MedGen UID:
490089
Concept ID:
C0796203
Disease or Syndrome
A craniodigital syndrome of prenatal growth retardation, microcephaly, mental retardation, syndactyly of the fingers, and minor facial anomalies.
Worster Drought syndrome
MedGen UID:
163228
Concept ID:
C0796204
Disease or Syndrome
A form of cerebral palsy with characteristics of congenital pseudobulbar (suprabulbar) paresis manifesting as selective weakness of the lips, tongue and soft palate, dysphagia, dysphonia, drooling and jaw jerking. Mean age at diagnosis is 6 years. The main clinical features are spasticity and limited movements around the mouth and throat from an early age, and brisk jaw jerks. Most cases are sporadic but several families with more than one affected member have been reported. Inheritance in these families appeared to follow an autosomal dominant pattern with variable expression and penetrance.
Mental retardation, X-linked 2
MedGen UID:
162922
Concept ID:
C0796207
Disease or Syndrome
Nonsyndromic mental retardation with a large head, relatively short stature, highly arched palate, square facies, short hands and feet, and macroorchidism.
Mental retardation 3, X-linked
MedGen UID:
167111
Concept ID:
C0796208
Disease or Syndrome
Disorders of intracellular cobalamin metabolism have a variable phenotype and age of onset that are influenced by the severity and location within the pathway of the defect. The prototype and best understood phenotype is cblC; it is also the most common of these disorders. The age of initial presentation of cblC spans a wide range: In utero with fetal presentation of nonimmune hydrops, cardiomyopathy, and intrauterine growth restriction. Newborns, who can have microcephaly, poor feeding, and encephalopathy. Infants, who can have poor feeding and slow growth, neurologic abnormality, and, rarely, hemolytic uremic syndrome (HUS). Toddlers, who can have poor growth, progressive microcephaly, cytopenias (including megaloblastic anemia), global developmental delay, encephalopathy, and neurologic signs such as hypotonia and seizures. Adolescents and adults, who can have neuropsychiatric symptoms, progressive cognitive decline, thromboembolic compications, and/or subacute combined degeneration of the spinal cord.
Mental retardation, X-linked 12
MedGen UID:
901885
Concept ID:
C0796218
Disease or Syndrome
Nonsyndromic mental retardation with hypotelorism, strabismus, large ears, and low birthweight.
Mental Retardation, X-Linked 17
MedGen UID:
163233
Concept ID:
C0796223
Disease or Syndrome
Nonsyndromic mental retardation.
Mental retardation, X-linked 19
MedGen UID:
208676
Concept ID:
C0796225
Disease or Syndrome
X-linked mental retardation-19 (MRX19) is a nonsyndromic form of mild to moderate mental retardation. Carrier females may be mildly affected. Mutation in the RPS6KA3 gene also causes Coffin-Lowry syndrome (CLS; 303600), a mental retardation syndrome with dysmorphic facial features and skeletal anomalies. Some patients with RPS6KA3 mutations have an intermediate phenotype with mental retardation and only mild anomalies reminiscent of CLS. These individuals have mutations resulting in some residual protein function, which likely explains the milder phenotype (summary by Field et al., 2006).
Mental retardation, X-linked 20
MedGen UID:
208677
Concept ID:
C0796226
Disease or Syndrome
Impaired mental functioning occurs as an isolated feature or as part of many syndromes listed in the X-linked catalog. Mental retardation that is not associated with other distinguishing features is referred to as 'nonspecific.' The Human Gene Mapping Nomenclature Committee (Mulley et al., 1992) proposed to designate each newly reported apparently unique X-linked mental retardation (MRX) family with gene symbols (e.g., MRX1, MRX2) if a minimal lod score of 2.0 was demonstrated between the MR locus and 1 or more X chromosome markers.
Mental retardation 23, X-linked
MedGen UID:
163234
Concept ID:
C0796229
Disease or Syndrome
Nonsyndromic mental retardation with speech disorders.
Mental retardation 30, X-linked
MedGen UID:
163235
Concept ID:
C0796237
Disease or Syndrome
Nonsyndromic mental retardation with microcephaly, restlessness, and hyperactivity.
Mental retardation, with or without seizures, ARX-related, X-linked
MedGen UID:
208681
Concept ID:
C0796244
Disease or Syndrome
ARX-related mental retardation is a form of nonsyndromic X-linked mental retardation. It is part of a phenotypic spectrum of disorders caused by mutation in the ARX gene comprising a nearly continuous series of developmental disorders ranging from lissencephaly (LISX2; 300215) to Proud syndrome (300004) to infantile spasms without brain malformations (EIEE1; 308350) to Partington syndrome (309510) (Kato et al., 2004; Wallerstein et al., 2008).
Partington X-linked mental retardation syndrome
MedGen UID:
163237
Concept ID:
C0796250
Disease or Syndrome
Partington syndrome is an X-linked developmental disorder characterized by mental retardation and variable movement disturbances. Partington syndrome is part of a phenotypic spectrum of disorders caused by mutation in the ARX gene comprising a nearly continuous series of developmental disorders ranging from hydranencephaly and lissencephaly (LISX2; 300215) to Proud syndrome (300004) to infantile spasms without brain malformations (EIEE1; 308350) to nonsyndromic mental retardation (300419). Although males with ARX mutations are often more severely affected, female mutation carriers may also be affected (Kato et al., 2004; Wallerstein et al., 2008).
Sabinas brittle hair syndrome
MedGen UID:
163238
Concept ID:
C0796271
Disease or Syndrome
The principal features of Sabinas brittle hair syndrome, a form of nonphotosensitive trichothiodystrophy (TTDN; see 234050), include congenital hypotrichosis, mild to moderate onychodysplasia, varying mental retardation, and sterility. Ocular dysplasias are sometimes present and dentition is normal (Howell et al., 1980).
Monoamine oxidase A deficiency
MedGen UID:
208683
Concept ID:
C0796275
Disease or Syndrome
Brunner syndrome is a recessive X-linked disorder characterized by impulsive aggressiveness and mild mental retardation associated with MAOA deficiency (Brunner et al., 1993).
Carnevale syndrome
MedGen UID:
167115
Concept ID:
C0796279
Disease or Syndrome
The term '3MC syndrome' encompasses 4 rare autosomal recessive disorders that were previously designated the Carnevale, Mingarelli, Malpuech, and Michels syndromes, respectively. The main features of these syndromes are facial dysmorphism that includes hypertelorism, blepharophimosis, blepharoptosis, and highly arched eyebrows, which are present in 70 to 95% of cases. Cleft lip and palate, postnatal growth deficiency, cognitive impairment, and hearing loss are also consistent findings, occurring in 40 to 68% of cases. Craniosynostosis, radioulnar synostosis, and genital and vesicorenal anomalies occur in 20 to 30% of cases. Rare features include anterior chamber defects, cardiac anomalies, caudal appendage, umbilical hernia (omphalocele), and diastasis recti (summary by Rooryck et al., 2011). For a discussion of genetic heterogeneity of 3MC syndrome, see 3MC1 (257920).
CAHMR syndrome
MedGen UID:
167117
Concept ID:
C0796282
Disease or Syndrome
This syndrome is characterised by congenital cataract, generalised hypertrichosis and intellectual deficit. It has been described in two Egyptian siblings born to consanguineous parents. It is transmitted as an autosomal recessive trait.
Brachioskeletogenital syndrome
MedGen UID:
923028
Concept ID:
C0809936
Disease or Syndrome
The core phenotype of Elsahy-Waters syndrome consists of brachycephaly, facial asymmetry, marked hypertelorism, proptosis, blepharochalasis, midface hypoplasia, broad nose with concave nasal ridge, and prognathism; radicular dentin dysplasia with consequent obliterated pulp chambers, apical translucent cysts, recurrent infections, and early loss of teeth; vertebral fusions, particularly at C2-C3; and moderate mental retardation. Skin wrinkling over the glabellar region seems common, and in males, hypospadias has always been present. Inter- and intrafamilial variability has been reported regarding the presence of vertebral fusions, hearing loss,and dentigerous cysts. Midface hypoplasia, facial asymmetry, progressive dental anomalies, and impaired cognitive development become more evident in adulthood (Castori et al., 2010).
Oculodentodigital dysplasia
MedGen UID:
167236
Concept ID:
C0812437
Congenital Abnormality
Oculodentodigital syndrome is characterized by a typical facial appearance and variable involvement of the eyes, dentition, and fingers. Characteristic facial features include a narrow, pinched nose with hypoplastic alae nasi, prominent columella and thin anteverted nares together with a narrow nasal bridge, and prominent epicanthic folds giving the impression of hypertelorism. The teeth are usually small and carious. Typical eye findings include microphthalmia and microcornea. The characteristic digital malformation is complete syndactyly of the fourth and fifth fingers (syndactyly type III) but the third finger may be involved and associated camptodactyly is a common finding (summary by Judisch et al., 1979). Neurologic abnormalities are sometimes associated (Gutmann et al., 1991), and lymphedema has been reported in some patients with ODDD (Brice et al., 2013). See review by De Bock et al. (2013). Genetic Heterogeneity of Oculodentodigital Syndrome An autosomal recessive form of ODDD (257850) is also caused by mutation in the GJA1 gene, but the majority of cases are autosomal dominant.
Danon disease
MedGen UID:
209235
Concept ID:
C0878677
Disease or Syndrome
Danon disease is an X-linked dominant disorder predominantly affecting cardiac muscle. Skeletal muscle involvement and mental retardation are variable features. The accumulation of glycogen in muscle and lysosomes originally led to the classification of Danon disease as a variant of glycogen storage disease II (Pompe disease; 232300) with 'normal acid maltase' or alpha-glucosidase (GAA; 606800) (Danon et al., 1981). However, Nishino et al. (2000) stated that Danon disease is not a glycogen storage disease because glycogen is not always increased. Sugie et al. (2005) classified Danon disease as a form of autophagic vacuolar myopathy, characterized by intracytoplasmic autophagic vacuoles with sarcolemmal features. The characteristic vacuole is believed to be an autolysosome surrounded by secondarily-generated membranes containing sarcolemmal proteins, basal lamina, and acetylcholinesterase activity. X-linked myopathy with excessive autophagy (XMEA; 310440) is a distinct disorder with similar pathologic features.
Salla disease
MedGen UID:
203368
Concept ID:
C1096903
Disease or Syndrome
The allelic disorders of free sialic acid metabolism – Salla disease, intermediate severe Salla disease, and infantile free sialic acid storage disease (ISSD) ? are neurodegenerative disorders resulting from increased lysosomal storage of free sialic acid. The mildest phenotype is Salla disease, which is characterized by normal appearance and neurologic findings at birth followed by slowly progressive neurologic deterioration resulting in mild to moderate psychomotor retardation, spasticity, athetosis, and epileptic seizures. The most severe phenotype is ISSD, characterized by severe developmental delay, coarse facial features, hepatosplenomegaly, and cardiomegaly; death usually occurs in early childhood.
Dyskeratosis congenita X-linked
MedGen UID:
216941
Concept ID:
C1148551
Disease or Syndrome
Dyskeratosis congenita (DC), a telomere biology disorder, is characterized by a classic triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia. The classic triad may not be present in all individuals. People with DC are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML), solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include: abnormal pigmentation changes not restricted to the upper chest and neck, eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), and dental abnormalities (caries, periodontal disease, taurodauntism). Although most persons with DC have normal psychomotor development and normal neurologic function, significant developmental delay is present in the two variants in which additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome). Onset and progression of manifestations of DC vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.
Diamond-Blackfan anemia
MedGen UID:
266045
Concept ID:
C1260899
Disease or Syndrome
Diamond-Blackfan anemia (DBA) in its classic form is characterized by a profound normochromic and usually macrocytic anemia with normal leukocytes and platelets, congenital malformations in up to 50% of affected individuals, and growth retardation in 30% of affected individuals. The hematologic complications occur in 90% of affected individuals during the first year of life. The phenotypic spectrum ranges from a mild form (e.g., mild anemia, no anemia with only subtle erythroid abnormalities, physical malformations without anemia) to a severe form of fetal anemia resulting in nonimmune hydrops fetalis. DBA is associated with an increased risk for acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), and solid tumors including osteogenic sarcoma.
Progeroid short stature with pigmented nevi
MedGen UID:
224702
Concept ID:
C1261128
Disease or Syndrome
Mulvihill-Smith syndrome is characterized by premature aging, multiple pigmented nevi, lack of facial subcutaneous fat, microcephaly, short stature, sensorineural hearing loss, and mental retardation. Immunodeficiency may also be a feature. Adult manifestations include the development of tumors, a sleep disorder with severe insomnia, and cognitive decline (summary by Yagihashi et al., 2009).
Merosin deficient congenital muscular dystrophy
MedGen UID:
224728
Concept ID:
C1263858
Disease or Syndrome
Merosin-deficient congenital muscular dystrophy is an autosomal recessive form of muscular dystrophy characterized by muscle weakness apparent at birth or in the first 6 months of life. Patients show hypotonia, poor suck and cry, and delayed motor development; most never achieve independent ambulation. Most patients also have periventricular white matter abnormalities on brain imaging, but mental retardation and/or seizures occur only rarely (summary by Xiong et al., 2015).
Carpenter syndrome
MedGen UID:
226897
Concept ID:
C1275078
Disease or Syndrome
Carpenter syndrome is a condition characterized by the premature fusion of certain skull bones (craniosynostosis), abnormalities of the fingers and toes, and other developmental problems.Craniosynostosis prevents the skull from growing normally, frequently giving the head a pointed appearance (acrocephaly). In severely affected individuals, the abnormal fusion of the skull bones results in a deformity called a cloverleaf skull. Craniosynostosis can cause differences between the two sides of the head and face (craniofacial asymmetry). Early fusion of the skull bones can affect the development of the brain and lead to increased pressure within the skull (intracranial pressure). Premature fusion of the skull bones can cause several characteristic facial features in people with Carpenter syndrome. Distinctive facial features may include a flat nasal bridge, outside corners of the eyes that point downward (down-slanting palpebral fissures), low-set and abnormally shaped ears, underdeveloped upper and lower jaws, and abnormal eye shape. Some affected individuals also have dental abnormalities including small primary (baby) teeth. Vision problems also frequently occur.Abnormalities of the fingers and toes include fusion of the skin between two or more fingers or toes (cutaneous syndactyly), unusually short fingers or toes (brachydactyly), or extra fingers or toes (polydactyly). In Carpenter syndrome, cutaneous syndactyly is most common between the third (middle) and fourth (ring) fingers, and polydactyly frequently occurs next to the big or second toe or the fifth (pinky) finger.People with Carpenter syndrome often have intellectual disability, which can range from mild to profound. However, some individuals with this condition have normal intelligence. The cause of intellectual disability is unknown, as the severity of craniosynostosis does not appear to be related to the severity of intellectual disability.Other features of Carpenter syndrome include obesity that begins in childhood, a soft out-pouching around the belly-button (umbilical hernia), hearing loss, and heart defects. Additional skeletal abnormalities such as deformed hips, a rounded upper back that also curves to the side (kyphoscoliosis), and knees that are angled inward (genu valgum) frequently occur. Nearly all affected males have genital abnormalities, most frequently undescended testes (cryptorchidism).A few people with Carpenter syndrome have organs or tissues within their chest and abdomen that are in mirror-image reversed positions. This abnormal placement may affect several internal organs (situs inversus); just the heart (dextrocardia), placing the heart on the right side of the body instead of on the left; or only the major (great) arteries of the heart, altering blood flow.The signs and symptoms of this disorder vary considerably, even within the same family. The life expectancy for individuals with Carpenter syndrome is shortened but extremely variable.The signs and symptoms of Carpenter syndrome are similar to another genetic condition called Greig cephalopolysyndactyly syndrome. The overlapping features, which include craniosynostosis, polydactyly, and heart abnormalities, can cause these two conditions to be misdiagnosed; genetic testing is often required for an accurate diagnosis.
Cardio-facio-cutaneous syndrome
MedGen UID:
266149
Concept ID:
C1275081
Congenital Abnormality
Cardiofaciocutaneous (CFC) syndrome is characterized by cardiac abnormalities (pulmonic stenosis and other valve dysplasias, septal defects, hypertrophic cardiomyopathy, rhythm disturbances), distinctive craniofacial appearance, and cutaneous abnormalities (including xerosis, hyperkeratosis, ichthyosis, keratosis pilaris, ulerythema ophryogenes, eczema, pigmented moles, hemangiomas, and palmoplantar hyperkeratosis). The hair is typically sparse, curly, fine or thick, woolly or brittle; eyelashes and eyebrows may be absent or sparse. Nails may be dystrophic or fast growing. Some form of neurologic and/or cognitive delay (ranging from mild to severe) is seen in all affected individuals. Neoplasia, mostly acute lymphoblastic leukemia (ALL), has been reported in some individuals.
Autosomal recessive keratitis-ichthyosis-deafness syndrome
MedGen UID:
224809
Concept ID:
C1275089
Disease or Syndrome
Keratitis-ichthyosis-deafness (KID) syndrome is characterized by eye problems, skin abnormalities, and hearing loss.People with KID syndrome usually have keratitis, which is inflammation of the front surface of the eye (the cornea). The keratitis may cause pain, increased sensitivity to light (photophobia), abnormal blood vessel growth over the cornea (neovascularization), and scarring. Over time, affected individuals experience a loss of sharp vision (reduced visual acuity); in severe cases the keratitis can lead to blindness.Most people with KID syndrome have thick, hard skin on the palms of the hands and soles of the feet (palmoplantar keratoderma). Affected individuals also have thick, reddened patches of skin (erythrokeratoderma) that are dry and scaly (ichthyosis). These dry patches can occur anywhere on the body, although they most commonly affect the neck, groin, and armpits. Breaks in the skin often occur and may lead to infections. In severe cases these infections can be life-threatening, especially in infancy. Approximately 12 percent of people with KID syndrome develop a type of skin cancer called squamous cell carcinoma, which may also affect mucous membranes such as the lining of the mouth.Partial hair loss is a common feature of KID syndrome, and often affects the eyebrows and eyelashes. Affected individuals may also have small, abnormally formed nails.Hearing loss in this condition is usually profound, but occasionally is less severe.
Deficiency of glycerate kinase
MedGen UID:
226941
Concept ID:
C1291386
Disease or Syndrome
D-glyceric aciduria is a rare autosomal recessive metabolic disorder with a highly variable phenotype. Some patients have an encephalopathic presentation, with severe mental retardation, seizures, microcephaly, and sometimes early death, whereas others have a mild phenotype with only mild speech delay or even normal development (summary by Sass et al., 2010).
Deficiency of phosphoserine phosphatase
MedGen UID:
452940
Concept ID:
C1291463
Disease or Syndrome
Deficiency of beta-ureidopropionase
MedGen UID:
226944
Concept ID:
C1291512
Disease or Syndrome
Beta-ureidopropionase deficiency is a rare autosomal recessive inborn error of metabolism due to a defect in pyrimidine degradation. Less than 10 patients have been reported, and the phenotype can range from severe neurologic involvement with mental retardation and seizures to normal neurologic development (Yaplito-Lee et al., 2008).
Sponastrime dysplasia
MedGen UID:
266247
Concept ID:
C1300260
Disease or Syndrome
Sponastrime dysplasia is a rare autosomal recessive bone disorder. Radiographic findings include abnormal vertebral bodies with age-dependent changes, and striations of the metaphyses, scoliosis, and retarded ossification of the carpal bones. Physical features include severe short stature, lumbar lordosis, midface hypoplasia, frontal bossing, and a depressed nasal root (summary by Cooper et al., 2000).
Nicolaides-Baraitser syndrome
MedGen UID:
220983
Concept ID:
C1303073
Disease or Syndrome
Nicolaides-Baraitser syndrome (NCBRS) is characterized by sparse scalp hair, prominence of the inter-phalangeal joints and distal phalanges due to decreased subcutaneous fat, characteristic coarse facial features, microcephaly, seizures, and developmental delay / intellectual disability. Seizures are of various types and can be difficult to manage. Developmental delay / intellectual disability (ID) is severe in nearly a half, moderate in a third, and mild in the remainder. Nearly a third never develop speech or language skills.
Barber-Say syndrome
MedGen UID:
230818
Concept ID:
C1319466
Disease or Syndrome
Barber-Say syndrome is a rare congenital condition characterized by severe hypertrichosis, especially of the back, skin abnormalities such as hyperlaxity and redundancy, and facial dysmorphism, including macrostomia, eyelid deformities, ocular telecanthus, abnormal and low-set ears, bulbous nasal tip with hypoplastic alae nasi, and low frontal hairline (summary by Roche et al., 2010).
Shprintzen-Goldberg syndrome
MedGen UID:
231160
Concept ID:
C1321551
Disease or Syndrome
Shprintzen-Goldberg syndrome (SGS) is characterized by: craniosynostosis of the coronal, sagittal, or lambdoid sutures; dolichocephaly; distinctive craniofacial features; skeletal changes (dolichostenomelia, arachnodactyly, camptodactyly, pes planus, pectus excavatum or carinatum, scoliosis, joint hypermobility or contractures and C1/C2 spine malformation); neurologic abnormalities; intellectual disability; and brain anomalies (hydrocephalus, dilatation of the lateral ventricles, and Chiari 1 malformation). Cardiovascular anomalies may include mitral valve prolapse, mitral regurgitation/incompetence, aortic regurgitation, and aortic root dilatation. Minimal subcutaneous fat, abdominal wall defects, myopia, and cryptorchidism in males are also characteristic findings.
Oral-facial-digital syndrome
MedGen UID:
307142
Concept ID:
C1510460
Disease or Syndrome
Oral-facial-digital syndrome type I (OFD1) is usually male lethal during gestation and predominantly affects females. OFD1 is characterized by the following features: Oral (lobulated tongue, tongue nodules, cleft of the hard or soft palate, accessory gingival frenulae, hypodontia, and other dental abnormalities). Facial (widely spaced eyes or telecanthus, hypoplasia of the alae nasi, median cleft or pseudocleft upper lip, micrognathia). Digital (brachydactyly, syndactyly, clinodactyly of the fifth finger; duplicated hallux [great toe]). Kidney (polycystic kidney disease). Brain (e.g., intracerebral cysts, agenesis of the corpus callosum, cerebellar agenesis with or without Dandy-Walker malformation). Intellectual disability (in ~50% of individuals).
Deficiency of acetyl-CoA acetyltransferase
MedGen UID:
280689
Concept ID:
C1536500
Disease or Syndrome
Alpha-methylacetoacetic aciduria, also known as 3-ketothiolase deficiency, is an inborn error of isoleucine catabolism characterized by urinary excretion of 2-methyl-3-hydroxybutyric acid, 2-methylacetoacetic acid, tiglylglycine, and 2-butanone.
Nephrogenic diabetes insipidus, X-linked
MedGen UID:
288785
Concept ID:
C1563705
Disease or Syndrome
Nephrogenic diabetes insipidus (NDI) is characterized by inability to concentrate the urine, which results in polyuria (excessive urine production) and polydipsia (excessive thirst). Affected untreated infants usually have poor feeding and failure to thrive, and rapid onset of severe dehydration with illness, hot environment, or the withholding of water. Short stature and secondary dilatation of the ureters and bladder from the high urine volume is common in untreated individuals.
Nephrogenic diabetes insipidus, autosomal
MedGen UID:
289643
Concept ID:
C1563706
Disease or Syndrome
Nephrogenic diabetes insipidus (NDI) is characterized by inability to concentrate the urine, which results in polyuria (excessive urine production) and polydipsia (excessive thirst). Affected untreated infants usually have poor feeding and failure to thrive, and rapid onset of severe dehydration with illness, hot environment, or the withholding of water. Short stature and secondary dilatation of the ureters and bladder from the high urine volume is common in untreated individuals.
Kallmann syndrome 2
MedGen UID:
289648
Concept ID:
C1563720
Disease or Syndrome
Isolated gonadotropin-releasing hormone (GnRH) deficiency (IGD) is characterized by inappropriately low serum concentrations of the gonadotropins LH (luteinizing hormone) and FSH (follicle-stimulating hormone) in the presence of low circulating concentrations of sex steroids. IGD is associated with a normal sense of smell (normosmic IGD) in approximately 40% of affected individuals and an impaired sense of smell (Kallmann syndrome) in approximately 60%. IGD can first become apparent in infancy, adolescence, or adulthood. Infant boys with congenital IGD often have micropenis and cryptorchidism. Adolescents and adults with IGD have clinical evidence of hypogonadism and incomplete sexual maturation on physical examination. Adult males with IGD tend to have prepubertal testicular volume (i.e., <4 mL), absence of secondary sexual features (e.g., facial and axillary hair growth, deepening of the voice), decreased muscle mass, diminished libido, erectile dysfunction, and infertility. Adult females have little or no breast development and primary amenorrhea. Although skeletal maturation is delayed, the rate of linear growth is usually normal except for the absence of a distinct pubertal growth spurt.
Opitz G/BBB syndrome
MedGen UID:
321463
Concept ID:
C1801950
Disease or Syndrome
Individuals with 22q11.2 deletion syndrome (22q11.2DS) have a range of findings including the following: Congenital heart disease (74% of individuals), particularly conotruncal malformations (tetralogy of Fallot, interrupted aortic arch, ventricular septal defect, and truncus arteriosus). Palatal abnormalities (69%), particularly velopharyngeal incompetence, submucosal cleft palate, bifid uvula, and cleft palate. Characteristic facial features (present in the majority of individuals of northern European heritage). Learning difficulties (70%-90%). An immune deficiency (regardless of the clinical presentation) (77%). Additional findings include the following: Hypocalcemia (50%). Significant feeding and swallowing problems; constipation with or without structural gastrointestinal anomalies (intestinal malrotation, imperforate anus, and Hirschsprung disease). Renal anomalies (31%). Hearing loss (both conductive and sensorineural). Laryngotracheoesophageal anomalies. Growth hormone deficiency. Autoimmune disorders. Seizures (idiopathic or associated with hypocalcemia). CNS anomalies including tethered cord. Skeletal abnormalities (scoliosis with or without vertebral anomalies, clubbed feet, polydactyly, and craniosynostosis). Ophthalmologic abnormalities (strabismus, posterior embryotoxon, tortuous retinal vessels, scleracornea, and anophthalmia). Enamel hypoplasia. Malignancies (rare). Developmental delay (in particular delays in emergence of language), intellectual disability, and learning differences (non-verbal learning disability where the verbal IQ is significantly greater than the performance IQ) are common. Autism or autistic spectrum disorder is found in approximately 20% of children and psychiatric illness (specifically schizophrenia) is present in 25% of adults; however, attention deficit disorder, anxiety, perseveration, and difficulty with social interactions are also common.
Congenital muscular hypertrophy-cerebral syndrome
MedGen UID:
315658
Concept ID:
C1802395
Disease or Syndrome
Classic Cornelia de Lange syndrome (CdLS) is characterized by distinctive facial features, growth retardation (prenatal onset; <5th centile throughout life), hirsutism, and upper-limb reduction defects that range from subtle phalangeal abnormalities to oligodactyly (missing digits). Craniofacial features include synophrys, highly arched eyebrows, long eyelashes, short nose with anteverted nares, small widely spaced teeth, and microcephaly. IQ ranges from below 30 to 102 (mean: 53). Many individuals demonstrate autistic and self-destructive tendencies. Frequent findings include cardiac septal defects, gastrointestinal dysfunction, hearing loss, myopia, and cryptorchidism or hypoplastic genitalia. Individuals with a milder phenotype have less severe growth, cognitive, and limb involvement, but often have facial features consistent with CdLS.
Cerebrofacioarticular syndrome
MedGen UID:
318616
Concept ID:
C1832390
Disease or Syndrome
A rare multiple congenital anomalies syndrome with mild to severe intellectual disability, a distinctive facial gestalt (blepharophimosis, maxillary hypoplasia, telecanthus, microtia and atresia of the external auditory meatus) as well as skeletal and articular abnormalities (e.g. camptodactyly of the fingers, cutaneous syndactyly, talipes equinovarus, flexion contractures of the proximal interphalangeal joints, hip or elbow subluxation, joint laxity). May also present with neonatal hypotonia, variable respiratory manifestations, chronic feeding difficulties and gray matter heterotopia.
Hunter-McAlpine syndrome
MedGen UID:
321949
Concept ID:
C1832408
Disease or Syndrome
This syndrome has characteristics of craniosynostosis, intellectual deficit, short stature, facial dysmorphism (oval face with almond-shaped palpebral fissures, droopy eyelids and a small nose) and minor distal anomalies. It has been described in 10 patients. Transmission is autosomal dominant and the syndrome is associated with partial duplication of the long arm of chromosome 5 (5q35-5qter).
Mental retardation, microcephaly, epilepsy, and coarse face
MedGen UID:
330468
Concept ID:
C1832437
Disease or Syndrome
Microphthalmia syndromic 8
MedGen UID:
330469
Concept ID:
C1832440
Disease or Syndrome
Potocki-Shaffer syndrome
MedGen UID:
318657
Concept ID:
C1832588
Disease or Syndrome
Potocki-Shaffer syndrome is a rare contiguous gene deletion syndrome due to haploinsufficiency of the 11p12-p11.2 region and is characterized by craniofacial abnormalities, developmental delay, intellectual disability, multiple exostoses (168500), and biparietal foramina (605957) (summary by Swarr et al., 2010).
Fallot complex with severe mental and growth retardation
MedGen UID:
322025
Concept ID:
C1832735
Disease or Syndrome
A rare disorder characterised by tetralogy of Fallot, minor facial anomalies, and severe intellectual deficiency and growth delay. Dysmorphic features include large, protruding, abnormally modelled ears and broad nasal root. Microcephaly and syndactyly of second and third toes have also been recorded. All patients have severe intellectual deficiency. The condition is transmitted as an autosomal recessive trait.
Spondyloepimetaphyseal dysplasia micromelic
MedGen UID:
318712
Concept ID:
C1832800
Disease or Syndrome
Ayme-gripp syndrome
MedGen UID:
371416
Concept ID:
C1832812
Disease or Syndrome
Ayme-Gripp syndrome is a clinically homogeneous phenotype characterized by congenital cataracts, sensorineural hearing loss, intellectual disability, seizures, brachycephaly, a distinctive flat facial appearance, and reduced growth (Niceta et al., 2015).
RESDAD
MedGen UID:
322043
Concept ID:
C1832814
Disease or Syndrome
Epilepsy, familial adult myoclonic, 1
MedGen UID:
371424
Concept ID:
C1832841
Disease or Syndrome
Familial cortical myoclonic tremor associated with epilepsy (FCMTE) is characterized by an autosomal dominant inheritance, adult-onset cortical myoclonus, and seizures in 40% of patients. Myoclonus is usually the first symptom and is characterized by tremulous finger movements and myoclonus of the extremities (summary by Depienne et al., 2010). FAME1 tends to occur in patients of Japanese or Han Chinese descent (summary by Cen et al., 2018). Genetic Heterogeneity of Familial Adult Myoclonic Epilepsy See also FAME2 (607876), caused by mutation in the ADRA2B gene (104260) on chromosome 2q11; FAME3 (613608), which maps to chromosome 5p15; FAME4 (615127), which maps to chromosome 3q26.32-q28; FAME5 (615400), caused by mutation in the CNTN2 gene (190197) on chromosome 1q32; FAME6 (618074), caused by mutation in the TNRC6A gene (610739) on chromosome 16p12; and FAME7 (618075), caused by mutation in the RAPGEF2 gene (609530) on chromosome 4. Progressive myoclonic epilepsy is a more severe disorder (see, e.g., EPM1, 254800).
Ichthyosis-mental retardation syndrome with large keratohyalin granules in the skin
MedGen UID:
318724
Concept ID:
C1832858
Disease or Syndrome
Timothy syndrome
MedGen UID:
331395
Concept ID:
C1832916
Disease or Syndrome
Timothy syndrome is a multisystem disorder characterized by cardiac, hand/foot, facial, and neurodevelopmental features. Typical cardiac findings include a rate-corrected QT interval >480 ms, functional 2:1 AV block with bradycardia, tachyarrhythmias, and congenital heart defects (patent ductus arteriosus, patent foramen ovale, ventricular septal defect, tetralogy of Fallot, hypertrophic cardiomyopathy). The diagnosis of Timothy syndrome is generally made within the first few days of life although it may be suspected prenatally due to 2:1 AV block or bradycardia in the fetus. Hand/foot findings are unilateral or bilateral cutaneous syndactyly variably involving fingers two (index), three (middle), four (ring), and five (little) and bilateral cutaneous syndactyly of toes two and three. Facial findings include depressed nasal bridge, low-set ears, thin vermilion border of the upper lip, and round face. Neuropsychiatric involvement includes global developmental delays and autism spectrum disorders. Ventricular tachyarrhythmia is the leading cause of death, followed by infection and complications of intractable hypoglycemia. Average age of death is 2.5 years.
Hydrocephalus, Skeletal Anomalies, and Mental Disturbance
MedGen UID:
318750
Concept ID:
C1832948
Disease or Syndrome
Cleft palate, cardiac defects, and mental retardation
MedGen UID:
318752
Concept ID:
C1832950
Disease or Syndrome
Kennerknecht syndrome
MedGen UID:
318801
Concept ID:
C1833162
Disease or Syndrome
Ectodermal dysplasia mental retardation syndactyly
MedGen UID:
322135
Concept ID:
C1833169
Disease or Syndrome
Cone-rod dystrophy 1
MedGen UID:
371596
Concept ID:
C1833564
Disease or Syndrome
Cone-rod dystrophy is a group of related eye disorders that causes vision loss, which becomes more severe over time. These disorders affect the retina, which is the layer of light-sensitive tissue at the back of the eye. In people with cone-rod dystrophy, vision loss occurs as the light-sensing cells of the retina gradually deteriorate.The first signs and symptoms of cone-rod dystrophy, which often occur in childhood, are usually decreased sharpness of vision (visual acuity) and increased sensitivity to light (photophobia). These features are typically followed by impaired color vision (dyschromatopsia), blind spots (scotomas) in the center of the visual field, and partial side (peripheral) vision loss. Over time, affected individuals develop night blindness and a worsening of their peripheral vision, which can limit independent mobility. Decreasing visual acuity makes reading increasingly difficult and most affected individuals are legally blind by mid-adulthood. As the condition progresses, individuals may develop involuntary eye movements (nystagmus).There are more than 30 types of cone-rod dystrophy, which are distinguished by their genetic cause and their pattern of inheritance: autosomal recessive, autosomal dominant, and X-linked. Additionally, cone-rod dystrophy can occur alone without any other signs and symptoms or it can occur as part of a syndrome that affects multiple parts of the body.
Ophthalmoplegia, progressive, with scrotal tongue and mental deficiency
MedGen UID:
318972
Concept ID:
C1833835
Disease or Syndrome
MOMO syndrome
MedGen UID:
371897
Concept ID:
C1834759
Disease or Syndrome
A very rare genetic overgrowth/obesity syndrome with characteristics of macrocephaly, obesity, mental (intellectual) disability and ocular abnormalities. Other frequent clinical signs include macrosomia, downslanting palpebral fissures, hypertelorism, broad nasal root, high and broad forehead and delay in bone maturation, in association with normal thyroid function and karyotype.
Holoprosencephaly 2
MedGen UID:
322517
Concept ID:
C1834877
Disease or Syndrome
Holoprosencephaly (HPE) is a structural anomaly of the brain in which there is failed or incomplete separation of the forebrain early in gestation. Classic HPE encompasses a continuum of brain malformations including (in order of decreasing severity): alobar, semilobar, lobar, and middle interhemispheric variant (MIHV) type HPE; a septopreoptic type has also been described. Other CNS abnormalities not specific to HPE may also occur. HPE is accompanied by a spectrum of characteristic craniofacial anomalies in approximately 80% of individuals with HPE. Developmental delay is present in virtually all individuals with the HPE spectrum of CNS anomalies. Seizures and pituitary dysfunction are common. Most affected fetuses do not survive; severely affected children typically do not survive beyond early infancy, while a significant proportion of more mildly affected children survive past 12 months. Mildly manifesting individuals without appreciable brain anomalies on conventional neuroimaging may be described as having "microform" HPE.
Mental and growth retardation with amblyopia
MedGen UID:
331885
Concept ID:
C1835028
Disease or Syndrome
Lentiginosis, centrofacial neurodysraphic
MedGen UID:
372055
Concept ID:
C1835484
Disease or Syndrome
Alopecia mental retardation syndrome 2
MedGen UID:
372142
Concept ID:
C1835852
Disease or Syndrome
Goldberg-Shprintzen megacolon syndrome
MedGen UID:
332131
Concept ID:
C1836123
Disease or Syndrome
Goldberg-Shprintzen syndrome is an autosomal recessive multiple congenital anomaly syndrome characterized by intellectual disability, microcephaly, and dysmorphic facial features. Most patients also have Hirschsprung disease and/or gyral abnormalities of the brain, consistent with defects in migration of neural crest cells and neurons. Other features, such as megalocornea or urogenital anomalies, may also be present. Goldberg-Shprintzen syndrome has some resemblance to Mowat-Wilson syndrome (MOWS; 235730) but is genetically distinct (summary by Drevillon et al., 2013). Yomo et al. (1991) referred to this disorder as Goldberg-Shprintzen syndrome, which should not be confused with Shprintzen-Goldberg craniosynostosis syndrome (182212) or 2 other Shprintzen syndromes (192430, 182210).
Mental retardation, enteropathy, deafness, peripheral neuropathy, ichthyosis, and keratoderma
MedGen UID:
322893
Concept ID:
C1836330
Disease or Syndrome
MEDNIK is a severe multisystem disorder characterized by mental retardation, enteropathy, deafness, peripheral neuropathy, ichthyosis, and keratoderma. It shows phenotypic similarities to CEDNIK (609528) (summary by Montpetit et al., 2008).
Limb-girdle muscular dystrophy-dystroglycanopathy, type C1
MedGen UID:
332193
Concept ID:
C1836373
Disease or Syndrome
Limb-girdle muscular dystrophies resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239) represent the mildest end of the phenotypic spectrum of muscular dystrophies collectively known as dystroglycanopathies. The limb-girdle phenotype is characterized by onset of muscular weakness apparent after ambulation is achieved; mental retardation and mild brain anomalies are variable (Balci et al., 2005; review by Godfrey et al., 2007). The most severe end of the phenotypic spectrum of dystroglycanopathies is represented by congenital muscular dystrophy-dystroglycanopathy with brain and eye anomalies (type A; see MDDGA1, 236670), previously designated Walker-Warburg syndrome (WWS) or muscle-eye-brain disease (MEB), and the intermediate range of the spectrum is represented by congenital muscular dystrophy-dystroglycanopathy with or without mental retardation (type B; see MDDGB1, 613155). Genetic Heterogeneity of Limb-Girdle Muscular Dystrophy-Dystroglycanopathy (Type C) Limb-girdle muscular dystrophy due to defective glycosylation of DAG1 is genetically heterogeneous. See also MDDGC2 (613158), caused by mutation in the POMT2 gene (607439); MDDGC3 (613157), caused by mutation in the POMGNT1 gene (606822); MDDGC4 (611588), caused by mutation in the FKTN gene (607440); MDDGC5 (607155), caused by mutation in the FKRP gene (606596); MDDGC7 (616052), caused by mutation in the ISPD gene (614631); MDDGC8 (618135), caused by mutation in the POMGNT2 gene (614828); MDDGC9 (613818) caused by mutation in the DAG1 gene (128239); MDDGC12 (616094), caused by mutation in the POMK gene (615247); MDDGC14 (615352) caused by mutation in the GMPPB gene (615320); and MDDGC15 (612937), caused by mutation in the DPM3 gene (605951).
Hyperthyroidism, nonautoimmune
MedGen UID:
373154
Concept ID:
C1836706
Disease or Syndrome
Peripheral demyelinating neuropathy, central dysmyelination, Waardenburg syndrome, and Hirschsprung disease
MedGen UID:
373160
Concept ID:
C1836727
Disease or Syndrome
PCWH syndrome is a complex neurocristopathy that includes features of 4 distinct syndromes: peripheral demyelinating neuropathy (see 118200), central dysmyelination, Waardenburg syndrome, and Hirschsprung disease (see 142623) (Inoue et al., 2004). Inoue et al. (2004) proposed the acronym PCWH for this disorder.
Ceroid lipofuscinosis neuronal 9
MedGen UID:
332304
Concept ID:
C1836841
Disease or Syndrome
The neuronal ceroid lipofuscinoses (NCL; CLN) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by the intracellular accumulation of autofluorescent lipopigment storage material in different patterns ultrastructurally. The clinical course includes progressive dementia, seizures, and progressive visual failure (Mole et al., 2005). For a discussion of genetic heterogeneity of neuronal ceroid lipofuscinosis, see CLN1 (256730).
Posterior column ataxia with retinitis pigmentosa
MedGen UID:
324636
Concept ID:
C1836916
Disease or Syndrome
Posterior column ataxia with retinitis pigmentosa is an autosomal recessive neurologic disorder characterized by childhood-onset retinitis pigmentosa and later onset of gait ataxia due to sensory loss (summary by Ishiura et al., 2011).
Emanuel syndrome
MedGen UID:
323030
Concept ID:
C1836929
Disease or Syndrome
Emanuel syndrome is characterized by pre- and postnatal growth deficiency, microcephaly, hypotonia, severe global developmental delays, ear anomalies, preauricular tags or pits, cleft or high-arched palate, congenital heart defects, kidney abnormalities, and genital abnormalities in males.
Stomatin-deficient cryohydrocytosis with neurologic defects
MedGen UID:
332390
Concept ID:
C1837206
Disease or Syndrome
Stomatin-deficient cryohydrocytosis with neurologic defects is an autosomal dominant disorder characterized by delayed psychomotor development, seizures, cataracts, and pseudohyperkalemia resulting from defects in the red blood cell membrane. The disorder combines the neurologic features of Glut1 deficiency syndrome-1 (GLUT1DS1; 606777), resulting from impaired glucose transport at the blood-brain barrier, and hemolytic anemia/pseudohyperkalemia with stomatocytosis, resulting from a cation leak in erythrocytes (summary by Bawazir et al., 2012). For a discussion of clinical and genetic heterogeneity of red cell stomatocyte disorders, see 194380.
Pyruvate dehydrogenase phosphatase deficiency
MedGen UID:
332448
Concept ID:
C1837429
Disease or Syndrome
Pyruvate dehydrogenase deficiency is characterized by the buildup of a chemical called lactic acid in the body and a variety of neurological problems. Signs and symptoms of this condition usually first appear shortly after birth, and they can vary widely among affected individuals. The most common feature is a potentially life-threatening buildup of lactic acid (lactic acidosis), which can cause nausea, vomiting, severe breathing problems, and an abnormal heartbeat. People with pyruvate dehydrogenase deficiency usually have neurological problems as well. Most have delayed development of mental abilities and motor skills such as sitting and walking. Other neurological problems can include intellectual disability, seizures, weak muscle tone (hypotonia), poor coordination, and difficulty walking. Some affected individuals have abnormal brain structures, such as underdevelopment of the tissue connecting the left and right halves of the brain (corpus callosum), wasting away (atrophy) of the exterior part of the brain known as the cerebral cortex, or patches of damaged tissue (lesions) on some parts of the brain. Because of the severe health effects, many individuals with pyruvate dehydrogenase deficiency do not survive past childhood, although some may live into adolescence or adulthood.
Ehlers-Danlos syndrome Beasley Cohen type
MedGen UID:
332459
Concept ID:
C1837462
Disease or Syndrome
Ehlers-Danlos syndrome is a group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. Defects in connective tissues cause the signs and symptoms of these conditions, which range from mildly loose joints to life-threatening complications.The various forms of Ehlers-Danlos syndrome have been classified in several different ways. Originally, 11 forms of Ehlers-Danlos syndrome were named using Roman numerals to indicate the types (type I, type II, and so on). In 1997, researchers proposed a simpler classification (the Villefranche nomenclature) that reduced the number of types to six and gave them descriptive names based on their major features. In 2017, the classification was updated to include rare forms of Ehlers-Danlos syndrome that were discovered more recently. The 2017 classification describes 13 types of Ehlers-Danlos syndrome.An unusually large range of joint movement (hypermobility) occurs in most forms of Ehlers-Danlos syndrome, and it is a hallmark feature of the hypermobile type. Infants and children with hypermobility often have weak muscle tone (hypotonia), which can delay the development of motor skills such as sitting, standing, and walking. The loose joints are unstable and prone to dislocation and chronic pain. In the arthrochalasia type of Ehlers-Danlos syndrome, infants have hypermobility and dislocations of both hips at birth.Many people with the Ehlers-Danlos syndromes have soft, velvety skin that is highly stretchy (elastic) and fragile. Affected individuals tend to bruise easily, and some types of the condition also cause abnormal scarring. People with the classical form of Ehlers-Danlos syndrome experience wounds that split open with little bleeding and leave scars that widen over time to create characteristic "cigarette paper" scars. The dermatosparaxis type of the disorder is characterized by loose skin that sags and wrinkles, and extra (redundant) folds of skin may be present.Some forms of Ehlers-Danlos syndrome, notably the vascular type and to a lesser extent the kyphoscoliotic, classical, and classical-like types, can cause unpredictable tearing (rupture) of blood vessels, leading to internal bleeding and other potentially life-threatening complications. The vascular type of Ehlers-Danlos syndrome is also associated with an increased risk of organ rupture, including tearing of the intestine and rupture of the uterus during pregnancy.Other types of Ehlers-Danlos syndrome have additional signs and symptoms. The cardiac-valvular type causes severe problems with the valves that control the movement of blood through the heart. People with the kyphoscoliotic type experience severe curvature of the spine that worsens over time and can interfere with breathing by restricting lung expansion. A type of Ehlers-Danlos syndrome called brittle cornea syndrome is characterized by thinness of the clear covering of the eye (the cornea) and other eye abnormalities. The spondylodysplastic type features short stature and skeletal abnormalities such as abnormally curved (bowed) limbs. Abnormalities of muscles, including hypotonia and permanently bent joints (contractures), are among the characteristic signs of the musculocontractural and myopathic forms of Ehlers-Danlos syndrome. The periodontal type causes abnormalities of the teeth and gums.
Insulin-like growth factor I deficiency
MedGen UID:
373337
Concept ID:
C1837475
Disease or Syndrome
Insufficient circulating insulin-like growth factor-I.
Primary autosomal recessive microcephaly 5
MedGen UID:
373344
Concept ID:
C1837501
Disease or Syndrome
Autosomal recessive primary microcephaly-5 (MCPH5) is characterized by decreased occipitofrontal circumference (OFC), usually less than 3 standard deviations (SD) of the mean, present at birth and associated with mental retardation and speech delay. Other features may include short stature or mild seizures. MCPH5 is associated with a simplification of the cerebral cortical gyral pattern in some cases, which is considered within the phenotypic spectrum of primary microcephaly (review by Woods et al., 2005; Saadi et al., 2009; Passemard et al., 2009). For a general phenotypic description and a discussion of genetic heterogeneity of primary microcephaly (MCPH), see MCPH1 (251200).
Joubert syndrome 3
MedGen UID:
332931
Concept ID:
C1837713
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Epilepsy, nocturnal frontal lobe, type 1
MedGen UID:
324932
Concept ID:
C1838049
Disease or Syndrome
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is characterized by clusters of nocturnal motor seizures, which are often stereotyped and brief (5 seconds to 5 minutes). They vary from simple arousals from sleep to dramatic, often bizarre hyperkinetic events with tonic or dystonic features. Affected individuals may experience aura. Retained awareness during seizures is common. A minority of individuals experience daytime seizures. Onset ranges from infancy to adulthood. About 80% of individuals develop ADNFLE in the first two decades of life; mean age of onset is ten years. Clinical neurologic examination is normal and intellect is usually preserved, but reduced intellect, psychiatric comorbidity, or cognitive deficits may occur. Within a family, the manifestations of the disorder may vary considerably. ADNFLE is lifelong but not progressive. As an individual reaches middle age, attacks may become milder and less frequent.
Mitochondrial myopathy with sideroblastic anemia syndrome
MedGen UID:
373888
Concept ID:
C1838103
Disease or Syndrome
Belongs to the heterogeneous family of metabolic myopathies. It is characterised by progressive exercise intolerance manifesting in childhood, onset of sideroblastic anaemia around adolescence, lactic acidaemia and mitochondrial myopathy. Less than 10 cases have been described so far. A 656C-->T mutation in the nuclear pseudouridine synthase 1 gene (PUS1), localised to 12q24.33, has recently been identified in some patients. Deficient pseudouridylation of mitochondrial tRNAs may be responsible for the oxidative phosphorylation disorder. Transmission is autosomal recessive.
Cleft palate, cardiac defect, genital anomalies, and ectrodactyly
MedGen UID:
324947
Concept ID:
C1838121
Disease or Syndrome
Aphalangia partial with syndactyly and duplication of metatarsal IV
MedGen UID:
324958
Concept ID:
C1838161
Disease or Syndrome
Pachygyria with mental retardation and seizures
MedGen UID:
333107
Concept ID:
C1838491
Disease or Syndrome
This autosomal recessive neurodevelopmental disorder is characterized by pachygyria, mental retardation, seizures, and diffuse localization of arachnoid cysts. It most likely represents a neuronal migration disorder within the lissencephaly spectrum (summary by Guzel et al., 2007).
Pterygium colli mental retardation digital anomalies
MedGen UID:
374001
Concept ID:
C1838562
Disease or Syndrome
This syndrome has characteristics of pterygium colli, digital anomalies and craniofacial abnormalities. Digital anomalies include abnormal small thumbs, widened interphalangeal joints, and broad terminal phalanges. Craniofacial abnormalities include brachycephaly, epicanthic folds, angulated eyebrows, upward slanting of the palpebral fissures, ptosis, hypertelorism, prominent low-set and posteriorly rotated ears. It has been described in a woman and her son, but the manifestations were much less severe in the mother. The son also had intellectual deficit. The inheritance is either X-linked dominant or autosomal dominant.
Male pseudohermaphroditism/mental retardation syndrome, Verloes type
MedGen UID:
325469
Concept ID:
C1838611
Disease or Syndrome
Warburg micro syndrome 1
MedGen UID:
333142
Concept ID:
C1838625
Disease or Syndrome
RAB18 deficiency is the molecular deficit underlying both Warburg micro syndrome (characterized by eye, nervous system, and endocrine abnormalities) and Martsolf syndrome (characterized by similar – but milder – findings). To date Warburg micro syndrome comprises >96% of reported individuals with genetically defined RAB18 deficiency. The hallmark ophthalmologic findings are bilateral congenital cataracts, usually accompanied by microphthalmia, microcornea (diameter <10), and small atonic pupils. Poor vision despite early cataract surgery likely results from progressive optic atrophy and cortical visual impairment. Individuals with Warburg micro syndrome have severe to profound intellectual disability (ID); those with Martsolf syndrome have mild to moderate ID. Some individuals with RAB18 deficiency also have epilepsy. In Warburg micro syndrome, a progressive ascending spastic paraplegia typically begins with spastic diplegia and contractures during the first year, followed by upper limb involvement leading to spastic quadriplegia after about age five years, often eventually causing breathing difficulties. In Martsolf syndrome infantile hypotonia is followed primarily by slowly progressive lower limb spasticity. Hypogonadism – when present – manifests in both syndromes, in males as micropenis and/or cryptorchidism and in females as hypoplastic labia minora, clitoral hypoplasia, and small introitus.
Wolfram syndrome, mitochondrial form
MedGen UID:
325511
Concept ID:
C1838782
Disease or Syndrome
Leber hereditary optic neuropathy with dystonia
MedGen UID:
333240
Concept ID:
C1839040
Disease or Syndrome
X-Linked Mental Retardation 89
MedGen UID:
333247
Concept ID:
C1839082
Mental or Behavioral Dysfunction
Hunter Rudd Hoffmann syndrome
MedGen UID:
374138
Concept ID:
C1839125
Disease or Syndrome
Syndrome with characteristics of short stature, trigonocephaly and developmental delay. It has been described in three males. Moderate intellectual deficit was reported in one of the males and the other two patients displayed psychomotor retardation. X-linked transmission has been suggested but autosomal recessive inheritance cannot be ruled out.
Spastic paraplegia 2
MedGen UID:
374177
Concept ID:
C1839264
Disease or Syndrome
PLP1-related disorders of central nervous system myelin formation include a range of phenotypes from Pelizaeus-Merzbacher disease (PMD) to spastic paraplegia 2 (SPG2). PMD typically manifests in infancy or early childhood with nystagmus, hypotonia, and cognitive impairment; the findings progress to severe spasticity and ataxia. Life span is shortened. SPG2 manifests as spastic paraparesis with or without CNS involvement and usually normal life span. Intrafamilial variation of phenotypes can be observed, but the signs are usually fairly consistent within families. Female carriers may manifest mild to moderate signs of the disease.
Schimke X-linked mental retardation syndrome
MedGen UID:
374193
Concept ID:
C1839320
Disease or Syndrome
SCARF syndrome
MedGen UID:
326461
Concept ID:
C1839321
Disease or Syndrome
Syndrome with the association of skeletal abnormalities, cutis laxa, craniostenosis, ambiguous genitalia, psychomotor retardation and facial abnormalities. So far, it has been described in two males (maternal first cousins). The mode of inheritance was suggested to be X-linked recessive.
Pyruvate dehydrogenase E1-alpha deficiency
MedGen UID:
326486
Concept ID:
C1839413
Disease or Syndrome
Genetic defects in the pyruvate dehydrogenase complex are one of the most common causes of primary lactic acidosis in children. Most cases are caused by mutation in the E1-alpha subunit gene on the X chromosome. X-linked PDH deficiency is one of the few X-linked diseases in which a high proportion of heterozygous females manifest severe symptoms. The clinical spectrum of PDH deficiency is broad, ranging from fatal lactic acidosis in the newborn to chronic neurologic dysfunction with structural abnormalities in the central nervous system without systemic acidosis (Robinson et al., 1987; Brown et al., 1994). Genetic Heterogeneity of Pyruvate Dehydrogenase Complex Deficiency PDH deficiency can also be caused by mutation in other subunits of the PDH complex, including a form (PDHXD; 245349) caused by mutation in the component X gene (PDHX; 608769) on chromosome 11p13; a form (PDHBD; 614111) caused by mutation in the PDHB gene (179060) on chromosome 3p14; a form (PDHDD; 245348) caused by mutation in the DLAT gene (608770) on chromosome 11q23; a form (PDHPD; 608782) caused by mutation in the PDP1 gene (605993) on chromosome 8q22; and a form (PDHLD; 614462) caused by mutation in the LIAS gene (607031) on chromosome 4p14.
Optic atrophy 2
MedGen UID:
326915
Concept ID:
C1839576
Disease or Syndrome
A rare form of hereditary optic atrophy seen in only 4 families to date. With onset in early childhood the disease has characteristics of progressive loss of visual acuity, significant optic nerve pallor and occasionally additional neurological manifestations, with females being unaffected.
Mental retardation with spastic paraplegia
MedGen UID:
374293
Concept ID:
C1839727
Disease or Syndrome
Mental retardation skeletal dysplasia abducens palsy
MedGen UID:
326949
Concept ID:
C1839729
Disease or Syndrome
This syndrome combines skeletal anomalies (short stature, ridging of the metopic suture, fusion of cervical vertebrae, thoracic hemivertebrae, scoliosis, sacral hypoplasia and short middle phalanges) and mild intellectual deficit. It has been described in four male cousins in three sibships. Glucose intolerance was present in three cases, and imperforated anus in one case. Carrier females had minor manifestations (fusion of cervical vertebrae and glucose intolerance). Transmission seems to be X-linked.
Prieto X-linked mental retardation syndrome
MedGen UID:
374294
Concept ID:
C1839730
Disease or Syndrome
Mental retardation syndrome with facial abnormalities, subcortical cerebral atrophy, defective tooth development, skin dimples at the lower back, lower limb defects, clinodactyly, luxation of the patella, and eye abnormalities.
Wilson-Turner X-linked mental retardation syndrome
MedGen UID:
333393
Concept ID:
C1839736
Disease or Syndrome
Wilson-Turner syndrome is an X-linked recessive neurologic disorder characterized by intellectual disability, dysmorphic facial features, hypogonadism, short stature, and truncal obesity. Females are unaffected (Wilson et al., 1991).
Mental retardation, X-linked, syndromic 12
MedGen UID:
333405
Concept ID:
C1839792
Disease or Syndrome
Lesch-nyhan phenotype with normal hgprt
MedGen UID:
374332
Concept ID:
C1839883
Finding
Corpus callosum, partial agenesis of, X-linked
MedGen UID:
374339
Concept ID:
C1839909
Disease or Syndrome
The phenotypic spectrum of L1 syndrome includes: X-linked hydrocephalus with stenosis of the aqueduct of Sylvius (HSAS); MASA syndrome (mental retardation [intellectual disability], aphasia [delayed speech], spastic paraplegia [shuffling gait], adducted thumbs); SPG1 (X-linked complicated hereditary spastic paraplegia type 1); and X-linked complicated corpus callosum agenesis. Males with HSAS are born with severe hydrocephalus, adducted thumbs, and spasticity; intellectual disability is severe. In less severely affected males, hydrocephalus may be subclinically present and documented only because of developmental delay; intellectual disability ranges from mild (IQ: 50-70) to moderate (IQ: 30-50).
IFAP syndrome with or without BRESHECK syndrome
MedGen UID:
327007
Concept ID:
C1839988
Disease or Syndrome
The IFAP/BRESHECK syndrome is an X-linked multiple congenital anomaly disorder with variable severity. The classic triad, which defines IFAP, is ichthyosis follicularis, atrichia, and photophobia. Some patients have additional features, including mental retardation, brain anomalies, Hirschsprung disease, corneal opacifications, kidney dysplasia, cryptorchidism, cleft palate, and skeletal malformations, particularly of the vertebrae, which constitutes BRESHECK syndrome (summary by Naiki et al., 2012).
Ichthyosis and male hypogonadism
MedGen UID:
333456
Concept ID:
C1839989
Disease or Syndrome
Hand and foot deformity with flat facies
MedGen UID:
333892
Concept ID:
C1841693
Disease or Syndrome
Gms syndrome
MedGen UID:
374804
Concept ID:
C1841854
Disease or Syndrome
An extremely rare syndrome involving goniodysgenesis, intellectual disability and short stature in addition to microcephaly, short nose, small hands and ears, and that has been seen in one family to date. There have been no further descriptions in the literature since 1992.
Lipodystrophy, generalized, with mental retardation, deafness, short stature, and slender bones
MedGen UID:
334166
Concept ID:
C1842465
Disease or Syndrome
Joubert syndrome 2
MedGen UID:
334114
Concept ID:
C1842577
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Autism 3
MedGen UID:
334211
Concept ID:
C1842632
Finding
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypic, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). For a discussion of genetic heterogeneity of autism, see 209850. See also chromosome 13q14 deletion syndrome (613884) in which retinoblastoma and mental retardation are features.
Congenital disorder of glycosylation type 1I
MedGen UID:
334618
Concept ID:
C1842836
Disease or Syndrome
Epilepsy, familial adult myoclonic 2
MedGen UID:
375031
Concept ID:
C1842852
Disease or Syndrome
Familial adult myoclonic epilepsy-2 is an autosomal dominant neurologic disorder characterized by rhythmic myoclonic jerks of cortical origin. Some affected individuals have generalized tonic-clonic seizures, and rare patients show cognitive decline (summary by De Fusco et al., 2014). For a phenotypic description and a discussion of genetic heterogeneity of familial adult myoclonic epilepsy, see FAME1 (601068).
Chromosome 1p36 deletion syndrome
MedGen UID:
334629
Concept ID:
C1842870
Disease or Syndrome
1p36 deletion syndrome is characterized by typical craniofacial features consisting of straight eyebrows, deeply set eyes, midface retrusion, wide and depressed nasal bridge, long philtrum, pointed chin, large, late-closing anterior fontanel (77%), microbrachycephaly (65%), epicanthal folds (50%), and posteriorly rotated, low-set, abnormal ears. Other characteristic findings include brachy/camptodactyly and short feet. Developmental delay/intellectual disability of variable degree are present in all, and hypotonia in 95%. Seizures occur in 44%-58% of affected individuals. Other findings include structural brain abnormalities (88%), congenital heart defects (71%), eye/vision problems (52%), hearing loss (47%), skeletal anomalies (41%), abnormalities of the external genitalia (25%), and renal abnormalities (22%).
Noonan syndrome-like disorder with loose anagen hair
MedGen UID:
334697
Concept ID:
C1843181
Disease or Syndrome
A Noonan-related syndrome with characteristics of facial anomalies suggestive of Noonan syndrome, a distinctive hair anomaly described as loose anagen hair syndrome, frequent congenital heart defects, distinctive skin features with darkly pigmented skin, keratosis pilaris, eczema or occasional neonatal ichthyosis and short stature, often associated with a growth hormone deficiency and psychomotor delay. There is evidence that this syndrome is caused by heterozygous mutation in the SHOC2 gene on chromosome 10q25.
Niemann-Pick disease type C2
MedGen UID:
335942
Concept ID:
C1843366
Disease or Syndrome
Niemann-Pick disease type C (NPC) is a lipid storage disease that can present in infants, children, or adults. Neonates can present with ascites and severe liver disease from infiltration of the liver and/or respiratory failure from infiltration of the lungs. Other infants, without liver or pulmonary disease, have hypotonia and developmental delay. The classic presentation occurs in mid-to-late childhood with the insidious onset of ataxia, vertical supranuclear gaze palsy (VSGP), and dementia. Dystonia and seizures are common. Dysarthria and dysphagia eventually become disabling, making oral feeding impossible; death usually occurs in the late second or third decade from aspiration pneumonia. Adults are more likely to present with dementia or psychiatric symptoms.
Pontocerebellar hypoplasia type 1
MedGen UID:
335969
Concept ID:
C1843504
Congenital Abnormality
Pontocerebellar hypoplasia is a group of related conditions that affect the development of the brain. The term "pontocerebellar" refers to the pons and the cerebellum, which are the brain structures that are most severely affected in many forms of this disorder. The pons is located at the base of the brain in an area called the brainstem, where it transmits signals between the cerebellum and the rest of the brain. The cerebellum, which is located at the back of the brain, normally coordinates movement. The term "hypoplasia" refers to the underdevelopment of these brain regions.Pontocerebellar hypoplasia also causes impaired growth of other parts of the brain, leading to an unusually small head size (microcephaly). This microcephaly is usually not apparent at birth but becomes noticeable as brain growth continues to be slow in infancy and early childhood.Researchers have described at least ten types of pontocerebellar hypoplasia. All forms of this condition are characterized by impaired brain development, delayed development overall, problems with movement, and intellectual disability. The brain abnormalities are usually present at birth, and in some cases they can be detected before birth. Many children with pontocerebellar hypoplasia live only into infancy or childhood, although some affected individuals have lived into adulthood.The two major forms of pontocerebellar hypoplasia are designated as type 1 (PCH1) and type 2 (PCH2). In addition to the brain abnormalities described above, PCH1 causes problems with muscle movement resulting from a loss of specialized nerve cells called motor neurons in the spinal cord, similar to another genetic disorder known as spinal muscular atrophy. Individuals with PCH1 also have very weak muscle tone (hypotonia), joint deformities called contractures, vision impairment, and breathing and feeding problems that are evident from early infancy.Common features of PCH2 include a lack of voluntary motor skills (such as grasping objects, sitting, or walking), problems with swallowing (dysphagia), and an absence of communication, including speech. Affected children typically develop temporary jitteriness (generalized clonus) in early infancy, abnormal patterns of movement described as chorea or dystonia, and stiffness (spasticity). Many also have impaired vision and seizures.The other forms of pontocerebellar hypoplasia, designated as type 3 (PCH3) through type 10 (PCH10), appear to be rare and have each been reported in only a small number of individuals. Because the different types have overlapping features, and some are caused by mutations in the same genes, researchers have proposed that the types be considered as a spectrum instead of distinct conditions.
Spastic paraplegia, ataxia, and mental retardation
MedGen UID:
336010
Concept ID:
C1843661
Disease or Syndrome
Spinocerebellar ataxia 21
MedGen UID:
375311
Concept ID:
C1843891
Disease or Syndrome
The hereditary ataxias are a group of genetic disorders characterized by slowly progressive incoordination of gait and often associated with poor coordination of hands, speech, and eye movements. Frequently, atrophy of the cerebellum occurs. In this GeneReview the hereditary ataxias are categorized by mode of inheritance and gene (or chromosome locus) in which pathogenic variants occur.
Coenzyme Q10 deficiency
MedGen UID:
334528
Concept ID:
C1843920
Disease or Syndrome
A genetically heterogeneous condition, typically inherited in an autosomal recessive fashion, characterized by coenzyme Q10 deficiency.
Hypogonadism, male, with mental retardation and skeletal anomalies
MedGen UID:
334557
Concept ID:
C1843994
Disease or Syndrome
Oto-palato-digital syndrome, type II
MedGen UID:
337064
Concept ID:
C1844696
Disease or Syndrome
The otopalatodigital (OPD) spectrum disorders, characterized primarily by skeletal dysplasia, include the following: Otopalatodigital syndrome type I (OPD1). Otopalatodigital syndrome type II (OPD2). Frontometaphyseal dysplasia (FMD). Melnick-Needles syndrome (MNS). Terminal osseous dysplasia with pigmentary skin defects (TODPD). In OPD1, most manifestations are present at birth; females can present with severity similar to affected males, although some have only mild manifestations. In OPD2, females are less severely affected than related affected males. Most males with OPD2 die during the first year of life, usually from thoracic hypoplasia resulting in pulmonary insufficiency. Males who live beyond the first year of life are usually developmentally delayed and require respiratory support and assistance with feeding. In FMD, females are less severely affected than related affected males. Males do not experience progression of skeletal dysplasia but may have joint contractures and hand and foot malformations. Progressive scoliosis is observed in both affected males and females. In MNS, wide phenotypic variability is observed; some individuals are diagnosed in adulthood, while others require respiratory support and have reduced longevity. Prenatal lethality is most common in males with MNS. TODPD is a female limited condition, characterized by terminal skeletal dysplasia, pigmentary defects of the skin, and recurrent digital fibromata.
Choroideremia with deafness and obesity syndrome
MedGen UID:
336796
Concept ID:
C1844836
Disease or Syndrome
An X-linked retinal dystrophy, characterised by choroideraemia, causing in affected males progressive nyctalopia and eventual central blindness. Obesity, moderate intellectual disability and congenital mixed (sensorineural and conductive) deafness are also observed. Female carriers show typical retinal changes indicative of the choroideraemia carrier state.
Charcot-Marie-Tooth disease, X-linked recessive, type 2
MedGen UID:
336803
Concept ID:
C1844873
Disease or Syndrome
Microphthalmia syndromic 4
MedGen UID:
337127
Concept ID:
C1844948
Disease or Syndrome
Lenz microphthalmia syndrome (LMS) is characterized by unilateral or bilateral microphthalmia and/or clinical anophthalmia with malformations of the ears, teeth, fingers, skeleton, and/or genitourinary system. Microphthalmia is often accompanied by microcornea and glaucoma. Coloboma is present in approximately 60% of microphthalmic eyes with severity ranging from isolated iris coloboma to coloboma of the ciliary body, choroid, and optic disk. Ears may be low set, anteverted, posteriorly rotated, simple, cup shaped, or abnormally modeled. Hearing loss has been observed. Dental findings include irregularly shaped, missing, or widely spaced teeth. Duplicated thumbs, syndactyly, clinodactyly, camptodactyly, and microcephaly are common, as are narrow/sloping shoulders, underdeveloped clavicles, kyphoscoliosis, exaggerated lumbar lordosis, long cylindric thorax, and webbed neck. Genitourinary anomalies include hypospadias, cryptorchidism, renal hypoplasia/aplasia, and hydroureter. Approximately 60% of affected males have mild-to-severe intellectual disability or developmental delay.
Pigmentary disorder, reticulate, with systemic manifestations, X-linked
MedGen UID:
336844
Concept ID:
C1845050
Disease or Syndrome
X-linked reticulate pigmentary disorder shows more severe manifestations in hemizygous males compared to heterozygous females. Affected males have early onset of recurrent respiratory infections and failure to thrive resulting from inflammatory gastroenteritis or colitis. Patients also show reticular pigmentation abnormalities of the skin and may develop corneal scarring. Carrier females may be unaffected or have only pigmentary abnormalities along the lines of Blaschko (summary by Starokadomskyy et al., 2016).
ATR-X syndrome
MedGen UID:
337145
Concept ID:
C1845055
Disease or Syndrome
Alpha-thalassemia X-linked intellectual disability (ATRX) syndrome is characterized by distinctive craniofacial features, genital anomalies, severe developmental delays, hypotonia, intellectual disability, and mild-to-moderate anemia secondary to alpha-thalassemia. Craniofacial abnormalities include small head circumference, telecanthus or widely spaced eyes, short nose, tented vermilion of the upper lip, and thick or everted vermilion of the lower lip with coarsening of the facial features over time. Although all affected individuals have a normal 46,XY karyotype, genital anomalies range from hypospadias and undescended testicles to severe hypospadias and ambiguous genitalia, to normal-appearing female external genitalia. Global developmental delays are evident in infancy and some affected individuals never walk independently or develop significant speech.
Cataracts, ataxia, short stature, and mental retardation
MedGen UID:
375579
Concept ID:
C1845094
Disease or Syndrome
Chromosome Xp11.3 deletion syndrome
MedGen UID:
336862
Concept ID:
C1845136
Disease or Syndrome
Mental retardation 92, X-linked
MedGen UID:
335109
Concept ID:
C1845144
Disease or Syndrome
Mental retardation, X-linked, syndromic, martin-probst type
MedGen UID:
375620
Concept ID:
C1845285
Disease or Syndrome
Mental retardation, X-linked 82
MedGen UID:
337201
Concept ID:
C1845286
Disease or Syndrome
Mental retardation, X-linked 84
MedGen UID:
337203
Concept ID:
C1845297
Disease or Syndrome
Mental Retardation, X-Linked 52
MedGen UID:
375624
Concept ID:
C1845298
Disease or Syndrome
Mental retardation, X-linked 45
MedGen UID:
375633
Concept ID:
C1845333
Disease or Syndrome
Autism, susceptibility to, X-linked 3
MedGen UID:
335161
Concept ID:
C1845336
Finding
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypic, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). For a discussion of genetic heterogeneity of autism, see 209850.
Mental retardation X-linked with cerebellar hypoplasia and distinctive facial appearance
MedGen UID:
336920
Concept ID:
C1845366
Disease or Syndrome
Corpus callosum, agenesis of, with mental retardation, ocular coloboma, and micrognathia
MedGen UID:
335185
Concept ID:
C1845446
Disease or Syndrome
Mental retardation, X-linked 77
MedGen UID:
335199
Concept ID:
C1845499
Disease or Syndrome
Mental retardation 46, X-linked
MedGen UID:
337255
Concept ID:
C1845526
Disease or Syndrome
Mental retardation, X-linked 81
MedGen UID:
335203
Concept ID:
C1845531
Disease or Syndrome
Autism, susceptibility to, X-linked 2
MedGen UID:
336964
Concept ID:
C1845539
Finding
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypic, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). For a discussion of genetic heterogeneity of autism, see 209850.
Autism, susceptibility to, X-linked 1
MedGen UID:
335205
Concept ID:
C1845540
Finding
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypic, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). For a discussion of genetic heterogeneity of autism, see 209850.
Mental retardation, X-linked, syndromic, Hedera type
MedGen UID:
337257
Concept ID:
C1845543
Disease or Syndrome
FG syndrome 4
MedGen UID:
336965
Concept ID:
C1845546
Disease or Syndrome
CASK-related disorders include a spectrum of phenotypes in both females and males. The two main types of clinical presentation are: Microcephaly with pontine and cerebellar hypoplasia (MICPCH), generally associated with pathogenic loss-of-function variants in CASK; and X-linked intellectual disability (XLID) with or without nystagmus, generally associated with hypomorphic CASK pathogenic variants. MICPCH is typically seen in females with moderate to severe intellectual disability, progressive microcephaly with or without ophthalmologic anomalies, and sensorineural hearing loss. To date a total of 53 females with MICPCH have been reported, the eldest of whom is 21 years old. Most are able to sit independently; 20%-25% attain the ability to walk; language is nearly absent in most. Neurologic features may include axial hypotonia, hypertonia/spasticity of the extremities, and dystonia or other movement disorders. Nearly 40% have seizures. Behaviors may include sleep disturbances, hand stereotypies, and self-biting. To date, only seven males have been reported with the severe phenotype. The under-representation in this cohort is likely to be a consequence of early male lethality. These males typically present with intellectual disability and MICPCH, or early-infantile epileptic encephalopathy (Ohtahara syndrome, West syndrome, or early myoclonic epilepsy). In individuals and families with milder (i.e., hypomorphic) pathogenic variants, the clinical phenotype is usually that of X-linked intellectual disability (XLID) with or without nystagmus and additional clinical features. More than 24 males and nine females have been reported. The males have mild to severe intellectual disability, with or without nystagmus and other ocular features. Females are typically normal, with some displaying mild intellectual disability with or without ocular features.
Mental retardation 63, X-linked
MedGen UID:
337002
Concept ID:
C1845672
Disease or Syndrome
Syndromic X-linked mental retardation, Cabezas type
MedGen UID:
337334
Concept ID:
C1845861
Disease or Syndrome
This form of syndromic X-linked mental retardation is characterized primarily by short stature, hypogonadism, and abnormal gait, with other more variable features such as speech delay, prominent lower lip, and tremor (Cabezas et al., 2000).
Creatine deficiency, X-linked
MedGen UID:
337451
Concept ID:
C1845862
Disease or Syndrome
The cerebral creatine deficiency syndromes (CCDS), inborn errors of creatine metabolism, include the two creatine biosynthesis disorders, guanidinoacetate methyltransferase (GAMT) deficiency and L-arginine:glycine amidinotransferase (AGAT) deficiency, and the creatine transporter (CRTR) deficiency. Intellectual disability and seizures are common to all three CCDS. The majority of individuals with GAMT deficiency have a behavior disorder that can include autistic behaviors and self-mutilation; about 40% have movement disorder. Onset is between ages three months and three years. Only 14 individuals with AGAT deficiency have been reported. The phenotype of CRTR deficiency in affected males ranges from mild intellectual disability and speech delay to severe intellectual disability, seizures, movement disorder and behavior disorder; age at diagnosis ranges from two to 66 years. Clinical phenotype of females heterozygous for CRTR deficiency ranges from asymptomatic to severe phenotype resembling male phenotype.
Mental retardation, X-linked 53
MedGen UID:
335296
Concept ID:
C1845889
Disease or Syndrome
Mental retardation, X-linked 72
MedGen UID:
375793
Concept ID:
C1846038
Disease or Syndrome
Spastic paraplegia 16
MedGen UID:
375796
Concept ID:
C1846046
Disease or Syndrome
Spastic paraplegias (SPGs) are a genetically heterogeneous group of neurologic disorders characterized by progressive weakness and spasticity of the legs. Complicated SPGs are accompanied by additional neurologic symptoms such as cerebellar ataxia, sensory loss, mental retardation, nystagmus, and optic atrophy (summary by Steinmuller et al., 1997). A locus for spastic paraplegia-16 has been mapped to Xq11.2-q23 (Steinmuller et al., 1997). For a discussion of genetic heterogeneity of X-linked spastic paraplegia, see 303350.
Siderius X-linked mental retardation syndrome
MedGen UID:
337375
Concept ID:
C1846055
Disease or Syndrome
X-linked intellectual disability, Siderius type is a condition characterized by mild to moderate intellectual disability that affects only males. Affected boys often have delayed development of motor skills such as walking, and their speech may be delayed.Individuals with X-linked intellectual disability, Siderius type frequently also have an opening in the lip (cleft lip) with an opening in the roof of the mouth (cleft palate). A cleft can occur on one or both sides of the upper lip.Some boys and men with this condition have distinctive facial features, including a long face, a sloping forehead, a broad nasal bridge, a prominent bone in the lower forehead (supraorbital ridge), and outside corners of the eyes that point upward (upslanting palpebral fissures). Affected individuals may also have low-set ears and large hands.
Abidi X-linked mental retardation syndrome
MedGen UID:
337376
Concept ID:
C1846056
Disease or Syndrome
Armfield X-linked mental retardation syndrome
MedGen UID:
375800
Concept ID:
C1846057
Disease or Syndrome
MECP2 duplication syndrome
MedGen UID:
337496
Concept ID:
C1846058
Mental or Behavioral Dysfunction
The MECP2 duplication syndrome is a severe neurodevelopmental disorder characterized by infantile hypotonia, delayed psychomotor development leading to severe intellectual disability, poor speech development, progressive spasticity, recurrent respiratory infections (in ~75% of affected individuals), and seizures (in ~50%). MECP2 duplication syndrome is 100% penetrant in males. Occasionally females have been described with a MECP2 duplication and related clinical findings, often associated with concomitant X-chromosomal abnormalities that prevent inactivation of the duplicated region. Generalized tonic-clonic seizures are most often observed; atonic seizures and absence seizures have also been described. One third of affected males are never able to walk independently. Almost 50% of affected males die before age 25 years, presumably from complications of recurrent infection and/or neurologic deterioration. In addition to the core features, autistic behaviors and gastrointestinal dysfunction have been observed in several affected boys. Although interfamilial phenotypic variability is observed, severity is usually consistent within families.
Mental retardation X-linked syndromic 7
MedGen UID:
337403
Concept ID:
C1846170
Disease or Syndrome
Amme complex
MedGen UID:
337424
Concept ID:
C1846242
Disease or Syndrome
This syndrome has characteristics of the association of Alport syndrome, midface hypoplasia, intellectual deficit and elliptocytosis. It has been described in two families. The syndrome is transmitted as an X-linked trait is caused by a contiguous gene deletion in Xq22.3 involving several genes including COL4A5, FACL4 and AMMECR1.
Focal cortical dysplasia type II
MedGen UID:
339510
Concept ID:
C1846385
Disease or Syndrome
Focal cortical dysplasia type II (FCORD2), or focal cortical dysplasia of Taylor (FCDT), is a cerebral developmental malformation that results in a clinical phenotype of intractable epilepsy, usually requiring surgery. FCORD2 has been classified histologically into 2 subtypes: a type without balloon cells, known as type IIA, and a type with balloon cells, known as type IIB (Palmini et al., 2004). Affected individuals have refractory seizures, usually with onset in early childhood, and may have persistent intellectual disability. Most patients require neurosurgical resection of affected brain tissue to ameliorate seizure frequency and severity (summary by Moller et al., 2016).
Lathosterolosis
MedGen UID:
375885
Concept ID:
C1846421
Disease or Syndrome
An extremely rare inborn error of sterol biosynthesis with manifestations of facial dysmorphism, congenital anomalies (including limb and kidney anomalies), failure to thrive, developmental delay and liver disease. Only 4 cases have been reported in the literature to date. Lathosterolosis is due to mutations in the SC5D gene (11q23.3). A mutation in this gene leads to a deficiency in 3-beta-hydroxysteroid-delta-5-desaturase, which is necessary in the conversion of lathosterol into 7-dehydrocholesterol. This prevents the synthesis of cholesterol, which among other functions acts as a structural lipid, a precursor for bile acids and steroid hormones, and is necessary for the maturation of hedgehog morphogens during embryonic development. Inherited in an autosomal recessive manner.
Anauxetic dysplasia
MedGen UID:
375972
Concept ID:
C1846796
Disease or Syndrome
Anauxetic dysplasia is a disorder characterized by extremely short stature (dwarfism) and other skeletal abnormalities, an unusually large range of joint movement (hypermobility), dental problems, and distinctive facial features. Mild intellectual disability can also occur in this disorder.People with anauxetic dysplasia have dwarfism with unusually short limbs for their height (disproportionate short stature) beginning before birth. Dislocation of the bones at the top of the spine (atlantoaxial subluxation) can also occur in this disorder, and may cause pinching (compression) of the spinal cord. As a result, affected individuals may experience neurological symptoms including pain, tingling, numbness, coordination problems, weakness, and paralysis. In severe cases, the spinal cord compression may lead to paralysis of the muscles needed for breathing, which can be life-threatening during early childhood.Other skeletal abnormalities in anauxetic dysplasia include a barrel-shaped chest and a rounded upper back that also curves to the side (kyphoscoliosis). Without surgical correction, the kyphoscoliosis can constrict the lungs and cause difficulty breathing. People with anauxetic dysplasia can also have an exaggerated curvature of the lower back (hyperlordosis), dislocation of the hips, and soles of the feet that are rounded outward (rocker-bottom feet).Typical facial features in anauxetic dysplasia include closely spaced eyes (hypotelorism), a flat or sunken appearance of the middle of the face (midface hypoplasia), an unusually large tongue (macroglossia), and a protruding chin (prognathism). Affected individuals can also have fewer teeth than normal (hypodontia).
Polymicrogyria, bilateral frontoparietal
MedGen UID:
376107
Concept ID:
C1847352
Disease or Syndrome
Polymicrogyria is a condition characterized by abnormal development of the brain before birth. The surface of the brain normally has many ridges or folds, called gyri. In people with polymicrogyria, the brain develops too many folds, and the folds are unusually small. The name of this condition literally means too many (poly-) small (micro-) folds (-gyria) in the surface of the brain.Polymicrogyria can affect part of the brain or the whole brain. When the condition affects one side of the brain, researchers describe it as unilateral. When it affects both sides of the brain, it is described as bilateral. The signs and symptoms associated with polymicrogyria depend on how much of the brain, and which particular brain regions, are affected.Researchers have identified multiple forms of polymicrogyria. The mildest form is known as unilateral focal polymicrogyria. This form of the condition affects a relatively small area on one side of the brain. It may cause minor neurological problems, such as mild seizures that can be easily controlled with medication. Some people with unilateral focal polymicrogyria do not have any problems associated with the condition.Bilateral forms of polymicrogyria tend to cause more severe neurological problems. Signs and symptoms of these conditions can include recurrent seizures (epilepsy), delayed development, crossed eyes, problems with speech and swallowing, and muscle weakness or paralysis. The most severe form of the disorder, bilateral generalized polymicrogyria, affects the entire brain. This condition causes severe intellectual disability, problems with movement, and seizures that are difficult or impossible to control with medication.Polymicrogyria most often occurs as an isolated feature, although it can occur with other brain abnormalities. It is also a feature of several genetic syndromes characterized by intellectual disability and multiple birth defects. These include 22q11.2 deletion syndrome, Adams-Oliver syndrome, Aicardi syndrome, Galloway-Mowat syndrome, Joubert syndrome, and Zellweger spectrum disorder.
Cree mental retardation syndrome
MedGen UID:
335673
Concept ID:
C1847361
Disease or Syndrome
Glucose transporter type 1 deficiency syndrome
MedGen UID:
337833
Concept ID:
C1847501
Disease or Syndrome
GLUT1 deficiency syndrome is a disorder affecting the nervous system that can have a variety of neurological signs and symptoms. Approximately 90 percent of affected individuals have a form of the disorder often referred to as common GLUT1 deficiency syndrome. These individuals generally have frequent seizures (epilepsy) beginning in the first months of life. In newborns, the first sign of the disorder may be involuntary eye movements that are rapid and irregular. Babies with common GLUT1 deficiency syndrome have a normal head size at birth, but growth of the brain and skull is often slow, which can result in an abnormally small head size (microcephaly). People with this form of GLUT1 deficiency syndrome may have developmental delay or intellectual disability. Most affected individuals also have other neurological problems, such as stiffness caused by abnormal tensing of the muscles (spasticity), difficulty in coordinating movements (ataxia), and speech difficulties (dysarthria). Some experience episodes of confusion, lack of energy (lethargy), headaches, or muscle twitches (myoclonus), particularly during periods without food (fasting).About 10 percent of individuals with GLUT1 deficiency syndrome have a form of the disorder often known as non-epileptic GLUT1 deficiency syndrome, which is usually less severe than the common form. People with the non-epileptic form do not have seizures, but they may still have developmental delay and intellectual disability. Most have movement problems such as ataxia or involuntary tensing of various muscles (dystonia); the movement problems may be more pronounced than in the common form.Several conditions that were originally given other names have since been recognized to be variants of GLUT1 deficiency syndrome. These include paroxysmal choreoathetosis with spasticity (dystonia 9); paroxysmal exercise-induced dyskinesia and epilepsy (dystonia 18); and certain types of epilepsy. In rare cases, people with variants of GLUT1 deficiency syndrome produce abnormal red blood cells and have uncommon forms of a blood condition known as anemia, which is characterized by a shortage of red blood cells.
Mental retardation, obesity, mandibular prognathism, and eye and skin anomalies
MedGen UID:
376145
Concept ID:
C1847522
Disease or Syndrome
Hyperinsulinism-hyperammonemia syndrome
MedGen UID:
376153
Concept ID:
C1847555
Disease or Syndrome
Congenital hyperinsulinism is a condition that causes individuals to have abnormally high levels of insulin, which is a hormone that helps control blood sugar levels. People with this condition have frequent episodes of low blood sugar (hypoglycemia). In infants and young children, these episodes are characterized by a lack of energy (lethargy), irritability, or difficulty feeding. Repeated episodes of low blood sugar increase the risk for serious complications such as breathing difficulties, seizures, intellectual disability, vision loss, brain damage, and coma.The severity of congenital hyperinsulinism varies widely among affected individuals, even among members of the same family. About 60 percent of infants with this condition experience a hypoglycemic episode within the first month of life. Other affected children develop hypoglycemia by early childhood. Unlike typical episodes of hypoglycemia, which occur most often after periods without food (fasting) or after exercising, episodes of hypoglycemia in people with congenital hyperinsulinism can also occur after eating.
Congenital muscular dystrophy-dystroglycanopathy (with or without mental retardation) type B5
MedGen UID:
335764
Concept ID:
C1847759
Disease or Syndrome
MDDGB5 is an autosomal recessive congenital muscular dystrophy with mental retardation and structural brain abnormalities (Brockington et al., 2001). It is part of a group of similar disorders resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239), collectively known as 'dystroglycanopathies' (Mercuri et al., 2006). For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (613155).
Early infantile epileptic encephalopathy 9
MedGen UID:
338393
Concept ID:
C1848137
Disease or Syndrome
Epileptic encephalopathy-9 is an X-linked disorder characterized by seizure onset in infancy and mild to severe intellectual impairment. Autistic and psychiatric features have been reported in some individuals. The disorder affects heterozygous females only; transmitting males are unaffected (summary by Jamal et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of EIEE, see EIEE1 (308350).
Lissencephaly type 1 due to doublecortin gene mutation
MedGen UID:
336286
Concept ID:
C1848199
Disease or Syndrome
Type 1 lissencephaly due to doublecortin (DCX) gene mutations is a semi-dominant X-linked disease characterised by intellectual deficiency and seizures that are more severe in male patients.
Zunich neuroectodermal syndrome
MedGen UID:
341214
Concept ID:
C1848392
Disease or Syndrome
Zunich neuroectodermal syndrome is an extremely rare autosomal recessive multisystem disorder clinically characterized by colobomas, congenital heart defects, migratory ichthyosiform dermatosis, mental retardation, and ear anomalies (CHIME). Other clinical features include distinctive facial features, abnormal growth, genitourinary abnormalities, seizures, and feeding difficulties (summary by Ng et al., 2012). The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis. For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
Mental retardation Wolff type
MedGen UID:
336345
Concept ID:
C1848439
Disease or Syndrome
A rare intellectual disability syndrome with manifestations of severe intellectual disability, characteristic facial features (low anterior hairline, upward slanting palpebral fissures, ocular hypertelorism, broad, bulbous nose, large ears with helix incompletely developed, thick lips, and micrognathia) and additional anomalies including peripheral joint contractures, delayed skeletal maturation, bilateral cleft lip and palate, strabismus, terminal hypoplasia of fingers, hypospadias, and bilateral inguinal hernias.
Vitiligo, progressive, with mental retardation and urethral duplication
MedGen UID:
336363
Concept ID:
C1848532
Disease or Syndrome
Methylmalonic acidemia with homocystinuria cblD
MedGen UID:
341253
Concept ID:
C1848552
Disease or Syndrome
Disorders of intracellular cobalamin metabolism have a variable phenotype and age of onset that are influenced by the severity and location within the pathway of the defect. The prototype and best understood phenotype is cblC; it is also the most common of these disorders. The age of initial presentation of cblC spans a wide range: In utero with fetal presentation of nonimmune hydrops, cardiomyopathy, and intrauterine growth restriction. Newborns, who can have microcephaly, poor feeding, and encephalopathy. Infants, who can have poor feeding and slow growth, neurologic abnormality, and, rarely, hemolytic uremic syndrome (HUS). Toddlers, who can have poor growth, progressive microcephaly, cytopenias (including megaloblastic anemia), global developmental delay, encephalopathy, and neurologic signs such as hypotonia and seizures. Adolescents and adults, who can have neuropsychiatric symptoms, progressive cognitive decline, thromboembolic compications, and/or subacute combined degeneration of the spinal cord.
Methylmalonic acidemia with homocystinuria
MedGen UID:
341256
Concept ID:
C1848561
Disease or Syndrome
Disorders of intracellular cobalamin metabolism have a variable phenotype and age of onset that are influenced by the severity and location within the pathway of the defect. The prototype and best understood phenotype is cblC; it is also the most common of these disorders. The age of initial presentation of cblC spans a wide range: In utero with fetal presentation of nonimmune hydrops, cardiomyopathy, and intrauterine growth restriction. Newborns, who can have microcephaly, poor feeding, and encephalopathy. Infants, who can have poor feeding and slow growth, neurologic abnormality, and, rarely, hemolytic uremic syndrome (HUS). Toddlers, who can have poor growth, progressive microcephaly, cytopenias (including megaloblastic anemia), global developmental delay, encephalopathy, and neurologic signs such as hypotonia and seizures. Adolescents and adults, who can have neuropsychiatric symptoms, progressive cognitive decline, thromboembolic compications, and/or subacute combined degeneration of the spinal cord.
T-substance anomaly
MedGen UID:
338528
Concept ID:
C1848724
Finding
Trichomegaly with mental retardation, dwarfism and pigmentary degeneration of retina
MedGen UID:
338532
Concept ID:
C1848745
Disease or Syndrome
PNPLA6-related disorders span a phenotypic continuum characterized by variable combinations of cerebellar ataxia, upper motor neuron involvement manifesting as spasticity and/or brisk reflexes, chorioretinal dystrophy associated with variable degrees of reduced visual function, and hypogonadotropic hypogonadism (delayed puberty and lack of secondary sex characteristics), either in isolation or as part of anterior hypopituitarism (growth hormone, thyroid hormone, or gonadotropin deficiencies). Common but less frequent features are peripheral neuropathy (usually of axonal type manifesting as reduced distal reflexes, diminished vibratory sensation, and/or distal muscle wasting), hair anomalies (long eyelashes, bushy eyebrows, or scalp alopecia), short stature, and impaired cognitive functioning (learning disabilities in children and deficits in attention, visuospatial abilities, and recall in adults). Some of these features can occur in distinct clusters on the phenotypic continuum: Boucher-Neuhäuser syndrome (cerebellar ataxia, chorioretinal dystrophy, and hypogonadotropic hypogonadism); Gordon Holmes syndrome (cerebellar ataxia, hypogonadotropic hypogonadism, and – to a variable degree – brisk reflexes); Oliver-McFarlane syndrome (trichomegaly, chorioretinal dystrophy, short stature, intellectual disability, and hypopituitarism); Laurence-Moon syndrome; and spastic paraplegia type 39 (SPG39) (upper motor neuron involvement, peripheral neuropathy, and sometimes reduced cognitive functioning and/or cerebellar ataxia).
Thyroid dyshormonogenesis 1
MedGen UID:
336422
Concept ID:
C1848805
Disease or Syndrome
Approximately 10% of patients with congenital hypothyroidism harbor inborn errors of metabolism in one of the steps for thyroid hormone synthesis in thyrocytes (Vono-Toniolo et al., 2005). Dyshormonogenesis can be caused by recessive defects at any of the steps required for normal thyroid hormone synthesis. In untreated patients thyroid dyshormonogenesis is typically associated with goitrous enlargement of the thyroid secondary to long-term thyrotropin (TSH; see 188540) stimulation. Park and Chatterjee (2005) reviewed the genetics of primary congenital hypothyroidism, summarizing the different phenotypes associated with known genetic defects and proposing an algorithm for investigating the genetic basis of the disorder. Genetic Heterogeneity of Thyroid Dyshormonogenesis Other forms of thyroid hormone dysgenesis include TDH2A (274500), caused by mutation in the thyroid peroxidase gene (TPO; 606765) on 2p25; Pendred syndrome, a form of thyroid hormone dysgenesis associated with deafness (TDH2B; 274600) and caused by mutation in the SLC26A4 gene (605646) on 7q31; TDH3 (274700), caused by mutation in the thyroglobulin gene (TG; 188450) on 8q24; TDH4 (274800), caused by mutation in the iodotyrosine deiodinase gene (IYD; 612025) on 6q25; TDH5 (274900), caused by mutation in the DUOXA2 gene (612772) on 15q21; and TDH6 (607200), caused by mutation in the DUOX2 gene (606759) on 15q21.
Cold-induced sweating syndrome 1
MedGen UID:
338577
Concept ID:
C1848947
Disease or Syndrome
Crisponi syndrome, the infantile presentation of cold-induced sweating syndrome (CISS), is characterized by dysmorphic features (distinctive facies, lower facial weakness, flexion deformity at the elbows, camptodactyly with fisted hands, misshapen feet, and overriding toes), poor suck reflex and severely impaired swallowing, and temperature spikes associated with an increased risk for seizures and sudden death. During the first decade of life, children with CISS develop profuse sweating of the face, arms, and chest with ambient temperatures below 18º to 22º C, and with other stimuli including apprehension or ingestion of sweets. Affected individuals sweat very little in hot environments and may feel overheated. In the second decade, progressive thoracolumbar kyphoscoliosis requires intervention.
Sucrosuria, hiatus hernia and mental retardation
MedGen UID:
338583
Concept ID:
C1848963
Disease or Syndrome
Spondyloepiphyseal dysplasia tarda with mental retardation
MedGen UID:
338603
Concept ID:
C1849053
Disease or Syndrome
Spinocerebellar degeneration and corneal dystrophy
MedGen UID:
341379
Concept ID:
C1849087
Disease or Syndrome
Syndrome with the unusual combination of spinocerebellar degeneration and corneal dystrophy. Three sisters born to normal consanguineous parents have been reported, one of who had only minor spinocerebellar signs without ocular involvement. This autosomal recessive syndrome differs from the Mousa-Al-Din-Al-Nassar syndrome by the subnormal intellectual development and the epithelial (versus stromal) nature of the corneal dystrophy.
Mitochondrial DNA depletion syndrome 7 (hepatocerebral type)
MedGen UID:
338613
Concept ID:
C1849096
Disease or Syndrome
Infantile-onset spinocerebellar ataxia (IOSCA) is a severe, progressive neurodegenerative disorder characterized by normal development until age one year, followed by onset of ataxia, muscle hypotonia, loss of deep-tendon reflexes, and athetosis. Ophthalmoplegia and sensorineural deafness develop by age seven years. By adolescence, affected individuals are profoundly deaf and no longer ambulatory; sensory axonal neuropathy, optic atrophy, autonomic nervous system dysfunction, and hypergonadotropic hypogonadism in females become evident. Epilepsy can develop into a serious and often fatal encephalopathy: myoclonic jerks or focal clonic seizures that progress to epilepsia partialis continua followed by status epilepticus with loss of consciousness.
Spinal muscular atrophy with microcephaly and mental subnormality
MedGen UID:
341384
Concept ID:
C1849108
Disease or Syndrome
Spinal muscular atrophy with mental retardation
MedGen UID:
376518
Concept ID:
C1849109
Disease or Syndrome
Spastic quadriplegia retinitis pigmentosa mental retardation
MedGen UID:
376519
Concept ID:
C1849112
Disease or Syndrome
Quadriplegia in association with mental retardation, retinitis pigmentosa, and impaired hearing.
Spastic paresis, glaucoma, and mental retardation
MedGen UID:
376520
Concept ID:
C1849113
Disease or Syndrome
Spastic paraplegia 15
MedGen UID:
341387
Concept ID:
C1849128
Disease or Syndrome
Spastic paraplegia-15 is an autosomal recessive neurodegenerative disorder characterized by progressive spasticity primarily affecting the lower limbs. It is a complex form of spastic paraplegia, associated with other neurologic dysfunction, including variable mental retardation, hearing and visual defects, and thin corpus callosum (summary by Goizet et al., 2009).
Spastic diplegia infantile type
MedGen UID:
376526
Concept ID:
C1849139
Disease or Syndrome
Spastic ataxia Charlevoix-Saguenay type
MedGen UID:
338620
Concept ID:
C1849140
Disease or Syndrome
ARSACS (autosomal recessive spastic ataxia of Charlevoix-Saguenay) is characterized in individuals born in Quebec Province by early-onset (age 12-18 months) difficulty in walking and gait unsteadiness. In individuals with ARSACS born outside the Province of Quebec, onset is often delayed until later childhood and even adulthood. Ataxia, dysarthria, spasticity, extensor plantar reflexes, distal muscle wasting, a distal sensorimotor neuropathy predominant in the legs, and horizontal gaze-evoked nystagmus constitute the most frequent progressive neurologic signs. Increased demarcation of the retinal nerve fibers located near the vessels close to the optic disc (formerly designated as yellow streaks of hypermyelinated fibers) is very common in individuals with ARSACS who originate from Quebec but may be absent in non-Quebec born individuals. Individuals with ARSACS born in the Province of Quebec become wheelchair bound at the average age of 41 years; cognitive skills are preserved in the long term as individuals remain able to perform daily living tasks late into adulthood. Death commonly occurs in the sixth decade.
Spastic ataxia
MedGen UID:
376528
Concept ID:
C1849156
Disease or Syndrome
Rodrigues blindness
MedGen UID:
340297
Concept ID:
C1849332
Disease or Syndrome
Robinow syndrome, autosomal recessive
MedGen UID:
341431
Concept ID:
C1849334
Disease or Syndrome
ROR2-related Robinow syndrome is characterized by distinctive craniofacial features, skeletal abnormalities, and other anomalies. Craniofacial features include macrocephaly, broad prominent forehead, low-set ears, ocular hypertelorism, prominent eyes, midface hypoplasia, short upturned nose with depressed nasal bridge and flared nostrils, large and triangular mouth with exposed incisors and upper gums, gum hypertrophy, misaligned teeth, ankyloglossia, and micrognathia. Skeletal abnormalities include short stature, mesomelic or acromesomelic limb shortening, hemivertebrae with fusion of thoracic vertebrae, and brachydactyly. Other common features include micropenis with or without cryptorchidism in males and reduced clitoral size and hypoplasia of the labia majora in females, renal tract abnormalities, and nail hypoplasia or dystrophy. The disorder is recognizable at birth or in early childhood.
Retinitis pigmentosa, deafness, mental retardation, and hypogonadism
MedGen UID:
340317
Concept ID:
C1849401
Disease or Syndrome
Pyridoxine-dependent epilepsy
MedGen UID:
340341
Concept ID:
C1849508
Disease or Syndrome
Pyridoxine-dependent epilepsy is characterized by intractable seizures within the first weeks to months of life that are not controlled with antiepileptic drugs but respond both clinically and electrographically to large daily supplements of pyridoxine (vitamin B6). Multiple types of clinical seizures have been reported in individuals with pyridoxine-dependent epilepsy. Dramatic presentations consisting of prolonged seizures and recurrent episodes of status epilepticus are typical; recurrent self-limited events including partial seizures, generalized seizures, atonic seizures, myoclonic events, and infantile spasms also occur. Affected individuals may have electrographic seizures without clinical correlates. Infants with the classic neonatal presentation begin to experience seizures soon after birth. Atypical features include: late-onset seizures (seizures that begin from late infancy up until age 3 years); seizures that initially respond to antiepileptic drugs and then become intractable; seizures during early life that do not respond to pyridoxine but are then controlled with pyridoxine several months later; and prolonged seizure-free intervals (=5.5 months) that occur after discontinuation of pyridoxine. Intellectual disability is common. Elevated concentration of a-aminoadipic semialdehyde (a-AASA) in urine and plasma is a strong biomarker of the disorder; pipecolic acid may also be elevated in plasma and cerebrospinal fluid.
Pseudouridinuria and mental defect
MedGen UID:
376629
Concept ID:
C1849648
Disease or Syndrome
Osteopenia and sparse hair
MedGen UID:
337979
Concept ID:
C1850140
Disease or Syndrome
A rare syndrome described in two sisters of Mennonite descent, with characteristics of sparse hair, osteopenia, intellectual disability, minor facial abnormalities, joint laxity and hypotonia. There have been no further descriptions in the literature since 1992.
Osteolysis syndrome recessive
MedGen UID:
376714
Concept ID:
C1850143
Disease or Syndrome
Oliver syndrome
MedGen UID:
342472
Concept ID:
C1850320
Disease or Syndrome
A very rare syndrome with characteristics of intellectual deficit, postaxial polydactyly and epilepsy. To date, seven individuals in three families have been reported. Facial features are not characteristic except for a prominent jaw. Concordant features in all subjects are postaxial polydactyly, which in four individuals affect also the feet, and intellectual deficit, which is usually severe, with absent or indistinct speech. Seizures are common with onset in the first months of life or in early childhood. Cutaneous syndactyly, camptodactyly and clinodactyly of fingers and brachydactyly and syndactyly of the toes have been recorded.
Oculorenocerebellar syndrome
MedGen UID:
340516
Concept ID:
C1850331
Disease or Syndrome
Oculopalatocerebral syndrome
MedGen UID:
338025
Concept ID:
C1850338
Congenital Abnormality
Oculopalatocerebral syndrome is a rare disorder characterized by low birth weight, microcephaly, persistent hyperplastic primary vitreous, microphthalmia, large ears, small hands and feet, cleft palate, joint hypermobility, developmental delay, and cerebral atrophy (summary by Pellegrino et al., 2001).
Giant axonal neuropathy
MedGen UID:
376775
Concept ID:
C1850386
Disease or Syndrome
Giant axonal neuropathy (GAN) is an early-onset fatal neurodegenerative disorder. GAN starts as severe peripheral motor and sensory neuropathy during infancy and evolves into central nervous system impairment (intellectual disability, seizures, cerebellar signs, and pyramidal tract signs). Most individuals become wheelchair dependent in the second decade of life and eventually bedridden with severe polyneuropathy, ataxia, and dementia. Death usually occurs in the third decade.
Ceroid lipofuscinosis neuronal 5
MedGen UID:
376792
Concept ID:
C1850442
Disease or Syndrome
The neuronal ceroid lipofuscinoses (NCL; CLN) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by the intracellular accumulation of autofluorescent lipopigment storage material in different patterns ultrastructurally. The lipopigment patterns observed most often in CLN5 comprise mixed combinations of 'granular,' 'curvilinear,' and 'fingerprint' profiles. The clinical course includes progressive dementia, seizures, and progressive visual failure (Mole et al., 2005). For a general phenotypic description and a discussion of genetic heterogeneity of CLN, see CLN1 (256730).
Ceroid lipofuscinosis neuronal 1
MedGen UID:
340540
Concept ID:
C1850451
Disease or Syndrome
The neuronal ceroid lipofuscinoses (NCL; CLN) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by the intracellular accumulation of autofluorescent lipopigment storage material in different patterns ultrastructurally. The lipopigment pattern seen most often in CLN1 is referred to as granular osmiophilic deposits (GROD). The patterns most often observed in CLN2 and CLN3 are 'curvilinear' and 'fingerprint' profiles, respectively. CLN4, CLN5, CLN6, CLN7, and CLN8 show mixed combinations of granular, curvilinear, fingerprint, and rectilinear profiles. The clinical course includes progressive dementia, seizures, and progressive visual failure (Mole et al., 2005). Zeman and Dyken (1969) referred to these conditions as the 'neuronal ceroid lipofuscinoses.' Goebel (1995) provided a comprehensive review of the NCLs and noted that they are possibly the most common group of neurodegenerative diseases in children. Mole et al. (2005) provided a detailed clinical and genetic review of the neuronal ceroid lipofuscinoses. Genetic Heterogeneity of Neuronal Ceroid Lipofuscinosis See also CLN2 (204500), caused by mutation in the TPP1 gene (607998) on chromosome 11p15; CLN3 (204200), caused by mutation in the CLN3 gene (607042) on 16p12; CLN4A (204300), caused by mutation in the CLN6 gene (606725) on 15q21; CLN4B (162350), caused by mutation in the DNAJC5 gene (611203) on 20q13; CLN5 (256731), caused by mutation in the CLN5 gene (608102) on 13q; CLN6 (601780), caused by mutation in the CLN6 gene (602780) on 15q21; CLN7 (610951), caused by mutation in the MFSD8 gene (611124) on 4q28; CLN8 (600143) and the Northern epilepsy variant of CLN8 (610003), caused by mutation in the CLN8 gene (607837) on 8pter; CLN10 (610127), caused by mutation in the CTSD gene (116840) on 11p15; CLN11 (614706), caused by mutation in the GRN gene (138945) on 17q; CLN13 (615362), caused by mutation in the CTSF gene (603539) on 11q13; and CLN14 (611726), caused by mutation in the KCTD7 gene (611725) on 7q11. CLN9 (609055) has not been molecularly characterized. A disorder that was formerly designated neuronal ceroid lipofuscinosis-12 (CLN12) is now considered to be a variable form of Kufor-Rakeb syndrome (KRS; 606693).
Native American myopathy
MedGen UID:
340586
Concept ID:
C1850625
Disease or Syndrome
Bailey-Bloch congenital myopathy, also known as Native American myopathy (NAM), is an autosomal recessive disorder characterized by congenital weakness and arthrogryposis, cleft palate, ptosis, myopathic facies, short stature, kyphoscoliosis, talipes deformities, and susceptibility to malignant hyperthermia provoked by anesthesia. It was first reported in the Lumbee Indian tribe in North Carolina (summary by Stamm et al., 2008).
Congenital nonprogressive myopathy with Moebius and Robin sequences
MedGen UID:
338115
Concept ID:
C1850746
Disease or Syndrome
Carey-Fineman-Ziter syndrome (CFZS) is a multisystem congenital disorder characterized by hypotonia, Moebius sequence (bilateral congenital facial palsy with impairment of ocular abduction), Pierre Robin complex (micrognathia, glossoptosis, and high-arched or cleft palate), delayed motor milestones, and failure to thrive. More variable features include dysmorphic facial features, brain abnormalities, and intellectual disability. It has been postulated that many clinical features in CFZS may be secondary effects of muscle weakness during development or brainstem anomalies (summary by Pasetti et al., 2016). Di Gioia et al. (2017) determined that CFZS represents a slowly progressive congenital myopathy resulting from a defect in myoblast fusion.
Ectrodactyly, ectodermal dysplasia, and cleft lip/palate syndrome 1
MedGen UID:
343663
Concept ID:
C1851841
Disease or Syndrome
Deficiency of mitochondrial complex III
MedGen UID:
377658
Concept ID:
C1852372
Disease or Syndrome
Coloboma, Uveal, with Cleft Lip and Palate and Mental Retardation
MedGen UID:
342303
Concept ID:
C1852750
Disease or Syndrome
Renal coloboma syndrome
MedGen UID:
339002
Concept ID:
C1852759
Disease or Syndrome
PAX2-related disorder is an autosomal dominant disorder associated with renal and eye abnormalities. The disorder was originally referred to as renal coloboma syndrome and characterized by renal hypodysplasia and abnormalities of the optic nerve; with improved access to molecular testing, a wider range of phenotypes has been recognized in association with pathogenic variants in PAX2. Abnormal renal structure or function is noted in 92% of affected individuals and ophthalmologic abnormalities in 77% of affected individuals. Renal abnormalities can be clinically silent in rare individuals. In most individuals, clinically significant renal insufficiency / renal failure is reported. End-stage renal disease requiring renal transplant is not uncommon. Uric acid nephrolithiasis has been reported. Ophthalmologic abnormalities are typically described as optic nerve coloboma or dysplasia. Iris colobomas have not been reported in any individual with PAX2–related disorder. Ophthalmologic abnormalities may significantly impair vision in some individuals, while others have subtle changes only noted after detailed ophthalmologic examination. Additional clinical findings include high-frequency sensorineural hearing loss, soft skin, and ligamentous laxity. PAX2 pathogenic variants have been identified in multiple sporadic and familial cases of nonsyndromic renal disease including renal hypodysplasia and focal segmental glomerulosclerosis.
Cornelia de Lange syndrome 3
MedGen UID:
339902
Concept ID:
C1853099
Disease or Syndrome
Classic Cornelia de Lange syndrome (CdLS) is characterized by distinctive facial features, growth retardation (prenatal onset; <5th centile throughout life), hirsutism, and upper-limb reduction defects that range from subtle phalangeal abnormalities to oligodactyly (missing digits). Craniofacial features include synophrys, highly arched eyebrows, long eyelashes, short nose with anteverted nares, small widely spaced teeth, and microcephaly. IQ ranges from below 30 to 102 (mean: 53). Many individuals demonstrate autistic and self-destructive tendencies. Frequent findings include cardiac septal defects, gastrointestinal dysfunction, hearing loss, myopia, and cryptorchidism or hypoplastic genitalia. Individuals with a milder phenotype have less severe growth, cognitive, and limb involvement, but often have facial features consistent with CdLS.
Joubert syndrome 6
MedGen UID:
342805
Concept ID:
C1853153
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Mental retardation, microcephaly, growth retardation, joint contractures, and facial dysmorphism
MedGen UID:
342889
Concept ID:
C1853480
Disease or Syndrome
Cerebrooculonasal syndrome
MedGen UID:
340138
Concept ID:
C1854108
Disease or Syndrome
A multisystem malformation syndrome that has been reported in about 10 patients. The clinical features include bilateral anophthalmia, abnormal nares, central nervous system anomalies, and neurodevelopmental delay. Additional features include brachycephaly and other facial anomalies. Non-facial anomalies have also been reported: postaxial polydactyly, genital hypoplasia. All cases reported so far have been sporadic, suggesting that the syndrome may be due to a new dominant mutation.
Tuberous sclerosis 1
MedGen UID:
344288
Concept ID:
C1854465
Disease or Syndrome
Tuberous sclerosis complex (TSC) involves abnormalities of the skin (hypomelanotic macules, confetti skin lesions, facial angiofibromas, shagreen patches, fibrous cephalic plaques, ungual fibromas); brain (subependymal nodules, cortical dysplasias, and subependymal giant cell astrocytomas [SEGAs], seizures, intellectual disability / developmental delay, psychiatric illness); kidney (angiomyolipomas, cysts, renal cell carcinomas); heart (rhabdomyomas, arrhythmias); and lungs (lymphangioleiomyomatosis [LAM], multifocal micronodular pneumonocyte hyperplasia). Central nervous system tumors are the leading cause of morbidity and mortality; renal disease is the second leading cause of early death.
Spinocerebellar ataxia 13
MedGen UID:
344297
Concept ID:
C1854488
Disease or Syndrome
In the families described to date, the phenotype of spinocerebellar ataxia type 13 (SCA13) has ranged from slowly progressive childhood-onset cerebellar gait ataxia associated with cerebellar dysarthria and often accompanied by mild intellectual disability and occasional seizures to adult-onset progressive ataxia. Life span is not shortened and many persons live beyond age 70 years, but assistance with gait may be required as the disease progresses.
Wiedemann-Steiner syndrome
MedGen UID:
340266
Concept ID:
C1854630
Disease or Syndrome
Wiedemann-Steiner syndrome is a congenital malformation syndrome characterized by hypertrichosis cubiti associated with short stature; consistent facial features, including long eyelashes, thick or arched eyebrows with a lateral flare, wide nasal bridge, and downslanting and vertically narrow palpebral fissures; mild to moderate intellectual disability; behavioral difficulties; and hypertrichosis on the back (summary by Jones et al., 2012 and Miyake et al., 2016).
Molybdenum cofactor deficiency, complementation group A
MedGen UID:
381530
Concept ID:
C1854988
Disease or Syndrome
Molybdenum cofactor deficiency is a rare condition characterized by brain dysfunction (encephalopathy) that worsens over time. Babies with this condition appear normal at birth, but within a week they have difficulty feeding and develop seizures that do not improve with treatment (intractable seizures). Brain abnormalities, including deterioration (atrophy) of brain tissue, lead to severe developmental delay; affected individuals usually do not learn to sit unassisted or to speak. A small percentage of affected individuals have an exaggerated startle reaction (hyperekplexia) to unexpected stimuli such as loud noises. Other features of molybdenum cofactor deficiency can include a small head size (microcephaly) and facial features that are described as "coarse."Tests reveal that affected individuals have high levels of chemicals called sulfite, S-sulfocysteine, xanthine, and hypoxanthine in the urine and low levels of a chemical called uric acid in the blood.Because of the serious health problems caused by molybdenum cofactor deficiency, affected individuals usually do not survive past early childhood.
Winship Viljoen Leary syndrome
MedGen UID:
381554
Concept ID:
C1855080
Disease or Syndrome
Syndrome with characteristics of severe intellectual deficit, microcephaly and dilated cardiomyopathy. Hand and foot anomalies have also been reported. The syndrome has been described in three individuals. Transmission is autosomal recessive.
Primary autosomal recessive microcephaly 1
MedGen UID:
344415
Concept ID:
C1855081
Disease or Syndrome
Primary microcephaly refers to the clinical finding of a head circumference more than than 3 standard deviations (SD) below the age- and sex-related mean, present at birth. Primary microcephaly is a static developmental anomaly, distinguished from secondary microcephaly, which refers to a progressive neurodegenerative condition. Microcephaly is a disorder of fetal brain growth; individuals with microcephaly have small brains and almost always have mental retardation, although rare individuals with mild microcephaly (-3 SD) and normal intelligence have been reported. Additional clinical features may include short stature or mild seizures. MCPH is associated with a simplification of the cerebral cortical gyral pattern and a slight reduction in the volume of the white matter, consistent with the small size of the brain, but the architecture of the brain in general is normal, with no evidence of a neuronal migration defect (review by Woods et al., 2005). Most cases of primary microcephaly show an autosomal recessive mode of inheritance. Because MCPH directly affects neurogenesis, or neurogenic mitosis, rather than growth of the skull, some prefer the term 'micrencephaly' (Hofman, 1984). MCPH1 in particular is associated with premature chromosome condensation in cell studies (Darvish et al., 2010). Genetic Heterogeneity of Primary Microcephaly Primary microcephaly is a genetically heterogeneous disorder. See MCPH2 (604317), caused by mutation in the WDR62 gene (613583) on chromosome 19q13; MCPH3 (604804), caused by mutation in the CDK5RAP2 gene (608201) on 9q33; MCPH4 (604321), caused by mutation in the CASC5 gene (609173) on 15q14; MCPH5 (608716), caused by mutation in the ASPM gene (605481) on 1q31; MCPH6 (608393), caused by mutation in the CENPJ gene (609279) on 13q12; MCPH7 (612703), caused by mutation in the STIL gene (181590) on 1p33; MCPH8 (614673), caused by mutation in the CEP135 gene (611423) on 4q12; MCPH9 (614852), caused by mutation in the CEP152 gene (613529) on 15q21; MCPH10 (615095), caused by mutation in the ZNF335 gene (610827) on 20q13; MCPH11 (615414), caused by mutation in the PHC1 gene (602978) on 12p13; MCPH12 (616080), caused by mutation in the CDK6 gene (603368) on 7q21; MCPH13 (616051), caused by mutation in the CENPE gene (117143) on 4q24; MCPH14 (616402), caused by mutation in the SASS6 gene (609321) on 1p21; MCPH15 (616486), caused by mutation in the MFSD2A gene (614397) on 1p34; MCPH16 (616681), caused by mutation in the ANKLE2 gene (616062) on 12q24; MCPH17 (617090), caused by mutation in the CIT gene (605629) on 12q24; MCPH18 (617520), caused by mutation in the WDFY3 gene (617485) on 4q21; and MCPH19 (617800), caused by mutation in the COPB2 gene (606990) on 3q23; MCPH20 (617914), caused by mutation in the KIF14 gene (611279) on 1q31; MCPH21 (617983), caused by mutation in the NCAPD2 gene (615638) on 12p13; MCPH22 (617984), caused by mutation in the NCAPD3 gene (609276) on 11q25; MCPH23 (617985), caused by mutation in the NCAPH gene (602332) on 2q11; MCPH24 (618179), caused by mutation in the NUP37 gene (609264) on 12q23; and MCPH25 (618351), caused by mutation in the MAP11 gene (618350) on 7q22.
Microcephalic primordial dwarfism Toriello type
MedGen UID:
381556
Concept ID:
C1855089
Disease or Syndrome
Growth retardation with prenatal onset, cataracts, microcephaly, intellectual deficit, immune deficiency, delayed ossification and enamel hypoplasia. Transmission is autosomal recessive.
METHYLCOBALAMIN DEFICIENCY, cblG TYPE
MedGen UID:
344426
Concept ID:
C1855128
Disease or Syndrome
Disorders of intracellular cobalamin metabolism have a variable phenotype and age of onset that are influenced by the severity and location within the pathway of the defect. The prototype and best understood phenotype is cblC; it is also the most common of these disorders. The age of initial presentation of cblC spans a wide range: In utero with fetal presentation of nonimmune hydrops, cardiomyopathy, and intrauterine growth restriction. Newborns, who can have microcephaly, poor feeding, and encephalopathy. Infants, who can have poor feeding and slow growth, neurologic abnormality, and, rarely, hemolytic uremic syndrome (HUS). Toddlers, who can have poor growth, progressive microcephaly, cytopenias (including megaloblastic anemia), global developmental delay, encephalopathy, and neurologic signs such as hypotonia and seizures. Adolescents and adults, who can have neuropsychiatric symptoms, progressive cognitive decline, thromboembolic compications, and/or subacute combined degeneration of the spinal cord.
Retinitis pigmentosa with or without skeletal anomalies
MedGen UID:
381579
Concept ID:
C1855188
Disease or Syndrome
Metaphyseal acroscyphodysplasia
MedGen UID:
344453
Concept ID:
C1855243
Disease or Syndrome
Mesangial sclerosis, diffuse renal, with ocular abnormalities
MedGen UID:
343307
Concept ID:
C1855282
Disease or Syndrome
Mental retardation, autosomal recessive 1
MedGen UID:
344468
Concept ID:
C1855304
Disease or Syndrome
Mastocytosis, cutaneous, with short stature, conductive hearing loss and microtia
MedGen UID:
383661
Concept ID:
C1855345
Disease or Syndrome
Marfanoid mental retardation syndrome, autosomal
MedGen UID:
343326
Concept ID:
C1855347
Disease or Syndrome
Marfanoid habitus with microcephaly and glomerulonephritis
MedGen UID:
343327
Concept ID:
C1855348
Disease or Syndrome
A syndrome marked by marfanoid habitus (tall stature with long and slim limbs, little subcutaneous fat, arachnodactyly, joint hyperextensibility, narrow face, small chin, large testes, and hypotonia) associated with microcephaly and glomerulonephritis.
Mandibulofacial Dysostosis with Mental Deficiency
MedGen UID:
340867
Concept ID:
C1855432
Disease or Syndrome
Limb defects, distal transverse, with mental retardation and spasticity
MedGen UID:
340888
Concept ID:
C1855501
Disease or Syndrome
Leukomelanoderma, infantilism, mental retardation, hypodontia, hypotrichosis
MedGen UID:
383698
Concept ID:
C1855504
Disease or Syndrome
Lambert syndrome
MedGen UID:
343381
Concept ID:
C1855551
Disease or Syndrome
A very rare syndrome described in four siblings of one French family and with characteristics of branchial dysplasia (malar hypoplasia, macrostomia, preauricular tags and meatal atresia), club feet, inguinal hernia and cholestasis due to paucity of interlobular bile ducts and intellectual deficit.
Lactic aciduria due to d-lactic acid
MedGen UID:
343382
Concept ID:
C1855552
Disease or Syndrome
Pyruvate dehydrogenase E3-binding protein deficiency
MedGen UID:
343383
Concept ID:
C1855553
Disease or Syndrome
Pyruvate dehydrogenase deficiency is characterized by the buildup of a chemical called lactic acid in the body and a variety of neurological problems. Signs and symptoms of this condition usually first appear shortly after birth, and they can vary widely among affected individuals. The most common feature is a potentially life-threatening buildup of lactic acid (lactic acidosis), which can cause nausea, vomiting, severe breathing problems, and an abnormal heartbeat. People with pyruvate dehydrogenase deficiency usually have neurological problems as well. Most have delayed development of mental abilities and motor skills such as sitting and walking. Other neurological problems can include intellectual disability, seizures, weak muscle tone (hypotonia), poor coordination, and difficulty walking. Some affected individuals have abnormal brain structures, such as underdevelopment of the tissue connecting the left and right halves of the brain (corpus callosum), wasting away (atrophy) of the exterior part of the brain known as the cerebral cortex, or patches of damaged tissue (lesions) on some parts of the brain. Because of the severe health effects, many individuals with pyruvate dehydrogenase deficiency do not survive past childhood, although some may live into adolescence or adulthood.
Ketoadipicaciduria
MedGen UID:
340920
Concept ID:
C1855626
Disease or Syndrome
Baraitser-Winter syndrome
MedGen UID:
340943
Concept ID:
C1855722
Disease or Syndrome
Baraitser-Winter syndrome is a condition that affects the development of many parts of the body, particularly the face and the brain.An unusual facial appearance is the most common characteristic of Baraitser-Winter syndrome. Distinctive facial features can include widely spaced eyes (hypertelorism), large eyelid openings, droopy eyelids (ptosis), high-arched eyebrows, a broad nasal bridge and tip of the nose, a long space between the nose and upper lip (philtrum), full cheeks, and a pointed chin.Structural brain abnormalities are also present in most people with Baraitser-Winter syndrome. These abnormalities are related to impaired neuronal migration, a process by which nerve cells (neurons) move to their proper positions in the developing brain. The most frequent brain abnormality associated with Baraitser-Winter syndrome is pachygyria, which is an area of the brain that has an abnormally smooth surface with fewer folds and grooves. Less commonly, affected individuals have lissencephaly, which is similar to pachygyria but involves the entire brain surface. These structural changes can cause mild to severe intellectual disability, developmental delay, and seizures.Other features of Baraitser-Winter syndrome can include short stature, ear abnormalities and hearing loss, heart defects, presence of an extra (duplicated) thumb, and abnormalities of the kidneys and urinary system. Some affected individuals have limited movement of large joints, such as the elbows and knees, which may be present at birth or develop over time. Rarely, people with Baraitser-Winter syndrome have involuntary muscle tensing (dystonia).
Indolylacroyl glycinuria with mental retardation
MedGen UID:
340949
Concept ID:
C1855738
Disease or Syndrome
Ichthyosis, split hairs, and amino aciduria
MedGen UID:
344576
Concept ID:
C1855786
Disease or Syndrome
Ichthyosis, mental retardation, dwarfism and renal impairment
MedGen UID:
340966
Concept ID:
C1855787
Disease or Syndrome
Ichthyosis alopecia eclabion ectropion mental retardation
MedGen UID:
344577
Concept ID:
C1855788
Disease or Syndrome
An ectodermal dysplasia syndrome characterised by severe generalised lamellar icthyosis at birth with alopecia, eclabium, ectropion and intellectual disability. Although similar to Sjogren-Larsson syndrome, this syndrome lacks the presence of neurologic or macular changes. There have been no further descriptions in the literature since 1987.
Ichthyosiform Erythroderma, Congenital, Nonbullous, 1
MedGen UID:
383774
Concept ID:
C1855792
Disease or Syndrome
Hypoparathyroidism retardation dysmorphism syndrome
MedGen UID:
340984
Concept ID:
C1855840
Disease or Syndrome
HRDS is an autosomal recessive multisystem disorder characterized by intrauterine and postnatal growth retardation, infantile-onset hypoparathyroidism that can result in severe hypocalcemic seizures, dysmorphic facial features, and developmental delay (summary by Padidela et al., 2009 and Ratbi et al., 2015).
Bartter syndrome, type 2, antenatal
MedGen UID:
343428
Concept ID:
C1855849
Disease or Syndrome
Bartter syndrome refers to a group of disorders that are unified by autosomal recessive transmission of impaired salt reabsorption in the thick ascending loop of Henle with pronounced salt wasting, hypokalemic metabolic alkalosis, and hypercalciuria. Clinical disease results from defective renal reabsorption of sodium chloride in the thick ascending limb (TAL) of the Henle loop, where 30% of filtered salt is normally reabsorbed (Simon et al., 1997). Patients with antenatal forms of Bartter syndrome typically present with premature birth associated with polyhydramnios and low birth weight and may develop life-threatening dehydration in the neonatal period. Patients with classic Bartter syndrome (see BARTS3, 607364) present later in life and may be sporadically asymptomatic or mildly symptomatic (summary by Simon et al., 1996 and Fremont and Chan, 2012). For a discussion of genetic heterogeneity of Bartter syndrome, see 607364.
Hypogonadism with low-grade mental deficiency and microcephaly
MedGen UID:
383787
Concept ID:
C1855858
Disease or Syndrome
Hyperuricemia, infantile, with abnormal behavior and normal hypoxanthine guanine phosphoribosyltransferase
MedGen UID:
383794
Concept ID:
C1855884
Disease or Syndrome
Hyperphosphatasia-intellectual disability syndrome
MedGen UID:
383800
Concept ID:
C1855923
Disease or Syndrome
Mabry syndrome is a condition characterized by intellectual disability, distinctive facial features, increased levels of an enzyme called alkaline phosphatase in the blood (hyperphosphatasia), and other signs and symptoms.People with Mabry syndrome have intellectual disability that is often moderate to severe. They typically have little to no speech development and are delayed in the development of motor skills (such as sitting, crawling, and walking). Many affected individuals have low muscle tone (hypotonia) and develop recurrent seizures (epilepsy) in early childhood. Seizures are usually the generalized tonic-clonic type, which involve muscle rigidity, convulsions, and loss of consciousness.Individuals with Mabry syndrome have distinctive facial features that include wide-set eyes (hypertelorism), long openings of the eyelids (long palpebral fissures), a nose with a broad bridge and a rounded tip, downturned corners of the mouth, and a thin upper lip. These facial features usually become less pronounced over time.Hyperphosphatasia begins within the first year of life in people with Mabry syndrome. There are many different types of alkaline phosphatase found in tissues; the type that is increased in Mabry syndrome is called the tissue non-specific type and is found throughout the body. In affected individuals, alkaline phosphatase levels in the blood are usually increased by one to two times the normal amount, but can be up to 20 times higher than normal. The elevated enzyme levels remain relatively stable over a person's lifetime. Hyperphosphatasia appears to cause no negative health effects, but this finding can help health professionals diagnose Mabry syndrome.Another common feature of Mabry syndrome is shortened bones at the ends of fingers (brachytelephalangy), which can be seen on x-ray imaging. Underdeveloped fingernails (nail hypoplasia) may also occur. Sometimes, individuals with Mabry syndrome have abnormalities of the digestive system, including narrowing or blockage of the anus (anal stenosis or anal atresia) or Hirschsprung disease, a disorder that causes severe constipation or blockage of the intestine. Rarely, affected individuals experience hearing loss.The signs and symptoms of Mabry syndrome vary among affected individuals. Those who are least severely affected have only intellectual disability and hyperphosphatasia, without distinctive facial features or the other health problems listed above.
Hyperlysinemia due to defect in lysine transport into mitochondria
MedGen UID:
341010
Concept ID:
C1855927
Disease or Syndrome
Hydroxylysinuria
MedGen UID:
343450
Concept ID:
C1855986
Disease or Syndrome
Hall Riggs mental retardation syndrome
MedGen UID:
341089
Concept ID:
C1856198
Disease or Syndrome
Hair defect with photosensitivity and mental retardation
MedGen UID:
383868
Concept ID:
C1856241
Disease or Syndrome
Syndrome with the association of stubby, coarse, sparse and fragile hair, eyebrows and eyelashes with photosensitivity and nonprogressive intellectual deficit, without a demonstrable metabolic aberration. It has been described in three sisters born to consanguineous parents.
Faciodigitogenital syndrome, autosomal recessive
MedGen UID:
341637
Concept ID:
C1856871
Disease or Syndrome
A very rare syndrome including short stature, facial dysmorphism, hand abnormalities and shawl scrotum. It has been observed in 16 subjects from five distantly related sibships of a large Kuwaiti Bedouin tribe. The affected patients had no intellectual deficit. Transmitted as an autosomal recessive trait.
Facial abnormalities, kyphoscoliosis, and mental retardation
MedGen UID:
347325
Concept ID:
C1856893
Disease or Syndrome
Epilepsy telangiectasia
MedGen UID:
384017
Concept ID:
C1856929
Disease or Syndrome
Epilepsy, photogenic, with spastic diplegia and mental retardation
MedGen UID:
347333
Concept ID:
C1856931
Disease or Syndrome
Epidermolysis bullosa, late-onset localized junctional, with mental retardation
MedGen UID:
341663
Concept ID:
C1856969
Disease or Syndrome
Encephalomalacia, multilocular
MedGen UID:
341670
Concept ID:
C1856991
Disease or Syndrome
Dysmyelination with jaundice
MedGen UID:
346526
Concept ID:
C1857143
Disease or Syndrome
Dyskeratosis congenita autosomal recessive 1
MedGen UID:
341705
Concept ID:
C1857144
Disease or Syndrome
Dyskeratosis congenita (DC), a telomere biology disorder, is characterized by a classic triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia. The classic triad may not be present in all individuals. People with DC are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML), solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include: abnormal pigmentation changes not restricted to the upper chest and neck, eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), and dental abnormalities (caries, periodontal disease, taurodauntism). Although most persons with DC have normal psychomotor development and normal neurologic function, significant developmental delay is present in the two variants in which additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome). Onset and progression of manifestations of DC vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.
Dysautonomia like disorder
MedGen UID:
347385
Concept ID:
C1857153
Disease or Syndrome
Dwarfism, low-birth-weight type with unresponsiveness to growth hormone
MedGen UID:
387764
Concept ID:
C1857197
Disease or Syndrome
Rhizomelic chondrodysplasia punctata type 2
MedGen UID:
341734
Concept ID:
C1857242
Disease or Syndrome
Rhizomelic chondrodysplasia punctata (RCDP) is a peroxisomal disorder characterized by disproportionately short stature primarily affecting the proximal parts of the extremities, a typical facial appearance including a broad nasal bridge, epicanthus, high-arched palate, dysplastic external ears, and micrognathia, congenital contractures, characteristic ocular involvement, dwarfism, and severe mental retardation with spasticity. Biochemically, plasmalogen synthesis and phytanic acid alpha-oxidation are defective. Most patients die in the first decade of life. RCDP1 (215100) is the most frequent form of RCDP (summary by Wanders and Waterham, 2005). Whereas RCDP1 is a peroxisomal biogenesis disorder (PBD), RCDP2 is classified as a single peroxisome enzyme deficiency (Waterham and Ebberink, 2012). For a discussion of genetic heterogeneity of rhizomelic chondrodysplasia punctata, see 215100.
Dicarboxylic aminoaciduria
MedGen UID:
387782
Concept ID:
C1857253
Disease or Syndrome
Characterised by infantile-onset hypoglycaemia and hyperprolinaemia associated, in certain cases, with intellectual deficit. Less than 10 cases have been reported to date. Defects in renal and intestinal glutamate and aspartate transport were also reported, suggesting that anomalies of the EAAC1 transporter, involved in the transport of these two amino acids, are the underlying cause of this syndrome.
Dextrocardia with unusual facies and microphthalmia
MedGen UID:
346559
Concept ID:
C1857298
Disease or Syndrome
Dermatoleukodystrophy
MedGen UID:
387794
Concept ID:
C1857314
Disease or Syndrome
This syndrome is characterised by the association of a progressive leukodystrophy marked by generalised mental and motor impairment with the presence of thickened and wrinkled skin. It has been described in a Japanese brother and sister born to healthy parents. Both patients died in early childhood.
Deafness, conductive, with malformed external ear
MedGen UID:
347429
Concept ID:
C1857341
Disease or Syndrome
Deafness, Cochlear, with Myopia and Intellectual Impairment
MedGen UID:
347430
Concept ID:
C1857342
Disease or Syndrome
Deafness, congenital, with total albinism
MedGen UID:
387799
Concept ID:
C1857343
Disease or Syndrome
Cysteine peptiduria
MedGen UID:
346587
Concept ID:
C1857438
Disease or Syndrome
Cutis verticis gyrata and mental retardation
MedGen UID:
387821
Concept ID:
C1857444
Disease or Syndrome
Craniosynostosis-mental retardation-clefting syndrome
MedGen UID:
387829
Concept ID:
C1857472
Disease or Syndrome
Cardiocranial syndrome
MedGen UID:
346598
Concept ID:
C1857495
Disease or Syndrome
An extremely rare disorder found in less than ten patients worldwide with characteristics of congenital heart defect, sagittal craniosynostosis and severe developmental delay. Genital and renal anomalies, and various dysmorphic features may be present. Joint and palpebral abnormalities may also occur. The occurrence of the syndrome in a brother-sister sibship supports the hypothesis of autosomal recessive inheritance. Autosomal dominant inheritance and submicroscopic deletions have also been proposed as possible causes.
Craniofacial dyssynostosis
MedGen UID:
347473
Concept ID:
C1857511
Disease or Syndrome
Convulsive disorder, familial, with prenatal or early onset
MedGen UID:
387859
Concept ID:
C1857575
Disease or Syndrome
3-methylglutaconic aciduria type V
MedGen UID:
347542
Concept ID:
C1857776
Disease or Syndrome
3-Methylglutaconic aciduria type V is an autosomal recessive disorder characterized by the onset of dilated or noncompaction cardiomyopathy in infancy or early childhood. Many patients die of cardiac failure. Other features include microcytic anemia, growth retardation, mild ataxia, mild muscle weakness, genital anomalies in males, and increased urinary excretion of 3-methylglutaconic acid. Some patients may have optic atrophy or delayed psychomotor development (summary by Davey et al., 2006 and Ojala et al., 2012). For a discussion of genetic heterogeneity of 3-methylglutaconic aciduria, see MGCA type I (250950).
Joubert syndrome 5
MedGen UID:
347545
Concept ID:
C1857780
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Bardet-Biedl syndrome 6
MedGen UID:
347610
Concept ID:
C1858054
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Familial focal epilepsy with variable foci
MedGen UID:
348951
Concept ID:
C1858477
Disease or Syndrome
A rare genetic epilepsy disorder with characteristics of autosomal dominant lesional and nonlesional focal epilepsy with variable penetrance. Focal seizures emanate from different cortical locations (temporal, frontal, centroparietal, parietal, parietal-occipital, occipital) in different family members, but for each individual a single focus remains constant throughout lifetime. Seizure type (tonic, tonic-clonic or hyperkinetic) and severity varies among family members and tends to decrease (but do not disappear) during adulthood. Many patients have an aura and show automatisms during diurnal seizures whereas others have nocturnal seizures. Most individuals are of normal intelligence but patients with intellectual disability, autistic spectrum disorder and obsessive-compulsive disorder have been described.
Spastic paraplegia 11, autosomal recessive
MedGen UID:
388073
Concept ID:
C1858479
Disease or Syndrome
Spastic paraplegia 11 (SPG11) is characterized by progressive spasticity and weakness of the lower limbs frequently associated with the following: mild intellectual disability with learning difficulties in childhood and/or progressive cognitive decline; peripheral neuropathy; pseudobulbar involvement; and increased reflexes in the upper limbs. Less frequent findings include: cerebellar signs (ataxia, nystagmus, saccadic pursuit); retinal degeneration; pes cavus; scoliosis; and parkinsonism. Onset occurs mainly during infancy or adolescence (range: age 1-31 years). Most affected individuals become wheelchair bound one or two decades after disease onset.
Primary autosomal recessive microcephaly 4
MedGen UID:
347655
Concept ID:
C1858516
Disease or Syndrome
Primary microcephaly (MCPH) is a clinical diagnosis made when an individual has a head circumference more than 3 standard deviations below the age- and sex-matched population mean and mental retardation, with no other associated malformations and with no apparent etiology. Most cases of primary microcephaly show an autosomal recessive mode of inheritance (summary by Woods et al., 2005). For a general phenotypic description and a discussion of genetic heterogeneity of primary microcephaly, see MCPH1 (251200).
Primary autosomal recessive microcephaly 2
MedGen UID:
346929
Concept ID:
C1858535
Disease or Syndrome
Microcephaly-2 with or without cortical malformations is an autosomal recessive neurodevelopmental disorder showing phenotypic variability. Classically, primary microcephaly is a clinical diagnosis made when an individual has a head circumference more than 3 standard deviations (SD) below the age- and sex-matched population mean, and mental retardation with no other associated malformations and with no apparent etiology (Hofman, 1984). Patients with WDR62 mutations have head circumferences ranging from low-normal to severe (-9.8 SD), and most patients with brain scans have shown various types of cortical malformations. All have delayed psychomotor development; seizures are variable (summary by Yu et al., 2010). For a general phenotypic description and a discussion of genetic heterogeneity of primary microcephaly, see MCPH1 (251200).
Blepharophimosis with facial and genital anomalies and mental retardation
MedGen UID:
347661
Concept ID:
C1858538
Disease or Syndrome
Ectrodactyly, ectodermal dysplasia, and cleft lip/palate syndrome 3
MedGen UID:
347666
Concept ID:
C1858562
Disease or Syndrome
The TP63-related disorders comprise six overlapping phenotypes: Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome (which includes Rapp-Hodgkin syndrome). Acro-dermo-ungual-lacrimal-tooth (ADULT) syndrome. Ectrodactyly, ectodermal dysplasia, cleft lip/palate syndrome 3 (EEC3). Limb-mammary syndrome. Split-hand/foot malformation type 4 (SHFM4). Isolated cleft lip/cleft palate (orofacial cleft 8). Individuals typically have varying combinations of ectodermal dysplasia (subjective hypohidrosis, nail dysplasia, sparse hair, tooth abnormalities), cleft lip/palate, split-hand/foot malformation/syndactyly, lacrimal duct obstruction, hypopigmentation, and hypoplastic breasts and/or nipples. Findings associated with a single phenotype include ankyloblepharon filiforme adnatum (tissue strands that completely or partially fuse the upper and lower eyelids), skin erosions especially on the scalp associated with areas of scarring and alopecia, hypospadias, trismus, and excessive freckling.
Congenital Cataracts, Facial Dysmorphism, and Neuropathy
MedGen UID:
346973
Concept ID:
C1858726
Congenital Abnormality
Congenital cataracts, facial dysmorphism, and neuropathy (CCFDN) is characterized by abnormalities of the eye (bilateral congenital cataracts, microcornea, microphthalmia, micropupils); mildly dysmorphic facial features apparent in late childhood; and a hypo/demyelinating, symmetric, distal peripheral neuropathy. The neuropathy is predominantly motor at the onset and results in delays in early motor development, progressing to severe disability by the third decade. Secondary scoliosis and foot deformities are common. Sensory neuropathy develops after age ten years. Most affected individuals have a mild non-progressive intellectual deficit and cerebellar involvement including ataxia, nystagmus, intention tremor, and dysmetria. All have short stature and subnormal weight. Adults have hypogonadotropic hypogonadism. Parainfectious rhabdomyolysis (profound muscle weakness, myoglobinuria, and excessively elevated serum concentration of creatine kinase usually following a viral infection) is a potentially life-threatening complication. To date all affected individuals and carriers identified have been from the Roma/Gypsy population.
Rhizomelic chondrodysplasia punctata type 1
MedGen UID:
347072
Concept ID:
C1859133
Disease or Syndrome
Rhizomelic chondrodysplasia punctata type 1 (RCDP1) classic type, a peroxisome biogenesis disorder (PBD), is characterized by proximal shortening of the humerus and to a lesser degree the femur (rhizomelia), punctate calcifications in cartilage with epiphyseal and metaphyseal abnormalities (chondrodysplasia punctata, or CDP), coronal clefts of the vertebral bodies, and cataracts that are usually present at birth or appear in the first few months of life. Birth weight, length, and head circumference are often at the lower range of normal; postnatal growth deficiency is profound. Intellectual disability is severe, and the majority of children develop seizures. Most affected children do not survive the first decade of life; a proportion die in the neonatal period. A milder phenotype in which all affected individuals have congenital cataracts and chondrodysplasia is now recognized; some do not have rhizomelia, and some have less severe intellectual disability and growth deficiency.
Griscelli syndrome type 1
MedGen UID:
347092
Concept ID:
C1859194
Disease or Syndrome
Griscelli syndrome type 1 (GS1) represents hypomelanosis with a primary neurologic deficit and without immunologic impairment or manifestations of hemophagocytic syndrome (Menasche et al., 2002). Griscelli syndrome with immune impairment, or Griscelli syndrome type 2 (607624), is caused by mutation in the RAB27A gene (603868). Griscelli syndrome type 3 (609227), characterized by hypomelanosis with no immunologic or neurologic manifestations, can be caused by mutation in the melanophilin (MLPH; 606526) or MYO5A genes. Griscelli syndrome is a rare autosomal recessive disorder that results in pigmentary dilution of the skin and hair, the presence of large clumps of pigment in hair shafts, and an accumulation of melanosomes in melanocytes. While most patients also develop hemophagocytic syndrome, leading to death in the absence of bone marrow transplantation (Menasche et al., 2000), some show severe neurologic impairment early in life without apparent immune abnormalities. Bahadoran et al. (2003) characterized GS1 as comprising hypomelanosis and severe central nervous system dysfunction, corresponding to the 'dilute' phenotype in the mouse, and GS2 as comprising hypomelanosis and lymphohistiocytotic hemophagocytosis, corresponding to the 'ashen' phenotype in mouse. Anikster et al. (2002), Menasche et al. (2002), Huizing et al. (2002), and Bahadoran et al. (2003, 2003) suggested that Elejalde syndrome (256710) in some patients and GS1 represent the same entity.
Cerebrohepatorenal Syndrome, Variant Types
MedGen UID:
347830
Concept ID:
C1859228
Disease or Syndrome
Craniofacial dysmorphism, skeletal anomalies, and mental retardation syndrome
MedGen UID:
347111
Concept ID:
C1859252
Disease or Syndrome
Cerebro-facio-thoracic dysplasia is a rare condition characterized by abnormal development (dysplasia) of the brain (cerebro) and structures in the face (facio) and torso (thoracic). The problems with development lead to the key features of cerebro-facio-thoracic dysplasia, which include severe intellectual disability, distinctive facial features, and abnormalities of the ribs and spinal bones (vertebrae).In addition to intellectual disability, individuals with cerebro-facio-thoracic dysplasia have delayed development of speech and movement (motor) skills, and in some, these skills never develop. Nearly one-quarter of affected individuals never learn to speak and almost half are unable to walk. Weak muscle tone (hypotonia) and difficulty feeding occur in some affected infants. People with cerebro-facio-thoracic dysplasia can have behavioral problems, such as anxiety, autism spectrum disorder, or self-injuring behavior; however, many people with the condition are described as friendly and good-natured.Distinctive facial features common in cerebro-facio-thoracic dysplasia include a wide, short skull (brachycephaly); highly arched eyebrows or eyebrows that grow together in the middle (synophrys); widely spaced eyes (hypertelorism); a wide nasal bridge; low-set ears; an upper lip with pronounced curves (Cupid's bow upper lip); and small teeth (microdontia). Some affected individuals have overgrowth of the gums (gingival hyperplasia), an opening in the roof of the mouth (cleft palate), or a split in the upper lip (cleft lip).Problems with bone development in the torso (thorax) commonly leads to bone abnormalities such as two or more ribs that are joined together (fused) or ribs that are abnormally shaped with two prongs at one end (bifid ribs). Many people with cerebro-facio-thoracic dysplasia have abnormal side-to-side curvature of the spine (scoliosis) due to malformation of the vertebrae; some vertebrae may also be fused. Additionally, the shoulder blades can be affected in people with this condition.A wide variety of other features can occur in cerebro-facio-thoracic dysplasia, such as abnormalities involving the eyes, skin, or hair. Heart defects, digestive problems, or genitourinary problems (such as abnormal kidneys or reproductive organs) can also occur. Affected individuals may also have bone or joint abnormalities in other parts of the body.
Spinocerebellar ataxia, autosomal recessive 2
MedGen UID:
349134
Concept ID:
C1859298
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-2 is an neurologic disorder characterized by onset of impaired motor development and ataxic gait in early childhood. Additional features often include loss of fine motor skills, dysarthria, nystagmus, cerebellar signs, and delayed cognitive development with intellectual disability. Brain imaging shows cerebellar atrophy. Overall, the disorder is non- or slowly progressive, with survival into adulthood (summary by Jobling et al., 2015).
Cephalin lipidosis
MedGen UID:
395225
Concept ID:
C1859307
Disease or Syndrome
Camptodactyly syndrome Guadalajara type 1
MedGen UID:
395241
Concept ID:
C1859359
Disease or Syndrome
A rare syndrome consisting of growth retardation, facial dysmorphism, camptodactyly and skeletal anomalies. To date only eight cases have been reported in the literature. Dysmorphic features include flat face, epicanthic folds, telecanthus, small downturned mouth, small ears with attached lobule and abnormal dental eruption and occlusion. Some patients had psychomotor development delayed. The reported cases suggest the condition is hereditary and is transmitted as an autosomal recessive trait.
Microcephalic osteodysplastic primordial dwarfism type 3
MedGen UID:
349167
Concept ID:
C1859439
Disease or Syndrome
Osteodysplastic primordial dwarfism, type 1
MedGen UID:
347149
Concept ID:
C1859452
Congenital Abnormality
Microcephalic osteodysplastic primordial dwarfism type I is a severe autosomal recessive skeletal dysplasia characterized by dwarfism, microcephaly, and neurologic abnormalities, including mental retardation, brain malformations, and ocular/auditory sensory deficits. Patients often die in early childhood (summary by Pierce and Morse, 2012).
Bird headed dwarfism Montreal type
MedGen UID:
347890
Concept ID:
C1859468
Disease or Syndrome
A rare genetic multiple congenital anomalies/dysmorphic syndrome with characteristics of severe short stature and craniofacial dysmorphism (microcephaly, narrow face with flat cheeks, ptosis, prominent nose with a convex ridge, low-set ears with small or absent lobes, high-arched/cleft palate, micrognathia), associated with premature graying and loss of scalp hair, redundant, dry and wrinkled skin of the palms, premature senility and varying degrees of intellectual disability. Cryptorchidism and skeletal anomalies may also be observed. There have been no further descriptions in the literature since 1970.
Biemond syndrome II
MedGen UID:
347159
Concept ID:
C1859487
Disease or Syndrome
An exceedingly rare genetic neurological and developmental disorder reported in a very small number of patients with a poorly defined phenotype including iris coloboma, short stature, obesity, hypogonadism, post axial polydactyly, and intellectual disability. Hydrocephalus and facial dysostosis were also reported. The syndrome shares features with Bardet-Biedl syndrome. There have been no new descriptions in the literature since 1997.
3-methylcrotonyl CoA carboxylase 2 deficiency
MedGen UID:
347898
Concept ID:
C1859499
Disease or Syndrome
3-methylcrotonyl-CoA carboxylase deficiency (also known as 3-MCC deficiency) is an inherited disorder in which the body is unable to process certain proteins properly. People with this disorder have a shortage of an enzyme that helps break down proteins containing a particular building block (amino acid) called leucine.Infants with 3-MCC deficiency appear normal at birth but usually develop signs and symptoms in infancy or early childhood. The characteristic features of this condition, which can range from mild to life-threatening, include feeding difficulties, recurrent episodes of vomiting and diarrhea, excessive tiredness (lethargy), and weak muscle tone (hypotonia). If untreated, this disorder can lead to delayed development, seizures, and coma. Many of these complications can be prevented with early detection and lifelong management with a low-protein diet and appropriate supplements. Some people with gene mutations that cause 3-MCC deficiency never experience any signs or symptoms of the condition.The characteristic features of 3-MCC deficiency are similar to those of Reye syndrome, a severe disorder that develops in children while they appear to be recovering from viral infections such as chicken pox or flu. Most cases of Reye syndrome are associated with the use of aspirin during these viral infections.
Bardet-Biedl syndrome 3
MedGen UID:
347179
Concept ID:
C1859564
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Bardet-Biedl syndrome 7
MedGen UID:
347180
Concept ID:
C1859565
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Bardet-Biedl syndrome 8
MedGen UID:
347181
Concept ID:
C1859566
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Bardet-Biedl syndrome 9
MedGen UID:
347182
Concept ID:
C1859567
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Aural atresia, multiple congenital anomalies, and mental retardation
MedGen UID:
347912
Concept ID:
C1859591
Disease or Syndrome
Ataxia, deafness and cardiomyopathy
MedGen UID:
395312
Concept ID:
C1859645
Disease or Syndrome
Arthrogryposis, distal, with mental retardation and characteristic facies
MedGen UID:
347220
Concept ID:
C1859723
Disease or Syndrome
Arterial tortuosity syndrome
MedGen UID:
347942
Concept ID:
C1859726
Disease or Syndrome
Arterial tortuosity syndrome (ATS) is characterized by the following: Severe and widespread arterial tortuosity of the aorta and middle-sized arteries (with an increased risk of aneurysms and dissections) and focal and widespread stenosis which can involve the aorta and/or pulmonary arteries. The risk for ischemic vascular events involving cerebrovascular circulation and the abdominal arteries is increased. In addition, large veins may be dilated and valvular regurgitation and mitral valve prolapse can occur. Craniofacial involvement with characteristic facies and high palate with dental crowding. Soft/doughy skin and other evidence of a generalized connective tissue disorder including skeletal findings (scoliosis, pectus excavatum/carinatum, joint laxity, knee/elbow contractures, arachnodactyly, camptodactyly); inguinal/abdominal wall hernia; sliding hiatal or diaphragmatic hernia; hypotonia; and ocular involvement (myopia, keratoconus).
Aniridia renal agenesis psychomotor retardation
MedGen UID:
347952
Concept ID:
C1859782
Disease or Syndrome
Amyloidosis of gingiva and conjunctiva with mental retardation
MedGen UID:
347240
Concept ID:
C1859815
Disease or Syndrome
Amino aciduria with mental deficiency, dwarfism, muscular dystrophy, osteoporosis and acidosis
MedGen UID:
347955
Concept ID:
C1859818
Disease or Syndrome
Leber congenital amaurosis 2
MedGen UID:
348473
Concept ID:
C1859844
Disease or Syndrome
Leber congenital amaurosis comprises a group of early-onset childhood retinal dystrophies characterized by vision loss, nystagmus, and severe retinal dysfunction. Patients usually present at birth with profound vision loss and pendular nystagmus. Electroretinogram (ERG) responses are usually nonrecordable. Other clinical findings may include high hypermetropia, photodysphoria, oculodigital sign, keratoconus, cataracts, and a variable appearance to the fundus (summary by Chung and Traboulsi, 2009). For a general description and a discussion of genetic heterogeneity of LCA, see 204000.
Cerebral white matter agenesis
MedGen UID:
347986
Concept ID:
C1859969
Pathologic Function
Congenital defect with failure of the development of the cerebral white matter.
Acrofrontofacionasal dysostosis
MedGen UID:
349729
Concept ID:
C1860118
Disease or Syndrome
A very rare congenital malformation syndrome with the association of facial and skeletal anomalies, severe intellectual deficit and occasional genitourinary anomalies. The cranio-facial malformations are numerous and variable and include brachycephaly or microbrachycephaly. Other skeletal malformations are also present, with syndactyly of fingers, hypoplastic toes, anomalies of feet structure and fibular hypoplasia. Short stature may be observed. Eye anomalies include bilateral ptosis, cataract and congenital glaucoma. In some male patients, hypospadias and bifid scrotum are reported. Patients suffer from potentially severe intellectual deficit and present with anomalies of the cortical gyration.
Achalasia microcephaly syndrome
MedGen UID:
349753
Concept ID:
C1860212
Disease or Syndrome
An extremely rare genetic syndrome, reported in a few families to date with characteristics of the association of microcephaly, intellectual deficit and achalasia. Symptoms of achalasia include coughing, dysphagia, vomiting, failure to thrive and aspiration appearing in infancy/early-childhood.
Tuberous sclerosis 2
MedGen UID:
348170
Concept ID:
C1860707
Disease or Syndrome
Tuberous sclerosis complex (TSC) involves abnormalities of the skin (hypomelanotic macules, confetti skin lesions, facial angiofibromas, shagreen patches, fibrous cephalic plaques, ungual fibromas); brain (subependymal nodules, cortical dysplasias, and subependymal giant cell astrocytomas [SEGAs], seizures, intellectual disability / developmental delay, psychiatric illness); kidney (angiomyolipomas, cysts, renal cell carcinomas); heart (rhabdomyomas, arrhythmias); and lungs (lymphangioleiomyomatosis [LAM], multifocal micronodular pneumonocyte hyperplasia). Central nervous system tumors are the leading cause of morbidity and mortality; renal disease is the second leading cause of early death.
Thumb stiff brachydactyly mental retardation
MedGen UID:
396073
Concept ID:
C1861166
Disease or Syndrome
Thumb deformity and alopecia
MedGen UID:
348284
Concept ID:
C1861168
Disease or Syndrome
Brachydactyly-nystagmus-cerebellar ataxia
MedGen UID:
350589
Concept ID:
C1862099
Disease or Syndrome
Bowing of legs, anterior with dwarfism
MedGen UID:
350610
Concept ID:
C1862172
Disease or Syndrome
The diagnostic hallmarks of Weismann-Netter syndrome (WNS) are anterior bowing of the diaphyses of the tibia and fibula, broadening or 'tibialization' of the fibula, posterior cortical thickening of both bones, and short stature. The diaphyses of other long bones may be similarly affected, but usually to a milder degree. Some WNS patients have also displayed mental retardation (summary by Peippo et al., 2009).
Axenfeld-Rieger anomaly with partially absent eye muscles, distinctive face, hydrocephaly, and skeletal abnormalities
MedGen UID:
349489
Concept ID:
C1862373
Disease or Syndrome
Aortic arch anomaly with peculiar facies and mental retardation
MedGen UID:
350734
Concept ID:
C1862682
Disease or Syndrome
Amyotrophic dystonic paraplegia
MedGen UID:
354871
Concept ID:
C1862956
Disease or Syndrome
Young Simpson syndrome
MedGen UID:
350209
Concept ID:
C1863557
Disease or Syndrome
KAT6B-related disorders include genitopatellar syndrome (GPS) and Say-Barber-Biesecker variant of Ohdo syndrome (Ohdo syndrome, SBBYS variant, or SBBYSS [Say-Barber-Biesecker-Young-Simpson syndrome]). Both phenotypes are characterized by significant global developmental delay / intellectual disability, hypotonia, genital abnormalities in males (cryptorchidism), and patellar hypoplasia/agenesis. Congenital heart defects, dental anomalies, hearing loss, and thyroid anomalies are common to both phenotypes. Also observed in GPS are flexion contractures of the hips and knees, clubfoot, agenesis of the corpus callosum with microcephaly, and hydronephrosis and/or multiple renal cysts. In SBBYS lower-extremity joint stiffness, long thumbs / great toes, immobile mask-like face, blepharophimosis/ptosis, and lacrimal duct anomalies are observed.
Acromelic frontonasal dysostosis
MedGen UID:
350933
Concept ID:
C1863616
Disease or Syndrome
Verloes et al. (1992) described a rare variant of frontonasal dysplasia (see FND1, 136760), designated acromelic frontonasal dysplasia (AFND), in which similar craniofacial anomalies are associated with variable central nervous system malformations and limb defects including tibial hypoplasia/aplasia, talipes equinovarus, and preaxial polydactyly of the feet.
Muenke syndrome
MedGen UID:
355217
Concept ID:
C1864436
Disease or Syndrome
Muenke syndrome is defined by the presence of the specific FGFR3 pathogenic variant – c.749C>G – that results in the protein change p.Pro250Arg. Muenke syndrome is characterized by considerable phenotypic variability: features may include coronal synostosis (more often bilateral than unilateral); synostosis of other sutures, all sutures (pan synostosis), or no sutures; or macrocephaly. Bilateral coronal synostosis typically results in brachycephaly (reduced anteroposterior dimension of the skull), although turribrachycephaly (a "tower-shaped" skull) or a cloverleaf skull can be observed. Unilateral coronal synostosis results in anterior plagiocephaly (asymmetry of the skull and face). Other craniofacial findings typically include: temporal bossing; widely spaced eyes, ptosis or proptosis (usually mild); midface retrusion (usually mild); and highly arched palate or cleft lip and palate. Strabismus is common. Other findings can include: hearing loss (in 33%-100% of affected individuals); developmental delay (~33%); epilepsy; intracranial anomalies; intellectual disability; carpal bone and/or tarsal bone fusions; brachydactyly, broad toes, broad thumbs, and/or clinodactyly; and radiographic findings of thimble-like (short and broad) middle phalanges and/or cone-shaped epiphyses. Phenotypic variability is considerable even within the same family. Of note, some individuals who have the p.Pro250Arg pathogenic variant may have no signs of Muenke syndrome on physical or radiographic examination.
Chromosome 16p13.3 deletion syndrome, proximal
MedGen UID:
350477
Concept ID:
C1864648
Disease or Syndrome
Hypomyelination and Congenital Cataract
MedGen UID:
501134
Concept ID:
C1864663
Congenital Abnormality
Hypomyelination and congenital cataract (HCC) is usually characterized by bilateral congenital cataracts and normal psychomotor development in the first year of life, followed by slowly progressive neurologic impairment manifest as ataxia, spasticity (brisk tendon reflexes and bilateral extensor plantar responses), and mild to moderate cognitive impairment. Dysarthria and truncal hypotonia are observed. Cerebellar signs (truncal titubation and intention tremor) and peripheral neuropathy (muscle weakness and wasting of the legs) are present in the majority of affected individuals. Seizures can occur. In a few cases cataracts may be absent.
Holoprosencephaly 5
MedGen UID:
355304
Concept ID:
C1864827
Disease or Syndrome
Holoprosencephaly (HPE) is a structural anomaly of the brain in which there is failed or incomplete separation of the forebrain early in gestation. Classic HPE encompasses a continuum of brain malformations including (in order of decreasing severity): alobar, semilobar, lobar, and middle interhemispheric variant (MIHV) type HPE; a septopreoptic type has also been described. Other CNS abnormalities not specific to HPE may also occur. HPE is accompanied by a spectrum of characteristic craniofacial anomalies in approximately 80% of individuals with HPE. Developmental delay is present in virtually all individuals with the HPE spectrum of CNS anomalies. Seizures and pituitary dysfunction are common. Most affected fetuses do not survive; severely affected children typically do not survive beyond early infancy, while a significant proportion of more mildly affected children survive past 12 months. Mildly manifesting individuals without appreciable brain anomalies on conventional neuroimaging may be described as having "microform" HPE.
Camptodactyly, tall stature, and hearing loss syndrome
MedGen UID:
355844
Concept ID:
C1864852
Disease or Syndrome
Koolen-de Vries syndrome
MedGen UID:
355853
Concept ID:
C1864871
Disease or Syndrome
Koolen-de Vries syndrome (KdVS) is characterized by developmental delay/intellectual disability, neonatal/childhood hypotonia, dysmorphisms, congenital malformations, and behavioral features. Psychomotor developmental delay is noted in all individuals from an early age. The majority of individuals with KdVS function in the mild-to-moderate range of intellectual disability. Other findings include speech and language delay (100%), epilepsy (~33%), congenital heart defects (25%-50%), renal and urologic anomalies (25%-50%), and cryptorchidism (71% of males). Behavior in most is described as friendly, amiable, and cooperative.
Spondyloepimetaphyseal dysplasia Genevieve type
MedGen UID:
355314
Concept ID:
C1864872
Disease or Syndrome
Spondyloepiphyseal dysplasia of the Genevieve type (SEMDG) is characterized by infantile-onset severe developmental delay and skeletal dysplasia, including short stature, premature carpal ossification, platyspondyly, longitudinal metaphyseal striations, and small epiphyses (summary by van Karnebeek et al., 2016).
Ceroid lipofuscinosis, neuronal, 8, northern epilepsy variant
MedGen UID:
355328
Concept ID:
C1864923
Disease or Syndrome
The neuronal ceroid lipofuscinoses (NCL; CLN) are a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by the intracellular accumulation of autofluorescent lipopigment storage material in different patterns ultrastructurally. The lipopigment patterns observed most often in CLN8 comprise mixed combinations of 'granular,' 'curvilinear,' and 'fingerprint' profiles (Mole et al., 2005). For a general phenotypic description and a discussion of genetic heterogeneity of CLN, see CLN1 (256730).
Hyperinsulinemic hypoglycemia, familial, 4
MedGen UID:
400646
Concept ID:
C1864948
Disease or Syndrome
Congenital hyperinsulinism is a condition that causes individuals to have abnormally high levels of insulin, which is a hormone that helps control blood sugar levels. People with this condition have frequent episodes of low blood sugar (hypoglycemia). In infants and young children, these episodes are characterized by a lack of energy (lethargy), irritability, or difficulty feeding. Repeated episodes of low blood sugar increase the risk for serious complications such as breathing difficulties, seizures, intellectual disability, vision loss, brain damage, and coma.The severity of congenital hyperinsulinism varies widely among affected individuals, even among members of the same family. About 60 percent of infants with this condition experience a hypoglycemic episode within the first month of life. Other affected children develop hypoglycemia by early childhood. Unlike typical episodes of hypoglycemia, which occur most often after periods without food (fasting) or after exercising, episodes of hypoglycemia in people with congenital hyperinsulinism can also occur after eating.
Hypertrichosis, hyperkeratosis, mental retardation, and distinctive facial features
MedGen UID:
355879
Concept ID:
C1864967
Disease or Syndrome
Scaphocephaly, maxillary retrusion, and mental retardation
MedGen UID:
355365
Concept ID:
C1865070
Disease or Syndrome
Muscular dystrophy, congenital, megaconial type
MedGen UID:
355943
Concept ID:
C1865233
Disease or Syndrome
Megaconial-type congenital muscular dystrophy is an autosomal recessive disorder characterized by early-onset muscle wasting and mental retardation. Some patients develop fatal cardiomyopathy. Muscle biopsy shows peculiar enlarged mitochondria that are prevalent toward the periphery of the fibers but are sparse in the center (summary by Mitsuhashi et al., 2011).
Grange syndrome
MedGen UID:
355427
Concept ID:
C1865267
Disease or Syndrome
Grange syndrome is a rare condition that primarily affects the blood vessels. It is characterized by narrowing (stenosis) or blockage (occlusion) of arteries that supply blood to various organs and tissues, including the kidneys, brain, and heart. Stenosis or occlusion of the arteries that supply blood to the kidneys (renal arteries) can result in chronic high blood pressure (hypertension). Blockage of the arteries that carry blood to the brain (cerebral arteries) can cause a stroke.Additional features of Grange syndrome can include short fingers and toes (brachydactyly), fusion of some of the fingers or toes (syndactyly), fragile bones that are prone to breakage, and learning disabilities. Most people with this disorder also have heart defects that are present from birth.
Bartter syndrome type 4
MedGen UID:
355430
Concept ID:
C1865270
Disease or Syndrome
Bartter syndrome refers to a group of disorders that are unified by autosomal recessive transmission of impaired salt reabsorption in the thick ascending loop of Henle with pronounced salt wasting, hypokalemic metabolic alkalosis, and hypercalciuria. Clinical disease results from defective renal reabsorption of sodium chloride in the thick ascending limb (TAL) of the Henle loop, where 30% of filtered salt is normally reabsorbed (Simon et al., 1997). Patients with antenatal (or neonatal) forms of Bartter syndrome typically present with premature birth associated with polyhydramnios and low birth weight and may develop life-threatening dehydration in the neonatal period. Patients with classic Bartter syndrome (see BARTS3, 607364) present later in life and may be sporadically asymptomatic or mildly symptomatic (summary by Simon et al., 1996 and Fremont and Chan, 2012). For a discussion of genetic heterogeneity of Bartter syndrome, see 607364.
Megalencephaly cutis marmorata telangiectatica congenita
MedGen UID:
355421
Concept ID:
C1865285
Disease or Syndrome
PIK3CA-associated segmental overgrowth includes disorders of brain (e.g., MCAP [megalencephaly-capillary malformation] syndrome, hemimegalencephaly); and segmental body overgrowth (e.g., CLOVES [congenital lipomatous asymmetric overgrowth of the trunk, lymphatic, capillary, venous, and combined-type vascular malformations, epidermal nevi, skeletal and spinal anomalies] syndrome, fibroadipose hyperplasia [FH]). Heterozygous (usually somatic mosaic) pathogenic variants of PIK3CA are causative. MCAP syndrome is characterized by the major findings of (1) megalencephaly (MEG) or hemimegalencephaly (HMEG) associated with neurologic findings of hypotonia, seizures, and mild to severe intellectual disability; and (2) cutaneous capillary malformations with focal or generalized somatic overgrowth. Additional findings can include digital anomalies (syndactyly, polydactyly), cortical malformations – most distinctively polymicrogyria (PMG); and variable connective tissue dysplasia. CLOVES (or CLOVE) syndrome and fibroadipose hyperplasia (FH) may be associated with (1) MEG or HMEG; and (2) patchy segmental overgrowth associated with skeletal anomalies, lipomatosis, vascular malformations, and epidermal nevi.
Hyperinsulinemic hypoglycemia familial 3
MedGen UID:
355435
Concept ID:
C1865290
Disease or Syndrome
Congenital hyperinsulinism is a condition that causes individuals to have abnormally high levels of insulin, which is a hormone that helps control blood sugar levels. People with this condition have frequent episodes of low blood sugar (hypoglycemia). In infants and young children, these episodes are characterized by a lack of energy (lethargy), irritability, or difficulty feeding. Repeated episodes of low blood sugar increase the risk for serious complications such as breathing difficulties, seizures, intellectual disability, vision loss, brain damage, and coma.The severity of congenital hyperinsulinism varies widely among affected individuals, even among members of the same family. About 60 percent of infants with this condition experience a hypoglycemic episode within the first month of life. Other affected children develop hypoglycemia by early childhood. Unlike typical episodes of hypoglycemia, which occur most often after periods without food (fasting) or after exercising, episodes of hypoglycemia in people with congenital hyperinsulinism can also occur after eating.
Familial hemiplegic migraine type 2
MedGen UID:
355962
Concept ID:
C1865322
Disease or Syndrome
Familial hemiplegic migraine (FHM) falls within the category of migraine with aura. In migraine with aura (including familial hemiplegic migraine) the neurologic symptoms of aura are unequivocally localizable to the cerebral cortex or brain stem and include visual disturbance (most common), sensory loss (e.g., numbness or paresthesias of the face or an extremity), and dysphasia (difficulty with speech); FHM must include motor involvement, i.e., hemiparesis (weakness of an extremity). Hemiparesis occurs with at least one other symptom during FHM aura. Neurologic deficits with FHM attacks can be prolonged for hours to days and may outlast the associated migrainous headache. FHM is often earlier in onset than typical migraine, frequently beginning in the first or second decade; the frequency of attacks tends to decrease with age. Approximately 40%-50% of families with FHM1 have cerebellar signs ranging from nystagmus to progressive, usually late-onset mild ataxia. Cerebral infarction and death have rarely been associated with hemiplegic migraine.
Ethylmalonic encephalopathy
MedGen UID:
355966
Concept ID:
C1865349
Disease or Syndrome
Ethylmalonic encephalopathy (EE) is a severe, early-onset, progressive disorder characterized by developmental delay / mild-to-severe intellectual disability; generalized infantile hypotonia that evolves into hypertonia, spasticity, and (in some instances) dystonia; generalized tonic-clonic seizures; and generalized microvascular damage (diffuse and spontaneous relapsing petechial purpura, hemorrhagic suffusions of mucosal surfaces, and chronic hemorrhagic diarrhea). Infants sometimes have frequent vomiting and loss of social interaction. Speech is delayed and in some instances absent. Swallowing difficulties and failure to thrive are common. Children may be unable to walk without support and may be wheelchair bound. Neurologic deterioration accelerates following intercurrent infectious illness, and the majority of children die in the first decade.
Phosphoglycerate dehydrogenase deficiency
MedGen UID:
400935
Concept ID:
C1866174
Disease or Syndrome
Phosphoglycerate dehydrogenase deficiency is an autosomal recessive inborn error of L-serine biosynthesis that is characterized by congenital microcephaly, psychomotor retardation, and seizures (summary by Jaeken et al., 1996).
Ehlers-Danlos syndrome, musculocontractural type
MedGen UID:
356497
Concept ID:
C1866294
Disease or Syndrome
The Ehlers-Danlos syndromes (EDS) are a group of heritable connective tissue disorders that share the common features of skin hyperextensibility, articular hypermobility, and tissue fragility (Beighton et al., 1998). The major characteristics of the musculocontractural form of EDS include distinctive craniofacial dysmorphism, congenital contractures of thumbs and fingers, clubfeet, severe kyphoscoliosis, muscular hypotonia, hyperextensible thin skin with easy bruisability and atrophic scarring, wrinkled palms, joint hypermobility, and ocular involvement (summary by Malfait et al., 2010). Janecke et al. (2015) reviewed the clinical findings in 34 reported EDSMC patients, 31 with CHST14 mutations and 3 with DSE (605942) mutations (see 615539), and stated that the disorder can be recognized based on the presence of distal arthrogryposis, including adducted thumbs or clenched fists and talipes equinovarus, as well as hands with atypically shallow palmar creases and tapering fingers, and neonatal muscular hypotonia. Characteristic craniofacial features include brachycephaly, large fontanel, hypertelorism, downslanting palpebral fissures, microcorneae, strabismus, prominent nasolabial folds, short philtrum, thin upper lip, small mouth, high palate, microretrognathia, and prominent and often low-set and posteriorly rotated ears. In addition, EDSMC patients show muscular hypoplasia and weakness, which has been confirmed by ultrasound and electromyography, and intellectual development appears to be normal. Genetic Heterogeneity of Musculocontractural Ehlers-Danlos Syndrome Ehlers-Danlos syndrome musculocontractural type 2 (EDSMC2; 615539) is caused by mutation in the DSE gene (605942) on chromosome 6q22.
Peroxisome Biogenesis Disorder, Complementation Group 11
MedGen UID:
356213
Concept ID:
C1866351
Disease or Syndrome
Peroxisome biogenesis disorder, complementation group R
MedGen UID:
356512
Concept ID:
C1866352
Disease or Syndrome
Bartter syndrome, type 1, antenatal
MedGen UID:
355727
Concept ID:
C1866495
Disease or Syndrome
Bartter syndrome refers to a group of disorders that are unified by autosomal recessive transmission of impaired salt reabsorption in the thick ascending loop of Henle with pronounced salt wasting, hypokalemic metabolic alkalosis, and hypercalciuria. Clinical disease results from defective renal reabsorption of sodium chloride in the thick ascending limb (TAL) of the Henle loop, where 30% of filtered salt is normally reabsorbed (Simon et al., 1997). Patients with antenatal forms of Bartter syndrome typically present with premature birth associated with polyhydramnios and low birth weight and may develop life-threatening dehydration in the neonatal period. Patients with classic Bartter syndrome (see BARTS3, 607364) present later in life and may be sporadically asymptomatic or mildly symptomatic (summary by Simon et al., 1996 and Fremont and Chan, 2012). For a discussion of genetic heterogeneity of Bartter syndrome, see 607364.
Trichothiodystrophy 1, photosensitive
MedGen UID:
355730
Concept ID:
C1866504
Disease or Syndrome
Trichothiodystrophy (TTD) is a rare autosomal recessive disorder in which patients have brittle, sulfur-deficient hair that displays a diagnostic alternating light and dark banding pattern, called 'tiger tail banding,' under polarizing microscopy. TTD patients display a wide variety of clinical features, including cutaneous, neurologic, and growth abnormalities. Common additional clinical features are ichthyosis, intellectual/developmental disabilities, decreased fertility, abnormal characteristics at birth, ocular abnormalities, short stature, and infections. There are both photosensitive and nonphotosensitive forms of the disorder. TTD patients have not been reported to have a predisposition to cancer (summary by Faghri et al., 2008). Genetic Heterogeneity of Trichothiodystrophy Also see TTD2 (616390), caused by mutation in the ERCC3/XPB gene (133510); TTD3 (616395), caused by mutation in the GTF2H5 gene (608780); TTD4 (234050), caused by mutation in the MPLKIP gene (609188); TTD5 (300953), caused by mutation in the RNF113A gene (300951); and TTD6 (616943), caused by mutation in the GTF2E2 gene (189964).
Spastic paraplegia with precocious puberty
MedGen UID:
401096
Concept ID:
C1866850
Disease or Syndrome
Spastic paraplegia, sensorineural deafness, mental retardation, and progressive nephropathy
MedGen UID:
355816
Concept ID:
C1866853
Disease or Syndrome
Spastic paraplegia epilepsy mental retardation
MedGen UID:
356631
Concept ID:
C1866854
Disease or Syndrome
Spastic paraplegia 4, autosomal dominant
MedGen UID:
401097
Concept ID:
C1866855
Disease or Syndrome
Spastic paraplegia 4 (SPG4; also known as SPAST-HSP) is characterized by insidiously progressive bilateral lower-limb gait spasticity. More than 50% of affected individuals have some weakness in the legs and impaired vibration sense at the ankles. Sphincter disturbances are very common. Onset is insidious, mostly in young adulthood, although symptoms may start as early as age one year and as late as age 76 years. Intrafamilial variation is considerable.
Pterygia, mental retardation and distinctive craniofacial features
MedGen UID:
357988
Concept ID:
C1867443
Disease or Syndrome
This syndrome has manifestation of short stature, craniofacial anomalies and genital hypoplasia. Intellectual deficit is also found in the majority of cases, sometimes together with pterygia. Less than 20 cases have been described so far. The mode of transmission is likely to be autosomal dominant with incomplete penetrance. The syndrome is caused by unbalanced reciprocal translocations of the distal parts of chromosomes 6q and 9p, leading to partial trisomy of the distal region of chromosome 6q and partial monosomy of the distal region of chromosome 9p.
Familial porencephaly
MedGen UID:
401353
Concept ID:
C1867983
Disease or Syndrome
Familial porencephaly is part of a group of conditions called the COL4A1-related disorders. The conditions in this group have a range of signs and symptoms that involve fragile blood vessels. In familial porencephaly, fluid-filled cysts develop in the brain (porencephaly) during fetal development or soon after birth. These cysts typically occur in only one side of the brain and vary in size. The cysts are thought to be the result of bleeding within the brain (hemorrhagic stroke). People with this condition also have leukoencephalopathy, which is a change in a type of brain tissue called white matter that can be seen with magnetic resonance imaging (MRI).During infancy, people with familial porencephaly typically have paralysis affecting one side of the body (infantile hemiplegia). Affected individuals may also have recurrent seizures (epilepsy), migraine headaches, speech problems, intellectual disability, and uncontrolled muscle tensing (dystonia). Some people are severely affected, and others may have no symptoms related to the brain cysts.
Orofaciodigital syndrome 5
MedGen UID:
358131
Concept ID:
C1868118
Disease or Syndrome
Oral-facial-digital syndrome is actually a group of related conditions that affect the development of the oral cavity (the mouth and teeth), facial features, and digits (fingers and toes).Researchers have identified at least 13 potential forms of oral-facial-digital syndrome. The different types are classified by their patterns of signs and symptoms. However, the features of the various types overlap significantly, and some types are not well defined. The classification system for oral-facial-digital syndrome continues to evolve as researchers find more affected individuals and learn more about this disorder.The signs and symptoms of oral-facial-digital syndrome vary widely. However, most forms of this disorder involve problems with development of the oral cavity, facial features, and digits. Most forms are also associated with brain abnormalities and some degree of intellectual disability.Abnormalities of the oral cavity that occur in many types of oral-facial-digital syndrome include a split (cleft) in the tongue, a tongue with an unusual lobed shape, and the growth of noncancerous tumors or nodules on the tongue. Affected individuals may also have extra, missing, or defective teeth. Another common feature is an opening in the roof of the mouth (a cleft palate). Some people with oral-facial-digital syndrome have bands of extra tissue (called hyperplastic frenula) that abnormally attach the lip to the gums.Distinctive facial features often associated with oral-facial-digital syndrome include a split in the lip (a cleft lip); a wide nose with a broad, flat nasal bridge; and widely spaced eyes (hypertelorism).Abnormalities of the digits can affect both the fingers and the toes in people with oral-facial-digital syndrome. These abnormalities include fusion of certain fingers or toes (syndactyly), digits that are shorter than usual (brachydactyly), or digits that are unusually curved (clinodactyly). The presence of extra digits (polydactyly) is also seen in most forms of oral-facial-digital syndrome.Other features occur in only one or a few types of oral-facial digital syndrome. These features help distinguish the different forms of the disorder. For example, the most common form of oral-facial-digital syndrome, type I, is associated with polycystic kidney disease. This kidney disease is characterized by the growth of fluid-filled sacs (cysts) that interfere with the kidneys' ability to filter waste products from the blood. Other forms of oral-facial-digital syndrome are characterized by neurological problems, particular changes in the structure of the brain, bone abnormalities, vision loss, and heart defects.
Telfer Sugar Jaeger syndrome
MedGen UID:
358177
Concept ID:
C1868311
Disease or Syndrome
Meier-Gorlin syndrome
MedGen UID:
401501
Concept ID:
C1868684
Disease or Syndrome
Meier-Gorlin syndrome is a condition primarily characterized by short stature. It is considered a form of primordial dwarfism because the growth problems begin before birth (intrauterine growth retardation). After birth, affected individuals continue to grow at a slow rate. Other characteristic features of this condition are underdeveloped or missing kneecaps (patellae), small ears, and, often, an abnormally small head (microcephaly). Despite a small head size, most people with Meier-Gorlin syndrome have normal intellect.Some people with Meier-Gorlin syndrome have other skeletal abnormalities, such as unusually narrow long bones in the arms and legs, a deformity of the knee joint that allows the knee to bend backwards (genu recurvatum), and slowed mineralization of bones (delayed bone age).Most people with Meier-Gorlin syndrome have distinctive facial features. In addition to being abnormally small, the ears may be low-set or rotated backward. Additional features can include a small mouth (microstomia), an underdeveloped lower jaw (micrognathia), full lips, and a narrow nose with a high nasal bridge.Abnormalities in sexual development may also occur in Meier-Gorlin syndrome. In some males with this condition, the testes are small or undescended (cryptorchidism). Affected females may have unusually small external genital folds (hypoplasia of the labia majora) and small breasts. Both males and females with this condition can have sparse or absent underarm (axillary) hair.Additional features of Meier-Gorlin syndrome can include difficulty feeding and a lung condition known as pulmonary emphysema or other breathing problems.
Frontonasal dysplasia 1
MedGen UID:
406292
Concept ID:
C1876203
Congenital Abnormality
Frontonasal dysplasia is a condition that results from abnormal development of the head and face before birth. People with frontonasal dysplasia have at least two of the following features: widely spaced eyes (ocular hypertelorism); a broad nose; a slit (cleft) in one or both sides of the nose; no nasal tip; a central cleft involving the nose, upper lip, or roof of the mouth (palate); incomplete formation of the front of the skull with skin covering the head where bone should be (anterior cranium bifidum occultum); or a widow's peak hairline.Other features of frontonasal dysplasia can include additional facial malformations, absence or malformation of the tissue that connects the left and right halves of the brain (the corpus callosum), and intellectual disability.There are at least three types of frontonasal dysplasia that are distinguished by their genetic causes and their signs and symptoms. In addition to the features previously described, each type of frontonasal dysplasia is associated with other distinctive features. Individuals with frontonasal dysplasia type 1 typically have abnormalities of the nose, a long area between the nose and upper lip (philtrum), and droopy upper eyelids (ptosis). Individuals with frontonasal dysplasia type 2 can have hair loss (alopecia) and an enlarged opening in the two bones that make up much of the top and sides of the skull (enlarged parietal foramina). Males with this form of the condition often have genital abnormalities. Features of frontonasal dysplasia type 3 include eyes that are missing (anophthalmia) or very small (microphthalmia) and low-set ears that are rotated backward. Frontonasal dysplasia type 3 is typically associated with the most severe facial abnormalities, but the severity of the condition varies widely, even among individuals with the same type.Life expectancy of affected individuals depends on the severity of the malformations and whether or not surgical intervention can improve associated health problems, such as breathing and feeding problems caused by the facial clefts.
Joubert syndrome 7
MedGen UID:
369401
Concept ID:
C1969053
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Mental retardation, autosomal dominant 1
MedGen UID:
409857
Concept ID:
C1969562
Disease or Syndrome
MBD5 haploinsufficiency is a neurodevelopmental disorder characterized by developmental delay / intellectual disability (ID), severe speech impairment, seizures, sleep disturbances, and abnormal behaviors. Most children lack speech entirely or have single words, short phrases, or short sentences. Seizures are present in about 80%; onset is usually around age two years. Sleep disturbances, present in about 80%, can result in excessive daytime drowsiness. Abnormal behaviors can include autistic-like behaviors (80%) and self-injury and aggression (60%).
Autism 8
MedGen UID:
409897
Concept ID:
C1969710
Finding
Autism, the prototypic pervasive developmental disorder (PDD), is usually apparent by 3 years of age. It is characterized by a triad of limited or absent verbal communication, a lack of reciprocal social interaction or responsiveness, and restricted, stereotypical, and ritualized patterns of interests and behavior (Bailey et al., 1996; Risch et al., 1999). 'Autism spectrum disorder,' sometimes referred to as ASD, is a broader phenotype encompassing the less severe disorders Asperger syndrome (see ASPG1; 608638) and pervasive developmental disorder, not otherwise specified (PDD-NOS). 'Broad autism phenotype' includes individuals with some symptoms of autism, but who do not meet the full criteria for autism or other disorders. Mental retardation coexists in approximately two-thirds of individuals with ASD, except for Asperger syndrome, in which mental retardation is conspicuously absent (Jones et al., 2008). Genetic studies in autism often include family members with these less stringent diagnoses (Schellenberg et al., 2006). For a discussion of genetic heterogeneity of autism, see 209850.
Mental retardation, fra12a type
MedGen UID:
369613
Concept ID:
C1969893
Disease or Syndrome
FRA12A is a folate-sensitive chromosomal fragile site prone to breakage. No consistent phenotype has been observed with FRA12A, and it can be inherited without phenotypic effect (Berg et al., 2000). However, mental retardation with or without other anomalies has been described in patients with over 40% of cells expressing FRA12A (Winnepenninckx et al., 2007).
Congenital disorder of glycosylation type 2H
MedGen UID:
409971
Concept ID:
C1970021
Disease or Syndrome
Syndrome with characteristics of severe psychomotor retardation, failure to thrive and intolerance to wheat and dairy products. So far, only two cases have been described. The disease is caused by mutations in the COG8 gene, which encodes a subunit of the COG complex. This complex is involved vesicle transport in the Golgi apparatus.
Aplasia Cutis Congenita, Congenital Heart Defect, And Frontonasal Cysts
MedGen UID:
370187
Concept ID:
C1970140
Disease or Syndrome
Mental retardation, autosomal recessive 4
MedGen UID:
370844
Concept ID:
C1970179
Disease or Syndrome
Mental retardation, autosomal recessive 7
MedGen UID:
370847
Concept ID:
C1970197
Disease or Syndrome
Mental retardation, autosomal recessive 6
MedGen UID:
370848
Concept ID:
C1970198
Disease or Syndrome
Mental retardation, autosomal recessive 5
MedGen UID:
370849
Concept ID:
C1970199
Disease or Syndrome
Mental retardation, autosomal recessive 12
MedGen UID:
370850
Concept ID:
C1970200
Disease or Syndrome
Polyhydramnios, megalencephaly, and symptomatic epilepsy
MedGen UID:
370203
Concept ID:
C1970203
Disease or Syndrome
Renal tubular acidosis, proximal, with ocular abnormalities and mental retardation
MedGen UID:
370883
Concept ID:
C1970309
Disease or Syndrome
Xeroderma Pigmentosum B-Cockayne Syndrome
MedGen UID:
373493
Concept ID:
C1970808
Disease or Syndrome
Mental retardation, syndromic 14, X-linked
MedGen UID:
372646
Concept ID:
C1970822
Disease or Syndrome
Phosphoribosylpyrophosphate synthetase superactivity
MedGen UID:
370358
Concept ID:
C1970827
Disease or Syndrome
Phosphoribosylpyrophosphate synthetase (PRS) superactivity is characterized by hyperuricemia and hyperuricosuria and is divided into a severe phenotype with infantile or early-childhood onset and a milder phenotype with late-juvenile or early-adult onset. Variable combinations of sensorineural hearing loss, hypotonia, and ataxia observed in the severe type are not usually present in the mild type. In the mild type, uric acid crystalluria or a urinary stone is commonly the first clinical finding, followed later by gouty arthritis if serum urate concentration is not controlled.
Leukoencephalopathy with metaphyseal chondrodysplasia
MedGen UID:
373499
Concept ID:
C1970840
Disease or Syndrome
Phosphoglycerate kinase 1 deficiency
MedGen UID:
410166
Concept ID:
C1970848
Disease or Syndrome
Phosphoglycerate kinase-1 deficiency is an X-linked recessive condition with a highly variable clinical phenotype that includes hemolytic anemia, myopathy, and neurologic involvement. Patients can express 1, 2, or all 3 of these manifestations (Shirakawa et al., 2006).
Macrocephalus
MedGen UID:
745757
Concept ID:
C2243051
Finding
Occipitofrontal (head) circumference greater than 97th centile compared to appropriate, age matched, sex-matched normal standards. Alternatively, a apparently increased size of the cranium.
Epilepsy, progressive myoclonic 3
MedGen UID:
388595
Concept ID:
C2673257
Disease or Syndrome
Mutations in the KCTD7 gene cause a severe neurodegenerative phenotype characterized by onset of intractable myoclonic seizures before age 2 years and accompanied by developmental regression. The initial description was consistent with a form of progressive myoclonic epilepsy (designated here as EPM3), whereas a later report identified intracellular accumulation of autofluorescent lipopigment storage material, consistent with neuronal ceroid lipofuscinosis (designated CLN14). Ultrastructural findings on skin biopsies thus appear to be variable. However, clinical features are generally consistent between reports (summary by Staropoli et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of progressive myoclonic epilepsy, see EPM1A (254800). For a general phenotypic description and a discussion of genetic heterogeneity of neuronal ceroid lipofuscinosis, see CLN1 (256730).
Dibasic amino aciduria i
MedGen UID:
435997
Concept ID:
C2673736
Disease or Syndrome
Bardet-Biedl syndrome 13
MedGen UID:
393032
Concept ID:
C2673873
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Bardet-Biedl syndrome 14
MedGen UID:
393033
Concept ID:
C2673874
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Severe achondroplasia with developmental delay and acanthosis nigricans
MedGen UID:
393098
Concept ID:
C2674173
Congenital Abnormality
SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans) is a rare disorder of bone growth characterized by skeletal, brain, and skin abnormalities.All people with this condition have extremely short stature with particularly short arms and legs. Other features include unusual bowing of the leg bones; a small chest with short ribs and curved collar bones; short, broad fingers; and folds of extra skin on the arms and legs. Structural abnormalities of the brain cause seizures, profound developmental delay, and intellectual disability. Several affected individuals also have had episodes in which their breathing slows or stops for short periods (apnea). Acanthosis nigricans, a progressive skin disorder characterized by thick, dark, velvety skin, is another characteristic feature of SADDAN that develops in infancy or early childhood.
Faciocardiomelic syndrome
MedGen UID:
436265
Concept ID:
C2674798
Disease or Syndrome
Loeys-Dietz Syndrome, Type 1b
MedGen UID:
390653
Concept ID:
C2674876
Disease or Syndrome
Chromosome 10q26 deletion syndrome
MedGen UID:
436306
Concept ID:
C2674937
Disease or Syndrome
3q29 microdeletion syndrome
MedGen UID:
393265
Concept ID:
C2674949
Disease or Syndrome
3q29 recurrent deletion is characterized by global developmental delay and/or intellectual disability, and commonly, speech delay, and increased risk for neuropsychiatric disorders (including autism spectrum disorder, anxiety disorder, psychosis, and/or schizophrenia). Other common findings are failure to thrive and feeding problems in infancy that persist into childhood, heart defects (especially patent ductus arteriosus), gastrointestinal disorders (including gastroesophageal reflux disease), and dental abnormalities. To date findings in fewer than 50 affected individuals have been reported.
Arginine:glycine amidinotransferase deficiency
MedGen UID:
436367
Concept ID:
C2675179
Disease or Syndrome
The cerebral creatine deficiency syndromes (CCDS), inborn errors of creatine metabolism, include the two creatine biosynthesis disorders, guanidinoacetate methyltransferase (GAMT) deficiency and L-arginine:glycine amidinotransferase (AGAT) deficiency, and the creatine transporter (CRTR) deficiency. Intellectual disability and seizures are common to all three CCDS. The majority of individuals with GAMT deficiency have a behavior disorder that can include autistic behaviors and self-mutilation; about 40% have movement disorder. Onset is between ages three months and three years. Only 14 individuals with AGAT deficiency have been reported. The phenotype of CRTR deficiency in affected males ranges from mild intellectual disability and speech delay to severe intellectual disability, seizures, movement disorder and behavior disorder; age at diagnosis ranges from two to 66 years. Clinical phenotype of females heterozygous for CRTR deficiency ranges from asymptomatic to severe phenotype resembling male phenotype.
Primary autosomal recessive microcephaly 7
MedGen UID:
436370
Concept ID:
C2675187
Disease or Syndrome
Autosomal recessive primary microcephaly (often shortened to MCPH, which stands for "microcephaly primary hereditary") is a condition in which infants are born with a very small head and a small brain. The term "microcephaly" comes from the Greek words for "small head."Infants with MCPH have an unusually small head circumference compared to other infants of the same sex and age. Head circumference is the distance around the widest part of the head, measured by placing a measuring tape above the eyebrows and ears and around the back of the head. Affected infants' brain volume is also smaller than usual, although they usually do not have any major abnormalities in the structure of the brain. The head and brain grow throughout childhood and adolescence, but they continue to be much smaller than normal.MCPH causes intellectual disability, which is typically mild to moderate and does not become more severe with age. Most affected individuals have delayed speech and language skills. Motor skills, such as sitting, standing, and walking, may also be mildly delayed.People with MCPH usually have few or no other features associated with the condition. Some have a narrow, sloping forehead; mild seizures; problems with attention or behavior; or short stature compared to others in their family. The condition typically does not affect any other major organ systems or cause other health problems.
Chromosome 15q11-q13 duplication syndrome
MedGen UID:
390767
Concept ID:
C2675336
Disease or Syndrome
15q duplication syndrome and related disorders (dup15q) are caused by presence of at least one extra maternally derived copy of the Prader-Willi/Angelman critical region (PWACR) within chromosome 15q11.2-q13.1. The extra copy or copies most commonly arise by one of two mechanisms: A maternal isodicentric 15q11.2-q13.1 supernumerary chromosome – idic(15) – typically comprising two extra copies of 15q11.2-q13.1 and resulting in tetrasomy for 15q11.2-q13.1 (~80% of cases); A maternal interstitial 15q11.2-q13.1 duplication that typically includes one extra copy of 15q11.2-q13.1 within chromosome 15, resulting in trisomy for 15q11.2-q13.1 (~20% of cases). Dup15q is characterized by hypotonia and motor delays, intellectual disability, autism spectrum disorder (ASD), and epilepsy including infantile spasms. Rarely, dup15q may also be associated with psychosis or sudden unexplained death. Those with maternal idic(15) are typically more severely affected than those with an interstitial duplication.
22q11.2 duplication syndrome
MedGen UID:
436417
Concept ID:
C2675369
Disease or Syndrome
22q11.2 duplication is defined for this GeneReview as the presence of a common 3-Mb or 1.5-Mb proximal tandem duplication. The 22q11.2 duplication phenotype appears to be generally mild and highly variable; findings range from apparently normal to intellectual disability/learning disability, delayed psychomotor development, growth retardation, and/or hypotonia. The high frequency with which the 22q11.2 duplication is found in an apparently normal parent of a proband suggests that many individuals can harbor a duplication of 22q11.2 with no discernible phenotypic effect.
Chromosome 15q26-qter deletion syndrome
MedGen UID:
390804
Concept ID:
C2675463
Disease or Syndrome
Mental retardation, autosomal dominant 5
MedGen UID:
382611
Concept ID:
C2675473
Disease or Syndrome
SYNGAP1-related intellectual disability (SYNGAP1-ID) is characterized by developmental delay (DD) or intellectual disability (ID) (100% of affected individuals), generalized epilepsy (~84%), and autism spectrum disorder (ASD) and other behavioral abnormalities (=50%). To date more than 50 individuals with SYNGAP1-ID have been reported. In the majority DD/ID was moderate to severe; in some it was mild. The epilepsy is generalized; a subset of individuals with epilepsy have myoclonic astatic epilepsy (Doose syndrome) or epilepsy with myoclonic absences. Behavioral abnormalities can include stereotypic behaviors (e.g., hand flapping, obsessions with certain objects) as well as poor social development. Feeding difficulties can be significant in some.
Chromosome 6pter-p24 deletion syndrome
MedGen UID:
393396
Concept ID:
C2675486
Disease or Syndrome
Mental retardation, autosomal dominant 4
MedGen UID:
393397
Concept ID:
C2675487
Disease or Syndrome
Mental retardation, autosomal dominant 3
MedGen UID:
436447
Concept ID:
C2675488
Disease or Syndrome
Chromosome 1q41-q42 deletion syndrome
MedGen UID:
382704
Concept ID:
C2675857
Disease or Syndrome
Nonsyndromic holoprosencephaly is an abnormality of brain development that also affects the head and face. Normally, the brain divides into two halves (hemispheres) during early development. Holoprosencephaly occurs when the brain fails to divide properly into the right and left hemispheres. This condition is called nonsyndromic to distinguish it from other types of holoprosencephaly caused by genetic syndromes, chromosome abnormalities, or substances that cause birth defects (teratogens). The severity of nonsyndromic holoprosencephaly varies widely among affected individuals, even within the same family.Nonsyndromic holoprosencephaly can be grouped into four types according to the degree of brain division. From most to least severe, the types are known as alobar, semi-lobar, lobar, and middle interhemispheric variant (MIHV). In the most severe forms of nonsyndromic holoprosencephaly, the brain does not divide at all. These affected individuals have one central eye (cyclopia) and a tubular nasal structure (proboscis) located above the eye. Most babies with severe nonsyndromic holoprosencephaly die before birth or soon after. In the less severe forms, the brain is partially divided and the eyes are usually set close together (hypotelorism). The life expectancy of these affected individuals varies depending on the severity of symptoms.People with nonsyndromic holoprosencephaly often have a small head (microcephaly), although they can develop a buildup of fluid in the brain (hydrocephalus) that causes increased head size (macrocephaly). Other features may include an opening in the roof of the mouth (cleft palate) with or without a split in the upper lip (cleft lip), one central front tooth instead of two (a single maxillary central incisor), and a flat nasal bridge. The eyeballs may be abnormally small (microphthalmia) or absent (anophthalmia).Some individuals with nonsyndromic holoprosencephaly have a distinctive pattern of facial features, including a narrowing of the head at the temples, outside corners of the eyes that point upward (upslanting palpebral fissures), large ears, a short nose with upturned nostrils, and a broad and deep space between the nose and mouth (philtrum). In general, the severity of facial features is directly related to the severity of the brain abnormalities. However, individuals with mildly affected facial features can have severe brain abnormalities. Some people do not have apparent structural brain abnormalities but have some of the facial features associated with this condition. These individuals are considered to have a form of the disorder known as microform holoprosencephaly and are typically identified after the birth of a severely affected family member.Most people with nonsyndromic holoprosencephaly have developmental delay and intellectual disability. Affected individuals also frequently have a malfunctioning pituitary gland, which is a gland located at the base of the brain that produces several hormones. Because pituitary dysfunction leads to the partial or complete absence of these hormones, it can cause a variety of disorders. Most commonly, people with nonsyndromic holoprosencephaly and pituitary dysfunction develop diabetes insipidus, a condition that disrupts the balance between fluid intake and urine excretion. Dysfunction in other parts of the brain can cause seizures, feeding difficulties, and problems regulating body temperature, heart rate, and breathing. The sense of smell may be diminished (hyposmia) or completely absent (anosmia) if the part of the brain that processes smells is underdeveloped or missing.
2p15-16.1 microdeletion syndrome
MedGen UID:
390902
Concept ID:
C2675875
Disease or Syndrome
Chromosome 2p16.1-p15 deletion syndrome is a neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, and variable but distinctive dysmorphic features, including microcephaly, bitemporal narrowing, smooth and long philtrum, hypertelorism, downslanting palpebral fissures, broad nasal root, thin upper lip, and high palate. Many patients have behavioral disorders, including autistic features, as well as structural brain abnormalities, such as pachygyria or hypoplastic corpus callosum. Those with deletions including the BCL11A gene (606557) also have persistence of fetal hemoglobin (HbF), which is asymptomatic and does not affected hematologic parameters or susceptibility to infection (summary by Funnell et al., 2015). Point mutation in the BCL11A gene causes intellectual developmental disorder with persistence of fetal hemoglobin (617101), which shows overlapping features. See also fetal hemoglobin quantitative trait locus-5 (HBFQTL5; 142335).
1q21.1 recurrent microdeletion
MedGen UID:
393913
Concept ID:
C2675897
Congenital Abnormality
The 1q21.1 recurrent microdeletion itself does not appear to lead to a clinically recognizable syndrome as some persons with the deletion have no obvious clinical findings and others have variable findings that most commonly include microcephaly (50%), mild intellectual disability (30%), mildly dysmorphic facial features, and eye abnormalities (26%). Other findings can include cardiac defects, genitourinary anomalies, skeletal malformations, and seizures (~15%). Psychiatric and behavioral abnormalities can include autism spectrum disorders, attention deficit hyperactivity disorder, autistic features, and sleep disturbances.
Diamond-Blackfan anemia 1
MedGen UID:
390966
Concept ID:
C2676137
Disease or Syndrome
Diamond-Blackfan anemia (DBA) in its classic form is characterized by a profound normochromic and usually macrocytic anemia with normal leukocytes and platelets, congenital malformations in up to 50% of affected individuals, and growth retardation in 30% of affected individuals. The hematologic complications occur in 90% of affected individuals during the first year of life. The phenotypic spectrum ranges from a mild form (e.g., mild anemia, no anemia with only subtle erythroid abnormalities, physical malformations without anemia) to a severe form of fetal anemia resulting in nonimmune hydrops fetalis. DBA is associated with an increased risk for acute myelogenous leukemia (AML), myelodysplastic syndrome (MDS), and solid tumors including osteogenic sarcoma.
Skeletal defects, genital hypoplasia, and mental retardation
MedGen UID:
382795
Concept ID:
C2676231
Disease or Syndrome
Leukodystrophy, hypomyelinating, 6
MedGen UID:
436642
Concept ID:
C2676244
Disease or Syndrome
TUBB4A-related leukodystrophy comprises a phenotypic spectrum in which the MRI findings range from hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) at the severe end to isolated hypomyelination at the mild end. Progressive neurologic findings reflect involvement of the pyramidal tracts (spasticity, brisk deep tendon reflexes, and Babinski sign), extrapyramidal system (rigidity, dystonia, choreoathetosis, oculogyric crisis, and perioral dyskinesia), cerebellum (ataxia, intention tremor, dysmetria), and bulbar function (dysarthria, dysphonia, and swallowing). Cognition is variably affected, usually less severely than motor function. Typically, those with H-ABC present in early childhood (ages one to three years) and those with isolated hypomyelination in later childhood or adulthood. The rate of progression varies with disease severity.
CHROMOSOME 1qter DELETION SYNDROME
MedGen UID:
382926
Concept ID:
C2676727
Disease or Syndrome
Chromosome 2q32-q33 deletion syndrome
MedGen UID:
436765
Concept ID:
C2676739
Disease or Syndrome
SATB2-associated syndrome (SAS) is a multisystem disorder characterized by significant neurodevelopmental compromise with limited to absent speech, behavioral issues, and craniofacial anomalies. All individuals described to date have manifest developmental delay / intellectual disability, with severe speech delay. Affected individuals often have hypotonia and feeding difficulties in infancy. Behavioral issues may include autistic features, hyperactivity, and aggressiveness. Craniofacial anomalies may include palatal abnormalities (cleft palate, high-arched palate, and bifid uvula), micrognathia, and abnormal shape or size of the upper central incisors. Less common features include skeletal anomalies (osteopenia, pectus deformities, kyphosis/lordosis, and scoliosis), growth restriction, strabismus/refractive errors, congenital heart defects, genitourinary anomalies, and epilepsy. While dysmorphic features have been described in individuals with this condition, these features are not typically distinctive enough to allow for a clinical diagnosis of SAS.
Birk Barel mental retardation dysmorphism syndrome
MedGen UID:
393583
Concept ID:
C2676770
Disease or Syndrome
KCNK9 imprinting syndrome is characterized by congenital central hypotonia (manifest as decreased movement, lethargy, and weak cry), severe feeding difficulties (resulting from facial weakness and poor suck), delayed development/intellectual disability, and dysmorphic manifestations. Poor feeding can cause failure to thrive during infancy unless managed appropriately. Significant dysphagia of solid foods typically persists until puberty. Intellectual disability can be severe. To date 19 individuals with a molecularly confirmed diagnosis have been reported.
Joubert syndrome 8
MedGen UID:
436772
Concept ID:
C2676771
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Joubert syndrome 9
MedGen UID:
382940
Concept ID:
C2676788
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Alopecia, neurologic defects, and endocrinopathy syndrome
MedGen UID:
394313
Concept ID:
C2677535
Disease or Syndrome
Coenzyme Q10 deficiency, primary, 4
MedGen UID:
436985
Concept ID:
C2677589
Disease or Syndrome
Primary coenzyme Q10 (CoQ10) deficiency is usually associated with multisystem involvement, including neurologic manifestations such as fatal neonatal encephalopathy with hypotonia; a late-onset slowly progressive multiple-system atrophy-like phenotype (neurodegeneration with autonomic failure and various combinations of parkinsonism and cerebellar ataxia, and pyramidal dysfunction); and dystonia, spasticity, seizures, and intellectual disability. Steroid-resistant nephrotic syndrome (SRNS), the hallmark renal manifestation, is often the initial manifestation either as isolated renal involvement that progresses to end-stage renal disease (ESRD), or associated with encephalopathy (seizures, stroke-like episodes, severe neurologic impairment) resulting in early death. Hypertrophic cardiomyopathy (HCM), retinopathy or optic atrophy, and sensorineural hearing loss can also be seen.
Stevenson-Carey syndrome
MedGen UID:
383183
Concept ID:
C2677763
Disease or Syndrome
Mental retardation 95, X-linked
MedGen UID:
394715
Concept ID:
C2678034
Disease or Syndrome
Mental retardation, syndromic 9, X-linked
MedGen UID:
395523
Concept ID:
C2678039
Disease or Syndrome
Mental retardation, X-linked, syndromic, Turner type
MedGen UID:
394425
Concept ID:
C2678046
Disease or Syndrome
Turner-type X-linked syndromic mental retardation (MRXST) is a neurodevelopmental disorder with a highly variable phenotype. Some affected families show X-linked recessive inheritance, with only males being affected and carrier females having no abnormal findings. In other affected families, males are severely affected, and female mutation carriers show milder cognitive abnormalities or dysmorphic features. In addition, there are female patients with de novo mutations who show the full phenotype, despite skewed X-chromosome inactivation. Affected individuals show global developmental delay from infancy, with variably impaired intellectual development and poor or absent speech, often with delayed walking. Dysmorphic features are common and can include macrocephaly, microcephaly, deep-set eyes, hypotelorism, small palpebral fissures, dysplastic, large, or low-set ears, long face, bitemporal narrowing, high-arched palate, thin upper lip, and scoliosis or mild distal skeletal anomalies, such as brachydactyly or tapered fingers. Males tend to have cryptorchidism. Other features, such as hypotonia, seizures, and delayed bone age, are more variable (summary by Moortgat et al., 2018).
Mental retardation, X-linked, syndromic, wu type
MedGen UID:
437111
Concept ID:
C2678051
Disease or Syndrome
Loeys-Dietz Syndrome Type 1
MedGen UID:
395828
Concept ID:
C2697933
Disease or Syndrome
A rare autosomal dominant syndrome caused by mutations in the TGFBR1 gene. It is characterized by vascular abnormalities (aortic and arterial aneurysms, aortic dissection, and tortuosity of the arteries), hypertelorism, bifid uvula, and early fusion of the skull bones.
Waardenburg syndrome type 2E
MedGen UID:
398476
Concept ID:
C2700405
Disease or Syndrome
Waardenburg syndrome type 2 is an auditory-pigmentary syndrome characterized by pigmentary abnormalities of the hair, skin, and eyes; congenital sensorineural hearing loss; and the absence of 'dystopia canthorum,' the lateral displacement of the inner canthus of each eye, which is seen in some other forms of WS (review by Read and Newton, 1997). Individuals with WS type 2E, which is caused by mutation in the SOX10 gene (602229), may have neurologic abnormalities, including mental impairment, myelination defects, and ataxia. Waardenburg syndrome type 2 is genetically heterogeneous (see WS2A; 193510). For a description of other clinical variants of Waardenburg syndrome, see WS1 (193500), WS3 (148820), and WS4 (277580).
Macroencephaly
MedGen UID:
439426
Concept ID:
C2720434
Congenital Abnormality
Mental retardation with spastic paraplegia and palmoplantar hyperkeratosis
MedGen UID:
411554
Concept ID:
C2745996
Disease or Syndrome
This syndrome has characteristics of intellectual deficit, spasticity in the lower limbs (spastic paraplegia), pes cavus deformity of both feet, an abnormal gait, and palmar and plantar hyperkeratosis. It has been reported in four brothers. The mother of the affected boys had normal intelligence, plantar hyperkeratosis and a strong facial resemblance to her retarded sons. Her three daughters were normal. This syndrome most likely an X-linked recessive condition.
Orofaciodigital syndrome 6
MedGen UID:
411200
Concept ID:
C2745997
Disease or Syndrome
Orofaciodigital syndrome type VI (OFD6), or Varadi syndrome, is a rare autosomal recessive disorder distinguished from other orofaciodigital syndromes by metacarpal abnormalities with central polydactyly and by cerebellar abnormalities, including the molar tooth sign (summary by Doss et al., 1998 and Lopez et al., 2014).
SeSAME syndrome
MedGen UID:
411243
Concept ID:
C2748572
Disease or Syndrome
Syndrome with characteristics of seizures, sensorineural deafness, ataxia, intellectual deficit, and electrolyte imbalance. It has been described in five patients from four families. The disease is caused by homozygous or compound heterozygous mutations in the KCNJ10 gene, encoding a potassium channel expressed in the brain, spinal cord, inner ear and kidneys. Transmission is autosomal recessive.
Joubert syndrome 10
MedGen UID:
440688
Concept ID:
C2749019
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
ZNF711-Related X-linked Mental Retardation
MedGen UID:
440689
Concept ID:
C2749020
Disease or Syndrome
Refsum disease, adult, 2
MedGen UID:
440765
Concept ID:
C2749346
Disease or Syndrome
Mitochondrial DNA depletion syndrome, encephalomyopathic form, with renal tubulopathy
MedGen UID:
412815
Concept ID:
C2749861
Disease or Syndrome
RRM2B-related mitochondrial disease can be grouped by disease pathogenesis, phenotype, and mode of inheritance into two major types: mitochondrial DNA (mtDNA) depletion and multiple mtDNA deletions. Mitochondrial DNA depletion usually manifests as severe multisystem disease (encephalomyopathy with proximal renal tubulopathy) and is often fatal in early life. Inheritance is autosomal recessive. Multiple mtDNA deletions cause tissue-specific cytochrome c oxidase (COX) deficiency. Inheritance can be either autosomal recessive (with progressive external ophthalmoplegia [PEO] and multisystem involvement manifesting during early childhood/adulthood) or autosomal dominant (with less severe, often tissue-specific manifestations [e.g., chronic PEO] developing in later adulthood). Other rarer phenotypes are Kearns-Sayre syndrome (KSS) and mitochondrial neurogastrointestinal encephalopathy (MNGIE).
Chromosome 3q29 microduplication syndrome
MedGen UID:
440897
Concept ID:
C2749873
Disease or Syndrome
3q29 microduplication syndrome (also known as 3q29 duplication syndrome) is a condition that results from the copying (duplication) of a small piece of chromosome 3 in each cell. The duplication occurs on the long (q) arm of the chromosome at a position designated q29.The features associated with 3q29 microduplication syndrome vary widely. Some individuals with this chromosomal change have very mild or no related signs and symptoms, and the duplication is discovered because they undergo genetic testing only after a family member is diagnosed. Other people with a 3q29 microduplication have delayed development (particularly speech delay) and intellectual disability or learning difficulties. Although most affected individuals have no major birth defects, eye abnormalities, heart defects, and an unusually small head (microcephaly) can occur. 3q29 microduplication syndrome may increase the likelihood of being overweight or obese, although it is hard to determine whether these weight issues are caused by the duplication.
Spastic paraplegia 18
MedGen UID:
442343
Concept ID:
C2749936
Disease or Syndrome
Spastic paraplegia-18 is a severe autosomal recessive neurologic disorder characterized by onset in early childhood of progressive spastic paraplegia resulting in motor disability. Most affected individuals have severe psychomotor retardation. Some may develop significant joint contractures (summary by Alazami et al., 2011 and Yildirim et al., 2011).
Pitt-Hopkins-like syndrome 1
MedGen UID:
413258
Concept ID:
C2750246
Disease or Syndrome
PTHSL1 is an autosomal recessive neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, severe speech impairment or regression, and behavioral abnormalities. Most patients have onset of seizures within the first years of life. Some patients may have cortical dysplasia on brain imaging (summary by Smogavec et al., 2016).
Polymicrogyria, Asymmetric
MedGen UID:
413259
Concept ID:
C2750247
Disease or Syndrome
Fibrosis of extraocular muscles, congenital, 3c
MedGen UID:
412956
Concept ID:
C2750404
Disease or Syndrome
Congenital fibrosis of the extraocular muscles (CFEOM) refers to at least eight genetically defined strabismus syndromes (CFEOM1A, CFEOM1B, CFEOM2, CFEOM3A, CFEOM3B, CFEOM3C, Tukel syndrome, and CFEOM3 with polymicrogyria) characterized by congenital non-progressive ophthalmoplegia (inability to move the eyes) with or without ptosis (droopy eyelids) affecting part or all of the oculomotor nucleus and nerve (cranial nerve III) and its innervated muscles (superior, medial, and inferior recti, inferior oblique, and levator palpabrae superioris) and/or the trochlear nucleus and nerve (cranial nerve IV) and its innervated muscle (the superior oblique). In general, affected individuals have severe limitation of vertical gaze (usually upgaze) and variable limitation of horizontal gaze. Individuals with CFEOM frequently compensate for the ophthalmoplegia by maintaining abnormal head positions at rest and by moving their heads rather than their eyes to track objects. Individuals with CFEOM3A may also have intellectual disability, social disability, Kallmann syndrome, facial weakness, and vocal cord paralysis; and/or may develop a progressive sensorimotor axonal polyneuropathy. Individuals with Tukel syndrome also have postaxial oligodactyly or oligosyndactyly of the hands. Those with CFEOM3 with polymicrogyria also have microcephaly and intellectual disability.
Muscular dystrophy, congenital, due to integrin alpha-7 deficiency
MedGen UID:
413044
Concept ID:
C2750786
Disease or Syndrome
Mental retardation, autosomal recessive 13
MedGen UID:
442564
Concept ID:
C2750791
Disease or Syndrome
Chromosome 5p13 duplication syndrome
MedGen UID:
416385
Concept ID:
C2750805
Disease or Syndrome
Bartter Syndrome, Type 4b
MedGen UID:
416521
Concept ID:
C2751312
Disease or Syndrome
Nijmegen breakage syndrome-like disorder
MedGen UID:
442700
Concept ID:
C2751318
Disease or Syndrome
A rare genetic multiple congenital anomalies/dysmorphic syndrome characterised by growth retardation, short stature, developmental delay, intellectual disability, craniofacial dysmorphism (severe microcephaly, sloping forehead, prominent eyes, broad nasal ridge, hypoplastic nasal septum, epicanthal folds), spontaneous chromosomal instability, cellular hypersensitivity to ionising radiation and radioresistant DNA synthesis, without severe infections, immunodeficiency or cancer predisposition. Additional reported features include mild spasticity, slight and nonprogressive ataxia, hyperopia, multiple pigmented nevi, widely spaced nipples, and clinodactyly.
Cerebral folate deficiency
MedGen UID:
442763
Concept ID:
C2751584
Disease or Syndrome
This is an autosomal recessive disorder resulting from brain-specific folate deficiency early in life. Onset is apparent in late infancy with severe developmental regression, movement disturbances, epilepsy, and leukodystrophy. Recognition and diagnosis of this disorder is critical because folinic acid therapy can reverse the clinical symptoms and improve brain abnormalities and function (Steinfeld et al., 2009).
Pituitary hormone deficiency, combined 1
MedGen UID:
414421
Concept ID:
C2751608
Disease or Syndrome
Combined pituitary hormone deficiency (CPHD) in man denotes impaired production of growth hormone (GH; 139250) and one or more of the other 5 anterior pituitary hormones. Mutations of the POU1F1 gene in the human and Pit1 in the mouse are responsible for pleiotropic deficiencies of GH, prolactin (PRL; 176760), and thyroid-stimulating hormone (TSH; see 188540), while the production of adrenocorticotrophic hormone (ACTH; see 176830), luteinizing hormone (LH; 152780), and follicle-stimulating hormone (FSH; 136530) are preserved (Wu et al., 1998). In infancy severe growth deficiency from birth as well as distinctive facial features with prominent forehead, marked midfacial hypoplasia with depressed nasal bridge, deep-set eyes, and a short nose with anteverted nostrils and hypoplastic pituitary gland by MRI examination can be seen (Aarskog et al., 1997). Some cases present with severe mental retardation along with short stature (Radovick et al., 1992). Genetic Heterogeneity of Combined Pituitary Hormone Deficiency CPHD2 (262600), associated with hypogonadism, is caused by mutation in the PROP1 gene (601538). CPHD3 (221750), which is associated with rigid cervical spine and variable sensorineural deafness, is caused by mutation in the LHX3 gene (600577). CPHD4 (262700) is caused by mutation in the LHX4 gene (602146). CPHD5 (see septooptic dysplasia, 182230) is caused by mutation in the HESX1 gene (601802). CPHD6 (613986) is caused by mutation in the OTX2 gene (600037).
19q13.11 microdeletion syndrome
MedGen UID:
414432
Concept ID:
C2751651
Disease or Syndrome
The 19q13.11 microdeletion is characterized by several major features including pre and postnatal growth retardation, slender habitus, severe postnatal feeding difficulties, microcephaly, intellectual deficit with speech disturbance, hypospadias and ectodermal dysplasia presented by scalp aplasia, thin and sparse hair, eyebrows and eyelashes, thin and dry skin and dysplasic nails.
Stargardt macular degeneration absent or hypoplastic corpus callosum mental retardation and dysmorphic features
MedGen UID:
414494
Concept ID:
C2751864
Disease or Syndrome
Hadziselimovic syndrome
MedGen UID:
414129
Concept ID:
C2751878
Disease or Syndrome
A rare syndrome with characteristics of onset growth retardation (low birth weight and short stature), hypotonia, developmental delay and intellectual disability associated with microcephaly and craniofacial (low anterior hairline, hypotelorism, thick lips with carp-shaped mouth, high-arched palate, low-set ears), cardiac (conotruncal heart malformations such as tetralogy of Fallot and skeletal (hypoplastic thumbs and first metacarpals) abnormalities.
Cerebral palsy, spastic quadriplegic, 1
MedGen UID:
442852
Concept ID:
C2751938
Disease or Syndrome
Cerebral palsy (CP) is defined as a nonprogressive but not unchanging disorder of posture or movement, caused by an abnormality of the brain and first evident at the stage of rapid brain development (Hughes and Newton, 1992). The most common forms result from factors surrounding difficulties before or at birth, such as severe perinatal asphyxia, congenital infection, prematurity, and multiple pregnancy (Blair and Stanley, 1988; Stanley, 1994). More rarely, familial clustering or absence of pre- or postpartum events indicate that there are genetic forms of the disorder (Lynex et al., 2004). Cerebral palsy can be classified according to the type of movement disorder: spastic cerebral palsy accounts for approximately 60% of cases and can be subdivided into hemiplegic, diplegic, quadriplegic, and monoplegic types, whereas other forms include athetoid/dyskinetic, ataxic (605388), and mixed (Gustavson et al., 1969). Genetic Heterogeneity of Spastic Quadriplegic Cerebral Palsy See also CPSQ2 (612900), caused by deletion of the ANKRD15 gene (KANK1; 607704) inherited on the paternal allele, and CPSQ3 (617008), caused by mutation in the ADD3 gene (601568) on 10q24. Related phenotypes that were formerly classified in the CPSQ series include spastic paraplegia-47 (SPG47; 614066), spastic paraplegia-50 (SPG50; 612936), spastic paraplegia-51 (SPG51; 613744), and spastic paraplegia-52 (614067).
Zechi Ceide syndrome
MedGen UID:
416693
Concept ID:
C2752047
Disease or Syndrome
Orofaciodigital syndrome 11
MedGen UID:
416694
Concept ID:
C2752048
Disease or Syndrome
Oral-facial-digital syndrome is actually a group of related conditions that affect the development of the oral cavity (the mouth and teeth), facial features, and digits (fingers and toes).Researchers have identified at least 13 potential forms of oral-facial-digital syndrome. The different types are classified by their patterns of signs and symptoms. However, the features of the various types overlap significantly, and some types are not well defined. The classification system for oral-facial-digital syndrome continues to evolve as researchers find more affected individuals and learn more about this disorder.The signs and symptoms of oral-facial-digital syndrome vary widely. However, most forms of this disorder involve problems with development of the oral cavity, facial features, and digits. Most forms are also associated with brain abnormalities and some degree of intellectual disability.Abnormalities of the oral cavity that occur in many types of oral-facial-digital syndrome include a split (cleft) in the tongue, a tongue with an unusual lobed shape, and the growth of noncancerous tumors or nodules on the tongue. Affected individuals may also have extra, missing, or defective teeth. Another common feature is an opening in the roof of the mouth (a cleft palate). Some people with oral-facial-digital syndrome have bands of extra tissue (called hyperplastic frenula) that abnormally attach the lip to the gums.Distinctive facial features often associated with oral-facial-digital syndrome include a split in the lip (a cleft lip); a wide nose with a broad, flat nasal bridge; and widely spaced eyes (hypertelorism).Abnormalities of the digits can affect both the fingers and the toes in people with oral-facial-digital syndrome. These abnormalities include fusion of certain fingers or toes (syndactyly), digits that are shorter than usual (brachydactyly), or digits that are unusually curved (clinodactyly). The presence of extra digits (polydactyly) is also seen in most forms of oral-facial-digital syndrome.Other features occur in only one or a few types of oral-facial digital syndrome. These features help distinguish the different forms of the disorder. For example, the most common form of oral-facial-digital syndrome, type I, is associated with polycystic kidney disease. This kidney disease is characterized by the growth of fluid-filled sacs (cysts) that interfere with the kidneys' ability to filter waste products from the blood. Other forms of oral-facial-digital syndrome are characterized by neurological problems, particular changes in the structure of the brain, bone abnormalities, vision loss, and heart defects.
Cerebral palsy, spastic quadriplegic, 2
MedGen UID:
442880
Concept ID:
C2752061
Disease or Syndrome
Spastic paraplegia 46, autosomal recessive
MedGen UID:
473687
Concept ID:
C2828721
Disease or Syndrome
Autosomal recessive spastic paraplegia-46 (SPG46) is a neurodegenerative disorder characterized by onset in childhood of slowly progressive spastic paraplegia and cerebellar signs. Some patients have cognitive impairment, cataracts, and cerebral, cerebellar, and corpus callosum atrophy on brain imaging (summary by Boukhris et al., 2010 and Martin et al., 2013).
Corneal hypesthesia with retinal abnormalities, sensorineural deafness, unusual facies, persistent ductus arteriosus, and mental retardation
MedGen UID:
418932
Concept ID:
C2930866
Disease or Syndrome
An extremely rare genetic disorder characterised by corneal anaesthesia, retinal abnormalities, bilateral hearing loss, distinct facies, patent ductus arteriosus, Hirschsprung disease, short stature and intellectual disability. The phenotype is variable. Some affected individuals have only mild disease manifestations. The aetiology of this syndrome is not yet known. Mutations in an as of yet unidentified gene, involved in autonomic nervous system function, are suspected. Follows an autosomal dominant pattern of inheritance, probably with variable expressivity.
Ring chromosome 14
MedGen UID:
419284
Concept ID:
C2930916
Cell or Molecular Dysfunction
Ring chromosome 14 syndrome is a condition characterized by seizures and intellectual disability. Recurrent seizures (epilepsy) develop in infancy or early childhood. In many cases, the seizures are resistant to treatment with anti-epileptic drugs. Most people with ring chromosome 14 syndrome also have some degree of intellectual disability or learning problems. Development may be delayed, particularly the development of speech and of motor skills such as sitting, standing, and walking.Additional features of ring chromosome 14 syndrome can include slow growth and short stature, a small head (microcephaly), puffy hands and/or feet caused by a buildup of fluid (lymphedema), and subtle differences in facial features. Some affected individuals have problems with their immune system that lead to recurrent infections, especially involving the respiratory system. Abnormalities of the retina, the specialized tissue at the back of the eye that detects light and color, have also been reported in some people with this condition. These changes typically do not affect vision. Major birth defects are rarely seen with ring chromosome 14 syndrome.
Congenital disorder of glycosylation type 1J
MedGen UID:
419694
Concept ID:
C2931004
Disease or Syndrome
Like all CDGs, which are caused by a shortage of precursor monosaccharide phosphate or deficiencies in the glycosyltransferases required for lipid-linked oligosaccharide precursor (LLO) synthesis, CDG Ij is caused by a defect in the formation of DPAGT1, the first dolichyl-linked intermediate of the protein N-glycosylation pathway. For a general discussion of CDGs, see CDG1A (212065).
Congenital disorder of glycosylation type 1x
MedGen UID:
419309
Concept ID:
C2931007
Disease or Syndrome
A form of congenital disorders of N-linked glycosylation with characteristics of intrauterine growth retardation, microcephaly, failure to thrive, developmental delay, intellectual disability, hypotonia, seizures, optic nerve atrophy and respiratory difficulties. Genital abnormalities (micropenis, hypoplastic scrotum, undescended testes) have also been reported. Caused by mutations in the gene STT3B (3p24.1).
Split-hand/foot malformation 1
MedGen UID:
419314
Concept ID:
C2931019
Congenital Abnormality
Split-hand/foot malformation (SHFM) is a limb malformation involving the central rays of the autopod and presenting with syndactyly, median clefts of the hands and feet, and aplasia and/or hypoplasia of the phalanges, metacarpals, and metatarsals. Some patients with SHFM1 have been found to have mental retardation, ectodermal and craniofacial findings, orofacial clefting (Elliott and Evans, 2006), and neurosensory hearing loss (Tackels-Horne et al., 2001). Genetic Heterogeneity of Split-Hand/Foot Malformation Additional SHFM loci include SHFM2 (313350) on chromosome Xq26; SHFM3 (246560), caused by duplication of chromosome 10q24; SHFM4 (605289), caused by mutation in the TP63 gene (603273) on chromosome 3q27; SHFM5 (606708) on chromosome 2q31; and SHFM6 (225300), caused by mutation in the WNT10B gene (601906) on chromosome 12q13. Also see SHFM1D (220600) for a form of SHFM1 with deafness that may be caused by homozygous mutation in the DLX5 gene (600028).
Clark-Baraitser syndrome
MedGen UID:
443983
Concept ID:
C2931130
Disease or Syndrome
Morquio syndrome C
MedGen UID:
443986
Concept ID:
C2931140
Disease or Syndrome
Morquio syndrome is an autosomal recessive mucopolysaccharidosis characterized by short trunk dwarfism, fine corneal opacities, skeletal changes, and normal intelligence. Morquio syndromes A (MPS4A; 253000) and B (MPS4B; 253010) are caused by mutations in the N-acetylglucosamine-6-sulfate sulfatase (GALNS; 612222) and beta-galactosidase (GLB1; 611458) genes, respectively. MPS4A and MPS4B are characterized biochemically by increased urinary excretion of keratan sulfate (Beck et al., 1986). There is some evidence of an additional form of Morquio syndrome, referred to here as type C, in which urinary excretion of keratan sulfate is absent. However, McKusick (1972) suggested that the nonkeratosulfate- excreting Morquio syndrome may be allelic to other forms of Morquio syndrome.
Tetraamelia with ectodermal dysplasia and lacrimal duct abnormalities
MedGen UID:
444003
Concept ID:
C2931214
Disease or Syndrome
Leber congenital amaurosis 1
MedGen UID:
419026
Concept ID:
C2931258
Disease or Syndrome
Leber congenital amaurosis is an eye disorder that primarily affects the retina, which is the specialized tissue at the back of the eye that detects light and color. People with this disorder typically have severe visual impairment beginning in infancy. The visual impairment tends to be stable, although it may worsen very slowly over time.Leber congenital amaurosis is also associated with other vision problems, including an increased sensitivity to light (photophobia), involuntary movements of the eyes (nystagmus), and extreme farsightedness (hyperopia). The pupils, which usually expand and contract in response to the amount of light entering the eye, do not react normally to light. Instead, they expand and contract more slowly than normal, or they may not respond to light at all. Additionally, the clear front covering of the eye (the cornea) may be cone-shaped and abnormally thin, a condition known as keratoconus.A specific behavior called Franceschetti's oculo-digital sign is characteristic of Leber congenital amaurosis. This sign consists of poking, pressing, and rubbing the eyes with a knuckle or finger. Researchers suspect that this behavior may contribute to deep-set eyes and keratoconus in affected children.In rare cases, delayed development and intellectual disability have been reported in people with the features of Leber congenital amaurosis. However, researchers are uncertain whether these individuals actually have Leber congenital amaurosis or another syndrome with similar signs and symptoms.At least 13 types of Leber congenital amaurosis have been described. The types are distinguished by their genetic cause, patterns of vision loss, and related eye abnormalities.
Mental retardation, X-linked 1
MedGen UID:
444070
Concept ID:
C2931498
Disease or Syndrome
Impaired mental functioning occurs as an isolated feature or as part of many syndromes listed in the X-linked catalog. Mental retardation that is not associated with other distinguishing features is referred to as 'nonspecific.' Classification Opitz and Sutherland (1984) reported on a conference in which fragile X mental retardation and X-linked mental retardation of numerous other types were discussed. The report contains a rather comprehensive discussion by Opitz of the nosology of X-linked mental retardation. Mulley et al. (1992) reviewed nomenclature guidelines for X-linked mental retardation. Raymond (2006) reviewed the diagnosis and classification of X-linked mental retardation and discussed the phenotypes associated with genes causing syndromic and nonsyndromic mental retardation.
Persistent hyperinsulinemic hypoglycemia of infancy
MedGen UID:
419505
Concept ID:
C2931832
Disease or Syndrome
Familial hyperinsulinism, also referred to as congenital hyperinsulinism, nesidioblastosis, or persistent hyperinsulinemic hypoglycemia of infancy (PPHI), is the most common cause of persistent hypoglycemia in infancy and is due to defective negative feedback regulation of insulin secretion by low glucose levels. Unless early and aggressive intervention is undertaken, brain damage from recurrent episodes of hypoglycemia may occur (Thornton et al., 1998). Genetic Heterogeneity of Hyperinsulinemic Hypoglycemia HHF2 (601820) is caused by mutation in the KCNJ11 gene (600937) on chromosome 11p15. HHF3 (602485) is caused by mutation in the glucokinase gene (GCK; 138079) on chromosome 7p13. HHF4 (609975) is caused by mutation in the HADH gene (601609) on chromosome 4q25. HHF5 (609968) is caused by mutation in the insulin receptor gene (INSR; 147670) on chromosome 19p13. HHF6 (606762) is caused by mutation in the GLUD1 gene (138130) on chromosome 10q23. HHF7 (610021) is caused by mutation in the SLC16A1 (600682) on chromosome 1p13. There is evidence of further genetic heterogeneity of HHF.
Deficiency of pyrroline-5-carboxylate reductase
MedGen UID:
419175
Concept ID:
C2931835
Disease or Syndrome
Hyperprolinemia is an excess of a particular protein building block (amino acid), called proline, in the blood. This condition generally occurs when proline is not broken down properly by the body. There are two inherited forms of hyperprolinemia, called type I and type II.People with hyperprolinemia type I often do not show any symptoms, although they have proline levels in their blood between 3 and 10 times the normal level. Some individuals with hyperprolinemia type I exhibit seizures, intellectual disability, or other neurological or psychiatric problems.Hyperprolinemia type II results in proline levels in the blood between 10 and 15 times higher than normal, and high levels of a related compound called pyrroline-5-carboxylate. This form of the disorder has signs and symptoms that vary in severity, and is more likely than type I to involve seizures or intellectual disability.Hyperprolinemia can also occur with other conditions, such as malnutrition or liver disease. In particular, individuals with conditions that cause elevated levels of lactic acid in the blood (lactic acidemia) may have hyperprolinemia as well, because lactic acid inhibits the breakdown of proline.
Pseudohypoparathyroidism type 1C
MedGen UID:
420958
Concept ID:
C2932716
Disease or Syndrome
Disorders of GNAS inactivation include the phenotypes pseudohypoparathyroidism Ia, Ib, and Ic (PHP-Ia, -Ib, -Ic), pseudopseudohypoparathyroidism (PPHP), progressive osseous heteroplasia (POH), and osteoma cutis (OC). PHP-Ia and PHP-Ic are characterized by: End-organ resistance to endocrine hormones including parathyroid hormone (PTH), thyroid-stimulating hormone (TSH), gonadotropins (LH and FSH), growth hormone-releasing hormone (GHRH), and CNS neurotransmitters (leading to obesity and variable degrees of intellectual disability and developmental delay); and The Albright hereditary osteodystrophy (AHO) phenotype (short stature, round facies, and subcutaneous ossifications) and brachydactyly type E (shortening mainly of the 4th and/or 5th metacarpals and metatarsals and distal phalanx of the thumb). Although PHP-Ib is characterized principally by PTH resistance, some individuals also have partial TSH resistance and mild features of AHO (e.g., brachydactyly). PPHP, a more limited form of PHP-Ia, is characterized by various manifestations of the AHO phenotype without the hormone resistance or obesity. POH and OC are even more restricted variants of PPHP: POH consists of dermal ossification beginning in infancy, followed by increasing and extensive bone formation in deep muscle and fascia. OC consists of extra-skeletal ossification that is limited to the dermis and subcutaneous tissues.
Antley-Bixler syndrome without genital anomalies or disordered steroidogenesis
MedGen UID:
422448
Concept ID:
C2936791
Disease or Syndrome
Cytochrome P450 oxidoreductase deficiency (PORD) is a disorder of steroidogenesis with a broad phenotypic spectrum including cortisol deficiency, altered sex steroid synthesis, disorders of sex development (DSD), and skeletal malformations of the Antley-Bixler syndrome (ABS) phenotype. Cortisol deficiency is usually partial, with some baseline cortisol production but failure to mount an adequate cortisol response in stress. Mild mineralocorticoid excess can be present and causes arterial hypertension, usually presenting in young adulthood. Manifestations of altered sex steroid synthesis include ambiguous genitalia/DSD in both males and females, large ovarian cysts in females, poor masculinization and delayed puberty in males, and maternal virilization during pregnancy with an affected fetus. Skeletal malformations can manifest as craniosynostosis, mid-face retrusion with proptosis and choanal stenosis or atresia, low-set dysplastic ears with stenotic external auditory canals, hydrocephalus, radiohumeral synostosis, neonatal fractures, congenital bowing of the long bones, joint contractures, arachnodactyly, and clubfeet; other anomalies observed include urinary tract anomalies (renal pelvic dilatation, vesicoureteral reflux). Cognitive impairment is of minor concern and likely associated with the severity of malformations; studies of developmental outcomes are lacking.
N syndrome
MedGen UID:
424834
Concept ID:
C2936859
Disease or Syndrome
Syndrome that is characterised by intellectual deficit, deafness, ocular anomalies, T-cell leukaemia, cryptorchidism, hypospadias and spasticity. Mutations in DNA polymerase alpha, leading to increased chromosome breakage, may be responsible for the syndrome. X-linked recessive transmission has been proposed.
Bardet-Biedl syndrome 2
MedGen UID:
422453
Concept ID:
C2936863
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
Bardet-Biedl syndrome 4
MedGen UID:
423627
Concept ID:
C2936864
Disease or Syndrome
Bardet-Biedl syndrome (BBS) is characterized by rod-cone dystrophy, truncal obesity, postaxial polydactyly, cognitive impairment, male hypogonadotropic hypogonadism, complex female genitourinary malformations, and renal abnormalities. The visual prognosis for children with BBS is poor. Night blindness is usually evident by age seven to eight years; the mean age of legal blindness is 15.5 years. Birth weight is usually normal, but significant weight gain begins within the first year and becomes a lifelong issue for most individuals. A majority of individuals have significant learning difficulties; a minority have severe impairment on IQ testing. Renal disease is a major cause of morbidity and mortality.
GLUT1 deficiency syndrome 1, autosomal recessive
MedGen UID:
460468
Concept ID:
C3149117
Disease or Syndrome
HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED
MedGen UID:
461694
Concept ID:
C3150344
Disease or Syndrome
Congenital muscular dystrophy-dystroglycanopathy with mental retardation, type B3
MedGen UID:
461762
Concept ID:
C3150412
Disease or Syndrome
MDDGB3 is an autosomal recessive congenital muscular dystrophy with mental retardation and mild brain abnormalities (Clement et al., 2008). It is part of a group of similar disorders resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239), collectively known as 'dystroglycanopathies' (Mercuri et al., 2009). For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (613155).
Congenital muscular dystrophy-dystroglycanopathy with brain and eye anomalies, type A6
MedGen UID:
461764
Concept ID:
C3150414
Disease or Syndrome
Congenital muscular dystrophy-dystroglycanopathy with brain and eye anomalies (type A), which includes both the more severe Walker-Warburg syndrome (WWS) and the slightly less severe muscle-eye-brain disease (MEB), is an autosomal recessive disorder with characteristic brain and eye malformations, profound mental retardation, congenital muscular dystrophy, and death usually in the first years of life. It represents the most severe end of a phenotypic spectrum of similar disorders resulting from defective glycosylation of DAG1 (128239), collectively known as 'dystroglycanopathies' (Godfrey et al., 2007). For a general phenotypic description and a discussion of genetic heterogeneity of muscular dystrophy-dystroglycanopathy type A, see MDDGA1 (236670).
Congenital muscular dystrophy-dystroglycanopathy with mental retardation, type B2
MedGen UID:
461766
Concept ID:
C3150416
Disease or Syndrome
MDDGB2 is an autosomal recessive congenital muscular dystrophy associated with mental retardation and mild structural brain abnormalities (Yanagisawa et al., 2007). It is part of a group of similar disorders, collectively known as 'dystroglycanopathies,' resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239) (Godfrey et al., 2007). For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (613155).
Nephronophthisis-like nephropathy 1
MedGen UID:
461769
Concept ID:
C3150419
Disease or Syndrome
The nephronophthisis (NPH) phenotype is characterized by reduced renal concentrating ability, chronic tubulointerstitial nephritis, cystic renal disease, and progression to end-stage renal disease (ESRD) before age 30 years. Three age-based clinical subtypes are recongnized: infantile, juvenile, and adolescent/adult. Infantile NPH can present in utero with oligohydramnios sequence (limb contractures, pulmonary hypoplasia and facial dysmorphisms) or postnatally with renal manifestations that progress to ESRD before age 3 years. Juvenile NPH, the most prevalent subtype, typically presents with polydipsia and polyuria, growth retardation, chronic iron-resistant anemia, or other findings related to chronic kidney disease (CKD). Hypertension is typically absent due to salt wasting. ESRD develops at a median age of 13 years. Ultrasound findings are increased echogenicity, reduced corticomedullary differentiation, and renal cysts (in 50% of affected individuals). Histologic findings include tubulointerstitial fibrosis, thickened and disrupted tubular basement membrane, sporadic corticomedullary cysts, and normal or reduced kidney size. Adolescent/ adult NPH is clinically similar to juvenile NPH, but ESRD develops at a median age of 19 years. Within a subtype inter- and intrafamilial variability in rate of progression to ESRD is considerable. Approximately 80%-90% of individuals with the NPH phenotype have no extrarenal features (i.e., they have isolated NPH); ~10%-20% have extrarenal manifestations that constitute a recognizable syndrome (e.g., Joubert syndrome, Bardet-Biedl syndrome, Jeune syndrome and related skeletal disorders, Meckel-Gruber syndrome, Senior-Løken syndrome, Leber congenital amaurosis, COACH syndrome, and oculomotor apraxia, Cogan type).
Warsaw breakage syndrome
MedGen UID:
462008
Concept ID:
C3150658
Disease or Syndrome
Warsaw syndrome is characterized by the clinical triad of severe congenital microcephaly, growth restriction, and sensorineural hearing loss due to cochlear hypoplasia. Intellectual disability is typically in the mild-to-moderate range. Severe speech delay is common. Gross and fine motor milestones are usually attained at the usual time, although a few individuals have mild delays. Additional common features include skeletal anomalies and cardiovascular anomalies. Abnormal skin pigmentation and genitourinary malformations have also been reported. Some individuals have had increased chromosome breakage and radial forms on cytogenetic testing of lymphocytes treated with diepoxybutane and mitomycin C.
CHROMOSOME 15q24 DELETION SYNDROME
MedGen UID:
462024
Concept ID:
C3150674
Disease or Syndrome
Frontonasal dysplasia 2
MedGen UID:
462053
Concept ID:
C3150703
Disease or Syndrome
Frontonasal dysplasia is a condition that results from abnormal development of the head and face before birth. People with frontonasal dysplasia have at least two of the following features: widely spaced eyes (ocular hypertelorism); a broad nose; a slit (cleft) in one or both sides of the nose; no nasal tip; a central cleft involving the nose, upper lip, or roof of the mouth (palate); incomplete formation of the front of the skull with skin covering the head where bone should be (anterior cranium bifidum occultum); or a widow's peak hairline.Other features of frontonasal dysplasia can include additional facial malformations, absence or malformation of the tissue that connects the left and right halves of the brain (the corpus callosum), and intellectual disability.There are at least three types of frontonasal dysplasia that are distinguished by their genetic causes and their signs and symptoms. In addition to the features previously described, each type of frontonasal dysplasia is associated with other distinctive features. Individuals with frontonasal dysplasia type 1 typically have abnormalities of the nose, a long area between the nose and upper lip (philtrum), and droopy upper eyelids (ptosis). Individuals with frontonasal dysplasia type 2 can have hair loss (alopecia) and an enlarged opening in the two bones that make up much of the top and sides of the skull (enlarged parietal foramina). Males with this form of the condition often have genital abnormalities. Features of frontonasal dysplasia type 3 include eyes that are missing (anophthalmia) or very small (microphthalmia) and low-set ears that are rotated backward. Frontonasal dysplasia type 3 is typically associated with the most severe facial abnormalities, but the severity of the condition varies widely, even among individuals with the same type.Life expectancy of affected individuals depends on the severity of the malformations and whether or not surgical intervention can improve associated health problems, such as breathing and feeding problems caused by the facial clefts.
Frontonasal dysplasia 3
MedGen UID:
462056
Concept ID:
C3150706
Disease or Syndrome
Frontonasal dysplasia is a condition that results from abnormal development of the head and face before birth. People with frontonasal dysplasia have at least two of the following features: widely spaced eyes (ocular hypertelorism); a broad nose; a slit (cleft) in one or both sides of the nose; no nasal tip; a central cleft involving the nose, upper lip, or roof of the mouth (palate); incomplete formation of the front of the skull with skin covering the head where bone should be (anterior cranium bifidum occultum); or a widow's peak hairline.Other features of frontonasal dysplasia can include additional facial malformations, absence or malformation of the tissue that connects the left and right halves of the brain (the corpus callosum), and intellectual disability.There are at least three types of frontonasal dysplasia that are distinguished by their genetic causes and their signs and symptoms. In addition to the features previously described, each type of frontonasal dysplasia is associated with other distinctive features. Individuals with frontonasal dysplasia type 1 typically have abnormalities of the nose, a long area between the nose and upper lip (philtrum), and droopy upper eyelids (ptosis). Individuals with frontonasal dysplasia type 2 can have hair loss (alopecia) and an enlarged opening in the two bones that make up much of the top and sides of the skull (enlarged parietal foramina). Males with this form of the condition often have genital abnormalities. Features of frontonasal dysplasia type 3 include eyes that are missing (anophthalmia) or very small (microphthalmia) and low-set ears that are rotated backward. Frontonasal dysplasia type 3 is typically associated with the most severe facial abnormalities, but the severity of the condition varies widely, even among individuals with the same type.Life expectancy of affected individuals depends on the severity of the malformations and whether or not surgical intervention can improve associated health problems, such as breathing and feeding problems caused by the facial clefts.
Hemolytic anemia, nonspherocytic, due to glucose phosphate isomerase deficiency
MedGen UID:
462080
Concept ID:
C3150730
Disease or Syndrome
Glucose phosphate isomerase (GPI) deficiency is an inherited disorder that affects red blood cells, which carry oxygen to the body's tissues. People with this disorder have a condition known as chronic hemolytic anemia, in which red blood cells are broken down (undergo hemolysis) prematurely, resulting in a shortage of red blood cells (anemia). Chronic hemolytic anemia can lead to unusually pale skin (pallor), yellowing of the eyes and skin (jaundice), extreme tiredness (fatigue), shortness of breath (dyspnea), and a rapid heart rate (tachycardia). An enlarged spleen (splenomegaly), an excess of iron in the blood, and small pebble-like deposits in the gallbladder or bile ducts (gallstones) may also occur in this disorder.Hemolytic anemia in GPI deficiency can range from mild to severe. In the most severe cases, affected individuals do not survive to birth. Individuals with milder disease can survive into adulthood. People with any level of severity of the disorder can have episodes of more severe hemolysis, called hemolytic crises, which can be triggered by bacterial or viral infections.A small percentage of individuals with GPI deficiency also have neurological problems, including intellectual disability and difficulty with coordinating movements (ataxia).
Chromosome 16p12.2-p11.2 deletion syndrome, 7.1- to 8.7-MB
MedGen UID:
462208
Concept ID:
C3150858
Disease or Syndrome
The chromosome 16p12.2-p11.2 deletion syndrome is characterized phenotypically by dysmorphic facial features, feeding difficulties, recurrent ear infections, developmental delay, and cognitive impairment. Additional features, such as heart defects and short stature, are variable (Ballif et al., 2007; Battaglia et al., 2009). The pericentric region of chromosome 16, specifically involving 16p12-p11, is a structurally complex region enriched in repetitive sequence elements, rendering this region susceptible to deletion or rearrangement (Ballif et al., 2007). There are several phenotypes associated with variation in this region: see 611913 for a deletion or duplication at 16p11.2 associated with autism; see 136570 for discussion of a recurrent 520-kb deletion at 16p12.1 associated with developmental delay and craniofacial dysmorphism; and see 613444 for a 220-kb deletion at 16p11.2 associated with isolated severe early-onset obesity and obesity with developmental delay. Battaglia et al. (2009) emphasized that the region at chromosome 16p11.2 that confers susceptibility to autism (AUTS14; see 611913) is located more centromeric to and is distinct from the 16p12.2-p11.2 region involved in the multiple congenital anomalies and intellectual disability phenotype.
Congenital disorder of glycosylation type 2i
MedGen UID:
462226
Concept ID:
C3150876
Disease or Syndrome
COG5-congenital disorder of glycosylation (COG5-CDG, formerly known as congenital disorder of glycosylation type IIi) is an inherited condition that causes neurological problems and other abnormalities. The pattern and severity of this disorder's signs and symptoms vary among affected individuals.Individuals with COG5-CDG typically develop signs and symptoms of the condition during infancy. These individuals often have weak muscle tone (hypotonia) and delayed development. Other neurological features include moderate to severe intellectual disability, poor coordination, and difficulty walking. Some affected individuals never learn to speak. Other features of COG5-CDG include short stature, an unusually small head size (microcephaly), and distinctive facial features, which can include ears that are set low and rotated backward, a short neck with a low hairline in the back, and a prominent nose. Less commonly, affected individuals can have hearing loss caused by changes in the inner ear (sensorineural hearing loss), vision impairment, damage to the nerves that control bladder function (a condition called neurogenic bladder), liver disease, and joint deformities (contractures).
Brachydactyly, type a1, with short stature, scoliosis, microcephaly, ptosis, hearing loss, and mental retardation
MedGen UID:
462240
Concept ID:
C3150890
Disease or Syndrome
An extremely rare syndrome with characteristics of the association of radioulnar synostosis with microcephaly, scoliosis, short stature and intellectual deficit.
MENTAL RETARDATION WITH LANGUAGE IMPAIRMENT AND AUTISTIC FEATURES
MedGen UID:
462273
Concept ID:
C3150923
Disease or Syndrome
Chromosome 17q11.2 deletion syndrome, 1.4 MB
MedGen UID:
462278
Concept ID:
C3150928
Disease or Syndrome
Approximately 5 to 20% of all patients with neurofibromatosis type I (162200) carry a heterozygous deletion of approximately 1.4 Mb involving the NF1 gene and contiguous genes lying in its flanking regions (Riva et al., 2000; Jenne et al., 2001), which is caused by nonallelic homologous recombination of NF1 repeats A and C (Dorschner et al., 2000). The 'NF1 microdeletion syndrome' is often characterized by a more severe phenotype than that observed in the majority of NF1 patients. In particular, patients with NF1 microdeletion often show variable facial dysmorphism, mental retardation, developmental delay, an excessive number of early-onset neurofibromas (Venturin et al., 2004), and an increased risk for malignant peripheral nerve sheath tumors (De Raedt et al., 2003).
Beaulieu-Boycott-Innes syndrome
MedGen UID:
462289
Concept ID:
C3150939
Disease or Syndrome
Beaulieu-Boycott-Innes syndrome (BBIS) is an autosomal recessive neurodevelopmental disorder characterized by delayed development, moderate to severe intellectual disability, and dysmorphic facial features. Other developmental anomalies, such as cardiac and renal defects, cryptorchidism in males, submucous cleft palate, and corpus callosum dysgenesis, may also be present (summary by Beaulieu et al., 2013 and Amos et al., 2017).
Noonan syndrome 7
MedGen UID:
462320
Concept ID:
C3150970
Disease or Syndrome
Noonan syndrome (NS) is characterized by characteristic facies, short stature, congenital heart defect, and developmental delay of variable degree. Other findings can include broad or webbed neck, unusual chest shape with superior pectus carinatum and inferior pectus excavatum, cryptorchidism, varied coagulation defects, lymphatic dysplasias, and ocular abnormalities. Although birth length is usually normal, final adult height approaches the lower limit of normal. Congenital heart disease occurs in 50%-80% of individuals. Pulmonary valve stenosis, often with dysplasia, is the most common heart defect and is found in 20%-50% of individuals. Hypertrophic cardiomyopathy, found in 20%-30% of individuals, may be present at birth or develop in infancy or childhood. Other structural defects include atrial and ventricular septal defects, branch pulmonary artery stenosis, and tetralogy of Fallot. Up to one fourth of affected individuals have mild intellectual disability, and language impairments in general are more common in NS than in the general population.
LEOPARD syndrome 3
MedGen UID:
462321
Concept ID:
C3150971
Disease or Syndrome
Noonan syndrome with multiple lentigines (NSML) is a condition in which the cardinal features consist of lentigines, hypertrophic cardiomyopathy, short stature, pectus deformity, and dysmorphic facial features, including widely spaced eyes and ptosis. Multiple lentigines present as dispersed flat, black-brown macules, mostly on the face, neck and upper part of the trunk with sparing of the mucosa. In general, lentigines do not appear until age four to five years but then increase to the thousands by puberty. Some individuals with NSML do not exhibit lentigines. Approximately 85% of affected individuals have heart defects, including hypertrophic cardiomyopathy (HCM) (typically appearing during infancy and sometimes progressive) and pulmonary valve stenosis. Postnatal growth retardation resulting in short stature occurs in fewer than 50% of affected persons, although most affected individuals have a height that is less than the 25th percentile for age. Sensorineural hearing deficits, present in approximately 20%, are poorly characterized. Intellectual disability, typically mild, is observed in approximately 30% of persons with NSML.
Early infantile epileptic encephalopathy 7
MedGen UID:
462336
Concept ID:
C3150986
Disease or Syndrome
KCNQ2-related disorders represent a continuum of overlapping neonatal epileptic phenotypes caused by a heterozygous pathogenic variant in KCNQ2. The clinical features of KCNQ2-related disorders range from KCNQ2-related benign familial neonatal epilepsy (KCNQ2-BFNE) at the mild end to KCNQ2-related neonatal epileptic encephalopathy (KCNQ2-NEE) at the severe end. KCNQ2-BFNE is characterized by a wide spectrum of seizure types (tonic or apneic episodes, focal clonic activity, or autonomic changes) that start in otherwise healthy infants between the second and eighth day of life and spontaneously disappear between the first and the sixth to twelfth month of life. Motor activity may be confined to one body part, migrate to other body regions, or generalize. Seizures are generally brief, lasting one to two minutes. Rarely, KCNQ2-BFNE may evolve into status epilepticus. About 10%-15% of individuals with BFNE develop epileptic seizures later in life. KCNQ2-NEE is characterized by multiple daily seizures beginning in the first week of life that are mostly tonic, with associated focal motor and autonomic features. Seizures generally cease between ages nine months and four years. At onset, EEG shows a burst-suppression pattern or multifocal epileptiform activity; early brain MRI can show basal ganglia and thalamic hyperintensities that later resolve. Moderate to severe developmental impairment is present.
Spinocerebellar ataxia, autosomal recessive 10
MedGen UID:
462348
Concept ID:
C3150998
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-10 is an autosomal recessive neurodegenerative disorder with onset in the teenage or young adult years of gait and limb ataxia, dysarthria, and nystagmus associated with marked cerebellar atrophy on brain imaging (summary by Vermeer et al., 2010). Some patients have low levels of coenzyme Q10 (CoQ10) in muscle and may show some clinical improvement with CoQ10 treatment (Balreira et al., 2014).
CHROMOSOME 1p32-p31 DELETION SYNDROME
MedGen UID:
462386
Concept ID:
C3151036
Disease or Syndrome
Hypermethioninemia with s-adenosylhomocysteine hydrolase deficiency
MedGen UID:
462408
Concept ID:
C3151058
Disease or Syndrome
Hypermethioninemia is an excess of a particular protein building block (amino acid), called methionine, in the blood. This condition can occur when methionine is not broken down (metabolized) properly in the body.People with hypermethioninemia often do not show any symptoms. Some individuals with hypermethioninemia exhibit intellectual disability and other neurological problems; delays in motor skills such as standing or walking; sluggishness; muscle weakness; liver problems; unusual facial features; and their breath, sweat, or urine may have a smell resembling boiled cabbage.Hypermethioninemia can occur with other metabolic disorders, such as homocystinuria, tyrosinemia and galactosemia, which also involve the faulty breakdown of particular molecules. It can also result from liver disease or excessive dietary intake of methionine from consuming large amounts of protein or a methionine-enriched infant formula.
Limb-girdle muscular dystrophy-dystroglycanopathy, type C9
MedGen UID:
462534
Concept ID:
C3151184
Disease or Syndrome
MDDGC9 is an autosomal recessive muscular dystrophy showing onset in early childhood. It is part of a group of similar disorders resulting from defective glycosylation of DAG1, collectively known as 'dystroglycanopathies' (summary by Hara et al., 2011). For a discussion of genetic heterogeneity of muscular dystrophy-dystroglycanopathy type C, see MDDGC1 (609308).
Seckel syndrome 5
MedGen UID:
462537
Concept ID:
C3151187
Disease or Syndrome
Seckel syndrome is an autosomal recessive disorder characterized by proportionate short stature, severe microcephaly, mental retardation, and a typical 'bird-head' facial appearance (summary by Kalay et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of Seckel syndrome, see 210600.
Megalencephalic leukoencephalopathy with subcortical cysts 2a
MedGen UID:
462705
Concept ID:
C3151355
Disease or Syndrome
The classic phenotype of megalencephalic leukoencephalopathy with subcortical cysts (MLC) is characterized by early-onset macrocephaly, often in combination with mild gross motor developmental delay and seizures; gradual onset of ataxia, spasticity, and sometimes extrapyramidal findings; and usually late onset of mild mental deterioration. Macrocephaly, observed in virtually all individuals, may be present at birth but more frequently develops during the first year of life. The degree of macrocephaly is variable and can be as great as 4 to 6 SD above the mean in some individuals. After the first year of life, head growth rate normalizes and growth follows a line parallel to and usually several centimeters above the 98th centile. Initial mental and motor development is normal in most individuals. Walking is often unstable, followed by ataxia of the trunk and extremities, then minor signs of pyramidal dysfunction and brisk deep-tendon stretch reflexes. Almost all individuals have epilepsy from an early age. The epilepsy is typically well controlled with medication, but status epilepticus occurs relatively frequently. Mental deterioration is late and mild. Disease severity ranges from independent walking for a few years only to independent walking in the fifth decade. Some individuals have died in their teens or twenties; others are alive in their fifties. An improving phenotype has a similar initial presentation with delayed mental or motor development, followed by an improving clinical course: macrocephaly usually persists, but some children become normocephalic; motor function improves or normalizes; hypotonia and clumsiness may persist in some or neurologic examination may become normal. Some have intellectual disability that is stable, with or without autism. Epilepsy and status epilepticus may occur.
Megalencephalic leukoencephalopathy with subcortical cysts 2b, remitting, with or without mental retardation
MedGen UID:
462706
Concept ID:
C3151356
Disease or Syndrome
The classic phenotype of megalencephalic leukoencephalopathy with subcortical cysts (MLC) is characterized by early-onset macrocephaly, often in combination with mild gross motor developmental delay and seizures; gradual onset of ataxia, spasticity, and sometimes extrapyramidal findings; and usually late onset of mild mental deterioration. Macrocephaly, observed in virtually all individuals, may be present at birth but more frequently develops during the first year of life. The degree of macrocephaly is variable and can be as great as 4 to 6 SD above the mean in some individuals. After the first year of life, head growth rate normalizes and growth follows a line parallel to and usually several centimeters above the 98th centile. Initial mental and motor development is normal in most individuals. Walking is often unstable, followed by ataxia of the trunk and extremities, then minor signs of pyramidal dysfunction and brisk deep-tendon stretch reflexes. Almost all individuals have epilepsy from an early age. The epilepsy is typically well controlled with medication, but status epilepticus occurs relatively frequently. Mental deterioration is late and mild. Disease severity ranges from independent walking for a few years only to independent walking in the fifth decade. Some individuals have died in their teens or twenties; others are alive in their fifties. An improving phenotype has a similar initial presentation with delayed mental or motor development, followed by an improving clinical course: macrocephaly usually persists, but some children become normocephalic; motor function improves or normalizes; hypotonia and clumsiness may persist in some or neurologic examination may become normal. Some have intellectual disability that is stable, with or without autism. Epilepsy and status epilepticus may occur.
Mental retardation, autosomal dominant 6
MedGen UID:
462761
Concept ID:
C3151411
Mental or Behavioral Dysfunction
GRIN2B-related neurodevelopmental disorder is characterized by mild to profound developmental delay / intellectual disability (DD/ID) in all affected individuals. Muscle tone abnormalities (spasticity and/or hypotonia, occasionally associated with feeding difficulties), as well as epilepsy and autism spectrum disorder (ASD) / behavioral issues, are common. Other infantile- or childhood-onset findings include microcephaly; dystonic, dyskinetic, or choreiform movement disorder; and/or cortical visual impairment. Brain MRI reveals a malformation of cortical development in a minority of affected individuals. To date, fewer than 100 individuals with GRIN2B-related neurodevelopmental disorder have been reported.
Dyskeratosis congenita, autosomal recessive 2
MedGen UID:
462791
Concept ID:
C3151441
Disease or Syndrome
Dyskeratosis congenita (DC), a telomere biology disorder, is characterized by a classic triad of dysplastic nails, lacy reticular pigmentation of the upper chest and/or neck, and oral leukoplakia. The classic triad may not be present in all individuals. People with DC are at increased risk for progressive bone marrow failure (BMF), myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML), solid tumors (usually squamous cell carcinoma of the head/neck or anogenital cancer), and pulmonary fibrosis. Other findings can include: abnormal pigmentation changes not restricted to the upper chest and neck, eye abnormalities (epiphora, blepharitis, sparse eyelashes, ectropion, entropion, trichiasis), and dental abnormalities (caries, periodontal disease, taurodauntism). Although most persons with DC have normal psychomotor development and normal neurologic function, significant developmental delay is present in the two variants in which additional findings include cerebellar hypoplasia (Hoyeraal Hreidarsson syndrome) and bilateral exudative retinopathy and intracranial calcifications (Revesz syndrome). Onset and progression of manifestations of DC vary: at the mild end of the spectrum are those who have only minimal physical findings with normal bone marrow function, and at the severe end are those who have the diagnostic triad and early-onset BMF.
Mental retardation, autosomal recessive 14
MedGen UID:
462812
Concept ID:
C3151462
Disease or Syndrome
Mitochondrial DNA depletion syndrome 9 (encephalomyopathic with methylmalonic aciduria)
MedGen UID:
462826
Concept ID:
C3151476
Disease or Syndrome
SUCLG1-related mitochondrial DNA (mtDNA) depletion syndrome, encephalomyopathic form with methylmalonic aciduria is characterized in the majority of affected newborns by hypotonia, muscle atrophy, feeding difficulties, and lactic acidosis. Affected infants commonly manifest developmental delay / cognitive impairment, growth retardation / failure to thrive, hepatopathy, sensorineural hearing impairment, dystonia, and hypertonia. Notable findings in some affected individuals include hypertrophic cardiomyopathy, epilepsy, myoclonus, microcephaly, sleep disturbance, rhabdomyolysis, contractures, hypothermia, and/or hypoglycemia. Life span is shortened, with median survival of 20 months.
NSDHL-Related Disorders
MedGen UID:
463131
Concept ID:
C3151781
Disease or Syndrome
The NSDHL-related disorders include: CHILD (congenital hemidysplasia with ichthyosiform nevus and limb defects) syndrome, an X-linked condition that is usually male lethal during gestation and thus predominantly affects females; and CK syndrome, an X-linked disorder that affects males. CHILD syndrome is characterized by unilateral distribution of ichthyosiform (yellow scaly) skin lesions and ipsilateral limb defects that range from shortening of the metacarpals and phalanges to absence of the entire limb. Intellect is usually normal. The ichthyosiform skin lesions are usually present at birth or in the first weeks of life; new lesions can develop in later life. Nail changes are also common. The heart, lung, and kidneys can also be involved. CK syndrome (named for the initials of the original proband) is characterized by mild to severe cognitive impairment and behavior problems (aggression, attention deficit hyperactivity disorder, and irritability). All affected males reported have developed seizures in infancy and have cerebral cortical malformations and microcephaly. All have distinctive facial features, a thin habitus, and relatively long, thin fingers and toes. Some have scoliosis and kyphosis. Strabismus is common. Optic atrophy is also reported.
D-2-hydroxyglutaric aciduria 1
MedGen UID:
463405
Concept ID:
C3152055
Disease or Syndrome
D-2-hydroxyglutaric aciduria is a neurometabolic disorder first described by Chalmers et al. (1980). Clinical symptoms include developmental delay, epilepsy, hypotonia, and dysmorphic features. Mild and severe phenotypes were characterized (van der Knaap et al., 1999). The severe phenotype is homogeneous and is characterized by early infantile-onset epileptic encephalopathy and, often, cardiomyopathy. The mild phenotype has a more variable clinical presentation. Genetic Heterogeneity of D-2-Hydroxyglutaric Aciduria D-2-hydroxyglutaric aciduria-2 (D2HGA2; 613657) is caused by heterozygous mutation in the mitochondrial isocitrate dehydrogenase-2 gene (IDH2; 147650) on chromosome 15q26.
Fanconi anemia, complementation group D2
MedGen UID:
463627
Concept ID:
C3160738
Disease or Syndrome
Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, gastrointestinal tract, and genitourinary tract – are more common in individuals with FA.
Fanconi anemia, complementation group E
MedGen UID:
463628
Concept ID:
C3160739
Disease or Syndrome
Fanconi anemia (FA) is characterized by physical abnormalities, bone marrow failure, and increased risk for malignancy. Physical abnormalities, present in approximately 75% of affected individuals, include one or more of the following: short stature, abnormal skin pigmentation, skeletal malformations of the upper and lower limbs, microcephaly, and ophthalmic and genitourinary tract anomalies. Progressive bone marrow failure with pancytopenia typically presents in the first decade, often initially with thrombocytopenia or leukopenia. The incidence of acute myeloid leukemia is 13% by age 50 years. Solid tumors – particularly of the head and neck, skin, gastrointestinal tract, and genitourinary tract – are more common in individuals with FA.
Niemann-Pick disease type C1
MedGen UID:
465922
Concept ID:
C3179455
Disease or Syndrome
Niemann-Pick disease type C (NPC) is a lipid storage disease that can present in infants, children, or adults. Neonates can present with ascites and severe liver disease from infiltration of the liver and/or respiratory failure from infiltration of the lungs. Other infants, without liver or pulmonary disease, have hypotonia and developmental delay. The classic presentation occurs in mid-to-late childhood with the insidious onset of ataxia, vertical supranuclear gaze palsy (VSGP), and dementia. Dystonia and seizures are common. Dysarthria and dysphagia eventually become disabling, making oral feeding impossible; death usually occurs in the late second or third decade from aspiration pneumonia. Adults are more likely to present with dementia or psychiatric symptoms.
Chromosome 15q11.2 deletion syndrome
MedGen UID:
467404
Concept ID:
C3180937
Disease or Syndrome
A heterozygous deletion of chromosome 15q11.2 may increase the susceptibility to neuropsychiatric or neurodevelopmental problems, including delayed psychomotor development, speech delay, autism spectrum disorder, attention deficit-hyperactivity disorder, obsessive-compulsive disorder, and possibly seizures (summary by Doornbos et al., 2009 and Burnside et al., 2011). See also chromosome 15q11.2 duplication syndrome (608636).
2-methyl-3-hydroxybutyric aciduria
MedGen UID:
781653
Concept ID:
C3266731
Disease or Syndrome
HSD10 mitochondrial disease most commonly presents as an X-linked neurodegenerative disorder with highly variable severity and age at onset ranging from the neonatal period to early childhood. The features are usually multisystemic, consistent with mitochondrial dysfunction. Some affected males have a severe infantile form associated with cardiomyopathy that may result in death in early childhood, whereas other rare patients may have juvenile onset or even atypical presentations with normal neurologic development. More severely affected males show developmental regression in infancy or early childhood, often associated with early-onset intractable seizures, progressive choreoathetosis and spastic tetraplegia, optic atrophy or retinal degeneration resulting in visual loss, and mental retardation. Heterozygous females may show non-progressive developmental delay and intellectual disability, but may also be clinically normal. Although the diagnosis can be aided by the observation of increased urinary levels of metabolites of isoleucine breakdown (2-methyl-3 hydroxybutyrate and tiglylglycine), there is not a correlation between these laboratory features and the phenotype. In addition, patients do not develop severe metabolic crises in the neonatal period as observed in other organic acidurias, but may show persistent lactic acidosis, most likely reflecting mitochondrial dysfunction (summary by Rauschenberger et al., 2010; review by Zschocke, 2012). In a review of the disorder, Zschocke (2012) noted that although this disorder was originally thought to be an inborn error of branched-chain fatty acid and isoleucine metabolism resulting from decreased HSD17B10 dehydrogenase activity (HSD17B10 'deficiency'), subsequent studies have shown that the HSD17B10 gene product has additional functions and also acts as a component of the mitochondrial RNase P holoenzyme, which is involved in mitochondrial tRNA processing and maturation and ultimately mitochondrial protein synthesis. The multisystemic features of HSD10MD most likely result from the adverse effect of HSD17B10 mutations on mitochondrial function, rather than from the effects on the dehydrogenase activity (see PATHOGENESIS below).
Mental retardation, X-linked, with or without nystagmus
MedGen UID:
476987
Concept ID:
C3275356
Disease or Syndrome
Mental retardation, X-linked, syndromic, Raymond type
MedGen UID:
477037
Concept ID:
C3275406
Disease or Syndrome
Mental retardation, X-linked 96
MedGen UID:
477039
Concept ID:
C3275408
Disease or Syndrome
X-Linked mental retardation 90
MedGen UID:
477074
Concept ID:
C3275443
Disease or Syndrome
X-Linked Mental Retardation 88
MedGen UID:
477075
Concept ID:
C3275444
Disease or Syndrome
Mental retardation, X-linked, syndromic 17
MedGen UID:
477091
Concept ID:
C3275460
Disease or Syndrome
Syndromic mental retardation, Nascimento type, X-linked
MedGen UID:
477095
Concept ID:
C3275464
Disease or Syndrome
The Nascimento type of X-linked syndromic mental retardation is characterized by dysmorphic features, including large head, synophrys, prominent supraorbital ridges, almond-shaped and deep-set eyes, large ears, wide mouth, myxedematous appearance, hirsutism, abnormal hair whorls, micropenis, and onychodystrophy. Female carriers have normal cognition, but may show subtle facial features (summary by Budny et al., 2010).
Mental retardation and psoriasis
MedGen UID:
477241
Concept ID:
C3275610
Disease or Syndrome
Acrodysostosis 1 with or without hormone resistance
MedGen UID:
477858
Concept ID:
C3276228
Disease or Syndrome
Acrodysostosis-1 is a form of skeletal dysplasia characterized by short stature, severe brachydactyly, facial dysostosis, and nasal hypoplasia. Affected individuals often have advanced bone age and obesity. Laboratory studies show resistance to multiple hormones, including parathyroid, thyrotropin, calcitonin, growth hormone-releasing hormone, and gonadotropin (summary by Linglart et al., 2011). However, not all patients show endocrine abnormalities (Lee et al., 2012). Genetic Heterogeneity of Acrodysostosis See also ACRDYS2 (614613), caused by mutation in the PDE4D gene (600129) on chromosome 5q12.
Microcephaly with chorioretinopathy, autosomal recessive
MedGen UID:
480111
Concept ID:
C3278481
Disease or Syndrome
Microcephaly and chorioretinopathy is an autosomal recessive developmental disorder characterized by delayed psychomotor development and visual impairment, often accompanied by short stature (summary by Martin et al., 2014). Genetic Heterogeneity of Microcephaly and Chorioretinopathy See also MCCRP2 (616171), caused by mutation in the PLK4 gene (605031) on chromosome 4q27, and MCCRP3 (616335), caused by mutation in the TUBGCP4 gene (609610) on chromosome 15q15. An autosomal dominant form of microcephaly with or without chorioretinopathy, lymphedema, or mental retardation is caused by heterozygous mutation in the KIF11 gene (148760) on chromosome 10q23. See also Mirhosseini-Holmes-Walton syndrome (autosomal recessive pigmentary retinopathy and mental retardation; 268050), which has been mapped to chromosome 8q21.3-q22.1.
Nuclearly-encoded mitochondrial complex V (ATP synthase) deficiency 3
MedGen UID:
481338
Concept ID:
C3279708
Disease or Syndrome
Mitochondrial complex V deficiency is a shortage (deficiency) of a protein complex called complex V or a loss of its function. Complex V is found in cell structures called mitochondria, which convert the energy from food into a form that cells can use. Complex V is the last of five mitochondrial complexes that carry out a multistep process called oxidative phosphorylation, through which cells derive much of their energy.Mitochondrial complex V deficiency can cause a wide variety of signs and symptoms affecting many organs and systems of the body, particularly the nervous system and the heart. The disorder can be life-threatening in infancy or early childhood. Affected individuals may have feeding problems, slow growth, low muscle tone (hypotonia), extreme fatigue (lethargy), and developmental delay. They tend to develop elevated levels of lactic acid in the blood (lactic acidosis), which can cause nausea, vomiting, weakness, and rapid breathing. High levels of ammonia in the blood (hyperammonemia) can also occur in affected individuals, and in some cases result in abnormal brain function (encephalopathy) and damage to other organs.Another common feature of mitochondrial complex V deficiency is hypertrophic cardiomyopathy. This condition is characterized by thickening (hypertrophy) of the heart (cardiac) muscle that can lead to heart failure. People with mitochondrial complex V deficiency may also have a characteristic pattern of facial features, including a high forehead, curved eyebrows, outside corners of the eyes that point downward (downslanting palpebral fissures), a prominent bridge of the nose, low-set ears, thin lips, and a small chin (micrognathia).Some people with mitochondrial complex V deficiency have groups of signs and symptoms that are classified as a specific syndrome. For example, mitochondrial complex V deficiency can cause a condition called neuropathy, ataxia, and retinitis pigmentosa (NARP). NARP causes a variety of signs and symptoms chiefly affecting the nervous system. Beginning in childhood or early adulthood, most people with NARP experience numbness, tingling, or pain in the arms and legs (sensory neuropathy); muscle weakness; and problems with balance and coordination (ataxia). Many affected individuals also have cognitive impairment and an eye disorder called retinitis pigmentosa that causes vision loss.A condition called Leigh syndrome can also be caused by mitochondrial complex V deficiency. Leigh syndrome is characterized by progressive loss of mental and movement abilities (developmental or psychomotor regression) and typically results in death within 2 to 3 years after the onset of symptoms. Both NARP and Leigh syndrome can also have other causes.
Immunodeficiency-centromeric instability-facial anomalies syndrome 2
MedGen UID:
481378
Concept ID:
C3279748
Disease or Syndrome
Immunodeficiency, centromeric instability, and facial dysmorphism (ICF) syndrome is a rare autosomal recessive disorder characterized by facial dysmorphism, immunoglobulin deficiency resulting in recurrent infections, and mental retardation. Laboratory studies of patient cells show hypomethylation of satellite regions of chromosomes 1, 9, and 16, as well as pericentromeric chromosomal instability in response to phytohemagglutinin stimulation (summary by de Greef et al., 2011). For a discussion of genetic heterogeneity of immunodeficiency-centromeric instability-facial anomalies syndrome, see ICF1 (242860).
Multiple congenital anomalies-hypotonia-seizures syndrome 1
MedGen UID:
481405
Concept ID:
C3279775
Disease or Syndrome
Multiple congenital anomalies-hypotonia-seizures syndrome is an autosomal recessive disorder characterized by neonatal hypotonia, lack of psychomotor development, seizures, dysmorphic features, and variable congenital anomalies involving the cardiac, urinary, and gastrointestinal systems. Most affected individuals die before 3 years of age (summary by Maydan et al., 2011). The disorder is caused by a defect in glycosylphosphatidylinositol biosynthesis; see GPIBD1 (610293). Genetic Heterogeneity of Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome MCAHS2 (300868) is caused by mutation in the PIGA gene (311770) on chromosome Xp22, and MCAHS3 (615398) is caused by mutation in the PIGT gene (610272) on chromosome 20q13. Knaus et al. (2018) provided a review of the main clinical features of the different types of MCAHS, noting that patients with mutations in the PIGN, PIGA, and PIGT genes have distinct patterns of facial anomalies that can be detected by computer-assisted comparison. Some individuals with MCAHS may have variable increases in alkaline phosphatase (AP) as well as variable decreases in GPI-linked proteins that can be detected by flow cytometry. However, there was no clear correlation between AP levels or GPI-linked protein abnormalities and degree of neurologic involvement, mutation class, or gene involved. Knaus et al. (2018) concluded that a distinction between MCAHS and HPMRS1 (239300), which is also caused by mutation in genes involved in GPI biosynthesis, may be artificial and even inaccurate, and that all these disorders should be considered and classified together under the more encompassing term of 'GPI biosynthesis defects' (GPIBD).
Mental retardation, autosomal dominant 7
MedGen UID:
481469
Concept ID:
C3279839
Disease or Syndrome
DYRK1A-related intellectual disability syndrome is characterized by intellectual disability including impaired speech development, autism spectrum disorder including anxious and/or stereotypic behavior problems, and microcephaly. Affected individuals often have a clinically recognizable phenotype including a typical facial gestalt, feeding problems, seizures, hypertonia, gait disturbances, and foot anomalies. The majority of affected individuals function in the moderate to severe range of intellectual disability; however, a few individuals with mild intellectual disability have been reported. About half of affected individuals develop epilepsy including atonic attacks, absences, and generalized myoclonic seizures. About half of affected individuals develop scoliosis, kyphosis, and/or pectus excavatum. About one third have short stature. Rarely, endocrine problems and dental, ophthalmologic, and/or cardiac anomalies are reported.
Mental retardation, autosomal dominant 2
MedGen UID:
481472
Concept ID:
C3279842
Disease or Syndrome
Mental retardation, autosomal recessive 16
MedGen UID:
481784
Concept ID:
C3280154
Disease or Syndrome
Chromosome 8q21.11 deletion syndrome
MedGen UID:
481861
Concept ID:
C3280231
Disease or Syndrome
The chromosome 8q21.11 deletion syndrome is characterized by intellectual disability and common facial dysmorphic features (summary by Palomares et al., 2011).
Mental retardation, autosomal recessive 18
MedGen UID:
481895
Concept ID:
C3280265
Disease or Syndrome
Neurodevelopmental disorder with or without hyperkinetic movements and seizures, autosomal dominant
MedGen UID:
481912
Concept ID:
C3280282
Disease or Syndrome
NDHMSD is a severe neurodevelopmental disorder characterized by profound developmental delay, severe intellectual disability with absent speech, muscular hypotonia, and a hyperkinetic movement disorder. Additional features may include cortical blindness, generalized cerebral atrophy, and seizures (summary by Lemke et al., 2016).
Mental retardation, autosomal dominant 9
MedGen UID:
481913
Concept ID:
C3280283
Disease or Syndrome
An autosomal dominant condition caused by mutation(s) in the KIF1A gene, encoding kinesin-like protein KIF1A. It is characterized by microcephaly, intellectual disability, and delayed psychomotor development. The condition is progressive, occurs in early infancy, and is of variable severity.
Mental retardation, autosomal dominant 10
MedGen UID:
481914
Concept ID:
C3280284
Disease or Syndrome
Mental retardation, autosomal dominant 11
MedGen UID:
481915
Concept ID:
C3280285
Disease or Syndrome
Cognitive impairment with or without cerebellar ataxia
MedGen UID:
482045
Concept ID:
C3280415
Disease or Syndrome
SCN8A-related epilepsy with encephalopathy is characterized by developmental delay, seizure onset in the first 18 months of life (mean 4 months), and intractable epilepsy characterized by multiple seizure types (generalized tonic-clonic seizures, infantile spasms, and absence and focal seizures). Epilepsy syndromes can include Lennox-Gastaut syndrome, West syndrome, and epileptic encephalopathies (e.g., Dravet syndrome). Hypotonia and movement disorders including dystonia, ataxia, and choreoathetosis are common. Psychomotor development varies from normal prior to seizure onset (with subsequent slowing or regression after seizure onset) to abnormal from birth. Intellectual disability, present in all, ranges from mild to severe (in ~50% of affected individuals). Autistic features are noted in some. Sudden unexpected death in epilepsy (SUDEP) of unknown cause has been reported in approximately 10% of published cases. To date SCN8A-related epilepsy with encephalopathy has been reported in the literature in about 50 individuals.
Spinocerebellar ataxia, autosomal recessive 12
MedGen UID:
482082
Concept ID:
C3280452
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-12 is a neurologic disorder characterized by onset of generalized seizures in infancy, delayed psychomotor development with mental retardation, and cerebellar ataxia. Some patients may also show spasticity (summary by Mallaret et al., 2014).
Feingold syndrome 2
MedGen UID:
482119
Concept ID:
C3280489
Disease or Syndrome
Feingold syndrome is an autosomal dominant disorder characterized by variable combinations of microcephaly, limb malformations, esophageal and duodenal atresias, and learning disability/mental retardation. Hand and foot abnormalities may include hypoplastic thumbs, clinodactyly of second and fifth fingers, syndactyly (characteristically between second and third and fourth and fifth toes), and shortened or absent middle phalanges. Cardiac and renal malformations, vertebral anomalies, and deafness have also been described in a minority of patients (summary by Teszas et al., 2006). For a discussion of genetic heterogeneity of Feingold syndrome, see FGLDS1 (164280).
Mental retardation, autosomal recessive 31
MedGen UID:
482153
Concept ID:
C3280523
Disease or Syndrome
Mental retardation, autosomal recessive 27
MedGen UID:
482168
Concept ID:
C3280538
Disease or Syndrome
Autosomal recessive cutis laxa type 3B
MedGen UID:
482429
Concept ID:
C3280799
Disease or Syndrome
De Barsy syndrome, also known as autosomal recessive cutis laxa type III (ARCL3), is a rare autosomal recessive disorder characterized by an aged appearance with distinctive facial features, sparse hair, ophthalmologic abnormalities, intrauterine growth retardation (IUGR), and cutis laxa (summary by Lin et al., 2011). For a phenotypic description and a discussion of genetic heterogeneity of de Barsy syndrome, see 219150. For a phenotypic description and a discussion of genetic heterogeneity of autosomal recessive cutis laxa, see 219200.
Joubert syndrome 15
MedGen UID:
482527
Concept ID:
C3280897
Disease or Syndrome
Classic Joubert syndrome (JS) is characterized by three primary findings: A distinctive cerebellar and brain stem malformation called the molar tooth sign (MTS). Hypotonia. Developmental delays. Often these findings are accompanied by episodic tachypnea or apnea and/or atypical eye movements. In general, the breathing abnormalities improve with age, truncal ataxia develops over time, and acquisition of gross motor milestones is delayed. Cognitive abilities are variable, ranging from severe intellectual disability to normal. Additional findings can include retinal dystrophy, renal disease, ocular colobomas, occipital encephalocele, hepatic fibrosis, polydactyly, oral hamartomas, and endocrine abnormalities. Both intra- and interfamilial variation are seen.
Mental retardation, autosomal recessive 34
MedGen UID:
482674
Concept ID:
C3281044
Disease or Syndrome
MRT34 is an autosomal recessive neurologic disorder characterized by mild to moderate intellectual disability and megalencephaly or enlarged head circumference. Brain imaging shows a mild variant of lissencephaly with anterior-predominant pachygyria with shallow and unusually wide sulci and mildly thickened cortex. Some patients may have seizures (summary by Di Donato et al., 2016).
Chromosome 17q12 duplication syndrome
MedGen UID:
482767
Concept ID:
C3281137
Disease or Syndrome
In individuals with clinical manifestations the 17q12 recurrent duplication is characterized by intellectual abilities ranging from normal to severe disability and other variable clinical manifestations. Speech delay is common, and most affected individuals have some degree of gross motor delay. Seizures are present in 75%. Up to one third have eye or vision problems; cardiac and renal anomalies occur in rare cases. Other neurodevelopmental and psychiatric conditions reported in a subset of affected individuals are autism spectrum disorder, schizophrenia, and behavioral abnormalities (aggression and self-injury). The 17q12 recurrent duplication likely has reduced penetrance and variable expressivity since it is inherited in most instances from a parent who is often minimally affected or phenotypically normal.
Chromosome 17q12 deletion syndrome
MedGen UID:
482768
Concept ID:
C3281138
Disease or Syndrome
The 17q12 recurrent deletion syndrome is characterized by variable combinations of the three following findings: structural or functional abnormalities of the kidney and urinary tract, maturity-onset diabetes of the young type 5 (MODY5), and neurodevelopmental or neuropsychiatric disorders (e.g., global developmental delay, intellectual disability, autism spectrum disorder, schizophrenia, anxiety, and bipolar disorder). Using a method of data analysis that avoids ascertainment bias, the authors determined that multicystic kidneys and other structural renal anomalies occur in 80% to 85% of affected individuals, MODY5 in approximately 40%, and some degree of developmental delay or learning disability in approximately 50%. MODY5 is most often diagnosed before age 25 years (range: age 10-50 years).
Early infantile epileptic encephalopathy 13
MedGen UID:
482821
Concept ID:
C3281191
Disease or Syndrome
SCN8A-related epilepsy with encephalopathy is characterized by developmental delay, seizure onset in the first 18 months of life (mean 4 months), and intractable epilepsy characterized by multiple seizure types (generalized tonic-clonic seizures, infantile spasms, and absence and focal seizures). Epilepsy syndromes can include Lennox-Gastaut syndrome, West syndrome, and epileptic encephalopathies (e.g., Dravet syndrome). Hypotonia and movement disorders including dystonia, ataxia, and choreoathetosis are common. Psychomotor development varies from normal prior to seizure onset (with subsequent slowing or regression after seizure onset) to abnormal from birth. Intellectual disability, present in all, ranges from mild to severe (in ~50% of affected individuals). Autistic features are noted in some. Sudden unexpected death in epilepsy (SUDEP) of unknown cause has been reported in approximately 10% of published cases. To date SCN8A-related epilepsy with encephalopathy has been reported in the literature in about 50 individuals.
Coffin-Siris syndrome 1
MedGen UID:
482831
Concept ID:
C3281201
Disease or Syndrome
Coffin-Siris syndrome (CSS) is classically characterized by aplasia or hypoplasia of the distal phalanx or nail of the fifth and additional digits, developmental or cognitive delay of varying degree, distinctive facial features, hypotonia, hirsutism/hypertrichosis, and sparse scalp hair. Congenital anomalies can include malformations of the cardiac, gastrointestinal, genitourinary, and/or central nervous systems. Other findings commonly include feeding difficulties, slow growth, ophthalmologic abnormalities, and hearing impairment.
Mental retardation, autosomal dominant 13
MedGen UID:
482832
Concept ID:
C3281202
Mental or Behavioral Dysfunction
MRD13 is an autosomal dominant form of mental retardation associated with variable neuronal migration defects resulting in cortical malformations. More variable features include early-onset seizures and mild dysmorphic features. Some patients may also show signs of peripheral neuropathy, such as abnormal gait, hyporeflexia, and foot deformities (summary by Willemsen et al., 2012 and Poirier et al., 2013).
Baraitser-Winter Syndrome 2
MedGen UID:
482865
Concept ID:
C3281235
Disease or Syndrome
Baraitser-Winter cerebrofrontofacial (BWCFF) syndrome is a multiple congenital anomaly syndrome characterized by typical craniofacial features and intellectual disability (ID) that ranges from mild (usually in those with normal brain structure) to profound (typically in those with a neuronal migration defect). Many (but not all) affected individuals have iris or retinal coloboma, sensorineural deafness, and muscle wasting resulting in a peculiar stance with kyphosis, anteverted shoulders, and slightly flexed elbows and knees. Seizures, congenital heart defects, and renal malformations also are common.
Epileptic encephalopathy, early infantile, 1
MedGen UID:
483052
Concept ID:
C3463992
Disease or Syndrome
Early infantile epileptic encephalopathy is a severe form of epilepsy first reported by Ohtahara et al. (1976). It is characterized by frequent tonic seizures or spasms beginning in infancy with a specific EEG finding of suppression-burst patterns, characterized by high-voltage bursts alternating with almost flat suppression phases. Approximately 75% of EIEE patients progress to 'West syndrome,' which is characterized by tonic spasms with clustering, arrest of psychomotor development, and hypsarrhythmia on EEG (Kato et al., 2007). Deprez et al. (2009) reviewed the genetics of epilepsy syndromes starting in the first year of life and included a diagnostic algorithm. EIEE1 is part of a phenotypic spectrum of disorders caused by mutation in the ARX gene comprising a nearly continuous series of developmental disorders ranging from lissencephaly (LISX2; 300215) to Proud syndrome (300004) to infantile spasms without brain malformations (EIEE1) to syndromic (309510) and nonsyndromic (300419) mental retardation. Although males with ARX mutations are often more severely affected, female mutation carriers may also be affected (Kato et al., 2004; Wallerstein et al., 2008). Genetic Heterogeneity of Early Infantile Epileptic Encephalopathy EIEE is a genetically heterogeneous disorder. Also see EIEE2 (300672), caused by mutation in the CDKL5 gene (300203); EIEE3 (609304), caused by mutation in the SLC25A22 gene (609302); EIEE4 (612164), caused by mutation in the STXBP1 gene (602926); EIEE5 (613477), caused by mutation in the SPTAN1 gene (182810); EIEE6 (607208), also known as Dravet syndrome, caused by mutation in the SCN1A gene (182389); EIEE7 (613720), caused by mutation in the KCNQ2 gene (602235); EIEE8 (300607), caused by mutation in the ARHGEF9 gene (300429); EIEE9 (300088), caused by mutation in the PCDH19 gene (300460); EIEE10 (613402), caused by mutation in the PNKP gene (605610); EIEE11 (613721), caused by mutation in the SCN2A gene (182390); EIEE12 (613722), caused by mutation in the PLCB1 gene (607120); EIEE13 (614558), caused by mutation in the SCN8A gene (600702); EIEE14 (614959), caused by mutation in the KCNT1 gene (608167); EIEE15 (615006), caused by mutation in the ST3GAL3 gene (606494); EIEE16 (615338), caused by mutation in the TBC1D24 gene (613577); EIEE17 (615473), caused by mutation in the GNAO1 gene (139311); EIEE18 (615476), caused by mutation in the SZT2 gene (615463); EIEE19 (615744), caused by mutation in the GABRA1 gene (137160); EIEE20 (300868), caused by mutation in the PIGA gene (311770); EIEE21 (615833), caused by mutation in the NECAP1 gene (611623); EIEE22 (300896), caused by mutation in the SLC35A2 gene (314375); EIEE23 (615859), caused by mutation in the DOCK7 gene (615730); EIEE24 (615871), caused by mutation in the HCN1 gene (602780); EIEE25 (615905), caused by mutation in the SLC13A5 gene (608305); EIEE26 (616056), caused by mutation in the KCNB1 gene (600397); EIEE27 (616139), caused by mutation in the GRIN2B gene (138252); EIEE28 (616211), caused by mutation in the WWOX gene (605131); EIEE29 (616339), caused by mutation in the AARS gene (601065); EIEE30 (616341), caused by mutation in the SIK1 gene (605705); EIEE31 (616346), caused by mutation in the DNM1 gene (602377); EIEE32 (616366), caused by mutation in the KCNA2 gene (176262); EIEE33 (616409), caused by mutation in the EEF1A2 gene (602959); EIEE34 (616645), caused by mutation in the SLC12A5 gene (606726); EIEE35 (616647), caused by mutation in the ITPA gene (147520); EIEE36 (300884), caused by mutation in the ALG13 gene (300776); EIEE37 (616981), caused by mutation in the FRRS1L gene (604574); EIEE38 (617020), caused by mutation in the ARV1 gene (611647); EIEE39 (612949), caused by mutation in the SLC25A12 gene (603667); EIEE40 (617065), caused by mutation in the GUF1 gene (617064); EIEE41 (617105), caused by mutation in the SLC1A2 gene (600300); EIEE42 (617106), caused by mutation in the CACNA1A gene (601011); EIEE43 (617113), caused by mutation in the GABRB3 gene (137192); EIEE44 (617132), caused by mutation in the UBA5 gene (610552); EIEE45 (617153), caused by mutation in the GABRB1 gene (137190); EIEE46 (617162), caused by mutation in the GRIN2D gene (602717); EIEE47 (617166), caused by mutation in the FGF12 gene (601513); EIEE48 (617276), caused by mutation in the AP3B2 gene (602166); EIEE49 (617281), caused by mutation in the DENND5A gene (617278); EIEE50 (616457) caused by mutation in the CAD gene (114010); EIEE51 (617339), caused by mutation in the MDH2 gene (154100); EIEE52 (617350), caused by mutation in the SCN1B gene (600235); EIEE53 (617389), caused by mutation in the SYNJ1 gene (604297); EIEE54 (617391), caused by mutation in the HNRNPU gene (602869); EIEE55 (617599), caused by mutation in the PIGP gene (605938); EIEE56 (617665), caused by mutation in the YWHAG gene (605356); EIEE57 (617771), caused by mutation in the KCNT2 gene (610044); EIEE58 (617830), caused by mutation in the NTRK2 gene (600456); EIEE59 (617904), caused by mutation in the GABBR2 gene (607340); EIEE60 (617929), caused by mutation in the CNPY3 gene (610774); EIEE61 (617933), caused by mutation in the ADAM22 gene (603709); EIEE62 (617938), caused by mutation in the SCN3A gene (182391); EIEE63 (617976), caused by mutation in the CPLX1 gene (605032); EIEE64