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nystagmus

MedGen UID:
45166
Concept ID:
C0028738
Disease or Syndrome
Synonym: Nystagmus
SNOMED CT: Nystagmus (563001)
 
HPO: HP:0000639
Monarch Initiative: MONDO:0004843

Definition

Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. [from HPO]

Conditions with this feature

ataxia-telangiectasia syndrome
MedGen UID:
439
Concept ID:
C0004135
Disease or Syndrome
Ataxia-telangiectasia (AT) is an autosomal recessive disorder characterized by cerebellar ataxia, telangiectases, immune defects, and a predisposition to malignancy. Chromosomal breakage is a feature. AT cells are abnormally sensitive to killing by ionizing radiation (IR), and abnormally resistant to inhibition of DNA synthesis by ionizing radiation. The latter trait has been used to identify complementation groups for the classic form of the disease (Jaspers et al., 1988). At least 4 of these (A, C, D, and E) map to chromosome 11q23 (Sanal et al., 1990) and are associated with mutations in the ATM gene.
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.
congenital ocular coloboma
MedGen UID:
1046
Concept ID:
C0009363
Congenital Abnormality
Coloboma is an ocular birth defect resulting from abnormal development of the eye during embryogenesis. It is defined as a congenital defect in any ocular tissue, typically presenting as absent tissue or a gap, at a site consistent with aberrant closure of the optic fissure. Failure of fusion can lead to coloboma of one or multiple regions of the inferior portion of the eye affecting any part of the globe traversed by the fissure, from the iris to the optic nerve, including the ciliary body, retina, and choroid. Coloboma is also frequently associated with small (microphthalmic) or absent (anophthalmic) eyes as part of an interrelated spectrum of developmental eye anomalies, and can affect either one or both eyes (summary by Kelberman et al., 2014). Genetic Heterogeneity of Ocular Coloboma A recessive form of ocular coloboma (216820) is caused by mutation in the SALL2 gene (602219) on chromosome 14q11.
dandy-walker syndrome
MedGen UID:
4150
Concept ID:
C0010964
Disease or Syndrome
Dandy-Walker malformation is defined by hypoplasia and upward rotation of the cerebellar vermis and cystic dilation of the fourth ventricle. Affected individuals often have motor deficits such as delayed motor development, hypotonia, and ataxia; about half have mental retardation and some have hydrocephalus. DWM is a heterogeneous disorder. The low empiric recurrence risk of approximately 1 to 2% for nonsyndromic DWM suggests that mendelian inheritance is unlikely (summary by Murray et al., 1985).
dejerine-sottas disease
MedGen UID:
3710
Concept ID:
C0011195
Disease or Syndrome
Dejerine-Sottas neuropathy is a demyelinating peripheral neuropathy with onset in infancy. It can show autosomal dominant or recessive inheritance. Affected individuals have delayed motor development due to severe distal motor and sensory impairment, resulting in difficulties in gait. Some patients have generalized hypotonia in infancy. Other features may include pes cavus, scoliosis, and sensory ataxia. Nerve conduction velocities are severely decreased (sometimes less than 10 m/s), and sural nerve biopsy shows severe loss of myelinated fibers (summary by Baets et al., 2011).
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.
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).
laurence-moon syndrome
MedGen UID:
44078
Concept ID:
C0023138
Disease or Syndrome
PNPLA6 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). The hypogonadotropic hypogonadism occurs 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; 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 (summary by Lake et al., 2015). Genetic Heterogeneity of Leigh Syndrome Leigh syndrome may be a clinical presentation of a primary deficiency caused by genes in 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), and complex V deficiency (see 604273) (summary by Lake et al., 2015). 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). Deficiency of coenzyme Q10 (607426) can present as Leigh syndrome. Some forms of combined oxidative phosphorylation deficiency can present as Leigh syndrome (see, e.g., 617664).
lentigines
MedGen UID:
7301
Concept ID:
C0023321
Disease or Syndrome
A flat, benign, pigmented spot on the skin caused by excessive deposition of melanin from an increased number of melanocytes in the cell layer directly above the basement membrane of the epidermis. Formation is usually related to sun exposure during youth, and the lesions do not typically progress to malignancy.
galactosylceramide beta-galactosidase deficiency
MedGen UID:
44131
Concept ID:
C0023521
Disease or Syndrome
Krabbe disease comprises a spectrum ranging from infantile-onset disease (i.e., onset of extreme irritability, spasticity, and developmental delay before age 12 months) to later-onset disease (i.e., onset of manifestations after age 12 months and as late as the seventh decade). Although historically 85%-90% of symptomatic individuals with Krabbe disease diagnosed by enzyme activity alone have infantile-onset Krabbe disease and 10%-15% have later-onset Krabbe disease, the experience with newborn screening (NBS) suggests that the proportion of individuals with possible later-onset Krabbe disease is higher than previously thought. Infantile-onset Krabbe disease is characterized by normal development in the first few months followed by rapid severe neurologic deterioration; the average age of death is 24 months (range 8 months to 9 years). Later-onset Krabbe disease is much more variable in its presentation and disease course.
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.
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.
pseudohypoparathyroidism
MedGen UID:
46178
Concept ID:
C0033806
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.
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.
phytanic acid storage disease
MedGen UID:
11161
Concept ID:
C0034960
Disease or Syndrome
Refsum disease is characterized by anosmia and early-onset retinitis pigmentosa, which are both universal findings with variable combinations of neuropathy, deafness, ataxia, and ichthyosis. Onset of symptoms ranges from age seven months to older than age 50 years. Cardiac arrhythmia and heart failure caused by cardiomyopathy are potentially severe health problems that develop later in life.
angelman syndrome
MedGen UID:
58144
Concept ID:
C0162635
Disease or Syndrome
Angelman syndrome (AS) is characterized by severe developmental delay or intellectual disability, severe speech impairment, gait ataxia and/or tremulousness of the limbs, and unique behavior with an apparent happy demeanor that includes frequent laughing, smiling, and excitability. Microcephaly and seizures are also common. Developmental delays are first noted at around age six months; however, the unique clinical features of AS do not become manifest until after age one year.
mitochondrial myopathy
MedGen UID:
56484
Concept ID:
C0162670
Disease or Syndrome
Mitochondrial diseases are a clinically heterogeneous group of disorders that arise as a result of dysfunction of the mitochondrial respiratory chain. They can be caused by mutation of genes encoded by either nuclear DNA or mitochondrial DNA (mtDNA). While some mitochondrial disorders only affect a single organ (e.g., the eye in Leber hereditary optic neuropathy [LHON]), many involve multiple organ systems and often present with prominent neurologic and myopathic features. Mitochondrial disorders may present at any age. Many individuals with a mutation of mtDNA display a cluster of clinical features that fall into a discrete clinical syndrome, such as the Kearns-Sayre syndrome (KSS), chronic progressive external ophthalmoplegia (CPEO), mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy with ragged-red fibers (MERRF), neurogenic weakness with ataxia and retinitis pigmentosa (NARP), or Leigh syndrome (LS). However, considerable clinical variability exists and many individuals do not fit neatly into one particular category, which is well-illustrated by the overlapping spectrum of disease phenotypes (including mitochondrial recessive ataxia syndrome (MIRAS) resulting from mutation of the nuclear gene POLG, which has emerged as a major cause of mitochondrial disease. Common clinical features of mitochondrial disease – whether involving a mitochondrial or nuclear gene – include ptosis, external ophthalmoplegia, proximal myopathy and exercise intolerance, cardiomyopathy, sensorineural deafness, optic atrophy, pigmentary retinopathy, and diabetes mellitus. Common central nervous system findings are fluctuating encephalopathy, seizures, dementia, migraine, stroke-like episodes, ataxia, and spasticity. A high incidence of mid- and late pregnancy loss is a common occurrence that often goes unrecognized.
smith-lemli-opitz syndrome
MedGen UID:
61231
Concept ID:
C0175694
Disease or Syndrome
Smith-Lemli-Opitz syndrome (SLOS) is a congenital multiple-anomaly / cognitive impairment 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 restriction, 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; individuals with normal development and only minor malformations have been described.
aicardi syndrome
MedGen UID:
61236
Concept ID:
C0175713
Disease or Syndrome
Aicardi syndrome is a neurodevelopmental disorder that affects primarily females. Initially it was characterized by a typical triad of agenesis of the corpus callosum, central chorioretinal lacunae, and infantile spasms. As more affected individuals have been ascertained, it has become clear that not all affected girls have all three features of the classic triad and that other neurologic and systemic defects are common, including other brain malformations, optic nerve abnormalities, other seizure types, intellectual disability of varying severity, and scoliosis.
pelizaeus-merzbacher disease
MedGen UID:
61440
Concept ID:
C0205711
Disease or Syndrome
PLP1 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. Heterozygous females may manifest mild-to-moderate signs of the disease.
spongy degeneration of central nervous system
MedGen UID:
61565
Concept ID:
C0206307
Disease or Syndrome
Most individuals with Canavan disease have the neonatal/infantile form. Although such infants appear normal early in life, by age three to five months, hypotonia, head lag, macrocephaly, and developmental delays become apparent. With age, children with neonatal/infantile-onset Canavan disease often become irritable and experience sleep disturbance, seizures, and feeding difficulties. Swallowing deteriorates, and some children require nasogastric feeding or permanent feeding gastrostomies. Joint stiffness increases, so that these children resemble individuals with cerebral palsy. Children with mild/juvenile Canavan disease may have normal or mildly delayed speech or motor development early in life without regression. In spite of developmental delay most of these children can be educated in typical classroom settings and may benefit from speech therapy or tutoring as needed. Most children with mild forms of Canavan disease have normal head size, although macrocephaly, retinitis pigmentosa, and seizures have been reported in a few individuals.
blepharophimosis, ptosis, and epicanthus inversus
MedGen UID:
66312
Concept ID:
C0220663
Disease or Syndrome
Blephariphimosis, ptosis, and epicanthus inversus syndrome (BPES) is a complex eyelid malformation invariably characterized by four major features: blepharophimosis, ptosis, epicanthus inversus, and telecanthus. BPES type I includes the four major features and premature ovarian insufficiency (POI); BPES type II includes only the four major features. Other ophthalmic manifestations that can be associated with BPES include lacrimal duct anomalies, amblyopia, strabismus, and refractive errors. Minor features include a broad nasal bridge, low-set ears, and a short philtrum. Individuals with BPES and an intragenic FOXL2 pathogenic variant are expected to have normal intelligence, in contrast to affected individuals with cytogenetic rearrangements that involve FOXL2 and additional genes.
cerebrooculofacioskeletal syndrome 1
MedGen UID:
66320
Concept ID:
C0220722
Disease or Syndrome
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).
craniofrontonasal syndrome
MedGen UID:
65095
Concept ID:
C0220767
Disease or Syndrome
Craniofrontonasal syndrome is an X-linked developmental disorder that shows paradoxically greater severity in heterozygous females than in hemizygous males. Females have frontonasal dysplasia, craniofacial asymmetry, craniosynostosis, bifid nasal tip, grooved nails, wiry hair, and abnormalities of the thoracic skeleton, whereas males typically show only hypertelorism (Twigg et al., 2004; Wieland et al., 2004).
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.
mietens syndrome
MedGen UID:
82695
Concept ID:
C0265249
Disease or Syndrome
Mietens syndrome is a very rare syndrome consisting of corneal opacity, nystagmus, strabismus, flexion contracture of the elbows with dislocation of the head of the radius and abnormally short ulnae and radii.
borjeson-forssman-lehmann syndrome
MedGen UID:
78557
Concept ID:
C0265339
Disease or Syndrome
Borjeson-Forssman-Lehmann syndrome (BFLS) is an uncommon X-linked intellectual developmental disorder that evolves with age. Clinical manifestations in males are quite variable, with the most consistent features being initial hypotonia, mild to moderate impaired intellectual development, large fleshy ears, underdeveloped genitalia, gynecomastia, truncal obesity, tapering fingers, and shortening of the fourth and fifth toes. Heterozygous females may have a milder similar clinical phenotype, which can include hypothyroidism; however, many carrier females appear unaffected (summary by Crawford et al., 2006).
congenital cerebellar hypoplasia
MedGen UID:
120578
Concept ID:
C0266470
Congenital Abnormality
Cerebellar hypoplasia/atrophy, epilepsy, and global developmental delay is an autosomal recessive neurodevelopmental disorder characterized by infantile onset of hypotonia and developmental delay with subsequent impaired intellectual development and severe speech delay. In childhood, affected individuals show delayed walking and develop epilepsy that is usually controlled by medication. Brain imaging shows cerebellar hypoplasia/atrophy (summary by Wang et al., 2019).
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.
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, 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).
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.\n\nThe 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.
alstrom syndrome
MedGen UID:
78675
Concept ID:
C0268425
Disease or Syndrome
Alström syndrome is characterized by cone-rod dystrophy, obesity, progressive bilateral sensorineural hearing impairment, acute infantile-onset cardiomyopathy and/or adolescent- or adult-onset restrictive cardiomyopathy, insulin resistance / type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), and chronic progressive kidney disease. Cone-rod dystrophy presents as progressive visual impairment, photophobia, and nystagmus usually starting between birth and age 15 months. Many individuals lose all perception of light by the end of the second decade, but a minority retain the ability to read large print into the third decade. Children usually have normal birth weight but develop truncal obesity during their first year. Sensorineural hearing loss presents in the first decade in as many as 70% of individuals and may progress to the severe or moderately severe range (40-70 db) by the end of the first to second decade. Insulin resistance is typically accompanied by the skin changes of acanthosis nigricans, and proceeds to T2DM in the majority by the third decade. Nearly all demonstrate hypertriglyceridemia. Other findings can include endocrine abnormalities (hypothyroidism, hypogonadotropic hypogonadism in males, and hyperandrogenism in females), urologic dysfunction / detrusor instability, progressive decrease in renal function, and hepatic disease (ranging from elevated transaminases to steatohepatitis/NAFLD). Approximately 20% of affected individuals have delay in early developmental milestones, most commonly in gross and fine motor skills. About 30% have a learning disability. Cognitive impairment (IQ <70) is very rare. Wide clinical variability is observed among affected individuals, even within the same family.
primary hypomagnesemia
MedGen UID:
120640
Concept ID:
C0268448
Disease or Syndrome
Familial hypomagnesemia with hypercalciuria and nephrocalcinosis is a progressive renal disorder characterized by excessive urinary Ca(2+) and Mg(2+) excretion. There is progressive loss of kidney function, and in about 50% of cases, the need for renal replacement therapy arises as early as the second decade of life (summary by Muller et al., 2006). Amelogenesis imperfecta may also be present in some patients (Bardet et al., 2016). A similar disorder with renal magnesium wasting, renal failure, and nephrocalcinosis (HOMG5; 248190) is caused by mutations in another tight-junction gene, CLDN19 (610036), and is distinguished by the association of severe ocular involvement. For a discussion of phenotypic and genetic heterogeneity of familial hypomagnesemia, see HOMG1 (602014).
tyrosinase-positive oculocutaneous albinism
MedGen UID:
82810
Concept ID:
C0268495
Disease or Syndrome
Tyrosinase-positive oculocutaneous albinism (OCA, type II) is an autosomal recessive disorder in which the biosynthesis of melanin pigment is reduced in skin, hair, and eyes. Although affected infants may appear at birth to have OCA type I, or complete absence of melanin pigment, most patients with OCA type II acquire small amounts of pigment with age. Individuals with OCA type II have the characteristic visual anomalies associated with albinism, including decreased acuity and nystagmus, which are usually less severe than in OCA type I (Lee et al., 1994; King et al., 2001). OCA type II has a highly variable phenotype. The hair of affected individuals may turn darker with age, and pigmented nevi or freckles may be seen. African and African American individuals may have yellow hair and blue-gray or hazel irides. One phenotypic variant, 'brown OCA,' has been described in African and African American populations and is characterized by light brown hair and skin color and gray to tan irides. The hair and irides may turn darker with time and the skin may tan with sun exposure; the ocular features of albinism are present in all variants (King et al., 2001). In addition, previous reports of so-called 'autosomal recessive ocular albinism,' (see, e.g., Witkop et al., 1978 and O'Donnell et al., 1978) with little or no obvious skin involvement, are now considered most likely to be part of the phenotypic spectrum of OCA1 or OCA2 (Lee et al., 1994; King et al., 2001).
ocular albinism, type ii
MedGen UID:
120643
Concept ID:
C0268505
Disease or Syndrome
Aland Island eye disease (AIED) is an X-linked recessive retinal disease characterized by fundus hypopigmentation, decreased visual acuity, nystagmus, astigmatism, protan color vision defect (303900), progressive myopia, and defective dark adaptation. Although AIED has been referred to as a form of albinism, there is no misrouting of the optic nerves, which excludes it from the formal diagnosis of classic albinism (King et al., 2001).
urocanate hydratase deficiency
MedGen UID:
120644
Concept ID:
C0268514
Disease or Syndrome
An increased concentration of urocanic acid in the urine.
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.
chondrodysplasia punctata 2 x-linked dominant
MedGen UID:
79381
Concept ID:
C0282102
Disease or Syndrome
The findings in X-linked chondrodysplasia punctata 2 (CDPX2) range from fetal demise with multiple malformations and severe growth retardation to much milder manifestations, including females with no recognizable physical abnormalities. At least 95% of liveborn individuals with CDPX2 are female. Characteristic features include growth deficiency; distinctive craniofacial appearance; chondrodysplasia punctata (stippling of the epiphyses of the long bones, vertebrae, trachea, and distal ends of the ribs); often asymmetric rhizomelic shortening of limbs; scoliosis; linear or blotchy scaling ichthyosis in the newborn; later appearance of linear or whorled atrophic patches involving hair follicles (follicular atrophoderma); coarse hair with scarring alopecia; and cataracts.
cone monochromatism
MedGen UID:
87386
Concept ID:
C0339537
Congenital Abnormality
Blue cone (OPN1SW; 613522) monochromatism is a rare X-linked congenital stationary cone dysfunction syndrome characterized by the absence of functional long wavelength-sensitive and medium wavelength-sensitive cones in the retina. Color discrimination is severely impaired from birth, and vision is derived from the remaining preserved blue (S) cones and rod photoreceptors. BCM typically presents with reduced visual acuity, pendular nystagmus, and photophobia. Patients often have myopia (review by Gardner et al., 2009). There is evidence for progression of disease in some BCM families (Nathans et al., 1989; Ayyagari et al., 2000; Michaelides et al., 2005).
megaloblastic anemia, thiamine-responsive, with diabetes mellitus and sensorineural deafness
MedGen UID:
83338
Concept ID:
C0342287
Congenital Abnormality
Thiamine-responsive megaloblastic anemia syndrome (TRMA) is characterized by megaloblastic anemia, progressive sensorineural hearing loss, and diabetes mellitus. Onset of megaloblastic anemia occurs between infancy and adolescence. The anemia is corrected with thiamine treatment, but the red cells remain macrocytic, and anemia can recur when treatment is withdrawn. Progressive sensorineural hearing loss has generally been early and can be detected in toddlers; hearing loss is irreversible and may not be prevented by thiamine treatment. The diabetes mellitus is non-type I in nature, with age of onset from infancy to adolescence. Thiamine treatment may delay onset of diabetes in some individuals.
oculocutaneous albinism type 3
MedGen UID:
87450
Concept ID:
C0342683
Disease or Syndrome
Researchers have identified multiple types of oculocutaneous albinism, which are distinguished by their specific skin, hair, and eye color changes and by their genetic cause. Oculocutaneous albinism type 1 is characterized by white hair, very pale skin, and light-colored irises. Type 2 is typically less severe than type 1; the skin is usually a creamy white color and hair may be light yellow, blond, or light brown. Type 3 includes a form of albinism called rufous oculocutaneous albinism, which usually affects dark-skinned people. Affected individuals have reddish-brown skin, ginger or red hair, and hazel or brown irises. Type 3 is often associated with milder vision abnormalities than the other forms of oculocutaneous albinism. Type 4 has signs and symptoms similar to those seen with type 2.\n\nSeveral additional types of this disorder have been proposed, each affecting one or a few families.\n\nOculocutaneous albinism is a group of conditions that affect coloring (pigmentation) of the skin, hair, and eyes. Affected individuals typically have very fair skin and white or light-colored hair. Long-term sun exposure greatly increases the risk of skin damage and skin cancers, including an aggressive form of skin cancer called melanoma, in people with this condition. Oculocutaneous albinism also reduces pigmentation of the colored part of the eye (the iris) and the light-sensitive tissue at the back of the eye (the retina). People with this condition usually have vision problems such as reduced sharpness; rapid, involuntary eye movements (nystagmus); and increased sensitivity to light (photophobia).
ocular albinism, type i
MedGen UID:
90991
Concept ID:
C0342684
Disease or Syndrome
X-linked ocular albinism (XLOA) is a disorder of melanosome biogenesis leading to minor cutaneous and adnexal manifestations and congenital and persistent visual impairment in affected males. XLOA is characterized by infantile nystagmus, reduced visual acuity, hypopigmentation of the iris pigment epithelium and the ocular fundus, and foveal hypoplasia. Significant refractive errors, reduced or absent binocular functions, photoaversion, and strabismus are common. XLOA is a non-progressive disorder and the visual acuity remains stable throughout life, often slowly improving into the mid-teens.
beta-hydroxyisobutyryl-coa deacylase deficiency
MedGen UID:
83349
Concept ID:
C0342738
Disease or Syndrome
3-Hydroxyisobutyryl-CoA hydrolase deficiency (HIBCHD) is an autosomal recessive inborn error of metabolism characterized by severely delayed psychomotor development, neurodegeneration, increased lactic acid, and brain lesions in the basal ganglia (summary by Ferdinandusse et al., 2013).
bifunctional peroxisomal enzyme deficiency
MedGen UID:
137982
Concept ID:
C0342870
Pathologic Function
D-bifunctional protein deficiency is a disorder of peroxisomal fatty acid beta-oxidation. See also peroxisomal acyl-CoA oxidase deficiency (264470), caused by mutation in the ACOX1 gene (609751) on chromosome 17q25. The clinical manifestations of these 2 deficiencies are similar to those of disorders of peroxisomal assembly, including X-linked adrenoleukodystrophy (ALD; 300100), Zellweger cerebrohepatorenal syndrome (see 214100) and neonatal adrenoleukodystrophy (NALD; see 601539) (Watkins et al., 1995). DBP deficiency has been classified into 3 subtypes depending upon the deficient enzyme activity. Type I is a deficiency of both 2-enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase; type II is a deficiency of hydratase activity alone; and type III is a deficiency of dehydrogenase activity alone. Virtually all patients with types I, II, and III have a severe phenotype characterized by infantile-onset of hypotonia, seizures, and abnormal facial features, and most die before age 2 years. McMillan et al. (2012) proposed a type IV deficiency on the basis of less severe features; these patients have a phenotype reminiscent of Perrault syndrome (PRLTS1; 233400). Pierce et al. (2010) noted that Perrault syndrome and DBP deficiency overlap clinically and suggested that DBP deficiency may be underdiagnosed.
aniridia 1
MedGen UID:
576337
Concept ID:
C0344542
Congenital Abnormality
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.
irido-corneo-trabecular dysgenesis
MedGen UID:
91031
Concept ID:
C0344559
Congenital Abnormality
Anterior segment dysgeneses (ASGD or ASMD) are a heterogeneous group of developmental disorders affecting the anterior segment of the eye, including the cornea, iris, lens, trabecular meshwork, and Schlemm canal. The clinical features of ASGD include iris hypoplasia, an enlarged or reduced corneal diameter, corneal vascularization and opacity, posterior embryotoxon, corectopia, polycoria, an abnormal iridocorneal angle, ectopia lentis, and anterior synechiae between the iris and posterior corneal surface (summary by Cheong et al., 2016). Anterior segment dysgenesis is sometimes divided into subtypes including aniridia (see 106210), Axenfeld and Rieger anomalies, iridogoniodysgenesis, Peters anomaly, and posterior embryotoxon (Gould and John, 2002). Patients with ASGD5 have been reported with the Peters anomaly, Axenfeld anomaly, and Rieger anomaly subtypes. Peters anomaly consists of a central corneal leukoma, absence of the posterior corneal stroma and Descemet membrane, and a variable degree of iris and lenticular attachments to the central aspect of the posterior cornea (Peters, 1906). It occurs as an isolated ocular abnormality or in association with other ocular defects. In Axenfeld anomaly, strands of iris tissue attach to the Schwalbe line; in Rieger anomaly, in addition to the attachment of iris tissue to the Schwalbe line, there is clinically evident iris stromal atrophy with hole or pseudo-hole formation and corectopia (summary by Smith and Traboulsi, 2012).
congenital disorder of glycosylation, type ia
MedGen UID:
138111
Concept ID:
C0349653
Disease or Syndrome
PMM2-CDG, the most common of a group of disorders of abnormal glycosylation of N-linked oligosaccharides, is divided into three clinical stages: infantile multisystem, late-infantile and childhood ataxia–intellectual disability, and adult stable disability. The clinical manifestations and course are highly variable, ranging from infants who die in the first year of life to mildly affected adults. Clinical findings tend to be similar in sibs. In the infantile multisystem presentation, infants show axial hypotonia, hyporeflexia, esotropia, and developmental delay. Feeding problems, vomiting, faltering growth, and developmental delay are frequently seen. Subcutaneous fat may be excessive over the buttocks and suprapubic region. Two distinct clinical courses are observed: (1) a nonfatal neurologic course with faltering growth, strabismus, developmental delay, cerebellar hypoplasia, and hepatopathy in infancy followed by neuropathy and retinitis pigmentosa in the first or second decade; and (2) a more severe neurologic-multivisceral course with approximately 20% mortality in the first year of life. The late-infantile and childhood ataxia–intellectual disability stage, which begins between ages three and ten years, is characterized by hypotonia, ataxia, severely delayed language and motor development, inability to walk, and IQ of 40 to 70; other findings include seizures, stroke-like episodes or transient unilateral loss of function, coagulopathy, retinitis pigmentosa, joint contractures, and skeletal deformities. In the adult stable disability stage, intellectual ability is stable; peripheral neuropathy is variable, progressive retinitis pigmentosa and myopia are seen, thoracic and spinal deformities with osteoporosis worsen, and premature aging is observed; females may lack secondary sexual development and males may exhibit decreased testicular volume. Hypogonadotropic hypogonadism and coagulopathy may occur. The risk for deep venous thrombosis is increased.
branchiooculofacial syndrome
MedGen UID:
91261
Concept ID:
C0376524
Disease or Syndrome
The branchiooculofacial syndrome (BOFS) is characterized by: branchial (cervical or infra- or supra-auricular) skin defects that range from barely perceptible thin skin or hair patch to erythematous "hemangiomatous" lesions to large weeping erosions; ocular anomalies that can include microphthalmia, anophthalmia, coloboma, and nasolacrimal duct stenosis/atresia; and facial anomalies that can include ocular hypertelorism or telecanthus, broad nasal tip, upslanted palpebral fissures, cleft lip or prominent philtral pillars that give the appearance of a repaired cleft lip (formerly called "pseudocleft lip") with or without cleft palate, upper lip pits, and lower facial weakness (asymmetric crying face or partial 7th cranial nerve weakness). Malformed and prominent pinnae and hearing loss from inner ear and/or petrous bone anomalies are common. Intellect is usually normal.
charcot-marie-tooth neuropathy x type 1
MedGen UID:
98290
Concept ID:
C0393808
Disease or Syndrome
GJB1 disorders are typically characterized by peripheral motor and sensory neuropathy with or without fixed CNS abnormalities and/or acute, self-limited episodes of transient neurologic dysfunction (especially weakness and dysarthria). Peripheral neuropathy typically manifests in affected males between ages five and 25 years. Although both men and women are affected, manifestations tend to be less severe in women, some of whom may remain asymptomatic. Less commonly, initial manifestations in some affected individuals are stroke-like episodes (acute fulminant episodes of reversible CNS dysfunction).
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).
gapo 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.
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).
cranioectodermal dysplasia 1
MedGen UID:
96586
Concept ID:
C0432235
Disease or Syndrome
Cranioectodermal dysplasia (CED) is a ciliopathy with skeletal involvement (narrow thorax, shortened proximal limbs, syndactyly, polydactyly, brachydactyly), ectodermal features (widely spaced hypoplastic teeth, hypodontia, sparse hair, skin laxity, abnormal nails), joint laxity, growth deficiency, and characteristic facial features (frontal bossing, low-set simple ears, high forehead, telecanthus, epicanthal folds, full cheeks, everted lower lip). Most affected children develop nephronophthisis that often leads to end-stage kidney disease in infancy or childhood, a major cause of morbidity and mortality. Hepatic fibrosis and retinal dystrophy are also observed. Dolichocephaly, often secondary to sagittal craniosynostosis, is a primary manifestation that distinguishes CED from most other ciliopathies. Brain malformations and developmental delay may also occur.
deletion of long arm of chromosome 18
MedGen UID:
96605
Concept ID:
C0432443
Disease or Syndrome
Monosomy 18q is a partial deletion of the long arm of chromosome 18 characterized by highly variable phenotype, most commonly including hypotonia, developmental delay, short stature, growth hormone deficiency, hearing loss and external ear anomalies, intellectual disability, palatal defects, dysmorphic facial features, skeletal anomalies (foot deformities, tapering fingers, scoliosis) and mood disorders.
muscle eye brain disease
MedGen UID:
105341
Concept ID:
C0457133
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' (summary by Godfrey et al., 2007). For a general phenotypic description and a discussion of genetic heterogeneity of muscular dystrophy-dystroglycanopathy type A, see MDDGA1 (236670).
chiari malformation type ii
MedGen UID:
108222
Concept ID:
C0555206
Congenital Abnormality
Chiari malformation type II (CM2), also known as the Arnold-Chiari malformation, consists of elongation and descent of the inferior cerebellar vermis, cerebellar hemispheres, pons, medulla, and fourth ventricle through the foramen magnum into the spinal canal. CM2 is uniquely associated with myelomeningocele (open spina bifida; see 182940) and is found only in this population (Stevenson, 2004). It is believed to be a disorder of neuroectodermal origin (Schijman, 2004). For a general phenotypic description of the different forms of Chiari malformations, see Chiari malformation type I (CM1; 118420).
arnold-chiari type i malformation
MedGen UID:
196689
Concept ID:
C0750929
Congenital Abnormality
cockayne syndrome b
MedGen UID:
155487
Concept ID:
C0751038
Disease or Syndrome
Cockayne syndrome (referred to as CS in this GeneReview) spans a continuous 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 (COFS) syndrome; CS type III, a milder and later-onset form; COFS syndrome, a fetal form of CS. CS type I 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 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 five years. CS type III is a phenotype in which major clinical features associated with CS only become apparent after age two years; growth and/or cognition exceeds the expectations for CS type I. COFS syndrome is characterized by very severe prenatal developmental anomalies (arthrogryposis and microphthalmia).
cockayne syndrome type a
MedGen UID:
155488
Concept ID:
C0751039
Disease or Syndrome
Cockayne syndrome (referred to as CS in this GeneReview) spans a continuous 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 (COFS) syndrome; CS type III, a milder and later-onset form; COFS syndrome, a fetal form of CS. CS type I 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 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 five years. CS type III is a phenotype in which major clinical features associated with CS only become apparent after age two years; growth and/or cognition exceeds the expectations for CS type I. COFS syndrome is characterized by very severe prenatal developmental anomalies (arthrogryposis and microphthalmia).
dentatorubral-pallidoluysian atrophy
MedGen UID:
155630
Concept ID:
C0751781
Disease or Syndrome
Dentatorubral-pallidoluysian atrophy (DRPLA) is a progressive disorder of ataxia, myoclonus, epilepsy, and progressive intellectual deterioration in children and ataxia, choreoathetosis, and dementia or character changes in adults. Onset ranges from before age one year to age 72 years; mean age of onset is 31.5 years. The clinical presentation varies depending on the age of onset. The cardinal features in adults are ataxia, choreoathetosis, and dementia. Cardinal features in children are progressive intellectual deterioration, behavioral changes, myoclonus, and epilepsy.
spinocerebellar ataxia type 1
MedGen UID:
155703
Concept ID:
C0752120
Disease or Syndrome
Spinocerebellar ataxia type 1 (SCA1) is characterized by progressive cerebellar ataxia, dysarthria, and eventual deterioration of bulbar functions. Early in the disease, affected individuals may have gait disturbance, slurred speech, difficulty with balance, brisk deep tendon reflexes, hypermetric saccades, nystagmus, and mild dysphagia. Later signs include slowing of saccadic velocity, development of up-gaze palsy, dysmetria, dysdiadochokinesia, and hypotonia. In advanced stages, muscle atrophy, decreased deep tendon reflexes, loss of proprioception, cognitive impairment (e.g., frontal executive dysfunction, impaired verbal memory), chorea, dystonia, and bulbar dysfunction are seen. Onset is typically in the third or fourth decade, although childhood onset and late-adult onset have been reported. Those with onset after age 60 years may manifest a pure cerebellar phenotype. Interval from onset to death varies from ten to 30 years; individuals with juvenile onset show more rapid progression and more severe disease. Anticipation is observed. An axonal sensory neuropathy detected by electrophysiologic testing is common; brain imaging typically shows cerebellar and brain stem atrophy.
spinocerebellar ataxia 7
MedGen UID:
156006
Concept ID:
C0752125
Disease or Syndrome
Spinocerebellar ataxia type 7 (SCA7) comprises a phenotypic spectrum ranging from adolescent- or adult-onset progressive cerebellar ataxia and cone-rod retinal dystrophy to infantile or early-childhood onset with multiorgan failure, an accelerated course, and early death. Anticipation in this nucleotide repeat disorder may be so dramatic that within a family a child with infantile or early-childhood onset may be diagnosed with what is thought to be an unrelated neurodegenerative disorder years before a parent or grandparent with a CAG repeat expansion becomes symptomatic. In adolescent-onset SCA7, the initial manifestation is typically impaired vision, followed by cerebellar ataxia. In those with adult onset, progressive cerebellar ataxia usually precedes the onset of visual manifestations. While the rate of progression varies in these two age groups, the eventual result for almost all affected individuals is loss of vision, severe dysarthria and dysphagia, and a bedridden state with loss of motor control.
bardet-biedl syndrome
MedGen UID:
156019
Concept ID:
C0752166
Disease or Syndrome
Bardet-Biedl syndrome is a disorder that affects many parts of the body. The signs and symptoms of this condition vary among affected individuals, even among members of the same family.\n\nVision loss is one of the major features of Bardet-Biedl syndrome. Loss of vision occurs as the light-sensing tissue at the back of the eye (the retina) gradually deteriorates. Problems with night vision become apparent by mid-childhood, followed by blind spots that develop in the side (peripheral) vision. Over time, these blind spots enlarge and merge to produce tunnel vision. Most people with Bardet-Biedl syndrome also develop blurred central vision (poor visual acuity) and become legally blind by adolescence or early adulthood.\n\nObesity is another characteristic feature of Bardet-Biedl syndrome. Abnormal weight gain typically begins in early childhood and continues to be an issue throughout life. Complications of obesity can include type 2 diabetes, high blood pressure (hypertension), and abnormally high cholesterol levels (hypercholesterolemia).\n\nOther major signs and symptoms of Bardet-Biedl syndrome include the presence of extra fingers or toes (polydactyly), intellectual disability or learning problems, and abnormalities of the genitalia. Most affected males produce reduced amounts of sex hormones (hypogonadism), and they are usually unable to father biological children (infertile). Many people with Bardet-Biedl syndrome also have kidney abnormalities, which can be serious or life-threatening.\n\nAdditional features of Bardet-Biedl syndrome can include impaired speech, delayed development of motor skills such as standing and walking, behavioral problems such as emotional immaturity and inappropriate outbursts, and clumsiness or poor coordination. Distinctive facial features, dental abnormalities, unusually short or fused fingers or toes, and a partial or complete loss of the sense of smell (anosmia) have also been reported in some people with Bardet-Biedl syndrome. Additionally, this condition can affect the heart, liver, and digestive system.
cataract-nephropathy-encephalopathy 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.
peters plus syndrome
MedGen UID:
163204
Concept ID:
C0796012
Disease or Syndrome
Peters plus syndrome is characterized by anterior chamber eye anomalies, short limbs with broad distal extremities, characteristic facial features, cleft lip/palate, and variable developmental delay/intellectual disability. The most common anterior chamber defect is Peters' anomaly, consisting of central corneal clouding, thinning of the posterior cornea, and iridocorneal adhesions. Cataracts and glaucoma are common. Developmental delay is observed in about 80% of children; intellectual disability can range from mild to severe.
lowry-wood syndrome
MedGen UID:
162899
Concept ID:
C0796021
Disease or Syndrome
Lowry-Wood syndrome (LWS) is characterized by multiple epiphyseal dysplasia and microcephaly. Patients exhibit intrauterine growth retardation and short stature, as well as developmental delay and intellectual disability. Retinal degeneration has been reported in some patients (Farach et al., 2018; Shelihan et al., 2018). Microcephalic osteodysplastic primordial dwarfism type I (MOPD1; 210710) and Roifman syndrome (RFMN; 616651), the features of which overlap with those of Lowry-Wood syndrome, are also caused by biallelic mutation in the RNU4ATAC gene.
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.
ataxia-microcephaly-cataract syndrome
MedGen UID:
167098
Concept ID:
C0796056
Disease or Syndrome
Ataxia, microcephaly, hypotonia, cataracts, and nystagmus.
nance-horan syndrome
MedGen UID:
208665
Concept ID:
C0796085
Disease or Syndrome
Nance-Horan syndrome is an X-linked disorder characterized by congenital cataracts, dental anomalies, dysmorphic features, and, in some cases, mental retardation (summary by Burdon et al., 2003).
oculocerebrocutaneous syndrome
MedGen UID:
163214
Concept ID:
C0796092
Disease or Syndrome
A rare neurologic disease typically characterized by the triad of eye, central nervous system and skin malformations, and often associated with an intellectual disability.
corpus callosum agenesis-abnormal genitalia syndrome
MedGen UID:
163217
Concept ID:
C0796124
Disease or Syndrome
Proud syndrome is an X-linked developmental disorder characterized by agenesis of the corpus callosum, severe mental retardation, seizures, and spasticity. Males are severely affected, whereas females may be unaffected or have a milder phenotype (Proud et al., 1992). Proud 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 lissencephaly (LISX2; 300215) to Proud syndrome to infantile spasms without brain malformations (DEE1; 308350) to syndromic (309510) and nonsyndromic (300419) mental retardation (Kato et al., 2004; Wallerstein et al., 2008).
aicardi goutieres syndrome 1
MedGen UID:
162912
Concept ID:
C0796126
Disease or Syndrome
Most characteristically, Aicardi-Goutières syndrome (AGS) manifests as an early-onset encephalopathy that usually, but not always, results in severe intellectual and physical disability. A subgroup of infants with AGS present at birth with abnormal neurologic findings, hepatosplenomegaly, elevated liver enzymes, and thrombocytopenia, a picture highly suggestive of congenital infection. Otherwise, most affected infants present at variable times after the first few weeks of life, frequently after a period of apparently normal development. Typically, they demonstrate the subacute onset of a severe encephalopathy characterized by extreme irritability, intermittent sterile pyrexias, loss of skills, and slowing of head growth. Over time, as many as 40% develop chilblain skin lesions on the fingers, toes, and ears. It is becoming apparent that atypical, sometimes milder, cases of AGS exist, and thus the true extent of the phenotype associated with pathogenic variants in the AGS-related genes is not yet known.
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
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.
spondylometaphyseal dysplasia, golden type
MedGen UID:
208672
Concept ID:
C0796172
Disease or Syndrome
A rare primary bone dysplasia disorder with characteristics of severe short stature, coarse facies, thoracolumbar kyphoscoliosis and enlarged joints with contractures. Psychomotor delay and intellectual disability may also be associated. Radiographic features include flat vertebral bodies, lacy ossification of the metaphyses of long bones and iliac crests, and marked sclerosis of the skull base.
spinocerebellar ataxia, x-linked 1
MedGen UID:
163229
Concept ID:
C0796205
Disease or Syndrome
SCAX1 is an X-linked recessive neurologic disorder characterized by hypotonia at birth, delayed motor development, gait ataxia, difficulty standing, dysarthria, and slow eye movements. Brain MRI shows cerebellar ataxia (summary by Bertini et al., 2000). Genetic Heterogeneity of X-linked Spinocerebellar Ataxia X-linked recessive spinocerebellar ataxia (SCAX) is a clinically and genetically heterogeneous disorder. See also SCAX2 (302600), SCAX3 (301790), SCAX4 (301840), and SCAX5 (300703).
mental retardation, x-linked 12
MedGen UID:
901885
Concept ID:
C0796218
Disease or Syndrome
X-linked intellectual disability-short stature-overweight syndrome is a multiple congenital anomalies syndrome characterized by borderline to severe intellectual disability, speech delay, short stature, elevated body mass index, a pattern of truncal obesity (reported in older males), and variable neurologic features (e.g. hypotonia, tremors, gait disturbances, behavioral problems, and seizure disorders). Less common manifestations include microcephaly, microorchidism and/or microphallus. Dysmorphic features have been reported in some patients but no consitent pattern has been noted.
x-linked intellectual disability brooks type
MedGen UID:
208682
Concept ID:
C0796272
Disease or Syndrome
A rare X-linked intellectual disability syndrome with characteristics of failure to thrive, speech delay, intellectual disability, muscle hypotonia, spastic diplegia, optic atrophy with myopia and distinct facial features (including triangular face, bifrontal narrowness, deeply set eyes, low-set/cupped ears, prominent nose, short philtrum, and thin upper lip with tented morphology) that can be evident from birth. Additional manifestations reported in some patients include large joint contractures and pectus excavatum (which become more evident with age) and seizures.
sialic acid storage disease, severe infantile type
MedGen UID:
203367
Concept ID:
C1096902
Disease or Syndrome
Free sialic acid storage disorders (FSASDs) are a spectrum of neurodegenerative disorders resulting from increased lysosomal storage of free sialic acid. Historically, FSASD was divided into separate allelic disorders: Salla disease, intermediate severe Salla disease, and infantile free sialic acid storage disease (ISSD). The mildest type was Salla disease, characterized by normal appearance and absence of neurologic findings at birth, followed by slowly progressive neurologic deterioration resulting in mild-to-moderate psychomotor delays, spasticity, athetosis, and epileptic seizures. Salla disease was named for a municipality in Finnish Lapland where a specific founder variant is relatively prevalent. However, the term Salla has been used in the literature to refer to less severe FSASD. More severe FSASD is historically referred to as ISSD, and is characterized by severe developmental delay, coarse facial features, hepatosplenomegaly, and cardiomegaly; death usually occurs in early childhood.
salla disease
MedGen UID:
203368
Concept ID:
C1096903
Disease or Syndrome
Free sialic acid storage disorders (FSASDs) are a spectrum of neurodegenerative disorders resulting from increased lysosomal storage of free sialic acid. Historically, FSASD was divided into separate allelic disorders: Salla disease, intermediate severe Salla disease, and infantile free sialic acid storage disease (ISSD). The mildest type was Salla disease, characterized by normal appearance and absence of neurologic findings at birth, followed by slowly progressive neurologic deterioration resulting in mild-to-moderate psychomotor delays, spasticity, athetosis, and epileptic seizures. Salla disease was named for a municipality in Finnish Lapland where a specific founder variant is relatively prevalent. However, the term Salla has been used in the literature to refer to less severe FSASD. More severe FSASD is historically referred to as ISSD, and is characterized by severe developmental delay, coarse facial features, hepatosplenomegaly, and cardiomegaly; death usually occurs in early childhood.
hereditary mucoepithelial dysplasia
MedGen UID:
220887
Concept ID:
C1274795
Congenital Abnormality
Hereditary mucoepithelial dysplasia (HMD) is a rare autosomal dominant genodermatosis characterized by onset in infancy of a panepithelial defect involving the oral, nasal, conjunctival, vaginal, cervical, perineal, urethral, and bladder mucosa. Patients develop cataracts, blindness, nonscarring alopecia, perineal psoriasiform lesions, and follicular keratoses (Witkop et al., 1982). Although 1 family was reported to have progressive severe interstitial lung disease (Witkop et al., 1979), this feature has not been reported in other families and is not considered a criterion for diagnosis. However, the clinical triad of nonscarring alopecia, well-demarcated fiery red mucosa, and psoriasiform perineal involvement has been consistently observed (review by Boralevi et al., 2005).
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, has been reported in some individuals.
deficiency of ribose-5-phosphate isomerase
MedGen UID:
220946
Concept ID:
C1291609
Disease or Syndrome
Ribose-5-P isomerase deficiency is an extremely rare, hereditary, disorder of pentose phosphate metabolism characterized by progressive leukoencephalopathy and a highly increased ribitol and D-arabitol levels in the brain and body fluids. Clinical presentation includes psychomotor delay, epilepsy, and childhood-onset slow neurological regression with ataxia, spasticity, optic atrophy and sensorimotor neuropathy.
trichothiodystrophy, nonphotosensitive 1
MedGen UID:
272036
Concept ID:
C1313961
Disease or Syndrome
A subtype of trichothiodystrophy caused by mutation(s) in the MPLKIP gene, encoding M-phase-specific PLK1-interacting protein.
revesz syndrome
MedGen UID:
231230
Concept ID:
C1327916
Disease or Syndrome
A rare severe phenotypic variant of dyskeratosis congenita with onset in early childhood. The syndrome has features of dyskeratosis congenita (for example skin hyper/hypopigmentation, nail dystrophy, high risk of bone marrow failure and cancer, developmental delay sparse and fine hair) in conjunction with bilateral exudative retinopathy and intracranial calcifications.
ataxia-pancytopenia syndrome
MedGen UID:
230896
Concept ID:
C1327919
Disease or Syndrome
SAMD9L ataxia-pancytopenia (ATXPC) syndrome is characterized by cerebellar ataxia, variable hematologic cytopenias, and predisposition to marrow failure, myelodysplasia, and myeloid leukemia, sometimes associated with monosomy 7. The onset of hematologic abnormalities has been reported as early as age three months. The cytopenias in all cell lineages range from mild to very severe. Onset of neurologic impairment is variable. Nystagmus, dysmetria, increased deep tendon reflexes, and clonus are common. Gait impairment and other neurologic abnormalities are slowly progressive.
narp syndrome
MedGen UID:
231285
Concept ID:
C1328349
Disease or Syndrome
Mitochondrial diseases are a clinically heterogeneous group of disorders that arise as a result of dysfunction of the mitochondrial respiratory chain. They can be caused by mutation of genes encoded by either nuclear DNA or mitochondrial DNA (mtDNA). While some mitochondrial disorders only affect a single organ (e.g., the eye in Leber hereditary optic neuropathy [LHON]), many involve multiple organ systems and often present with prominent neurologic and myopathic features. Mitochondrial disorders may present at any age. Many individuals with a mutation of mtDNA display a cluster of clinical features that fall into a discrete clinical syndrome, such as the Kearns-Sayre syndrome (KSS), chronic progressive external ophthalmoplegia (CPEO), mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy with ragged-red fibers (MERRF), neurogenic weakness with ataxia and retinitis pigmentosa (NARP), or Leigh syndrome (LS). However, considerable clinical variability exists and many individuals do not fit neatly into one particular category, which is well-illustrated by the overlapping spectrum of disease phenotypes (including mitochondrial recessive ataxia syndrome (MIRAS) resulting from mutation of the nuclear gene POLG, which has emerged as a major cause of mitochondrial disease. Common clinical features of mitochondrial disease – whether involving a mitochondrial or nuclear gene – include ptosis, external ophthalmoplegia, proximal myopathy and exercise intolerance, cardiomyopathy, sensorineural deafness, optic atrophy, pigmentary retinopathy, and diabetes mellitus. Common central nervous system findings are fluctuating encephalopathy, seizures, dementia, migraine, stroke-like episodes, ataxia, and spasticity. A high incidence of mid- and late pregnancy loss is a common occurrence that often goes unrecognized.
cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss syndrome
MedGen UID:
318633
Concept ID:
C1832466
Disease or Syndrome
ATP1A3-related neurologic disorders represent a clinical continuum in which at least three distinct phenotypes have been delineated: rapid-onset dystonia-parkinsonism (RDP); alternating hemiplegia of childhood (ACH); and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS). However, some affected individuals have intermediate phenotypes or only a few features that do not fit well into one of these major phenotypes. RDP has been characterized by: abrupt onset of dystonia over days to weeks with parkinsonism (primarily bradykinesia and postural instability); common bulbar involvement; and absence or minimal response to an adequate trial of L-dopa therapy, with few exceptions. Often fever, physiologic stress, or alcoholic binges trigger the onset of symptoms. After their initial appearance, symptoms often stabilize with little improvement; occasionally second episodes occur with abrupt worsening of symptoms. Rarely, affected individuals have reported a more gradual onset of symptoms over weeks to months. Anxiety, depression, and seizures have been reported. Age of onset ranges from four to 55 years, although a childhood variation of RDP with onset between ages nine and 14 months has been reported. AHC is a complex neurodevelopmental syndrome most frequently manifesting in infancy or early childhood with paroxysmal episodic neurologic dysfunction including alternating hemiparesis or dystonia, quadriparesis, seizure-like episodes, and oculomotor abnormalities. Episodes can last for minutes, hours, days, or even weeks. Remission of symptoms occurs with sleep and immediately after awakening. Over time, persistent neurologic deficits including oculomotor apraxia, ataxia, choreoathetosis, dystonia, parkinsonism, and cognitive and behavioral dysfunction develop in the majority of those affected; more than 50% develop epilepsy in addition to their episodic movement disorder phenotype. CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) syndrome is characterized by episodes of ataxic encephalopathy and/or weakness during and after a febrile illness. Onset is between ages six months and four years. Some acute symptoms resolve; progression of sensory losses and severity vary.
cerebellar ataxia, cayman type
MedGen UID:
331319
Concept ID:
C1832585
Disease or Syndrome
Individuals with Cayman cerebellar ataxia (ATCAY) have hypotonia from birth, variable psychomotor retardation, and cerebellar dysfunction, including nystagmus, intention tremor, dysarthria, ataxic gait, and truncal ataxia. The disorder is restricted to an isolated region of Grand Cayman Island (summary by Nystuen et al., 1996; Bomar et al., 2003).
hereditary spastic paraplegia 9a
MedGen UID:
322007
Concept ID:
C1832669
Disease or Syndrome
Autosomal dominant spastic paraplegia-9A is a neurologic disorder characterized by onset of slowly progressive spasticity mainly affecting the lower limbs. The age at onset usually ranges from adolescence to adulthood, and patients have gait difficulties, motor neuropathy, and dysarthria. Additional variable features include cerebellar signs, cataract, pes cavus, and urinary urgency (summary by Coutelier et al., 2015). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal dominant spastic paraplegia, see SPG3A (182600).
familial hemiplegic migraine type 1
MedGen UID:
331388
Concept ID:
C1832884
Disease or Syndrome
Familial hemiplegic migraine (FHM) falls within the category of migraine with aura. In migraine with aura (including FHM) 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, such as 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 CACNA1A-FHM have cerebellar signs ranging from nystagmus to progressive, usually late-onset mild ataxia.
progressive bifocal chorioretinal atrophy
MedGen UID:
371537
Concept ID:
C1833321
Disease or Syndrome
Progressive bifocal chorioretinal atrophy (PBCRA) is a rare, autosomal dominant congenital chorioretinal dystrophy. The disorder is characterized by progressive macular and nasal retinal atrophic lesions, nystagmus, myopia, and poor vision. Invariably, there are 2 distinct foci of atrophy, a temporal focus that is present at birth and a nasal focus that appears early in life. Retinal detachment is an additional complication of the disease (Douglas et al., 1968; Kelsell et al., 1995).
optic nerve hypoplasia, bilateral
MedGen UID:
322281
Concept ID:
C1833797
Disease or Syndrome
A congenital abnormality characterized by the underdevelopment of both optic nerves.
ophthalmoplegia, familial static
MedGen UID:
371666
Concept ID:
C1833839
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.
microphthalmia, isolated, with cataract 1
MedGen UID:
320475
Concept ID:
C1834919
Disease or Syndrome
microcephaly with or without chorioretinopathy, lymphedema, or mental retardation
MedGen UID:
320559
Concept ID:
C1835265
Disease or Syndrome
Microcephaly with or without chorioretinopathy, lymphedema, or mental retardation is an autosomal dominant disorder that involves an overlapping but variable spectrum of central nervous system and ocular developmental anomalies. Microcephaly ranges from mild to severe and is often associated with mild to moderate developmental delay and a characteristic facial phenotype with upslanting palpebral fissures, broad nose with rounded tip, long philtrum with thin upper lip, prominent chin, and prominent ears. Chorioretinopathy is the most common eye abnormality, but retinal folds, microphthalmia, and myopic and hypermetropic astigmatism have also been reported, and some individuals have no overt ocular phenotype. Congenital lymphedema, when present, is typically confined to the dorsa of the feet, and lymphoscintigraphy reveals the absence of radioactive isotope uptake from the webspaces between the toes (summary by Ostergaard et al., 2012). Robitaille et al. (2014) found that MCLMR includes a broader spectrum of ocular disease, including retinal detachment with avascularity of the peripheral retina, and noted phenotypic overlap with familial exudative vitreoretinopathy (FEVR; see EVR1, 133780). Birtel et al. (2017) observed intrafamilial and intraindividual variability in retinal phenotype, and noted that syndromic manifestations in some patients are too subtle to be detected during a routine ophthalmologic evaluation. Variable expressivity and reduced penetrance have also been observed in some families (Jones et al., 2014; Li et al., 2016). Autosomal recessive forms of microcephaly with chorioretinopathy have been reported (see 251270). See also Mirhosseini-Holmes-Walton syndrome (autosomal recessive microcephaly with pigmentary retinopathy and mental retardation; 268050), which has been mapped to chromosome 8q21.3-q22.1.
aicardi goutieres syndrome 3
MedGen UID:
324389
Concept ID:
C1835916
Disease or Syndrome
Most characteristically, Aicardi-Goutières syndrome (AGS) manifests as an early-onset encephalopathy that usually, but not always, results in severe intellectual and physical disability. A subgroup of infants with AGS present at birth with abnormal neurologic findings, hepatosplenomegaly, elevated liver enzymes, and thrombocytopenia, a picture highly suggestive of congenital infection. Otherwise, most affected infants present at variable times after the first few weeks of life, frequently after a period of apparently normal development. Typically, they demonstrate the subacute onset of a severe encephalopathy characterized by extreme irritability, intermittent sterile pyrexias, loss of skills, and slowing of head growth. Over time, as many as 40% develop chilblain skin lesions on the fingers, toes, and ears. It is becoming apparent that atypical, sometimes milder, cases of AGS exist, and thus the true extent of the phenotype associated with pathogenic variants in the AGS-related genes is not yet known.
spastic paraplegia, optic atrophy, and neuropathy
MedGen UID:
324411
Concept ID:
C1836010
Disease or Syndrome
Spastic paraplegia, optic atrophy, and neuropathy (SPOAN) is an autosomal recessive neurodegenerative disorder characterized by early-onset progressive spastic paraplegia resulting in loss of independent ambulation in the teenage years. Additional features include optic atrophy, later onset of sensorimotor peripheral neuropathy, and progressive joint contractures; cognition remains intact (summary by Melo et al., 2015).
spinocerebellar ataxia type 26
MedGen UID:
373077
Concept ID:
C1836395
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.
childhood-onset autosomal recessive slowly progressive spinocerebellar ataxia
MedGen UID:
324520
Concept ID:
C1836474
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia is a neurologic disorder characterized by onset of progressive gait difficulties, eye movement abnormalities, and dysarthria in the first or second decade of life (summary by Dy et al., 2015).
alpha-n-acetylgalactosaminidase deficiency type 1
MedGen UID:
373113
Concept ID:
C1836544
Disease or Syndrome
Alpha-N-acetylgalactosaminidase (NAGA) deficiency is a very rare lysosomal storage disorder. It is clinically heterogeneous with 3 main phenotypes: type I is an infantile-onset neuroaxonal dystrophy; type II, also known as Kanzaki disease (609242), is an adult-onset disorder characterized by angiokeratoma corporis diffusum and mild intellectual impairment; and type III is an intermediate disorder with mild to moderate neurologic manifestations (Desnick and Schindler, 2001).
hereditary spastic paraplegia 26
MedGen UID:
373138
Concept ID:
C1836632
Disease or Syndrome
SPG26 is an autosomal recessive form of complicated spastic paraplegia characterized by onset in the first 2 decades of life of gait abnormalities due to lower limb spasticity and muscle weakness. Some patients have upper limb involvement. Additional features include intellectual disability, peripheral neuropathy, dysarthria, cerebellar signs, extrapyramidal signs, and cortical atrophy. The disorder is slowly progressive (summary by Boukhris et al., 2013). For a discussion of genetic heterogeneity of autosomal recessive SPG, see SPG5A (270800).
mpdu1-cdg
MedGen UID:
322968
Concept ID:
C1836669
Disease or Syndrome
Congenital disorders of glycosylation (CDGs) are metabolic deficiencies in glycoprotein biosynthesis that usually cause severe mental and psychomotor retardation. Different forms of CDGs can be recognized by altered isoelectric focusing (IEF) patterns of serum transferrin. For a general discussion of CDGs, see CDG Ia (212065) and CDG Ib (602579).
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.
distal arthrogryposis type 4
MedGen UID:
373169
Concept ID:
C1836756
Disease or Syndrome
Distal arthrogryposis type 4 (DA4) is distinguished by the presence of scoliosis (summary by Bamshad et al., 2009). For a phenotypic description and a discussion of genetic heterogeneity of distal arthrogryposis, see DA1 (108120).
combined oxidative phosphorylation deficiency 1
MedGen UID:
322999
Concept ID:
C1836797
Disease or Syndrome
Combined oxidative phosphorylation deficiency is an autosomal recessive multisystem disorder with variable manifestations resulting from a defect in the mitochondrial oxidative phosphorylation (OXPHOS) system. Onset occurs at or soon after birth, and features can include growth retardation, microcephaly, hypertonicity, axial hypotonia, encephalopathy, cardiomyopathy, and liver dysfunction. Death usually occurs in the first weeks or years of life (summary by Smits et al., 2011). Genetic Heterogeneity of Combined Oxidative Phosphorylation Deficiency See also COXPD2 (610498), caused by mutation in the MRPS16 gene (609204) on 10q22; COXPD3 (610505), caused by mutation in the TSFM gene (604723) on 12q14; COXPD4 (610678), caused by mutation in the TUFM gene (602389) on 16p11; COXPD5 (611719), caused by mutation in the MRPS22 gene (605810) on 3q23; COXPD6 (300816), caused by mutation in the AIFM1 gene (300169) on Xq26; COXPD7 (613559), caused by mutation in the MTRFR gene (613541) on 12q24; COXPD8 (614096), caused by mutation in the AARS2 gene (612035) on 6p21; COXPD9 (614582), caused by mutation in the MRPL3 gene (607118) on 3q22; COXPD10 (614702), caused by mutation in the MTO1 gene (614667) on 6q13; COXPD11 (614922), caused by mutation in the RMND1 gene (614917) on 6q25; COXPD12 (614924), caused by mutation in the EARS2 gene (612799) on 16p13; COXPD13 (614932), caused by mutation in the PNPT1 gene (610316) on 2p16; COXPD14 (614946), caused by mutation in the FARS2 gene (611592) on 6p25; COXPD15 (614947), caused by mutation in the MTFMT gene (611766) on 15q; COXPD16 (615395), caused by mutation in the MRPL44 gene (611849) on 2q36; COXPD17 (615440), caused by mutation in the ELAC2 gene (605367) on 17p11; COXPD18 (615578), caused by mutation in the SFXN4 gene (615564) on 10q26; COXPD19 (615595), caused by mutation in the LYRM4 gene (613311) on 6p25; COXPD20 (615917), caused by mutation in the VARS2 gene (612802) on 6p21; COXPD21 (615918), caused by mutation in the TARS2 gene (612805) on 1q21; COXPD22 (616045), caused by mutation in the ATP5A1 gene (164360) on 18q12; COXPD23 (616198), caused by mutation in the GTPBP3 (608536) gene on 19p13; COXPD24 (616239), caused by mutation in the NARS2 gene (612803) on 11q14; COXPD25 (616430), caused by mutation in the MARS2 gene (609728) on 2q33; COXPD26 (616539), caused by mutation in the TRMT5 gene (611023) on 14q23; COXPD27 (616672), caused by mutation in the CARS2 gene (612800) on 13q34; COXPD28 (616794), caused by mutation in the SLC25A26 gene (611037) on 3p14; COXPD29 (616811), caused by mutation in the TXN2 gene (609063) on 22q12; COXPD30 (616974), caused by mutation in the TRMT10C gene (615423) on 3q12; and COXPD31 (617228), caused by mutation in the MIPEP gene (602241) on 13q12; COXPD32 (617664), caused by mutation in the MRPS34 gene (611994) on 16q13; COXPD33 (617713), caused by mutation in the C1QBP gene (601269) on 17p13; and COXPD34 (617872), caused by mutation in the MRPS7 gene (611974) on 17q25; COXPD35 (617873), caused by mutation in the TRIT1 gene (617840) on 1p34; COXPD36 (617950), caused by mutation in the MRPS2 gene (611971) on 9q34; COXPD37 (618329), caused by mutation in the MICOS13 gene (616658) on 19p13; COXPD38 (618378), caused by mutation in the MRPS14 gene (611978) on 1q23; COXPD39 (618397), caused by mutation in the GFM2 gene (606544) on 5q13; COXPD40 (618835), caused by mutation in the QRSL1 gene (617209) on 6q21; COXPD41 (618838), caused by mutation in the GATB gene (603645) on 4q31; COXPD42 (618839), caused by mutation in the GATC gene (617210) on 12q24; COXPD43 (618851), caused by mutation in the TIMM22 gene (607251) on 17p13; COXPD44 (618855), caused by mutation in the FASTKD2 gene (612322) on 2q33; COXPD45 (618951), caused by mutation in the MRPL12 gene (602375) on 17q25; COXPD46 (618952), caused by mutation in the MRPS23 gene (611985) on 17q22; COXPD47 (618958), caused by mutation in the MRPS28 gene (611990) on 8q21; COXPD48 (619012), caused by mutation in the NSUN3 gene (617491) on 3q11; COXPD49 (619024), caused by mutation in the MIEF2 gene (615498) on 17p11; COXPD50 (619025), caused by mutation in the MRPS25 gene (611987) on 3p25; and COXPD51 (619057), caused by mutation in the PTCD3 gene (614918) on 2p11.
spondylometaphyseal dysplasia-cone-rod dystrophy syndrome
MedGen UID:
324684
Concept ID:
C1837073
Disease or Syndrome
Spondylometaphyseal dysplasia with cone-rod dystrophy (SMDCRD) is characterized by postnatal growth deficiency resulting in profound short stature, rhizomelia with bowing of the lower extremities, platyspondyly with anterior vertebral protrusions, progressive metaphyseal irregularity and cupping with shortened tubular bones, and early-onset progressive visual impairment associated with a pigmentary maculopathy and electroretinographic evidence of cone-rod dysfunction (summary by Hoover-Fong et al., 2014). Yamamoto et al. (2014) reviewed 16 reported cases of SMDCRD, noting that all affected individuals presented uniform skeletal findings, with rhizomelia and bowed lower limbs observed in the first year of life, whereas retinal dystrophy had a more variable age of onset. There was severe disproportionate short stature, with a final height of less than 100 cm; scoliosis was usually mild. Visual loss was progressive, with stabilization in adolescence.
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.
congenital disorder of glycosylation type 1e
MedGen UID:
324784
Concept ID:
C1837396
Disease or Syndrome
Congenital disorders of glycosylation (CDGs) are metabolic deficiencies in glycoprotein biosynthesis that usually cause severe mental and psychomotor retardation. Different forms of CDGs can be recognized by altered isoelectric focusing (IEF) patterns of serum transferrin. For a general discussion of CDGs, see CDG Ia (212065) and CDG Ib (602579).
pyruvate dehydrogenase phosphatase deficiency
MedGen UID:
332448
Concept ID:
C1837429
Disease or Syndrome
Pyruvate dehydrogenase phosphatase deficiency (PDHPD) is an autosomal recessive disorder of pyruvate metabolism characterized by neonatal/infantile and childhood lactic acidosis, normal lactate to pyruvate ratio, elevated plasma alanine, delayed psychomotor development, epileptic encephalopathy, and hypotonia (summary by Bedoyan et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of pyruvate dehydrogenase (PDH) deficiency, see 312170.
spinocerebellar ataxia type 8
MedGen UID:
332457
Concept ID:
C1837454
Disease or Syndrome
SCA8 is a slowly progressive ataxia with onset typically in the third to fifth decade but with a range from before age one year to after age 60 years. Common initial manifestations are scanning dysarthria with a characteristic drawn-out slowness of speech and gait instability. Over the disease course other findings can include eye movement abnormalities (nystagmus, abnormal pursuit and abnormal saccades, and, rarely, ophthalmoplegia); upper motor neuron involvement; extrapyramidal signs; brain stem signs (dysphagia and poor cough reflex); sensory neuropathy; and cognitive impairment (e.g., executive dysfunction, psychomotor slowing and other features of cerebellar cognitive-affective disorder in some). Life span is typically not shortened.
spinocerebellar ataxia type 25
MedGen UID:
373347
Concept ID:
C1837518
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.
spinocerebellar ataxia type 20
MedGen UID:
373352
Concept ID:
C1837541
Disease or Syndrome
Spinocerebellar ataxia type 20 (SCA20) is characterized by a slowly progressive ataxia and dysarthria. Approximately two thirds of those affected also display palatal tremor ("myoclonus") and/or abnormal phonation clinically resembling spasmodic adductor dysphonia. Dysarthria, which may be abrupt in onset, precedes the onset of ataxia in about two thirds of affected individuals, sometimes by a number of years. Hypermetric horizontal saccades (without nystagmus or disturbance of vestibulo-ocular reflex gain) are seen in about half of affected persons. Although minor pyramidal signs (brisk knee jerks, crossed adductor spread) may be seen, spasticity and extensor plantar responses are not. Cognition is normal. Clinical information is based on the findings in 16 personally examined affected members of a single Australian family of Anglo-Celtic descent.
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.
leber congenital amaurosis 9
MedGen UID:
325277
Concept ID:
C1837873
Disease or Syndrome
Early-onset neurodegeneration in the human retina can lead to Leber congenital amaurosis (LCA), the most severe human form of inherited photoreceptor-neuron degeneration resulting in congenital blindness, with an incidence of approximately 1 in 80,000 (summary by Koenekoop et al., 2012). NMNAT1 mutations have been observed to cause severe and rapidly progressive macular degeneration, leading to severe central atrophy with an appearance of congenital macular coloboma in the neonatal period, as well as an unusual early-onset atrophy of the optic nerve (Perrault et al., 2012). Some patients present with later onset and milder phenotype than typical LCA (Kumaran et al., 2021). For a general discussion of the phenotypic and genetic heterogeneity in Leber congenital amaurosis, see LCA1 (204000).
toriello-lacassie-droste syndrome
MedGen UID:
333068
Concept ID:
C1838329
Disease or Syndrome
Oculoectodermal syndrome (OES) is characterized by the association of epibulbar dermoids and aplasia cutis congenita. Affected individuals exhibit congenital scalp lesions which are atrophic, nonscarring, hairless regions that are often multiple and asymmetric in distribution, and may have associated hamartomas. Ectodermal changes include linear hyperpigmentation that may follow the lines of Blaschko and, rarely, epidermal nevus-like lesions. Epibulbar dermoids may be uni- or bilateral. Additional ocular anomalies such as skin tags of the upper eyelid and rarely optic nerve or retinal changes or microphthalmia can be present. Phenotypic expression is highly variable, and various other abnormalities have occasionally been reported, including growth failure, lymphedema, and cardiovascular defects, as well as neurodevelopmental symptoms such as developmental delay, epilepsy, learning difficulties, and behavioral abnormalities. Benign tumor-like lesions such as nonossifying fibromas of the long bones and giant cell granulomas of the jaws have repeatedly been observed and appear to be age-dependent, becoming a common manifestation in individuals aged 5 years or older (summary by Boppudi et al., 2016).
carasil syndrome
MedGen UID:
325051
Concept ID:
C1838577
Disease or Syndrome
HTRA1 disorder is a phenotypic spectrum in which some individuals have few to no symptoms and others manifest with the more severe CARASIL (cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy) phenotype. Those who have a heterozygous HTRA1 pathogenic variant may have mild neurologic findings (sometimes identified only on neuroimaging) or mild-to-moderate neurologic signs and symptoms of CARASIL. In this chapter, the term "classic CARASIL" refers to the more severe phenotype associated with biallelic pathogenic variants, and "HTRA1 cerebral small vessel disease" (HTRA1-CSVD) refers to the milder phenotype associated with a heterozygous HTRA1 pathogenic variant. Classic CARASIL is characterized by early-onset changes in the deep white matter of the brain observed on MRI, and associated neurologic findings. The most frequent initial symptom is gait disturbance from spasticity beginning between ages 20 and 40 years. Forty-four percent of affected individuals have stroke-like episodes before age 40 years. Mood changes (apathy and irritability), pseudobulbar palsy, and cognitive dysfunction begin between ages 20 and 50 years. The disease progresses slowly following the onset of neurologic symptoms. Scalp alopecia and acute mid- to lower-back pain (lumbago) before age 30 years are characteristic. The most frequent initial symptom in individuals with HTRA1-CSVD is slowly progressive gait disturbance after age 40 years, which may be followed by the development of mood changes and cognitive dysfunction. A majority of affected individuals have a stroke-like episode after age 40 years. Spondylosis and alopecia are seen in a minority of individuals with HTRA1-CSVD.
retinitis pigmentosa 14
MedGen UID:
325056
Concept ID:
C1838603
Disease or Syndrome
retinitis pigmentosa 12
MedGen UID:
374019
Concept ID:
C1838647
Disease or Syndrome
wolfram syndrome, mitochondrial form
MedGen UID:
325511
Concept ID:
C1838782
Disease or Syndrome
mitochondrial complex i deficiency
MedGen UID:
374101
Concept ID:
C1838979
Disease or Syndrome
Isolated complex I deficiency is a rare inborn error of metabolism due to mutations in nuclear or mitochondrial genes encoding subunits or assembly factors of the human mitochondrial complex I (NADH: ubiquinone oxidoreductase) and is characterized by a wide range of manifestations including marked and often fatal lactic acidosis, cardiomyopathy, leukoencephalopathy, pure myopathy and hepatopathy with tubulopathy. Among the numerous clinical phenotypes observed are Leigh syndrome, Leber hereditary optic neuropathy and MELAS syndrome (see these terms).
hereditary spastic paraplegia 2
MedGen UID:
374177
Concept ID:
C1839264
Disease or Syndrome
PLP1 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. Heterozygous females may manifest mild-to-moderate signs of the disease.
nystagmus, myoclonic
MedGen UID:
326918
Concept ID:
C1839579
Disease or Syndrome
prieto syndrome
MedGen UID:
374294
Concept ID:
C1839730
Disease or Syndrome
An X-linked syndromic intellectual disability characterized by intellectual disability, subcortical cerebral atrophy, dental anomalies, patella luxation, lower back skin dimple, and dysmorphic facial features.
fragile x tremor/ataxia syndrome
MedGen UID:
333403
Concept ID:
C1839780
Disease or Syndrome
FMR1 disorders include fragile X syndrome (FXS), fragile X-associated tremor/ataxia syndrome (FXTAS), and fragile X-associated primary ovarian insufficiency (FXPOI). Fragile X syndrome occurs in individuals with an FMR1 full mutation or other loss-of-function variant and is nearly always characterized in affected males by developmental delay and intellectual disability along with a variety of behavioral issues. Autism spectrum disorder is present in 50%-70% of individuals with FXS. Affected males may have characteristic craniofacial features (which become more obvious with age) and medical problems including hypotonia, gastroesophageal reflux, strabismus, seizures, sleep disorders, joint laxity, pes planus, scoliosis, and recurrent otitis media. Adults may have mitral valve prolapse or aortic root dilatation. The physical and behavioral features seen in males with FXS have been reported in females heterozygous for the FMR1 full mutation, but with lower frequency and milder involvement. FXTAS occurs in individuals who have an FMR1 premutation and is characterized by late-onset, progressive cerebellar ataxia and intention tremor followed by cognitive impairment. Psychiatric disorders are common. Age of onset is typically between 60 and 65 years and is more common among males who are hemizygous for the premutation (40%) than among females who are heterozygous for the premutation (16%-20%). FXPOI, defined as hypergonadotropic hypogonadism before age 40 years, has been observed in 20% of women who carry a premutation allele compared to 1% in the general population.
leber congenital amaurosis 11
MedGen UID:
326698
Concept ID:
C1840284
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.
achromatopsia 4
MedGen UID:
330669
Concept ID:
C1841721
Disease or Syndrome
Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography.
hermansky-pudlak syndrome 2
MedGen UID:
374912
Concept ID:
C1842362
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
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.
alg2-cdg
MedGen UID:
334618
Concept ID:
C1842836
Disease or Syndrome
(9q31.1). Transmission is autosomal recessive.
chromosome 1p36 deletion syndrome
MedGen UID:
334629
Concept ID:
C1842870
Disease or Syndrome
The constitutional deletion of chromosome 1p36 results in a syndrome with multiple congenital anomalies and mental retardation (Shapira et al., 1997). Monosomy 1p36 is the most common terminal deletion syndrome in humans, occurring in 1 in 5,000 births (Shaffer and Lupski, 2000; Heilstedt et al., 2003). See also neurodevelopmental disorder with or without anomalies of the brain, eye, or heart (NEDBEH; 616975), which shows overlapping features and is caused by heterozygous mutation in the RERE gene (605226) on proximal chromosome 1p36. See also Radio-Tartaglia syndrome (RATARS; 619312), caused by mutation in the SPEN gene (613484) on chromosome 1p36, which shows overlapping features.
cataract, congenital, with mental impairment and dentate gyrus atrophy
MedGen UID:
334365
Concept ID:
C1843257
Disease or Syndrome
biotin-responsive basal ganglia disease
MedGen UID:
375289
Concept ID:
C1843807
Disease or Syndrome
Biotin-thiamine-responsive basal ganglia disease (BTBGD) may present in childhood, early infancy, or adulthood. The classic presentation of BTBGD occurs in childhood (age 3-10 years) and is characterized by recurrent subacute encephalopathy manifest as confusion, seizures, ataxia, dystonia, supranuclear facial palsy, external ophthalmoplegia, and/or dysphagia which, if left untreated, can eventually lead to coma and even death. Dystonia and cogwheel rigidity are nearly always present; hyperreflexia, ankle clonus, and Babinski responses are common. Hemiparesis or quadriparesis may be seen. Episodes are often triggered by febrile illness or mild trauma or stress. Simple partial or generalized seizures are easily controlled with antiepileptic drugs. An early-infantile Leigh-like syndrome / atypical infantile spasms presentation occurs in the first three months of life with poor feeding, vomiting, acute encephalopathy, and severe lactic acidosis. An adult-onset Wernicke-like encephalopathy presentation is characterized by acute onset of status epilepticus, ataxia, nystagmus, diplopia, and ophthalmoplegia in the second decade of life. Prompt administration of biotin and thiamine early in the disease course results in partial or complete improvement within days in the childhood and adult presentations, but most with the infantile presentation have had poor outcome even after supplementation with biotin and thiamine.
sensory ataxic neuropathy-dysarthria-ophthalmoparesis syndrome
MedGen UID:
375302
Concept ID:
C1843851
Disease or Syndrome
POLG-related disorders comprise a continuum of overlapping phenotypes that were clinically defined long before their molecular basis was known. Most affected individuals have some, but not all, of the features of a given phenotype; nonetheless, the following nomenclature can assist the clinician in diagnosis and management. Onset of the POLG-related disorders ranges from infancy to late adulthood. Alpers-Huttenlocher syndrome (AHS), one of the most severe phenotypes, is characterized by childhood-onset progressive and ultimately severe encephalopathy with intractable epilepsy and hepatic failure. Childhood myocerebrohepatopathy spectrum (MCHS) presents between the first few months of life and about age three years with developmental delay or dementia, lactic acidosis, and a myopathy with failure to thrive. Other findings can include liver failure, renal tubular acidosis, pancreatitis, cyclic vomiting, and hearing loss. Myoclonic epilepsy myopathy sensory ataxia (MEMSA) now describes the spectrum of disorders with epilepsy, myopathy, and ataxia without ophthalmoplegia. MEMSA now includes the disorders previously described as spinocerebellar ataxia with epilepsy (SCAE). The ataxia neuropathy spectrum (ANS) includes the phenotypes previously referred to as mitochondrial recessive ataxia syndrome (MIRAS) and sensory ataxia neuropathy dysarthria and ophthalmoplegia (SANDO). About 90% of persons in the ANS have ataxia and neuropathy as core features. Approximately two thirds develop seizures and almost one half develop ophthalmoplegia; clinical myopathy is rare. Autosomal recessive progressive external ophthalmoplegia (arPEO) is characterized by progressive weakness of the extraocular eye muscles resulting in ptosis and ophthalmoparesis (or paresis of the extraocular muscles) without associated systemic involvement; however, caution is advised because many individuals with apparently isolated arPEO at the onset develop other manifestations of POLG-related disorders over years or decades. Of note, in the ANS spectrum the neuropathy commonly precedes the onset of PEO by years to decades. Autosomal dominant progressive external ophthalmoplegia (adPEO) typically includes a generalized myopathy and often variable degrees of sensorineural hearing loss, axonal neuropathy, ataxia, depression, parkinsonism, hypogonadism, and cataracts (in what has been called "chronic progressive external ophthalmoplegia plus," or "CPEO+").
spinocerebellar ataxia type 18
MedGen UID:
336066
Concept ID:
C1843884
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.
spinocerebellar ataxia type 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.
familial exudative vitreoretinopathy, x-linked
MedGen UID:
337030
Concept ID:
C1844579
Disease or Syndrome
Familial exudative vitreoretinopathy (FEVR) is an inherited disorder characterized by the incomplete development of the retinal vasculature. Its clinical appearance varies considerably, even within families, with severely affected patients often registered as blind during infancy, whereas mildly affected patients with few or no visual problems may have such a small area of avascularity in their peripheral retina that it is visible only by fluorescein angiography. It is believed that this peripheral avascularity is the primary anomaly in FEVR and results from defective retinal angiogenesis. The sight-threatening features of the FEVR phenotype are considered secondary to retinal avascularity and develop because of the resulting retinal ischemia; they include the development of hyperpermeable blood vessels, neovascularization, vitreoretinal traction, retinal folds, and retinal detachments (summary by Poulter et al., 2010). For a discussion of genetic heterogeneity of FEVR, see EVR1 (133780).
cone-rod dystrophy, x-linked 1
MedGen UID:
336777
Concept ID:
C1844776
Disease or Syndrome
X-linked cone-rod dystrophy is a rare, progressive visual disorder primarily affecting cone photoreceptors (Demirci et al., 2002). Affected individuals, essentially all of whom are males, present with decreased visual acuity, myopia, photophobia, abnormal color vision, full peripheral visual fields, decreased photopic electroretinographic responses, and granularity of the macular retinal pigment epithelium. The degree of rod photoreceptor involvement is variable, with increasing degeneration. Although penetrance appears to be nearly 100%, there is variable expressivity with respect to age at onset, severity of symptoms, and findings (Hong et al., 1994). Genetic Heterogeneity of X-linked Cone-Rod Dystrophy Additional forms of X-linked cone-rod dystrophy include CORDX2 (300085), mapped to chromosome Xq27, and CORDX3 (300476), caused by mutation in the CACNA1F gene (300110) on chromosome Xp11.23. For a discussion of autosomal forms of cone-rod dystrophy, see CORD2 (120970).
charcot-marie-tooth peroneal muscular atrophy and friedreich ataxia, combined
MedGen UID:
337104
Concept ID:
C1844863
Disease or Syndrome
ocular albinism with late-onset sensorineural deafness
MedGen UID:
337149
Concept ID:
C1845069
Congenital Abnormality
Ocular albinism is a genetic condition that primarily affects the eyes. This condition reduces the coloring (pigmentation) of the iris, which is the colored part of the eye, and the retina, which is the light-sensitive tissue at the back of the eye. Pigmentation in the eye is essential for normal vision.\n\nOcular albinism is characterized by severely impaired sharpness of vision (visual acuity) and problems with combining vision from both eyes to perceive depth (stereoscopic vision). Although the vision loss is permanent, it does not worsen over time. Other eye abnormalities associated with this condition include rapid, involuntary eye movements (nystagmus); eyes that do not look in the same direction (strabismus); and increased sensitivity to light (photophobia). Many affected individuals also have abnormalities involving the optic nerves, which carry visual information from the eye to the brain.\n\nUnlike some other forms of albinism, ocular albinism does not significantly affect the color of the skin and hair. People with this condition may have a somewhat lighter complexion than other members of their family, but these differences are usually minor.\n\nThe most common form of ocular albinism is known as the Nettleship-Falls type or type 1. Other forms of ocular albinism are much rarer and may be associated with additional signs and symptoms, such as hearing loss.
nystagmus 5, congenital, x-linked
MedGen UID:
375583
Concept ID:
C1845116
Disease or Syndrome
Classic congenital or infantile nystagmus presents as conjugate, horizontal oscillations of the eyes, in primary or eccentric gaze, often with a preferred head turn or tilt. Other associated features may include mildly decreased visual acuity, strabismus, astigmatism, and occasionally head nodding. Eye movement recordings reveal that infantile nystagmus is predominantly a horizontal jerk waveform, with a diagnostic accelerating velocity slow phase. However, pendular and triangular waveforms may also be present. The nystagmus may rarely be vertical. As these patients often have normal visual acuity, it is presumed that the nystagmus represents a primary defect in the parts of the brain responsible for ocular motor control; thus the disorder has sometimes been termed 'congenital motor nystagmus' (Tarpey et al., 2006; Shiels et al., 2007). For a discussion of genetic heterogeneity of congenital nystagmus, see NYS1 (310700).
mental retardation x-linked with cerebellar hypoplasia and distinctive facial appearance
MedGen UID:
336920
Concept ID:
C1845366
Disease or Syndrome
X-linked intellectual deficit-cerebellar hypoplasia, also known as OPHN1 syndrome, is a rare syndromic form of cerebellar dysgenesis characterized by moderate to severe intellectual deficit and cerebellar abnormalities.
x-linked cone-rod dystrophy 3
MedGen UID:
336932
Concept ID:
C1845407
Disease or Syndrome
Cone-rod dystrophy is a retinal disorder with predominantly cone involvement. Rod impairment may occur at the same time as the cone impairment or appear later. Patients with CORD usually have reduced visual acuity, photophobia, and color vision defects (summary by Huang et al., 2013). For a discussion of genetic heterogeneity of X-linked cone-rod dystrophy, see 304020.
autosomal recessive cerebellar ataxia-saccadic intrusion syndrome
MedGen UID:
335442
Concept ID:
C1846492
Disease or Syndrome
VPS13D movement disorder is a hyperkinetic movement disorder (dystonia, chorea, and/or ataxia) of variable age of onset that can be associated with developmental delay. Onset ranges from birth to adulthood. Individuals can present in childhood with motor delays and gait instability. Cognitive impairment ranging from mild intellectual disability to developmental delay has been reported, and several individuals have normal cognitive function. Individuals have also presented as young adults with gait difficulties caused by spastic ataxia or ataxia. In addition to gait ataxia, affected individuals had limb ataxia, dysarthria, and eye movement abnormalities (macro-saccadic oscillations, nystagmus, and saccadic pursuit). Additional features reported in some individuals include peripheral neuropathy and/or seizures. The disorder progresses to spastic ataxia or generalized dystonia, which can lead to loss of independent ambulation.
hereditary spastic paraplegia 7
MedGen UID:
339552
Concept ID:
C1846564
Disease or Syndrome
Spastic paraplegia 7 (SPG7) is characterized by insidiously progressive bilateral leg weakness and spasticity. Most affected individuals have decreased vibration sense and cerebellar signs. Onset is mostly in adulthood, although symptoms may start as early as age 11 years and as late as age 72 years. Additional features including ataxia (gait and limbs), spastic dysarthria, dysphagia, pale optic disks, ataxia, nystagmus, strabismus, ptosis, hearing loss, motor and sensory neuropathy, amyotrophy, scoliosis, pes cavus, and urinary sphincter disturbances may be observed.
joubert syndrome 4
MedGen UID:
335526
Concept ID:
C1846790
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.
senior-loken syndrome 3
MedGen UID:
335569
Concept ID:
C1846980
Disease or Syndrome
Senior-Løken syndrome is a rare disorder characterized by the combination of two specific features: a kidney condition called nephronophthisis and an eye condition known as Leber congenital amaurosis.\n\nLeber congenital amaurosis primarily affects the retina, which is the specialized tissue at the back of the eye that detects light and color. This condition causes vision problems, including an increased sensitivity to light (photophobia), involuntary movements of the eyes (nystagmus), and extreme farsightedness (hyperopia). Some people with Senior-Løken syndrome develop the signs of Leber congenital amaurosis within the first few years of life, while others do not develop vision problems until later in childhood.\n\nNephronophthisis causes fluid-filled cysts to develop in the kidneys beginning in childhood. These cysts impair kidney function, initially causing increased urine production (polyuria), excessive thirst (polydipsia), general weakness, and extreme tiredness (fatigue). Nephronophthisis leads to end-stage renal disease (ESRD) later in childhood or in adolescence. ESRD is a life-threatening failure of kidney function that occurs when the kidneys are no longer able to filter fluids and waste products from the body effectively.
oculocutaneous albinism type 1b
MedGen UID:
337712
Concept ID:
C1847024
Disease or Syndrome
Oculocutaneous albinism type I is an autosomal recessive disorder characterized by absence of pigment in hair, skin, and eyes, and does not vary with race or age. Severe nystagmus, photophobia, and reduced visual acuity are common features. OCA type I is divided into 2 types: type IA, characterized by complete lack of tyrosinase activity due to production of an inactive enzyme, and type IB, characterized by reduced activity of tyrosinase. Although OCA caused by mutations in the TYR gene was classically known as 'tyrosinase-negative' OCA, Tripathi et al. (1992) noted that some patients with 'tyrosinase-positive' OCA may indeed have TYR mutations resulting in residual enzyme activity. These patients can be classified as having OCA1B.
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.\n\nPolymicrogyria 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.\n\nResearchers 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.\n\nBilateral 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.\n\nPolymicrogyria 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.
oculocutaneous albinism type 4
MedGen UID:
338324
Concept ID:
C1847836
Disease or Syndrome
Oculocutaneous albinism type 4 (OCA4) is characterized by hypopigmentation of the hair and skin plus the characteristic ocular changes found in all other types of albinism, including: nystagmus; reduced iris pigment with iris translucency; reduced retinal pigment with visualization of the choroidal blood vessels on ophthalmoscopic examination; foveal hypoplasia associated with reduction in visual acuity; and misrouting of the optic nerves at the chiasm associated with alternating strabismus, reduced stereoscopic vision, and an altered visual evoked potential (VEP). Individuals with OCA4 are usually recognized within the first year of life because of hypopigmentation of the hair and skin and the ocular features of nystagmus and strabismus. Vision is likely to be stable after early childhood. The amount of cutaneous pigmentation in OCA4 ranges from minimal to near normal. Newborns with OCA4 usually have some pigment in their hair, with color ranging from silvery white to light yellow. Hair color may darken with time, but does not vary significantly from childhood to adulthood.
waardenburg syndrome type 4a
MedGen UID:
341244
Concept ID:
C1848519
Disease or Syndrome
Waardenburg syndrome type 4 (WS4), also known as Waardenburg-Shah syndrome, is an auditory-pigmentary syndrome characterized by pigmentary abnormalities of the hair, skin, and eyes, congenital sensorineural hearing loss, and Hirschsprung disease (reviews by Read and Newton, 1997 and Pingault et al., 2010). WS type 4A is caused by mutation in the EDNRB gene (131244). Clinical Variability of Waardenburg Syndrome Types 1-4 Waardenburg syndrome has been classified into 4 main phenotypes. Type I Waardenburg syndrome (WS1; 193500) is characterized by pigmentary abnormalities of the hair, including a white forelock and premature graying; pigmentary changes of the iris, such as heterochromia iridis and brilliant blue eyes; congenital sensorineural hearing loss; and 'dystopia canthorum.' WS type II (WS2) is distinguished from type I by the absence of dystopia canthorum. WS type III (WS3; 148820) has dystopia canthorum and is distinguished by the presence of upper limb abnormalities. WS type 4 has the additional feature of Hirschsprung disease (reviews by Read and Newton, 1997 and Pingault et al., 2010). Genetic Heterogeneity of Waardenburg Syndrome Type 4 Waardenburg syndrome type 4 is genetically heterogeneous. WS4B (613265) is caused by mutation in the EDN3 gene (131242) on chromosome 20q13, and WS4C (613266) is caused by mutation in the SOX10 gene (602229) on chromosome 22q13.
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 complications, and/or subacute combined degeneration of the spinal cord.
cobalamin c disease
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 complications, and/or subacute combined degeneration of the spinal cord.
trichomegaly-retina pigmentary degeneration-dwarfism syndrome
MedGen UID:
338532
Concept ID:
C1848745
Disease or Syndrome
PNPLA6 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). The hypogonadotropic hypogonadism occurs 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; 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).
teratoma, pineal
MedGen UID:
336449
Concept ID:
C1848902
Neoplastic Process
infantile onset spinocerebellar ataxia
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.
hereditary spastic paraplegia 5a
MedGen UID:
376521
Concept ID:
C1849115
Disease or Syndrome
Spastic paraplegia-5A (SPG5A) is an autosomal recessive neurologic disorder with a wide phenotypic spectrum. Some patients have pure spastic paraplegia affecting only gait, whereas others may have a complicated phenotype with additional manifestations, including optic atrophy or cerebellar ataxia (summary by Arnoldi et al., 2012). The hereditary spastic paraplegias (SPG) are a group of clinically and genetically diverse disorders characterized by progressive, usually severe, lower extremity spasticity; see reviews of Fink et al. (1996) and Fink (1997). Inheritance is most often autosomal dominant (see 182600), but X-linked (see 303350) and autosomal recessive forms also occur. Genetic Heterogeneity of Autosomal Recessive Spastic Paraplegia Autosomal recessive forms of SPG include SPG7 (607259), caused by mutation in the paraplegin gene (602783) on chromosome 16q24; SPG9B (616586), caused by mutation in the ALDH18A1 gene (138250) on 10q24; SPG11 (604360), caused by mutation in the spatacsin gene (610844) on 15q21; SPG15 (270700), caused by mutation in the ZFYVE26 gene (612012) on 14q24; SPG18 (611225), caused by mutation in the ERLIN2 gene (611605) on 8p11; SPG20 (275900), caused by mutation in the spartin gene (607111) on 13q12; SPG21 (248900), caused by mutation in the maspardin gene (608181) on 15q21; SPG26 (609195), caused by mutation in the B4GALNT1 gene (601873) on 12q13; SPG28 (609340), caused by mutation in the DDHD1 gene (614603) on 14q22; SPG30 (610357), caused by mutation in the KIF1A gene (601255) on 2q37; SPG35 (612319), caused by mutation in the FA2H gene (611026) on 16q23; SPG39 (612020), caused by mutation in the PNPLA6 gene (603197) on 19p13.3; SPG43 (615043), caused by mutation in the C19ORF12 gene (614297) on 19q12; SPG44 (613206), caused by mutation in the GJC2 gene (608803) on 1q42; SPG45 (613162), caused by mutation in the NT5C2 gene (600417) on 10q24; SPG46 (614409), caused by mutation in the GBA2 gene (609471) on 9p13; SPG48 (613647), caused by mutation in the KIAA0415 gene (613653) on 7p22.1; SPG49 (615031) caused by mutation in the TECPR2 gene (615000) on 14q32; SPG54 (615033), caused by mutation in the DDHD2 gene (615003) on 8p11; SPG55 (615035), caused by mutation in the MTRFR gene on 12q24; SPG56 (615030), caused by mutation in the CYP2U1 gene (610670) on 4q25; SPG57 (615658), caused by mutation in the TFG gene (602498) on 3q12; SPG61 (615685), caused by mutation in the ARL6IP1 gene (607669) on 1p12; SPG62 (615681), caused by mutation in the ERLIN1 gene on 10q24; SPG63 (615686), caused by mutation in the AMPD2 gene (102771) on 1p13; SPG64 (615683), caused by mutation in the ENTPD1 gene (601752) on 10q24; SPG72 (615625), caused by mutation in the REEP2 gene (609347) on 5q31; SPG74 (616451), caused by mutation in the IBA57 gene (615316) on 1q42; SPG75 (616680), caused by mutation in the MAG gene (159460) on 19q13; SPG76 (616907), caused by mutation in the CAPN1 gene (114220) on 11q13; SPG77 (617046), caused by mutation in the FARS2 gene (611592) on 6p25; SPG78, caused by mutation in the ATP13A2 gene (610513) on 1p36; SPG79 (615491), caused by mutation in the UCHL1 gene (191342) on 4p13; SPG81 (618768), caused by mutation in the SELENOI gene (607915) on 2p23; SPG82 (618770), caused by mutation in the PCYT2 gene (602679) on 17q25; and SPG83 (619027), caused by mutation in the HPDL gene (618994) on chromosome 1p34. Additional autosomal recessive forms of SPG have been mapped to chromosomes 3q (SPG14; 605229), 13q14 (SPG24; 607584), 6q (SPG25; 608220), and 10q22 (SPG27; 609041).
hereditary spastic paraplegia 15
MedGen UID:
341387
Concept ID:
C1849128
Disease or Syndrome
Spastic paraplegia 15 (SPG15), typically an early-onset complex hereditary spastic paraplegia, is characterized by progressive spasticity that begins in the lower extremities and is associated with several manifestations resulting from central and peripheral nervous system dysfunction. While onset of spasticity is typically in mid- to late childhood or adolescence (i.e., between ages 5 and 18 years), other manifestations, such as developmental delay or learning disability, may be present earlier, often preceding motor involvement. Individuals with adult onset have also been reported.
charlevoix-saguenay spastic ataxia
MedGen UID:
338620
Concept ID:
C1849140
Disease or Syndrome
Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is clinically characterized by a progressive cerebellar ataxia, peripheral neuropathy, and spasticity. Disease onset of classic ARSACS is often in early childhood, leading to delayed walking because of gait unsteadiness in very young toddlers, while an increasing number of individuals with disease onset in teenage or early-adult years are now being described. Typically the ataxia is followed by lower-limb spasticity and later by peripheral neuropathy – although pronounced peripheral neuropathy has been observed as a first sign of ARSACS. Oculomotor disturbances, dysarthria, and upper-limb ataxia develop with slower progression than the other findings. Brain imaging demonstrates atrophy of the superior vermis and the cerebellar hemisphere with additional findings on MRI, such as linear hypointensities in the pons and hyperintense rims around the thalami. Many affected individuals (though not all) have yellow streaks of hypermyelinated fibers radiating from the edges of the optic disc noted on ophthalmologic exam, and thickened retinal fibers can be demonstrated by optical coherence tomography. Mild intellectual disability, hearing loss, and urinary urgency and incontinence have been reported in some individuals.
spastic ataxia
MedGen UID:
376528
Concept ID:
C1849156
Disease or Syndrome
retinitis pigmentosa-intellectual disability-deafness-hypogenitalism syndrome
MedGen UID:
340317
Concept ID:
C1849401
Disease or Syndrome
Retinitis pigmentosa - intellectual disability - deafness - hypogenitalism is an extremely rare syndromic retinitis pigmentosa characterized by pigmentary retinopathy, diabetes mellitus with hyperinsulinism, acanthosis nigricans, secondary cataracts, neurogenic deafness, short stature mild hypogonadism in males and polycystic ovaries with oligomenorrhea in females. Inheritance is thought to be autosomal recessive. It can be distinguished from Alstrom syndrome (see this term) by the presence of intellectual disability and the absence of renal insufficiency. There have been no further descriptions in the literature since 1993.
saldino-mainzer syndrome
MedGen UID:
341455
Concept ID:
C1849437
Disease or Syndrome
Short-rib thoracic dysplasia (SRTD) with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a constricted thoracic cage, short ribs, shortened tubular bones, and a 'trident' appearance of the acetabular roof. SRTD encompasses Ellis-van Creveld syndrome (EVC) and the disorders previously designated as Jeune syndrome or asphyxiating thoracic dystrophy (ATD), short rib-polydactyly syndrome (SRPS), and Mainzer-Saldino syndrome (MZSDS). Polydactyly is variably present, and there is phenotypic overlap in the various forms of SRTDs, which differ by visceral malformation and metaphyseal appearance. Nonskeletal involvement can include cleft lip/palate as well as anomalies of major organs such as the brain, eye, heart, kidneys, liver, pancreas, intestines, and genitalia. Some forms of SRTD are lethal in the neonatal period due to respiratory insufficiency secondary to a severely restricted thoracic cage, whereas others are compatible with life (summary by Huber and Cormier-Daire, 2012 and Schmidts et al., 2013). There is phenotypic overlap with the cranioectodermal dysplasias (Sensenbrenner syndrome; see CED1, 218330). For a discussion of genetic heterogeneity of short-rib thoracic dysplasia, see SRTD1 (208500).
red skin pigment anomaly of new guinea
MedGen UID:
341457
Concept ID:
C1849451
Disease or Syndrome
peroxisomal acyl-coa oxidase deficiency
MedGen UID:
376636
Concept ID:
C1849678
Disease or Syndrome
Peroxisomal acyl-CoA oxidase deficiency is a disorder of peroxisomal fatty acid beta-oxidation. See also D-bifunctional protein deficiency (261515), caused by mutation in the HSD17B4 gene (601860) on chromosome 5q2. The clinical manifestations of these 2 deficiencies are similar to those of disorders of peroxisomal assembly, including Zellweger cerebrohepatorenal syndrome (see 214100) and neonatal adrenoleukodystrophy (see 601539) (Watkins et al., 1995).
hypomyelinating leukodystrophy 3
MedGen UID:
342403
Concept ID:
C1850053
Disease or Syndrome
Autosomal recessive hypomyelinating leukodystrophy-3 (HLD3) is a severe neurologic disorder characterized by early infantile onset of global developmental delay, lack of development, lack of speech acquisition, and peripheral spasticity associated with decreased myelination in the central nervous system (summary by Feinstein et al., 2010). The disorder is phenotypically similar to X-linked Pelizaeus-Merzbacher disease (PMD; 312080), which is caused by mutation in the PLP1 gene (300401). For a general phenotypic description and a discussion of genetic heterogeneity of HLD, see 312080.
autosomal recessive osteopetrosis 1
MedGen UID:
376708
Concept ID:
C1850127
Disease or Syndrome
Osteopetrosis (OPT) is a life-threatening disease caused by subnormal osteoclast function, with an incidence of 1 in 250,000 births. The disease usually manifests in the first few months of life with macrocephaly and frontal bossing, resulting in a characteristic facial appearance. Defective bone remodeling of the skull results in choanal stenosis with concomitant respiratory problems and feeding difficulties, which are the first clinical manifestation of disease. The expanding bone encroaches on neural foramina, leading to blindness, deafness, and facial palsy. Complete visual loss invariably occurs in all untreated patients, and hearing loss is estimated to affect 78% of patients with OPT. Tooth eruption defects and severe dental caries are common. Calcium feedback hemostasis is impaired, and children with OPT are at risk of developing hypocalcemia with attendant tetanic seizures and secondary hyperparathyroidism. The most severe complication of OPT, limiting survival, is bone marrow insufficiency. The abnormal expansion of cortical and trabecular bone physically limits the availability of medullary space for hematopoietic activity, leading to life-threatening cytopenia and secondary expansion of extramedullary hematopoiesis at sites such as the liver and spleen (summary by Aker et al., 2012). Genetic Heterogeneity of Autosomal Recessive Osteopetrosis Other forms of autosomal recessive infantile malignant osteopetrosis include OPTB4 (611490), which is caused by mutation in the CLCN7 gene (602727) on chromosome 16p13, and OPTB5 (259720), which is caused by mutation in the OSTM1 gene (607649) on chromosome 6q21. A milder, osteoclast-poor form of autosomal recessive osteopetrosis (OPTB2; 259710) is caused by mutation in the TNFSF11 gene (602642) on chromosome 13q14, an intermediate form (OPTB6; 611497) is caused by mutation in the PLEKHM1 gene (611466) on chromosome 17q21, and a severe osteoclast-poor form associated with hypogammaglobulinemia (OPTB7; 612301) is caused by mutation in the TNFRSF11A gene (603499) on chromosome 18q22. Another form of autosomal recessive osteopetrosis (OPTB8; 615085) is caused by mutation in the SNX10 gene (614780) on chromosome 7p15. A form of autosomal recessive osteopetrosis associated with renal tubular acidosis (OPTB3; 259730) is caused by mutation in the CA2 gene (611492) on chromosome 8q21. Autosomal dominant forms of osteopetrosis are more benign (see OPTA1, 607634).
mosaic variegated aneuploidy syndrome 1
MedGen UID:
338026
Concept ID:
C1850343
Disease or Syndrome
Mosaic variegated aneuploidy is an autosomal recessive disorder characterized by mosaic aneuploidies, predominantly trisomies and monosomies, involving multiple different chromosomes and tissues. The proportion of aneuploid cells varies but is usually more than 25% and is substantially greater than in normal individuals. Affected individuals typically present with severe intrauterine growth retardation and microcephaly. Eye anomalies, mild dysmorphism, variable developmental delay, and a broad spectrum of additional congenital abnormalities and medical conditions may also occur. The risk of malignancy is high, with rhabdomyosarcoma, Wilms tumor, and leukemia reported in several cases (summary by Hanks et al., 2004). Genetic Heterogeneity of Mosaic Variegated Aneuploidy Syndrome See also MVA2 (614114), caused by mutation in the CEP57 gene (607951) on chromosome 11q21, and MVA3 (617598), caused by mutation in the TRIP13 gene (604507) on chromosome 5p15.
giant axonal neuropathy 1
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.
navajo neurohepatopathy
MedGen UID:
338045
Concept ID:
C1850406
Disease or Syndrome
MPV17-related mitochondrial DNA (mtDNA) maintenance defect presents in the vast majority of affected individuals as an early-onset encephalohepatopathic (hepatocerebral) disease that is typically associated with mtDNA depletion, particularly in the liver. A later-onset neuromyopathic disease characterized by myopathy and neuropathy, and associated with multiple mtDNA deletions in muscle, has also rarely been described. MPV17-related mtDNA maintenance defect, encephalohepatopathic form is characterized by: Hepatic manifestations (liver dysfunction that typically progresses to liver failure, cholestasis, hepatomegaly, and steatosis); Neurologic involvement (developmental delay, hypotonia, microcephaly, and motor and sensory peripheral neuropathy); Gastrointestinal manifestations (gastrointestinal dysmotility, feeding difficulties, and failure to thrive); and Metabolic derangements (lactic acidosis and hypoglycemia). Less frequent manifestations include renal tubulopathy, nephrocalcinosis, and hypoparathyroidism. Progressive liver disease often leads to death in infancy or early childhood. Hepatocellular carcinoma has been reported.
neuronal ceroid lipofuscinosis 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).
spinocerebellar ataxia type 34
MedGen UID:
338703
Concept ID:
C1851481
Disease or Syndrome
Spinocerebellar ataxia-34 is an autosomal dominant disorder characterized by slowly progressive cerebellar ataxia. The age at onset is usually during the young adult years, and most patients remain ambulatory until late in life. One family with SCA34 also had onset of erythema and hyperkeratosis in early childhood (Cadieux-Dion et al., 2014), whereas other families have additional neurologic signs, including ocular movement disturbances and pyramidal tract signs (Ozaki et al., 2015). For a general discussion of autosomal dominant spinocerebellar ataxia, see SCA1 (164400).
cerebrooculofacioskeletal syndrome 4
MedGen UID:
342798
Concept ID:
C1853100
Disease or Syndrome
Cerebrooculofacioskeletal syndrome-4 is a severe autosomal recessive disorder characterized by growth retardation, dysmorphic facial features, arthrogryposis, and neurologic abnormalities. Cellular studies show a defect in both transcription-coupled and global genome nucleotide excision repair (TC-NER and GG-NER) (summary by Jaspers et al., 2007 and Kashiyama et al., 2013). For a discussion of genetic heterogeneity of cerebrooculofacioskeletal syndrome, see 214150.
spinocerebellar ataxia, autosomal recessive 8
MedGen UID:
343973
Concept ID:
C1853116
Disease or Syndrome
SYNE1 deficiency comprises a phenotypic spectrum that ranges from autosomal recessive cerebellar ataxia at the mild end to arthrogryposis multiplex congenita (AMC) at the severe end. SYNE1-deficient cerebellar ataxia, the most commonly recognized manifestation of SYNE1 deficiency to date, is a slowly progressive disorder typically beginning in adulthood (age range 6-45 years). While some individuals have a pure cerebellar syndrome (i.e., cerebellar ataxia, dysarthria, dysmetria, abnormalities in ocular saccades and smooth pursuit), many also have upper motor neuron dysfunction (spasticity, hyperreflexia, Babinski sign) and/or lower motor neuron dysfunction (amyotrophy, reduced reflexes, fasciculations). Most patients develop features of the cerebellar cognitive and affective syndrome (i.e., significant deficits in attention, executive functioning, verbal working memory, and visuospatial/visuoconstructional skills). The two less common phenotypes are SYNE1-deficient childhood-onset multisystem disease (ataxia, upper and lower motor neuron dysfunction, muscle weakness and wasting, intellectual disability) and SYNE1-deficient arthrogryposis multiplex congenita (decreased fetal movements and severe neonatal hypotonia associated with multiple congenital joint contractures including clubfoot).
congenital primary aphakia
MedGen UID:
339935
Concept ID:
C1853230
Congenital Abnormality
Anterior segment dysgeneses are a heterogeneous group of developmental disorders affecting the anterior segment of the eye, including the cornea, iris, lens, trabecular meshwork, and Schlemm canal. The clinical features of ASGD include iris hypoplasia, an enlarged or reduced corneal diameter, corneal vascularization and opacity, posterior embryotoxon, corectopia, polycoria, an abnormal iridocorneal angle, ectopia lentis, and anterior synechiae between the iris and posterior corneal surface (summary by Cheong et al., 2016). Anterior segment dysgenesis is sometimes divided into subtypes, including aniridia (see 106210), Axenfeld and Rieger anomalies, iridogoniodysgenesis, Peters anomaly, and posterior embryotoxon (Gould and John, 2002). Some patients with ASGD2 have been reported with a congenital primary aphakia subtype. Congenital primary aphakia is a rare developmental disorder characterized by absence of the lens, the development of which is normally induced during the fourth to fifth week of human embryogenesis. This original failure leads, in turn, to complete aplasia of the anterior segment of the eye, which is the diagnostic histologic criterion for CPAK. In contrast, in secondary aphakia, lens induction occurs and the lens vesicle develops to some degree, but is progressively resorbed perinatally, resulting in less severe ocular defects (summary by Valleix et al., 2006).
laryngeal abductor paralysis with cerebellar ataxia and motor neuropathy
MedGen UID:
381205
Concept ID:
C1853556
Disease or Syndrome
spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2
MedGen UID:
340052
Concept ID:
C1853761
Disease or Syndrome
Ataxia with oculomotor apraxia type 2 (AOA2) is characterized by onset of ataxia between age three and 30 years after initial normal development, axonal sensorimotor neuropathy, oculomotor apraxia, cerebellar atrophy, and elevated serum concentration of alpha-fetoprotein (AFP).
spinocerebellar ataxia type 14
MedGen UID:
343106
Concept ID:
C1854369
Disease or Syndrome
Spinocerebellar ataxia type 14 (SCA14) is characterized by slowly progressive cerebellar ataxia, dysarthria, and nystagmus. Axial myoclonus, cognitive impairment, tremor, and sensory loss may also be observed. Parkinsonian features including rigidity and tremor have been described in some families. Findings seen in other ataxia disorders (e.g., dysphagia, dysphonia) may also occur in SCA14. The average age of onset is in the 30s, with a range from childhood to the seventh decade. Life span is not shortened.
spinocerebellar ataxia type 13
MedGen UID:
344297
Concept ID:
C1854488
Disease or Syndrome
Spinocerebellar ataxia type 13 (SCA13) is a phenotypic spectrum that includes both non-progressive infantile-onset ataxia and progressive childhood-onset and adult-onset cerebellar ataxia. Three phenotypes are seen: Cerebellar hypoplasia with non-progressive infantile-onset limb, truncal, and gait ataxia with mild-to-moderate intellectual disability and occasionally seizures and/or psychiatric manifestations. Cognition and motor skills improve over time. Childhood-onset slowly progressive cerebellar atrophy with slowly progressive cerebellar ataxia and dysarthria, delayed motor milestones, and mild-to-moderate intellectual disability. Adult-onset progressive cerebellar atrophy with progressive ataxia and spasticity.
molybdenum cofactor deficiency, complementation group a
MedGen UID:
381530
Concept ID:
C1854988
Disease or Syndrome
Because of the serious health problems caused by molybdenum cofactor deficiency, affected individuals usually do not survive past early childhood.\n\nTests 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.\n\nMolybdenum 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."
molybdenum cofactor deficiency, complementation group b
MedGen UID:
340760
Concept ID:
C1854989
Disease or Syndrome
Molybdenum cofactor deficiency is a rare autosomal recessive metabolic disorder characterized by neonatal onset of intractable seizures, opisthotonus, and facial dysmorphism associated with hypouricemia and elevated urinary sulfite levels. Affected individuals show severe neurologic damage and often die in early childhood (summary by Reiss et al., 1999). For a general phenotypic description and a discussion of genetic heterogeneity of MOCOD, see MOCODA (252150), which is clinically indistinguishable from MOCODB.
mitochondrial complex ii deficiency, nuclear type 1
MedGen UID:
344401
Concept ID:
C1855008
Disease or Syndrome
Mitochondrial complex II deficiency is an autosomal recessive multisystemic metabolic disorder with a highly variable phenotype. Some patients have multisystem involvement of the brain, heart, and muscle with onset in infancy, whereas others have only isolated cardiac or muscle involvement. Measurement of complex II activity in muscle is the most reliable means of diagnosis; however, there is no clear correlation between residual complex II activity and severity or clinical outcome. In some cases, treatment with riboflavin may have clinical benefit (summary by Jain-Ghai et al., 2013). Complex II, also known as succinate dehydrogenase, is part of the mitochondrial respiratory chain. Genetic Heterogeneity of Mitochondrial Complex II Deficiency See MC2DN2 (619166), caused by mutation in the SDHAF1 gene (612848) on chromosome 19q13; MC2DN3 (619167), caused by mutation in the SDHD gene (602690) on chromosome 11q23; and MC2DN4 (619224), caused by mutation in the SDHB gene (185470) on chromosome 1p36.
methylcobalamin deficiency type cblg
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 complications, and/or subacute combined degeneration of the spinal cord.
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
pyruvate dehydrogenase e2 deficiency
MedGen UID:
343386
Concept ID:
C1855565
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.
kaufman oculocerebrofacial syndrome
MedGen UID:
343403
Concept ID:
C1855663
Disease or Syndrome
Kaufman oculocerebrofacial syndrome (KOS) is characterized by severe intellectual disability and distinctive craniofacial features. Most affected children have prenatal-onset microcephaly, failure to thrive, hypotonia, and short stature. Eye abnormalities are common and can include structural abnormalities (microcornea or microphthalmia, coloboma, optic nerve hypoplasia), refractive errors (myopia ± astigmatism, hyperopia), strabismus, and entropion. Less common findings can include: unilateral or bilateral conductive hearing loss or mixed conductive-sensorineural hearing loss of variable severity; congenital heart defects; breathing problems; feeding difficulties; urogenital abnormalities; and/or skeletal abnormalities.
arima syndrome
MedGen UID:
340930
Concept ID:
C1855675
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.
vici syndrome
MedGen UID:
340962
Concept ID:
C1855772
Disease or Syndrome
Vici syndrome is a rare congenital multisystem disorder characterized by agenesis of the corpus callosum (ACC), cataracts, pigmentary defects, progressive cardiomyopathy, and variable immunodeficiency. Affected individuals also have profound psychomotor retardation and hypotonia due to a myopathy (summary by Finocchi et al., 2012).
l-2-hydroxyglutaric aciduria
MedGen UID:
341029
Concept ID:
C1855995
Disease or Syndrome
2-hydroxyglutaric aciduria is a condition that causes progressive damage to the brain. The major types of this disorder are called D-2-hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and combined D,L-2-hydroxyglutaric aciduria (D,L-2-HGA).\n\nThe main features of D-2-HGA are delayed development, seizures, weak muscle tone (hypotonia), and abnormalities in the largest part of the brain (the cerebrum), which controls many important functions such as muscle movement, speech, vision, thinking, emotion, and memory. Researchers have described two subtypes of D-2-HGA, type I and type II. The two subtypes are distinguished by their genetic cause and pattern of inheritance, although they also have some differences in signs and symptoms. Type II tends to begin earlier and often causes more severe health problems than type I. Type II may also be associated with a weakened and enlarged heart (cardiomyopathy), a feature that is typically not found with type I.\n\nL-2-HGA particularly affects a region of the brain called the cerebellum, which is involved in coordinating movements. As a result, many affected individuals have problems with balance and muscle coordination (ataxia). Additional features of L-2-HGA can include delayed development, seizures, speech difficulties, and an unusually large head (macrocephaly). Typically, signs and symptoms of this disorder begin during infancy or early childhood. The disorder worsens over time, usually leading to severe disability by early adulthood.\n\nCombined D,L-2-HGA causes severe brain abnormalities that become apparent in early infancy. Affected infants have severe seizures, weak muscle tone (hypotonia), and breathing and feeding problems. They usually survive only into infancy or early childhood.
homocystinuria-megaloblastic anemia due to defect in cobalamin metabolism, cble complementation type
MedGen UID:
344640
Concept ID:
C1856057
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 complications, and/or subacute combined degeneration of the spinal cord.
friedreich ataxia and congenital glaucoma
MedGen UID:
344787
Concept ID:
C1856688
Disease or Syndrome
friedreich ataxia 1
MedGen UID:
383962
Concept ID:
C1856689
Disease or Syndrome
Friedreich ataxia (FRDA) is characterized by slowly progressive ataxia with onset usually before age 25 years (mean age at onset: 10-15 yrs). FRDA is typically associated with dysarthria, muscle weakness, spasticity particularly in the lower limbs, scoliosis, bladder dysfunction, absent lower-limb reflexes, and loss of position and vibration sense. Approximately two thirds of individuals with FRDA have cardiomyopathy, up to 30% have diabetes mellitus, and approximately 25% have an "atypical" presentation with later onset or retained tendon reflexes.
2,4-dienoyl-coa reductase deficiency
MedGen UID:
346552
Concept ID:
C1857252
Disease or Syndrome
2,4-Dienoyl-CoA reductase deficiency (DECRD) is a rare autosomal recessive inborn error of metabolism resulting in mitochondrial dysfunction due to impaired production of NADPH, which is an essential cofactor for several mitochondrial enzymes. Affected individuals have a variable phenotype: some may have severe neurologic symptoms and metabolic dysfunction beginning in early infancy, whereas others may present with more subtle features, such as childhood-onset optic atrophy or intermittent muscle weakness. The variable severity is putatively dependent on the effect of the mutation on the NADK2 enzyme. Biochemical analysis typically shows hyperlysinemia, due to defective activity of the mitochondrial NADP(H)-dependent enzyme AASS (605113), which is usually a benign finding. More severe cases have increased C10:2-carnitine levels, due to defective activity of the enzyme DECR (DECR1; 222745) (summary by Houten et al., 2014 and Pomerantz et al., 2018).
dandy-walker malformation-postaxial polydactyly syndrome
MedGen UID:
341751
Concept ID:
C1857351
Disease or Syndrome
A syndromic disorder with the association between Dandy-Walker malformation and postaxial polydactyly as a major feature. The Dandy-Walker malformation has a variable expression and characteristics of a posterior fossa cyst communicating with the fourth ventricle, the partial or complete absence of the cerebellar vermis, and facultative hydrocephalus. Postaxial polydactyly includes tetramelic postaxial polydactyly of hands and feet with possible enlargement of the fifth metacarpal and metatarsal bones, as well as bifid fifth metacarpals.
facial dysmorphism-macrocephaly-myopia-dandy-walker malformation syndrome
MedGen UID:
341752
Concept ID:
C1857352
Disease or Syndrome
A rare disorder characterized by Dandy-Walker malformation, severe intellectual deficit, macrocephaly, brachytelephalangy, facial dysmorphism and severe myopia. Three cases have been described. Transmission appears to be autosomal recessive.
achromatopsia 2
MedGen UID:
387867
Concept ID:
C1857618
Disease or Syndrome
Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography.
coloboma of macula and skeletal anomalies
MedGen UID:
341812
Concept ID:
C1857619
Disease or Syndrome
Macular coloboma-cleft palate-hallux valgus syndrome is characterised by the association of bilateral macular coloboma, cleft palate, and hallux valgus. It has been described in a brother and sister. Pelvic, limb and digital anomalies were also reported. Transmission is autosomal recessive.
combined oxidative phosphorylation deficiency 4
MedGen UID:
387884
Concept ID:
C1857682
Disease or Syndrome
Combined oxidative phosphorylation defect type 4 is a rare mitochondrial disorder due to a defect in mitochondrial protein synthesis characterized by a neonatal onset of severe metabolic acidosis and respiratory distress, persistent lactic acidosis with episodes of metabolic crises, developmental regression, microcephaly, abnormal gaze fixation and pursuit, axial hypotonia with limb spasticity and reduced spontaneous movements. Neuroimaging studies reveal polymicrogyria, white matter abnormalities and multiple cystic brain lesions, including basal ganglia, and cerebral atrophy. Decreased activity of complex I and IV have been determined in muscle biopsy.
leber congenital amaurosis 12
MedGen UID:
347535
Concept ID:
C1857743
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.\n\nLeber 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.\n\nAt 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.\n\nA 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.\n\nIn 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.
neurodegeneration with brain iron accumulation 2b
MedGen UID:
346658
Concept ID:
C1857747
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.
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.
leber congenital amaurosis 5
MedGen UID:
388031
Concept ID:
C1858301
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.\n\nLeber 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.\n\nAt 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.\n\nA 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.\n\nIn 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.
spinocerebellar ataxia type 11
MedGen UID:
346799
Concept ID:
C1858351
Disease or Syndrome
Spinocerebellar ataxia type 11 (SCA11) is characterized by progressive cerebellar ataxia and abnormal eye signs (jerky pursuit, horizontal and vertical nystagmus). Pyramidal features are seen on occasion. Peripheral neuropathy and dystonia are rare. Six families have been reported to date, one each from the UK, Pakistan, France, Germany, Denmark, and China. Age of onset ranged from early childhood to the mid-40s. Life span is thought to be normal.
leber congenital amaurosis 3
MedGen UID:
346964
Concept ID:
C1858677
Disease or Syndrome
Autosomal recessive childhood-onset severe retinal dystrophy is a heterogeneous group of disorders affecting rod and cone photoreceptors simultaneously. The most severe cases are termed Leber congenital amaurosis, whereas the less aggressive forms are usually considered juvenile retinitis pigmentosa (Gu et al., 1997). Mackay et al. (2011) concluded that SPATA7 retinopathy is an infantile-onset severe cone-rod dystrophy with early extensive peripheral retinal atrophy but with variable foveal involvement. For a general phenotypic description and a discussion of genetic heterogeneity of Leber congenital amaurosis, see LCA1 (204000); for retinitis pigmentosa, see 268000.
cataract, autosomal dominant
MedGen UID:
347693
Concept ID:
C1858679
Disease or Syndrome
Mutations in the CRYAA gene have been found to cause multiple types of cataract, which have been described as nuclear, zonular central nuclear, laminar, lamellar, anterior polar, posterior polar, cortical, embryonal, anterior subcapsular, fan-shaped, and total. Cataract associated with microcornea, sometimes called the cataract-microcornea syndrome, is also caused by mutation in the CRYAA gene. Both autosomal dominant and autosomal recessive modes of inheritance have been reported. The symbol CATC1 was formerly used for the autosomal recessive form of cataract caused by mutation in the CRYAA gene.
encephalopathy, familial, with neuroserpin inclusion bodies
MedGen UID:
346965
Concept ID:
C1858680
Disease or Syndrome
Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is a disorder that causes progressive dysfunction of the brain (encephalopathy). It is characterized by a loss of intellectual functioning (dementia) and seizures. At first, affected individuals may have difficulty sustaining attention and concentrating. They may experience repetitive thoughts, speech, or movements. As the condition progresses, their personality changes and judgment, insight, and memory become impaired. Affected people lose the ability to perform the activities of daily living, and most eventually require comprehensive care.\n\nThe signs and symptoms of FENIB vary in their severity and age of onset. In severe cases, the condition causes seizures and episodes of sudden, involuntary muscle jerking or twitching (myoclonus) in addition to dementia. These signs can appear as early as a person's teens. Less severe cases are characterized by a progressive decline in intellectual functioning beginning in a person's forties or fifties.
congenital cataracts-facial dysmorphism-neuropathy syndrome
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.
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).
cerebellar hypoplasia with endosteal sclerosis
MedGen UID:
347849
Concept ID:
C1859301
Disease or Syndrome
Endosteal sclerosis-cerebellar hypoplasia syndrome is characterized by congenital cerebellar hypoplasia, endosteal sclerosis, hypotonia, ataxia, mild to moderate developmental delay, short stature, hip dislocation, and tooth eruption disturbances. It has been described in four patients. Less common manifestations are microcephaly, strabismus, nystagmus, optic atrophy, and dysarthria. It is appears to be transmitted as an autosomal recessive trait.
sengers syndrome
MedGen UID:
395228
Concept ID:
C1859317
Disease or Syndrome
Sengers syndrome is an autosomal recessive mitochondrial disorder characterized by congenital cataracts, hypertrophic cardiomyopathy, skeletal myopathy, exercise intolerance, and lactic acidosis. Mental development is normal, but affected individuals may die early from cardiomyopathy (summary by Mayr et al., 2012). Skeletal muscle biopsies of 2 affected individuals showed severe mtDNA depletion (Calvo et al., 2012).
brachymetapody-anodontia-hypotrichosis-albinoidism
MedGen UID:
347867
Concept ID:
C1859385
Disease or Syndrome
This syndrome has characteristics of congenital anodontia, a small maxilla, short stature with shortened metacarpals and metatarsals, sparse hair, albinoidism and multiple ocular anomalies. It has been described in three siblings (one brother and two sisters). Transmission is autosomal recessive.
neuroectodermal melanolysosomal disease
MedGen UID:
348553
Concept ID:
C1860157
Disease or Syndrome
Syndrome that is characterized by silvery to leaden hair, bronze skin color in sun-exposed areas and severe neurological impairment. The syndrome was first described in 1979 in three consanguineous families. It is either congenital or develops during childhood (seizures, severe hypotonia and intellectual deficit). There is no impairment of the immune system and a wide spectrum of ophthalmologic abnormalities has been described. Molecular data has shed light on the complex relationship that exists between this syndrome and Griscelli syndrome. Mutations in the myosin Va gene (MYOVA) result in the so-called Griscelli syndrome type 1. MYOVA encodes myosin Va, an actin-based motor protein important for the intracellular transport of organelles in melanocyte and neuronal cells. It is very likely that Griscelli syndrome type 1 corresponds to with this syndrome.
tremor, nystagmus, and duodenal ulcer
MedGen UID:
349908
Concept ID:
C1860860
Disease or Syndrome
A rare hyperkinetic movement disorder with characteristics of mild to severe, progressive essential tremor, nystagmus (principally horizontal), duodenal ulceration and a narcolepsy-like sleep disturbance. Refractive errors and cerebellar signs such as gait ataxia and adiadochokinesia may be associated. There have been no further descriptions in the literature since 1976.
spinocerebellar ataxia type 29
MedGen UID:
350085
Concept ID:
C1861732
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.
spinocerebellar ataxia type 31
MedGen UID:
348439
Concept ID:
C1861736
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.
branchial myoclonus with spastic paraparesis and cerebellar ataxia
MedGen UID:
349424
Concept ID:
C1862071
Disease or Syndrome
brachydactyly-nystagmus-cerebellar ataxia
MedGen UID:
350589
Concept ID:
C1862099
Disease or Syndrome
Brachydactyly-nystagmus-cerebellar ataxia syndrome is characterized by brachydactyly, nystagmus and cerebellar ataxia. Intellectual deficit and strabismus are also reported in some patients.
spastic ataxia 7, autosomal dominant
MedGen UID:
354750
Concept ID:
C1862441
Disease or Syndrome
A rare hereditary ataxia with characteristics of an apparently non-progressive or slowly progressive symmetrical ataxia of gait, pyramidal signs in the limbs, spasticity and hyperreflexia (especially in the lower limbs) together with dysarthria and impaired pupillary reaction to light, presenting as a fixed miosis. Nystagmus may also be present.
amyotrophic dystonic paraplegia
MedGen UID:
354871
Concept ID:
C1862956
Disease or Syndrome
microphthalmia with brain and digit anomalies
MedGen UID:
355268
Concept ID:
C1864689
Disease or Syndrome
gene, which has already been shown to play a role in eye development.
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).
retinal cone dystrophy 3a
MedGen UID:
355864
Concept ID:
C1864900
Disease or Syndrome
Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography.
macrophthalmia, colobomatous, with microcornea
MedGen UID:
400728
Concept ID:
C1865286
Disease or Syndrome
desmosterolosis
MedGen UID:
400801
Concept ID:
C1865596
Disease or Syndrome
Desmosterolosis is a rare autosomal recessive disorder characterized by multiple congenital anomalies and elevated levels of the cholesterol precursor desmosterol in plasma, tissue, and cultured cells (summary by Waterham et al., 2001).
axial spondylometaphyseal dysplasia
MedGen UID:
356065
Concept ID:
C1865695
Disease or Syndrome
Axial spondylometaphyseal dysplasia (SMDAX) is characterized by postnatal growth failure, including rhizomelic short stature in early childhood that evolves into short trunk in late childhood, and thoracic hypoplasia that may cause mild to moderate respiratory problems in the neonatal period and later susceptibility to airway infection. Impaired visual acuity comes to medical attention in early life and vision rapidly deteriorates. Retinal changes are diagnosed as retinitis pigmentosa or pigmentary retinal degeneration on funduscopic examination and as cone-rod dystrophy on electroretinogram. Radiologic hallmarks include short ribs with flared and cupped anterior ends, mild spondylar dysplasia, lacy iliac crests, and metaphyseal irregularities essentially confined to the proximal femora (summary by Suzuki et al., 2011).
friedreich ataxia 2
MedGen UID:
356134
Concept ID:
C1865981
Disease or Syndrome
Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder characterized by progressive gait and limb ataxia with associated limb muscle weakness, absent lower limb reflexes, extensor plantar responses, dysarthria, and decreased vibratory sense and proprioception. Onset is usually in the first or second decade, before the end of puberty (summary by Delatycki et al., 2000). For a general phenotypic description of Friedreich ataxia (FRDA), see FRDA1 (229300), which is caused by mutation in the FXN gene (606829) on chromosome 9q13.
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).
cone-rod dystrophy 6
MedGen UID:
400963
Concept ID:
C1866293
Disease or Syndrome
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.\n\nThe 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).\n\nCone-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.
deaf blind hypopigmentation syndrome, yemenite type
MedGen UID:
355712
Concept ID:
C1866425
Disease or Syndrome
An exceedingly rare genetic disorder with characteristics of cutaneous pigmentation anomalies, ocular disorders and hearing loss. The syndrome was described in 1990 in two patients from the same Yemenite family. A brother and sister were described as having cutaneous patchy hypo and hyperpigmentation on the trunk and extremities, gray hair, white brows and lashes. Ocular manifestations were microcornea, coloboma and abnormalities of the anterior chamber of the eye. Both patients had severe hearing loss and dental abnormalities. Intelligence was reported to be normal. Their parents were unaffected and possibly consanguineous. The cause of this syndrome has not been determined. The inheritance pattern appears to be autosomal recessive.
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); TTD6 (616943), caused by mutation in the GTF2E2 gene (189964); and TTD7 (618546), caused by mutation in the TARS gene (187790).
charcot-marie-tooth disease, type 4c
MedGen UID:
356581
Concept ID:
C1866636
Disease or Syndrome
SH3TC2-related hereditary motor and sensory neuropathy (SH3TC2-HMSN) is a demyelinating neuropathy characterized by severe spine deformities (scoliosis or kyphoscoliosis) and foot deformities (pes cavus, pes planus, or pes valgus) that typically present in the first decade of life or early adolescence. Other findings can include cranial nerve involvement (most commonly tongue involvement, facial weakness/paralysis, hearing impairment, dysarthria) and respiratory problems.
karsch-neugebauer syndrome
MedGen UID:
401072
Concept ID:
C1866740
Disease or Syndrome
A rare syndrome with characteristics of split-hand and split-foot deformity and ocular abnormalities mainly a congenital nystagmus. Ten cases from four families have been reported in the literature. In some cases the hands are monodactylous. The affected patients have normal mental development. The condition seems to be autosomal dominant with a relatively high proportion of gonadal mosaicism.
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.
leukodystrophy, adult-onset, autosomal dominant
MedGen UID:
356995
Concept ID:
C1868512
Disease or Syndrome
Autosomal dominant leukodystrophy with autonomic disease (ADLD) is a slowly progressive disorder of central nervous system white matter characterized by onset of autonomic dysfunction in the fourth to fifth decade, followed in months to years by pyramidal and cerebellar involvement. Autonomic dysfunction can include bladder dysfunction, constipation, postural hypotension, feeding difficulties, erectile dysfunction, and (less often) impaired sweating. Pyramidal signs are often more prominent in the lower extremities (i.e., spastic weakness, hypertonia, clonus, brisk deep tendon reflexes, and bilateral Babinski signs). Cerebellar signs typically appear at the same time as the pyramidal signs and can include gait ataxia, dysdiadochokinesia, intention tremor, dysmetria, and nystagmus. Although cognitive function is usually preserved or only mildly impaired early in the disease course, dementia and psychiatric manifestations can occur as late manifestations. Affected individuals may survive for decades after onset.
4p partial monosomy syndrome
MedGen UID:
408255
Concept ID:
C1956097
Disease or Syndrome
Wolf-Hirschhorn syndrome is a congenital malformation syndrome characterized by pre- and postnatal growth deficiency, developmental disability of variable degree, characteristic craniofacial features ('Greek warrior helmet' appearance of the nose, high forehead, prominent glabella, hypertelorism, high-arched eyebrows, protruding eyes, epicanthal folds, short philtrum, distinct mouth with downturned corners, and micrognathia), and a seizure disorder (Battaglia et al., 2008).
dihydropyrimidine dehydrogenase deficiency
MedGen UID:
409522
Concept ID:
C1959620
Disease or Syndrome
Dihyropyrimidine dehydrogenase deficiency shows large phenotypic variability, ranging from no symptoms to a convulsive disorder with motor and mental retardation in homozygous patients. In addition, homozygous and heterozygous mutation carriers can develop severe toxicity after the administration of the antineoplastic drug 5-fluorouracil (5FU), which is also catabolized by the DPYD enzyme. This is an example of a pharmacogenetic disorder (Van Kuilenburg et al., 1999). Since there is no correlation between genotype and phenotype in DPD deficiency, it appears that the deficiency is a necessary, but not sufficient, prerequisite for the development of clinical abnormalities (Van Kuilenburg et al., 1999; Enns et al., 2004).
mevalonic aciduria
MedGen UID:
368373
Concept ID:
C1959626
Disease or Syndrome
Mevalonic aciduria, the first recognized defect in the biosynthesis of cholesterol and isoprenoids, is a consequence of a deficiency of mevalonate kinase (ATP:mevalonate 5-phosphotransferase; EC 2.7.1.36). Mevalonic acid accumulates because of failure of conversion to 5-phosphomevalonic acid, which is catalyzed by mevalonate kinase. Mevalonic acid is synthesized from 3-hydroxy-3-methylglutaryl-CoA, a reaction catalyzed by HMG-CoA reductase (142910). Mevalonic aciduria is characterized by dysmorphology, psychomotor retardation, progressive cerebellar ataxia, and recurrent febrile crises, usually manifesting in early infancy, accompanied by hepatosplenomegaly, lymphadenopathy, arthralgia, and skin rash. The febrile crises are similar to those observed in hyperimmunoglobulinemia D and to periodic fever syndrome (HIDS; 260920), which is also caused by mutation in the MVK gene (summary by Prietsch et al., 2003).
spinocerebellar ataxia type 10
MedGen UID:
369786
Concept ID:
C1963674
Disease or Syndrome
Spinocerebellar ataxia type 10 (SCA10) is characterized by slowly progressive cerebellar ataxia that usually starts as poor balance and unsteady gait, followed by upper-limb ataxia, scanning dysarthria, and dysphagia. Abnormal tracking eye movements are common. Recurrent seizures after the onset of gait ataxia have been reported with variable frequencies among different families. Some individuals have cognitive dysfunction, behavioral disturbances, mood disorders, mild pyramidal signs, and peripheral neuropathy. Age of onset ranges from 12 to 48 years.
osteopetrosis, autosomal recessive 5
MedGen UID:
409627
Concept ID:
C1968603
Disease or Syndrome
Autosomal recessive osteopetrosis-5 is a form of infantile malignant osteopetrosis, characterized by defective osteoclast function resulting in decreased bone resorption and generalized osteosclerosis. Defective resorption causes development of densely sclerotic fragile bones and progressive obliteration of the marrow spaces and cranial foramina. Marrow obliteration is associated with extramedullary hematopoiesis and hepatosplenomegaly, and results in anemia and thrombocytopenia, whereas nerve entrapment accounts for progressive blindness and hearing loss. Other major manifestations include failure to thrive, pathologic fractures, and increased infection rate. Most affected children succumb to severe bone marrow failure and overwhelming infection in the first few years of life (Quarello et al., 2004).
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.
leukoencephalopathy with brain stem and spinal cord involvement-high lactate syndrome
MedGen UID:
370845
Concept ID:
C1970180
Disease or Syndrome
Leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation (LBSL) is characterized by slowly progressive cerebellar ataxia and spasticity with dorsal column dysfunction (decreased position and vibration sense) in most individuals. The neurologic dysfunction involves the legs more than the arms. The tendon reflexes are retained. Deterioration of motor skills usually starts in childhood or adolescence, but occasionally not until adulthood. Dysarthria develops over time. Occasional findings include epilepsy; learning problems; cognitive decline; and reduced consciousness, neurologic deterioration, and fever following minor head trauma. Individuals with neonatal or early-infantile onset have a severe disease course often associated with early death. Those with childhood onset have slow progression with wheelchair dependence in the teens or twenties. Adult onset is associated with slow progression and mild impairment.
congenital disorder of glycosylation type 2f
MedGen UID:
370234
Concept ID:
C1970344
Disease or Syndrome
An extremely rare form of carbohydrate deficient glycoprotein syndrome characterized clinically in the single reported case by repeated hemorrhagic incidents, including severe pulmonary hemorrhage.
polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract
MedGen UID:
436373
Concept ID:
C2675204
Disease or Syndrome
Fiskerstrand type peripheral neuropathy is a slowly-progressive Refsum-like disorder associating signs of peripheral neuropathy with late-onset hearing loss, cataract and pigmentary retinopathy that become evident during the third decade of life.
episodic ataxia, type 6
MedGen UID:
390739
Concept ID:
C2675211
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.
hypomyelinating leukodystrophy 7
MedGen UID:
390993
Concept ID:
C2676243
Disease or Syndrome
POLR3-related leukodystrophy, a hypomyelinating leukodystrophy with specific features on brain MRI, is characterized by varying combinations of four major clinical findings: Neurologic dysfunction, typically predominated by motor dysfunction (progressive cerebellar dysfunction, and to a lesser extent extrapyramidal [i.e., dystonia], pyramidal [i.e., spasticity] and cognitive dysfunctions). Abnormal dentition (delayed dentition, hypodontia, oligodontia, and abnormally placed or shaped teeth). Endocrine abnormalities such as short stature (in ~50% of individuals) with or without growth hormone deficiency, and more commonly, hypogonadotropic hypogonadism manifesting as delayed, arrested, or absent puberty. Ocular abnormality in the form of myopia, typically progressing over several years and becoming severe. POLR3-related leukodystrophy and 4H leukodystrophy are the two recognized terms for five previously described overlapping clinical phenotypes (initially described as distinct entities before their molecular basis was known). These include: Hypomyelination, hypodontia, hypogonadotropic hypogonadism (4H syndrome); Ataxia, delayed dentition, and hypomyelination (ADDH); Tremor-ataxia with central hypomyelination (TACH); Leukodystrophy with oligodontia (LO); Hypomyelination with cerebellar atrophy and hypoplasia of the corpus callosum (HCAHC). Age of onset is typically in early childhood but later-onset cases have also been reported. An infant with Wiedemann-Rautenstrauch syndrome (neonatal progeroid syndrome) was recently reported to have pathogenic variants in POLR3A on exome sequencing. Confirmation of this as a very severe form of POLR3-related leukodystrophy awaits replication in other individuals with a clinical diagnosis of Wiedemann-Rautenstrauch 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.
autosomal recessive osteopetrosis 7
MedGen UID:
436770
Concept ID:
C2676766
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.\n\nAutosomal 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.\n\nAutosomal 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.\n\nOther 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).\n\nA 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.\n\nRarely, 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.
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.
leukodystrophy, hypomyelinating, 4
MedGen UID:
383026
Concept ID:
C2677109
Disease or Syndrome
oculoauricular syndrome
MedGen UID:
393758
Concept ID:
C2677500
Disease or Syndrome
Oculoauricular syndrome, Schorderet type is a rare, genetic developmental defect during embryogenesis syndrome characterized by various ophthalmic anomalies (including congenital microphthalmia, microcornea, cataract, anterior segment dysgenesis, ocular coloboma and early onset rod-cone dystrophy) and abnormal external ears (low-set pinna with crumpled helix, narrow intertragic incisures, abnormal bridge connecting the crus of the helix and the antihelix, narrow external acoustic meatus, and lobule aplasia).
mental retardation and microcephaly with pontine and cerebellar hypoplasia
MedGen UID:
437070
Concept ID:
C2677903
Disease or Syndrome
CASK disorders include a spectrum of phenotypes in both females and males. Two main types of clinical presentation are seen: Microcephaly with pontine and cerebellar hypoplasia (MICPCH), generally associated with pathogenic loss-of-function variants in CASK. 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. 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 by age ten years. Behaviors may include sleep disturbances, hand stereotypies, and self biting. MICPCH in males may occur with or without severe epileptic encephalopathy in addition to severe-to-profound developmental delay. When seizures are present they occur early and may be intractable. In individuals and families with milder (i.e., hypomorphic) pathogenic variants, the clinical phenotype is usually that of XLID with or without nystagmus and additional clinical features. Males have mild-to-severe intellectual disability, with or without nystagmus and other ocular features. Females typically have normal intelligence with some displaying mild-to-severe intellectual disability with or without ocular features.
syndromic x-linked intellectual disability 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).
spinocerebellar ataxia, x-linked 5
MedGen UID:
394718
Concept ID:
C2678048
Disease or Syndrome
X-linked non progressive cerebellar ataxia is a rare hereditary ataxia characterized by delayed early motor development, severe neonatal hypotonia, non-progressive ataxia and slow eye movements, presenting normal cognitive abilities and absence of pyramidal signs. Frequently patients also manifest intention tremor, mild dysphagia, and dysarthria. Brain MRI reveals global cerebellar atrophy with absence of other malformations or degenerations of the central and peripheral nervous systems.
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).
orofaciodigital syndrome type 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).
leber congenital amaurosis 14
MedGen UID:
442375
Concept ID:
C2750063
Disease or Syndrome
Autosomal recessive childhood-onset severe retinal dystrophy is a heterogeneous group of disorders affecting rod and cone photoreceptors simultaneously. The most severe cases are termed Leber congenital amaurosis, whereas the less aggressive forms are usually considered juvenile retinitis pigmentosa (Gu et al., 1997). For a general phenotypic description and a discussion of genetic heterogeneity of Leber congenital amaurosis, see LCA1 (204000); for retinitis pigmentosa, see 268000.
congenital stationary night blindness, type 1c
MedGen UID:
416373
Concept ID:
C2750747
Disease or Syndrome
The vision problems associated with this condition are congenital, which means they are present from birth. They tend to remain stable (stationary) over time.\n\nAutosomal recessive congenital stationary night blindness is a disorder of the retina, which is the specialized tissue at the back of the eye that detects light and color. People with this condition typically have difficulty seeing and distinguishing objects in low light (night blindness). For example, they may not be able to identify road signs at night or see stars in the night sky. They also often have other vision problems, including loss of sharpness (reduced acuity), nearsightedness (myopia), involuntary movements of the eyes (nystagmus), and eyes that do not look in the same direction (strabismus).
cone dystrophy 4
MedGen UID:
416518
Concept ID:
C2751308
Disease or Syndrome
Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography.
amyloidogenic transthyretin amyloidosis
MedGen UID:
414031
Concept ID:
C2751492
Disease or Syndrome
Hereditary transthyretin (ATTR) amyloidosis is characterized by a slowly progressive peripheral sensorimotor and/or autonomic neuropathy as well as non-neuropathic changes of cardiomyopathy, nephropathy, vitreous opacities, and CNS amyloidosis. The disease usually begins in the third to fifth decade in persons from endemic foci in Portugal and Japan; onset is later in persons from other areas. Typically, sensory neuropathy starts in the lower extremities with paresthesias and hypesthesias of the feet, followed within a few years by motor neuropathy. In some persons, particularly those with early-onset disease, autonomic neuropathy is the first manifestation of the condition; findings can include: orthostatic hypotension, constipation alternating with diarrhea, attacks of nausea and vomiting, delayed gastric emptying, sexual impotence, anhidrosis, and urinary retention or incontinence. Cardiac amyloidosis is mainly characterized by progressive cardiomyopathy. Individuals with leptomeningeal amyloidosis may have the following CNS findings: dementia, psychosis, visual impairment, headache, seizures, motor paresis, ataxia, myelopathy, hydrocephalus, or intracranial hemorrhage.
leukoencephalopathy, cystic, without megalencephaly
MedGen UID:
416646
Concept ID:
C2751843
Disease or Syndrome
RNAse T2-deficient leukoencephalopathy is a disorder that affects the brain. People with RNAse T2-deficient leukoencephalopathy have neurological problems that become apparent during infancy; the problems generally do not worsen over time (progress). Most affected individuals have severe intellectual disability; muscle stiffness (spasticity); and a delay in developing motor skills such as sitting, crawling, and walking. Some do not learn to walk, and most do not develop the ability to speak. Other neurological features that can occur in RNAse T2-deficient leukoencephalopathy include hearing loss caused by abnormalities in the inner ear (sensorineural deafness), seizures, involuntary writhing movements of the hands (athetosis), uncontrolled muscle tensing (dystonia), and involuntary eye movements (nystagmus). In addition to the neurological problems associated with this disorder, some affected individuals have unusual facial features sometimes described as a "doll-like face."\n\nThe neurological problems in this disorder are caused by abnormalities in the brain. People with this condition have leukoencephalopathy, an abnormality of the brain's white matter that can be detected with medical imaging. White matter consists of nerve fibers covered by a fatty substance called myelin. Myelin insulates nerve fibers and promotes the rapid transmission of nerve impulses. In people with RNAse T2-deficient leukoencephalopathy, myelin is not made in sufficient amounts during development, leading to patchy white matter abnormalities (lesions) in the brain. In addition, individuals with RNAse T2-deficient leukoencephalopathy may have cysts in regions of the brain called the temporal lobes and enlargement of the fluid-filled cavities (ventricles) near the center of the brain. The white matter lesions are primarily concentrated around the cysts and the ventricles. An abnormally small head and brain size (microcephaly) often occurs in this disorder.
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).
dpagt1-cdg
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).
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.\n\nLeber 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.\n\nAt 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.\n\nA 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.\n\nIn 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.
hermansky-pudlak syndrome 1
MedGen UID:
419514
Concept ID:
C2931875
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
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.
bardet-biedl syndrome 1
MedGen UID:
422452
Concept ID:
C2936862
Disease or Syndrome
Bardet-Biedl syndrome is an autosomal recessive and genetically heterogeneous ciliopathy characterized by retinitis pigmentosa, obesity, kidney dysfunction, polydactyly, behavioral dysfunction, and hypogonadism (summary by Beales et al., 1999). Eight proteins implicated in the disorder assemble to form the BBSome, a stable complex involved in signaling receptor trafficking to and from cilia (summary by Scheidecker et al., 2014). Genetic Heterogeneity of Bardet-Biedl Syndrome BBS1 is caused by mutation in a gene on chromosome 11q13 (209901); BBS2 (615981), by mutation in a gene on 16q13 (606151); BBS3 (600151), by mutation in the ARL6 gene on 3q11 (608845); BBS4 (615982), by mutation in a gene on 15q22 (600374); BBS5 (615983), by mutation in a gene on 2q31 (603650); BBS6 (605231), by the MKKS gene on 20p12 (604896), mutations in which also cause McKusick-Kaufman syndrome (236700); BBS7 (615984), by mutation in a gene on 4q27 (607590); BBS8 (615985), by mutation in the TTC8 gene on 14q32 (608132); BBS9 (615986), by mutation in a gene on 7p14 (607968); BBS10 (615987), by mutation in a gene on 12q (610148); BBS11 (615988), by mutation in the TRIM32 gene on 9q33 (602290); BBS12 (615989), by mutation in a gene on 4q27 (610683); BBS13 (615990), by mutation in the MKS1 gene (609883) on 17q23, mutations in which also cause Meckel syndrome-1 (249000); BBS14 (615991), by mutation in the CEP290 gene (610142) on 12q21, mutations in which also cause Meckel syndrome-4 (611134) and several other disorders; BBS15 (615992), by mutation in the C2ORF86 gene (613580), which encodes a homolog of the Drosophila planar cell polarity gene 'fritz,' on 2p15; BBS16 (615993), by mutation in the SDCCAG8 gene (613524) on 1q43, mutations in which also cause Senior-Loken syndrome-7 (613615); BBS17 (615994), by mutation in the LZTFL1 gene (606568) on 3p21; BBS18 (615995), by mutation in the BBIP1 gene (613605) on 10q25; BBS19 (615996), by mutation in the IFT27 gene (615870) on 22q12; BBS20 (617119), by mutation in the IFT74 gene (608040) on 9p21; and BBS21 (617406), by mutation in the C8ORF37 gene (614477). The CCDC28B gene (610162) modifies the expression of BBS phenotypes in patients who have mutations in other genes. Mutations in MKS1, MKS3 (TMEM67; 609884), and C2ORF86 also modify the expression of BBS phenotypes in patients who have mutations in other genes. Although BBS had originally been thought to be a recessive disorder, Katsanis et al. (2001) demonstrated that clinical manifestation of some forms of Bardet-Biedl syndrome requires recessive mutations in 1 of the 6 loci plus an additional mutation in a second locus. While Katsanis et al. (2001) called this 'triallelic inheritance,' Burghes et al. (2001) suggested the term 'recessive inheritance with a modifier of penetrance.' Mykytyn et al. (2002) found no evidence of involvement of the common BBS1 mutation in triallelic inheritance. However, Fan et al. (2004) found heterozygosity in a mutation of the BBS3 gene (608845.0002) as an apparent modifier of the expression of homozygosity of the met390-to-arg mutation in the BBS1 gene (209901.0001). Allelic disorders include nonsyndromic forms of retinitis pigmentosa: RP51 (613464), caused by TTC8 mutation, and RP55 (613575), caused by ARL6 mutation.
congenital disorder of glycosylation type 2j
MedGen UID:
462086
Concept ID:
C3150736
Disease or Syndrome
COG4-CDG is an extremely rare form of CDG syndrome (see this term) characterized clinically in the single reported case to date by seizures, some dysmorphic features, axial hyponia, slight peripheral hypertonia and hyperreflexia.
nephronophthisis 11
MedGen UID:
462146
Concept ID:
C3150796
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 recognized: 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).
combined oxidative phosphorylation deficiency 7
MedGen UID:
462151
Concept ID:
C3150801
Disease or Syndrome
Combined oxidative phosphorylation defect type 7 is a rare mitochondrial disease due to a defect in mitochondrial protein synthesis characterized by a variable phenotype that includes onset in infancy or early childhood of failure to thrive and psychomotor regression (after initial normal development), as well as ocular manifestations (such as ptosis, nystagmus, optic atrophy, ophthalmoplegia and reduced vision). Additional manifestations include bulbar paresis with facial weakness, hypotonia, difficulty chewing, dysphagia, mild dysarthria, ataxia, global muscle atrophy, and areflexia. It has a relatively slow disease progression with patients often living into the third decade of life.
myopathy, lactic acidosis, and sideroblastic anemia 2
MedGen UID:
462152
Concept ID:
C3150802
Disease or Syndrome
Myopathy, lactic acidosis, and sideroblastic anemia-2 is an autosomal recessive disorder of the mitochondrial respiratory chain. The disorder shows marked phenotypic variability: some patients have a severe multisystem disorder from infancy, including cardiomyopathy and respiratory insufficiency resulting in early death, whereas others present in the second or third decade of life with sideroblastic anemia and mild muscle weakness (summary by Riley et al., 2013). For a discussion of genetic heterogeneity of MLASA, see MLASA1 (600462).
chromosome 19p13.13 deletion syndrome
MedGen UID:
462244
Concept ID:
C3150894
Disease or Syndrome
19p13.13 deletion syndrome is a condition that results from a chromosomal change in which a small piece of chromosome 19 is deleted in each cell. The deletion occurs on the short (p) arm of the chromosome at a position designated p13.13.\n\nFeatures commonly associated with this chromosomal change include an unusually large head size (macrocephaly), tall stature, and intellectual disability that is usually moderate in severity. Many affected individuals have significantly delayed development, including speech, and children may speak few or no words. Weak muscle tone (hypotonia) and problems with coordinating muscle movement (ataxia) contribute to delays in gross motor skills (such as sitting and walking) and fine motor skills (such as holding a pencil).\n\nOther signs and symptoms that can occur with 19p13.13 deletion syndrome include seizures, abnormalities of brain structure, and mild differences in facial features (such as a prominent forehead). Many affected individuals have problems with feeding and digestion, including constipation, diarrhea, vomiting, and abdominal pain. Eye problems that can impair vision are also common. These include eyes that do not point in the same direction (strabismus) and underdevelopment of the optic nerves, which carry visual information from the eyes to the brain.\n\nThe signs and symptoms of 19p13.13 deletion syndrome vary among affected individuals. In part, this variation occurs because the size of the deletion, and the number of genes it affects, varies from person to person.
ataxia, spastic, 4, autosomal recessive
MedGen UID:
462275
Concept ID:
C3150925
Disease or Syndrome
A rare, genetic, autosomal recessive spastic ataxia disease characterized by onset in early childhood of spastic paraparesis, cerebellar ataxia, dysarthria and optic atrophy.
microphthalmia, isolated, with coloboma 6
MedGen UID:
462318
Concept ID:
C3150968
Disease or Syndrome
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).
spastic paraplegia 51, autosomal recessive
MedGen UID:
462406
Concept ID:
C3151056
Disease or Syndrome
AP-4-associated hereditary spastic paraplegia (HSP), also known as AP-4 deficiency syndrome, is a group of neurodegenerative disorders characterized by a progressive, complex spastic paraplegia with onset typically in infancy or early childhood. Early-onset hypotonia evolves into progressive lower-extremity spasticity. The majority of children become nonambulatory and usually wheelchair bound. Over time spasticity progresses to involve the upper extremities, resulting in a spastic tetraplegia. Associated complications include dysphagia, contractures, foot deformities, dysregulation of bladder and bowel function, and a pseudobulbar affect. About 50% of affected individuals have seizures. Postnatal microcephaly (usually in the -2SD to -3SD range) is common. All have developmental delay. Speech development is significantly impaired and many affected individuals remain nonverbal. Intellectual disability in older children is usually moderate to severe.
retinitis pigmentosa 20
MedGen UID:
462436
Concept ID:
C3151086
Disease or Syndrome
leber congenital amaurosis 15
MedGen UID:
462556
Concept ID:
C3151206
Disease or Syndrome
Autosomal recessive childhood-onset severe retinal dystrophy is a heterogeneous group of disorders affecting rod and cone photoreceptors simultaneously. The most severe cases are termed Leber congenital amaurosis, whereas the less aggressive forms are usually considered juvenile retinitis pigmentosa (summary by Gu et al., 1997). Mutation in TULP1 can also cause a form of autosomal recessive retinitis pigmentosa (RP14; 600132). For a general phenotypic description and a discussion of the genetic heterogeneity of Leber congenital amaurosis, see LCA1 (204000); for retinitis pigmentosa, see 268000.
mitochondrial dna-depletion syndrome 3, hepatocerebral
MedGen UID:
462863
Concept ID:
C3151513
Disease or Syndrome
The two forms of deoxyguanosine kinase (DGUOK) deficiency are a neonatal multisystem disorder and an isolated hepatic disorder that presents later in infancy or childhood. The majority of affected individuals have the multisystem illness with hepatic disease (jaundice, cholestasis, hepatomegaly, and elevated transaminases) and neurologic manifestations (hypotonia, nystagmus, and psychomotor retardation) evident within weeks of birth. Those with isolated liver disease may also have renal involvement and some later develop mild hypotonia. Progressive hepatic disease is the most common cause of death in both forms.
muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type a3
MedGen UID:
462869
Concept ID:
C3151519
Disease or Syndrome
An autosomal recessive muscular dystrophy caused by mutations in the POMGNT1 gene. It is associated with characteristic brain and eye malformations, profound mental retardation, and death usually in the first years of life.
nystagmus, congenital, autosomal recessive
MedGen UID:
462921
Concept ID:
C3151571
Disease or Syndrome
ataxia, spastic, childhood-onset, autosomal recessive, with optic atrophy and mental retardation
MedGen UID:
462969
Concept ID:
C3151619
Disease or Syndrome
This progressive neurodegenerative disorder is characterized by early childhood onset of spastic ataxia with mental retardation, cerebellar signs, and variable optic atrophy (Hogan and Bauman, 1977).
hsd10 disease
MedGen UID:
781653
Concept ID:
C3266731
Disease or Syndrome
HSD10 mitochondrial disease (HSD10MD) 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; Zschocke, 2012). In a review of this disorder, Zschocke (2012) noted that although it 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).
microcephaly and chorioretinopathy, autosomal recessive, 1
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.
hermansky-pudlak syndrome 7
MedGen UID:
481386
Concept ID:
C3279756
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
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).
hermansky-pudlak syndrome 9
MedGen UID:
481656
Concept ID:
C3280026
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
leber congenital amaurosis 16
MedGen UID:
481692
Concept ID:
C3280062
Disease or Syndrome
nephrotic syndrome, type 5, with or without ocular abnormalities
MedGen UID:
481743
Concept ID:
C3280113
Disease or Syndrome
Nephrotic syndrome type 5 is an autosomal recessive disorder characterized by very early onset of progressive renal failure manifest as proteinuria with consecutive edema starting in utero or within the first 3 months of life. A subset of patients may develop mild ocular anomalies, such as myopia, nystagmus, and strabismus (summary by Hasselbacher et al., 2006). Mutation in the LAMB2 gene can also cause Pierson syndrome (609049), which is characterized by nephrotic syndrome, distinct ocular anomalies, namely microcoria, and neurodevelopmental delay. For a general phenotypic description and a discussion of genetic heterogeneity of nephrotic syndrome, see NPHS1 (256300).
warburg micro syndrome 3
MedGen UID:
481833
Concept ID:
C3280203
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.
spinocerebellar ataxia, autosomal recessive 11
MedGen UID:
481856
Concept ID:
C3280226
Disease or Syndrome
A rare, hereditary, cerebellar ataxia disorder characterized by late-onset spinocerebellar ataxia, manifesting with slowly progressive gait disturbances, dysarthria, limb and truncal ataxia, and smooth-pursuit eye movement disturbance, associated with a history of psychomotor delay from childhood. Mild atrophy of the cerebellar vermis and hemispheres is observed on brain imaging.
joubert syndrome 14
MedGen UID:
482396
Concept ID:
C3280766
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.
congenital cataracts, hearing loss, and neurodegeneration
MedGen UID:
482595
Concept ID:
C3280965
Disease or Syndrome
Huppke-Brendel syndrome (HBS) is characterized by bilateral congenital cataracts, sensorineural hearing loss, and severe developmental delay. To date, six individuals with HBS have been reported in the literature. All presented in infancy with axial hypotonia; motor delay was apparent in the first few months of life with lack of head control and paucity of limb movement. Seizures have been reported infrequently. In all individuals described to date serum copper and ceruloplasmin levels were very low or undetectable. Brain MRI examination showed hypomyelination, cerebellar hypoplasia mainly affecting the vermis, and wide subarachnoid spaces. None of the individuals reported to date were able to sit or walk independently. All affected individuals died between age ten months and six years.
infantile cerebellar-retinal degeneration
MedGen UID:
482822
Concept ID:
C3281192
Disease or Syndrome
Infantile cerebellar-retinal degeneration (ICRD) is a severe autosomal recessive neurodegenerative disorder characterized by onset between ages 2 and 6 months of truncal hypotonia, athetosis, seizures, and ophthalmologic abnormalities, particularly optic atrophy and retinal degeneration. Affected individuals show profound psychomotor retardation, with only some achieving rolling, sitting, or recognition of family. Brain MRI shows progressive cerebral and cerebellar degeneration (summary by Spiegel et al., 2012). A subset of patients may have a milder phenotype with variable features, including ataxia, developmental delay, and behavioral abnormalities (Blackburn et al., 2020).
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.
congenital stationary night blindness, type 1e
MedGen UID:
482845
Concept ID:
C3281215
Disease or Syndrome
Complete congenital stationary night blindness (cCSNB) is a clinically and genetically heterogeneous group of retinal disorders characterized by nonprogressive impairment of night vision, absence of the electroretinogram (ERG) b-wave, and variable degrees of involvement of other visual functions. Individuals with cCSNB and animal models of the disorder have an ERG waveform that lacks the b-wave because of failure to transmit the photoreceptor signal through the retinal depolarizing bipolar cells (summary by Peachey et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of congenital stationary night blindness, see CSNB1A (310500).
spinocerebellar ataxia 36
MedGen UID:
483339
Concept ID:
C3472711
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.
pseudohypoparathyroidism type i a
MedGen UID:
488447
Concept ID:
C3494506
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.
acrocephalopolydactyly
MedGen UID:
501209
Concept ID:
C3495588
Disease or Syndrome
Acrocephalopolydactylous dysplasia, or Elejalde syndrome, is a lethal multiple congenital disorder characterized by increased birth weight, globular body with thick skin, organomegaly, and fibrosis in multiple tissues (summary by Phadke et al., 2011).
jalili syndrome
MedGen UID:
501210
Concept ID:
C3495589
Disease or Syndrome
Jalili syndrome is an autosomal recessive disorder consisting of cone-rod dystrophy and amelogenesis imperfecta. Significant visual impairment with nystagmus and photophobia is present from infancy or early childhood and progresses with age. Enamel of primary and secondary dentitions is grossly abnormal and prone to rapid posteruptive failure, in part reflecting hypomineralization (summary by Parry et al., 2009).
spastic paraplegia 35
MedGen UID:
501249
Concept ID:
C3496228
Disease or Syndrome
Fatty acid hydroxylase-associated neurodegeneration (FAHN) is characterized early in the disease course by central nervous system involvement including corticospinal tract involvement (spasticity), mixed movement disorder (ataxia/dystonia), and eye findings (optic atrophy, oculomotor abnormalities), and later in the disease course by progressive intellectual impairment and seizures. With disease progression, dystonia and spasticity compromise the ability to ambulate, leading to wheelchair dependence. Life expectancy is variable. FAHN is considered to be a subtype of neurodegeneration with brain iron accumulation (NBIA).
aicardi-goutieres syndrome 6
MedGen UID:
761287
Concept ID:
C3539013
Disease or Syndrome
Most characteristically, Aicardi-Goutières syndrome (AGS) manifests as an early-onset encephalopathy that usually, but not always, results in severe intellectual and physical disability. A subgroup of infants with AGS present at birth with abnormal neurologic findings, hepatosplenomegaly, elevated liver enzymes, and thrombocytopenia, a picture highly suggestive of congenital infection. Otherwise, most affected infants present at variable times after the first few weeks of life, frequently after a period of apparently normal development. Typically, they demonstrate the subacute onset of a severe encephalopathy characterized by extreme irritability, intermittent sterile pyrexias, loss of skills, and slowing of head growth. Over time, as many as 40% develop chilblain skin lesions on the fingers, toes, and ears. It is becoming apparent that atypical, sometimes milder, cases of AGS exist, and thus the true extent of the phenotype associated with pathogenic variants in the AGS-related genes is not yet known.
spastic paraplegia 55, autosomal recessive
MedGen UID:
761342
Concept ID:
C3539506
Disease or Syndrome
gene (12q24.31) encoding probable peptide chain release factor C12orf65, mitochondrial.
pontine tegmental cap dysplasia
MedGen UID:
762040
Concept ID:
C3541340
Disease or Syndrome
Pontine tegmental cap dysplasia (PTCD) refers to a neurologic condition characterized by a distinct pattern of hindbrain malformations apparent on brain imaging. The abnormalities affect the pons, medulla, and cerebellum. In neuroradiologic studies, the ventral side of the pons is flattened, whereas there is vaulting ('capping') of the dorsal pontine border into the fourth ventricle. Affected individuals show a variety of neurologic deficits, most commonly sensorineural deafness, impaired cranial nerve function, and variable psychomotor retardation (summary by Barth et al., 2007).
nephronophthisis 15
MedGen UID:
762112
Concept ID:
C3541853
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 recognized: 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).
peroxisome biogenesis disorder 5b
MedGen UID:
762202
Concept ID:
C3542026
Disease or Syndrome
The overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD) represent the milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy, and visual impairment. Children with the NALD presentation may reach their teens, and those with the IRD presentation may reach adulthood (summary by Waterham and Ebberink, 2012). For a complete phenotypic description and a discussion of genetic heterogeneity of PBD(NALD/IRD), see 601539. Individuals with mutations in the PEX2 gene have cells of complementation group 5 (CG5, equivalent to CG10 and CGF). For information on the history of PBD complementation groups, see 214100.
alternating hemiplegia of childhood 1
MedGen UID:
762361
Concept ID:
C3549447
Disease or Syndrome
Alternating hemiplegia of childhood is a rare syndrome of episodic hemi- or quadriplegia lasting minutes to days. Most cases are accompanied by dystonic posturing, choreoathetoid movements, nystagmus, other ocular motor abnormalities, autonomic disturbances, and progressive cognitive impairment (Mikati et al., 1992). The disorder may mimic or overlap with other disorders, including familial hemiplegic migraine (FHM1; 141500) and GLUT1 deficiency syndrome (606777) (Rotstein et al., 2009). Genetic Heterogeneity of Alternating Hemiplegia of Childhood See also AHC2 (614820), caused by mutation in the ATP1A3 gene (182350).
coenzyme q10 deficiency, primary 1
MedGen UID:
764868
Concept ID:
C3551954
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.
pontocerebellar hypoplasia, type 1b
MedGen UID:
766363
Concept ID:
C3553449
Disease or Syndrome
EXOSC3 pontocerebellar hypoplasia (EXOSC3-PCH) is characterized by abnormalities in the posterior fossa and degeneration of the anterior horn cells. At birth, skeletal muscle weakness manifests as hypotonia (sometimes with congenital joint contractures) and poor feeding. In persons with prolonged survival, spasticity, dystonia, and seizures become evident. Within the first year of life respiratory insufficiency and swallowing difficulties are common. Intellectual disability is severe. Life expectancy ranges from a few weeks to adolescence. To date, 82 individuals (from 58 families) with EXOSC3-PCH have been described.
brown-vialetto-van laere syndrome 2
MedGen UID:
766452
Concept ID:
C3553538
Disease or Syndrome
Brown-Vialetto-Van Laere syndrome-2 is an autosomal recessive progressive neurologic disorder characterized by early childhood onset of sensorineural deafness, bulbar dysfunction, and severe diffuse muscle weakness and wasting of the upper and lower limbs and axial muscles, resulting in respiratory insufficiency. Some patients may lose independent ambulation. Because it results from a defect in riboflavin metabolism, some patients may benefit from high-dose riboflavin supplementation (summary by Johnson et al., 2012; Foley et al., 2014). For discussion of genetic heterogeneity of Brown-Vialetto-Van Laere syndrome, see BVVLS1 (211530).
sotos syndrome 2
MedGen UID:
766574
Concept ID:
C3553660
Disease or Syndrome
Sotos syndrome-2 (SOTOS2) is clinically characterized by overgrowth, advanced bone age, macrocephaly, and dysmorphic facial features. Patients develop marfanoid habitus, with long and slender body, very low body mass, long narrow face, and arachnodactyly, with age. Impaired intellectual development and behavior anomalies are present (summary by Martinez et al., 2015). For a discussion of genetic heterogeneity of Sotos syndrome, see 117550.
alternating hemiplegia of childhood 2
MedGen UID:
766702
Concept ID:
C3553788
Disease or Syndrome
ATP1A3-related neurologic disorders represent a clinical continuum in which at least three distinct phenotypes have been delineated: rapid-onset dystonia-parkinsonism (RDP); alternating hemiplegia of childhood (ACH); and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS). However, some affected individuals have intermediate phenotypes or only a few features that do not fit well into one of these major phenotypes. RDP has been characterized by: abrupt onset of dystonia over days to weeks with parkinsonism (primarily bradykinesia and postural instability); common bulbar involvement; and absence or minimal response to an adequate trial of L-dopa therapy, with few exceptions. Often fever, physiologic stress, or alcoholic binges trigger the onset of symptoms. After their initial appearance, symptoms often stabilize with little improvement; occasionally second episodes occur with abrupt worsening of symptoms. Rarely, affected individuals have reported a more gradual onset of symptoms over weeks to months. Anxiety, depression, and seizures have been reported. Age of onset ranges from four to 55 years, although a childhood variation of RDP with onset between ages nine and 14 months has been reported. AHC is a complex neurodevelopmental syndrome most frequently manifesting in infancy or early childhood with paroxysmal episodic neurologic dysfunction including alternating hemiparesis or dystonia, quadriparesis, seizure-like episodes, and oculomotor abnormalities. Episodes can last for minutes, hours, days, or even weeks. Remission of symptoms occurs with sleep and immediately after awakening. Over time, persistent neurologic deficits including oculomotor apraxia, ataxia, choreoathetosis, dystonia, parkinsonism, and cognitive and behavioral dysfunction develop in the majority of those affected; more than 50% develop epilepsy in addition to their episodic movement disorder phenotype. CAPOS (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) syndrome is characterized by episodes of ataxic encephalopathy and/or weakness during and after a febrile illness. Onset is between ages six months and four years. Some acute symptoms resolve; progression of sensory losses and severity vary.
peroxisome biogenesis disorder 4b
MedGen UID:
766851
Concept ID:
C3553937
Disease or Syndrome
Peroxisome biogenesis disorder-4B (PBD4B) includes the overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD), which represent milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders (PBDs). The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy, and visual impairment. Children with the NALD presentation may reach their teens, and those with the IRD presentation may reach adulthood (summary by Waterham and Ebberink, 2012). For a complete phenotypic description and a discussion of genetic heterogeneity of PBD(NALD/IRD), see 601539. Individuals with mutations in the PEX6 gene have cells of complementation group 4 (CG4, equivalent to CG6 and CGC). For information on the history of PBD complementation groups, see 214100.
peroxisome biogenesis disorder 6b
MedGen UID:
766862
Concept ID:
C3553948
Disease or Syndrome
The overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD) represent the milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy, and visual impairment. Children with the NALD presentation may reach their teens, and those with the IRD presentation may reach adulthood. Some patients with PEX10 mutations have a milder disorder characterized by childhood-onset cerebellar ataxia and neuropathy without mental retardation (summary by Waterham and Ebberink, 2012). For a complete phenotypic description and a discussion of genetic heterogeneity of PBD(NALD/IRD), see 601539. Individuals with mutations in the PEX10 gene have cells of complementation group 7 (CG7, equivalent to CGB). For information on the history of PBD complementation groups, see 214100.
peroxisome biogenesis disorder 8b
MedGen UID:
766874
Concept ID:
C3553960
Disease or Syndrome
The overlapping phenotypes of neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD) represent the milder manifestations of the Zellweger syndrome spectrum (ZSS) of peroxisome biogenesis disorders. The clinical course of patients with the NALD and IRD presentation is variable and may include developmental delay, hypotonia, liver dysfunction, sensorineural hearing loss, retinal dystrophy, and visual impairment. Children with the NALD presentation may reach their teens, and those with the IRD presentation may reach adulthood (summary by Waterham and Ebberink, 2012). For a complete phenotypic description and a discussion of genetic heterogeneity of PBD(NALD/IRD), see 601539. Individuals with mutations in the PEX16 gene have cells of complementation group 9 (CG9, equivalent to CGD). For information on the history of PBD complementation groups, see 214100.
peroxisome biogenesis disorder 14b
MedGen UID:
766969
Concept ID:
C3554055
Disease or Syndrome
PBD14B is an autosomal recessive peroxisome biogenesis disorder characterized clinically by mild intellectual disability, congenital cataracts, progressive hearing loss, and polyneuropathy (Ebberink et al., 2012), all of which had been observed in patients with mild peroxisomal biogenesis disorders (e.g., Kelley et al., 1986; Poll-The et al., 1987). Additionally, recurrent migraine-like episodes following mental stress or physical exertion, not a common feature in peroxisome disorders, was reported. Thoms and Gartner (2012) classified the disorder described by Ebberink et al. (2012) in their patient as a mild 'Zellweger syndrome (214100) spectrum' (ZSS) disorder. See PBD1B (601539) for a phenotypic description and discussion of genetic heterogeneity of less severe phenotypes on the Zellweger syndrome spectrum. See PBD9B (614879) for another atypical peroxisome biogenesis disorder.
combined oxidative phosphorylation deficiency 13
MedGen UID:
767043
Concept ID:
C3554129
Disease or Syndrome
Combined oxidative phosphorylation deficiency-13 is an autosomal recessive multisystem disorder resulting from mitochondrial dysfunction. Affected individuals develop severe neurologic impairment in the first months of life, including hypotonia, abnormal dystonic movements, hearing loss, poor feeding, global developmental delay, and abnormal eye movements. Brain imaging shows signal abnormalities in putamen, basal ganglia, caudate nuclei, or corpus callosum, as well as delayed myelination. Analysis of patient tissues shows multiple defects in enzymatic activities of the mitochondrial respiratory chain, although some tissues may show normal values since tissue expression of the mitochondrial defect and metabolic needs of specific tissues are variable (summary by Vedrenne et al., 2012).
combined oxidative phosphorylation deficiency 15
MedGen UID:
767096
Concept ID:
C3554182
Disease or Syndrome
Combined oxidative phosphorylation defect type 15 is a rare mitochondrial disease due to a defect in mitochondrial protein synthesis characterized by onset in infancy or early childhood of muscular hypotonia, gait ataxia, mild bilateral pyramidal tract signs, developmental delay (affecting mostly speech and coordination) and subsequent intellectual disability. Short stature, obesity, microcephaly, strabismus, nystagmus, reduced visual acuity, lactic acidosis, and a brain neuropathology consistent with Leigh syndrome are also reported.
pontocerebellar hypoplasia type 8
MedGen UID:
767123
Concept ID:
C3554209
Disease or Syndrome
Pontocerebellar hypoplasia type 8 is an autosomal recessive neurodevelopmental disorder characterized by severe psychomotor retardation, abnormal movements, hypotonia, spasticity, and variable visual defects. Brain MRI shows pontocerebellar hypoplasia, decreased cerebral white matter, and a thin corpus callosum (summary by Mochida et al., 2012). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
pontocerebellar hypoplasia, type 7
MedGen UID:
767140
Concept ID:
C3554226
Disease or Syndrome
Pontocerebellar hypoplasia type 7 is a severe neurologic condition characterized by delayed psychomotor development, hypotonia, breathing abnormalities, and gonadal abnormalities (summary by Anderson et al., 2011). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
basal ganglia calcification, idiopathic, 4
MedGen UID:
767235
Concept ID:
C3554321
Disease or Syndrome
Primary familial brain calcification (PFBC) is a neurodegenerative disorder with characteristic calcium deposits in the basal ganglia and other brain areas visualized on neuroimaging. Most affected individuals are in good health during childhood and young adulthood and typically present in the fourth to fifth decade with a gradually progressive movement disorder and neuropsychiatric symptoms. The movement disorder first manifests as clumsiness, fatigability, unsteady gait, slow or slurred speech, dysphagia, involuntary movements, or muscle cramping. Neuropsychiatric symptoms, often the first or most prominent manifestations, range from mild difficulty with concentration and memory to changes in personality and/or behavior, to psychosis and dementia. Seizures of various types occur frequently, some individuals experience chronic headache and vertigo; urinary urgency or incontinence may be present.
schuurs-hoeijmakers syndrome
MedGen UID:
767257
Concept ID:
C3554343
Disease or Syndrome
PACS1 neurodevelopmental disorder (PACS1-NDD) is characterized by mild-to-severe neurodevelopmental delays. Language skills are more severely affected than motor skills. Hypotonia is reported in about a third of individuals and is noted to improve over time. Approximately 60% of individuals are ambulatory. Feeding difficulty is common, with 25% requiring gastrostomy tube to maintain appropriate caloric intake. Other common features include constipation, seizures, behavioral issues, congenital heart anomalies, short stature, and microcephaly. Common facial features include hypertelorism, downslanting palpebral fissures, bulbous nasal tip, low-set and simple ears, smooth philtrum, wide mouth with downturned corners, thin upper vermilion, and wide-spaced teeth. To date approximately 35 individuals with PACS1-NDD have been reported.
mitochondrial complex iii deficiency, nuclear type 2
MedGen UID:
767519
Concept ID:
C3554605
Disease or Syndrome
Mitochondrial complex III deficiency nuclear type 2 is an autosomal recessive severe neurodegenerative disorder that usually presents in childhood, but may show later onset, even in adulthood. Affected individuals have motor disability, with ataxia, apraxia, dystonia, and dysarthria, associated with necrotic lesions throughout the brain. Most patients also have cognitive impairment and axonal neuropathy and become severely disabled later in life (summary by Ghezzi et al., 2011). The disorder may present clinically as spinocerebellar ataxia or Leigh syndrome, or with psychiatric disturbances (Morino et al., 2014; Atwal, 2014; Nogueira et al., 2013). For a discussion of genetic heterogeneity of mitochondrial complex III deficiency, see MC3DN1 (124000).
ataxia-oculomotor apraxia 3
MedGen UID:
767604
Concept ID:
C3554690
Disease or Syndrome
AOA3 is an autosomal recessive progressive neurologic disorder with onset in the second decade of life (Al Tassan et al., 2012). For a discussion of genetic heterogeneity of ataxia-oculomotor apraxia, see AOA1 (208920).
muscular dystrophy-dystroglycanopathy (limb-girdle), type c, 14
MedGen UID:
811507
Concept ID:
C3714932
Disease or Syndrome
MDDGC14 is an autosomal recessive form of muscular dystrophy characterized by onset in early childhood of mild proximal muscle weakness. Some patients may have additional features, such as mild intellectual disability or seizures. It is part of a group of similar disorders resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239), collectively known as 'dystroglycanopathies' (summary by Carss et al., 2013). Some patients with GMPPB mutations may show features consistent with a congenital myasthenic syndrome (see, e.g., CMS1A; 601462), such as fatigability and decremental compound muscle action potential response to repetitive nerve stimulation; these patients may show a positive therapeutic response to treatment with pyridostigmine (Belaya et al., 2015). For a discussion of genetic heterogeneity of muscular dystrophy-dystroglycanopathy type C, see MDDGC1 (609308).
skin/hair/eye pigmentation, variation in, 4
MedGen UID:
811705
Concept ID:
C3805375
Disease or Syndrome
Oculocutaneous albinism (OCA) is a heterogeneous autosomal recessive disorder, with a worldwide prevalence of approximately 1:17,000. It manifests as a reduction or complete loss of melanin in the skin, hair, and eyes, often accompanied by eye symptoms such as photophobia, strabismus, moderate to severe visual impairment, and nystagmus (summary by Wei et al., 2013). For a discussion of genetic heterogeneity of oculocutaneous albinism, see OCA1 (203100). For a general phenotypic description and a discussion of genetic heterogeneity of variation in skin, hair, and eye pigmentation, see SHEP1 (227220).
slc35a2-cdg
MedGen UID:
813018
Concept ID:
C3806688
Disease or Syndrome
Congenital disorder of glycosylation type IIm, or early infantile epileptic encephalopathy-22, is an X-linked dominant severe neurologic disorder characterized by infantile-onset seizures, hypsarrhythmia on EEG, hypotonia, and developmental delay associated with severe intellectual disability and lack of speech. These features are consistent with developmental and epileptic encephalopathy (DEE). Brain malformations usually include cerebral and cerebellar atrophy. Additionally, some patients may have dysmorphic features or coarse facies (Ng et al., 2013; Kodera et al., 2013). For a general discussion of CDGs, see CDG1A (212065) and CDG2A (212066). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
partial lipodystrophy, congenital cataracts, and neurodegeneration syndrome
MedGen UID:
813897
Concept ID:
C3807567
Disease or Syndrome
Lipodystrophies are rare disorders characterized by loss of body fat from various regions and predisposition to metabolic complications of insulin resistance and lipid abnormalities. FPLD7 is an autosomal dominant disorder with a highly variable phenotype. Additional features, including early-onset cataracts and later onset of spasticity of the lower limbs, have been noted in some patients (summary by Garg et al., 2015). For a general phenotypic description and a discussion of genetic heterogeneity of familial partial lipodystrophy (FPLD), see 151660.
foveal hypoplasia 2
MedGen UID:
814203
Concept ID:
C3807873
Disease or Syndrome
Foveal hypoplasia is defined as the lack of foveal depression with continuity of all neurosensory retinal layers in the presumed foveal area. Foveal hypoplasia as an isolated entity is a rare phenomenon; it is usually described in association with other ocular disorders, such as aniridia (106210), microphthalmia (see 251600), albinism (see 203100), or achromatopsia (see 216900). All reported cases of foveal hypoplasia have been accompanied by decreased visual acuity and nystagmus (summary by Perez et al., 2014). For a discussion of genetic heterogeneity of foveal hypoplasia, see FVH1 (136520).
cortical dysplasia, complex, with other brain malformations 1
MedGen UID:
814727
Concept ID:
C3808397
Disease or Syndrome
Complex cortical dysplasia with other brain malformations (CDCBM) is a disorder of aberrant neuronal migration and disturbed axonal guidance. Affected individuals have mild to severe mental retardation, strabismus, axial hypotonia, and spasticity. Brain imaging shows variable malformations of cortical development, including polymicrogyria, gyral disorganization, and fusion of the basal ganglia, as well as thin corpus callosum, hypoplastic brainstem, and dysplastic cerebellar vermis. Extraocular muscles are not involved (summary by Poirier et al., 2010). Mutation in the TUBB3 gene can also cause congenital fibrosis of extraocular muscles-3A (CFEOM3A; 600638), a milder and somewhat different neurologic phenotype. Genetic Heterogeneity of Complex Cortical Dysplasia With Other Brain Malformations See also CDCBM2 (615282), caused by mutation in the KIF5C gene (604593) on chromosome 2q23; CDCBM3 (615411), caused by mutation in the KIF2A gene (602591) on chromosome 5q12; CDCBM4 (615412), caused by mutation in the TUBG1 gene (191135) on chromosome 17q21; CDCBM5 (615763), caused by mutation in the TUBB2A gene (615101) on chromosome 6p25; CDCBM6 (615771), caused by mutation in the TUBB gene (191130) on chromosome 6p21; CDCBM7 (610031), caused by mutation in the TUBB2B gene (612850) on chromosome 6p25; CDCBM9 (618174), caused by mutation in the CTNNA2 gene (114025) on chromosome 2p12; and CDCBM10 (618677), caused by mutation in the APC2 gene (612034) on chromosome 19p13. The designation CDCBM8 was previously used to represent a phenotype caused by mutation in the TUBA8 gene (see 605742.0001) on chromosome 22q11; the patients with this phenotype were subsequently found to have a homozygous mutation in the SNAP29 gene (604202.0002), also on chromosome 22q11, that was likely responsible for a similar disorder, CEDNIK syndrome (609528). See also lissencephaly (e.g., LIS1, 607432), which shows overlapping features and may result from mutation in tubulin genes.
albinism, oculocutaneous, type vii
MedGen UID:
815116
Concept ID:
C3808786
Disease or Syndrome
Oculocutaneous albinism is a group of conditions that affect coloring (pigmentation) of the skin, hair, and eyes. Affected individuals typically have very fair skin and white or light-colored hair. Long-term sun exposure greatly increases the risk of skin damage and skin cancers, including an aggressive form of skin cancer called melanoma, in people with this condition. Oculocutaneous albinism also reduces pigmentation of the colored part of the eye (the iris) and the light-sensitive tissue at the back of the eye (the retina). People with this condition usually have vision problems such as reduced sharpness; rapid, involuntary eye movements (nystagmus); and increased sensitivity to light (photophobia).\n\nSeveral additional types of this disorder have been proposed, each affecting one or a few families.\n\nResearchers have identified multiple types of oculocutaneous albinism, which are distinguished by their specific skin, hair, and eye color changes and by their genetic cause. Oculocutaneous albinism type 1 is characterized by white hair, very pale skin, and light-colored irises. Type 2 is typically less severe than type 1; the skin is usually a creamy white color and hair may be light yellow, blond, or light brown. Type 3 includes a form of albinism called rufous oculocutaneous albinism, which usually affects dark-skinned people. Affected individuals have reddish-brown skin, ginger or red hair, and hazel or brown irises. Type 3 is often associated with milder vision abnormalities than the other forms of oculocutaneous albinism. Type 4 has signs and symptoms similar to those seen with type 2.
mitochondrial complex v (atp synthase) deficiency, nuclear type 4
MedGen UID:
815229
Concept ID:
C3808899
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.\n\nMitochondrial 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.\n\nAnother 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).\n\nSome 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.\n\nA 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.
cataract 19, multiple types
MedGen UID:
815334
Concept ID:
C3809004
Disease or Syndrome
Mutation in the LIM2 gene has been identified in 1 family with cataracts described as late-onset cortical pulverulent and in another family with congenital cataracts described as total.
cardiofaciocutaneous syndrome 3
MedGen UID:
815336
Concept ID:
C3809006
Disease or Syndrome
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, has been reported in some individuals.
cardiofaciocutaneous syndrome 4
MedGen UID:
815337
Concept ID:
C3809007
Disease or Syndrome
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, has been reported in some individuals.
hypomyelination with brainstem and spinal cord involvement and leg spasticity
MedGen UID:
815338
Concept ID:
C3809008
Disease or Syndrome
Hypomyelination with brainstem and spinal cord involvement and leg spasticity is an autosomal recessive leukoencephalopathy characterized by onset in the first year of life of severe spasticity, mainly affecting the lower limbs and resulting in an inability to achieve independent ambulation. Affected individuals show delayed motor development and nystagmus; some may have mild mental retardation. Brain MRI shows hypomyelination and white matter lesions in the cerebrum, brainstem, cerebellum, and spinal cord (summary by Taft et al., 2013).
multiple mitochondrial dysfunctions syndrome 3
MedGen UID:
815495
Concept ID:
C3809165
Disease or Syndrome
MMDS3 is an autosomal recessive severe neurodegenerative disorder characterized by loss of previously acquired developmental milestones in the first months or years of life. Some affected patients have normal development in early infancy before the onset of symptoms, whereas others show delays from birth. Features included loss of motor function, spasticity, pyramidal signs, loss of speech, and cognitive impairment. The disease course is highly variable: some patients die of respiratory failure early in childhood, whereas some survive but may be bedridden with a feeding tube. Less commonly, some patients may survive and have a stable course with motor deficits and mild or even absent cognitive impairment, although there may be fluctuating symptoms, often in response to infection. Other variable features include visual problems and seizures. Brain imaging shows diffuse leukodystrophy in the subcortical region, brainstem, cerebellum, and spinal cord. Laboratory studies tend to show increased lactate and CSF glycine, and decreased activity of mitochondrial complexes I and II, although these findings are also variable. There may be additional biochemical evidence of mitochondrial dysfunction (summary by Liu et al., 2018). For a general description and a discussion of genetic heterogeneity of multiple mitochondrial dysfunctions syndrome, see MMDS1 (605711).
muscular dystrophy-dystroglycanopathy (congenital with mental retardation), type b, 14
MedGen UID:
815551
Concept ID:
C3809221
Disease or Syndrome
MDDGB14 is an autosomal recessive congenital muscular dystrophy characterized by severe muscle weakness apparent in infancy and impaired intellectual development. Some patients may have additional features, such as microcephaly, cardiac dysfunction, seizures, or cerebellar hypoplasia. It is part of a group of similar disorders resulting from defective glycosylation of alpha-dystroglycan (DAG1; 128239), collectively known as 'dystroglycanopathies' (summary by Carss et al., 2013). For a discussion of genetic heterogeneity of congenital muscular dystrophy-dystroglycanopathy type B, see MDDGB1 (613155).
spinocerebellar ataxia, autosomal recessive 14
MedGen UID:
815657
Concept ID:
C3809327
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-14 (SCAR14) is a neurologic disorder characterized by delayed psychomotor development, severe early-onset gait ataxia, eye movement abnormalities, cerebellar atrophy on brain imaging, and impaired intellectual development (summary by Lise et al., 2012).
multiple congenital anomalies-hypotonia-seizures syndrome 3
MedGen UID:
815686
Concept ID:
C3809356
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 (GPI) biosynthesis. For a discussion of genetic heterogeneity of MCAHS, see MCAHS1 (614080). For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
cortical dysplasia, complex, with other brain malformations 3
MedGen UID:
815744
Concept ID:
C3809414
Disease or Syndrome
hypotonia, infantile, with psychomotor retardation and characteristic facies 1
MedGen UID:
815784
Concept ID:
C3809454
Disease or Syndrome
Infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) is a severe autosomal recessive neurologic disorder with onset at birth or in early infancy. Affected individuals show very poor, if any, normal cognitive development. Some patients are never learn to sit or walk independently (summary by Al-Sayed et al., 2013). Genetic Heterogeneity of Infantile Hypotonia with Psychomotor Retardation and Characteristic Facies See also IHPRF2 (616801), caused by mutation in the UNC80 gene (612636) on chromosome 2q34; and IHPRF3 (616900), caused by mutation in the TBCK gene (616899) on chromosome 4q24.
mitochondrial dna depletion syndrome 13 (encephalomyopathic type)
MedGen UID:
815922
Concept ID:
C3809592
Disease or Syndrome
FBXL4-related encephalomyopathic mitochondrial DNA (mtDNA) depletion syndrome is a multi-system disorder characterized primarily by congenital or early-onset lactic acidosis and growth failure, feeding difficulty, hypotonia, and developmental delay. Other neurologic manifestations can include seizures, movement disorders, ataxia, autonomic dysfunction, and stroke-like episodes. All affected individuals alive at the time they were reported (median age: 3.5 years) demonstrated significant developmental delay. Other findings can involve the heart (hypertrophic cardiomyopathy, congenital heart malformations, arrhythmias), liver (mildly elevated transaminases), eyes (cataract, strabismus, nystagmus, optic atrophy), hearing (sensorineural hearing loss), and bone marrow (neutropenia, lymphopenia). Survival varies; the median age of reported deaths was two years (range 2 days – 75 months), although surviving individuals as old as 36 years have been reported. To date FBXL4-related mtDNA depletion syndrome has been reported in 50 individuals.
spastic paraplegia 79, autosomal recessive
MedGen UID:
815995
Concept ID:
C3809665
Disease or Syndrome
SPG79 is an autosomal recessive progressive neurologic disorder characterized by onset of spastic paraplegia and optic atrophy in the first decade of life. Additional features are variable, but may include peripheral neuropathy, cerebellar ataxia, and cognitive impairment (summary by Rydning et al., 2017). For a discussion of genetic heterogeneity of autosomal recessive spastic paraplegia, see SPG5A (270800).
mental retardation, autosomal recessive 40
MedGen UID:
816410
Concept ID:
C3810080
Disease or Syndrome
A rare, genetic, syndromic intellectual disability disease characterized by progressive postnatal microcephaly and global developmental delay, as well as moderate to profound intellectual disability, difficulty or inability to walk, pyramidal signs (including spasticity, hyperreflexia and extensor plantar response) and thin corpus callosum revealed by brain imaging. Ophthalmologic signs (including nystagmus, strabismus and abnormal retinal pigmentation), foot deformity and genital anomalies may also be associated.
spinocerebellar ataxia, autosomal recessive 15
MedGen UID:
816656
Concept ID:
C3810326
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-15 (SCAR15) is characterized by early-onset ataxia, cognitive impairment, dysarthria, and developmental delay. Variable features include seizures, nystagmus, and abnormal reflexes (Seidahmed et al., 2020).
bosch-boonstra-schaaf optic atrophy syndrome
MedGen UID:
816693
Concept ID:
C3810363
Disease or Syndrome
Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is an autosomal dominant disorder characterized by delayed development, moderately impaired intellectual development, and optic atrophy. Most patients also have evidence of cerebral visual impairment. Dysmorphic facial features are variable and nonspecific (summary by Bosch et al., 2014).
hermansky-pudlak syndrome 6
MedGen UID:
854714
Concept ID:
C3888007
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
vitreoretinochoroidopathy
MedGen UID:
854768
Concept ID:
C3888099
Disease or Syndrome
Bestrophinopathies, the spectrum of ophthalmic disorders caused by pathogenic variants in BEST1, are typically characterized by retinal degeneration. The four recognized phenotypes are the three autosomal dominant disorders: Best vitelliform macular dystrophy (BVMD), BEST1 adult-onset vitelliform macular dystrophy (AVMD), and autosomal dominant vitreoretinochoroidopathy (ADVIRC); and autosomal recessive bestrophinopathy (ARB). Onset is usually in the first decade (except AVMD in which onset is age 30 to 50 years). Slow visual deterioration is the usual course. Choroidal neovascularization can occur in rare cases. ADVIRC is also associated with panophthalmic involvement including nanophthalmos, microcornea, hyperopia, and narrow anterior chamber angle with angle closure glaucoma.
cataract, congenital nuclear, autosomal recessive 3
MedGen UID:
854781
Concept ID:
C3888124
Disease or Syndrome
Mutations in the CRYBB1 gene have been found to cause multiple types of cataract, which have been described as congenital nuclear, congenital nuclear with anterior and posterior Y-suture and polar opacities, and pulverulent. The preferred title/symbol for this entry was formerly 'Cataract, Congenital Nuclear, Autosomal Recessive 3; CATCN3.'
spastic paraplegia 45, autosomal recessive
MedGen UID:
854816
Concept ID:
C3888209
Disease or Syndrome
Autosomal recessive spastic paraplegia type 45 is a rare, pure or complex form of hereditary spastic paraplegia characterized by onset in infancy of progressive lower limb spasticity, abnormal gait, increased deep tendon reflexes and extensor plantar responses, that may be associated with intellectual disability. Additional signs, such as contractures in the lower limbs, amyotrophy, clubfoot and optic atrophy, have also been reported.
peroxisome biogenesis disorder 7a
MedGen UID:
854881
Concept ID:
C3888385
Disease or Syndrome
Zellweger syndrome (ZS) is an autosomal recessive multiple congenital anomaly syndrome resulting from disordered peroxisome biogenesis. Affected children present in the newborn period with profound hypotonia, seizures, and inability to feed. Characteristic craniofacial anomalies, eye abnormalities, neuronal migration defects, hepatomegaly, and chondrodysplasia punctata are present. Children with this condition do not show any significant development and usually die in the first year of life (summary by Steinberg et al., 2006). For a complete phenotypic description and a discussion of genetic heterogeneity of Zellweger syndrome, see 214100. Individuals with PBDs of complementation group 8 (CG8, equivalent to CGA) have mutations in the PEX26 gene. For information on the history of PBD complementation groups, see 214100.
albinism, oculocutaneous, type v
MedGen UID:
854888
Concept ID:
C3888401
Disease or Syndrome
Oculocutaneous albinism is a genetically heterogeneous disorder manifested as a loss of pigmentation in the eyes, skin, and hair (summary by Kausar et al., 2013). For a general phenotypic description and a discussion of genetic heterogeneity of oculocutaneous albinism, see OCA1 (203100).
bardet-biedl syndrome 19
MedGen UID:
855173
Concept ID:
C3889475
Disease or Syndrome
BBS19 is an autosomal recessive ciliopathy characterized by obesity, intellectual disability, polydactyly, renal failure, retinitis pigmentosa, and hypogonadism (Aldahmesh et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of Bardet-Biedl syndrome, see BBS1 (209900).
spinocerebellar ataxia 37
MedGen UID:
855217
Concept ID:
C3889636
Disease or Syndrome
Spinocerebellar ataxia type 37 (SCA37) is characterized by adult onset, dysarthria, slowly progressive gait and limb ataxia with severe dysmetria in the lower extremities, mild dysmetria in the upper extremities, dysphagia, and abnormal ocular movements (dysmetric vertical saccades, irregular and slow vertical smooth pursuit, slow vertical optokinetic nystagmus, and oscillopsia (visual disturbance in which objects appear to oscillate). In most individuals, the initial signs/symptoms include falls, dysarthria, or clumsiness followed by a complete cerebellar syndrome. A distinctive clinical feature is the presence of altered vertical eye movements in early stages of the disease, even preceding ataxia symptoms. Clinical progression is slow and affected individuals usually become wheelchair bound between ten and 33 years after disease onset.
ocular coloboma, autosomal recessive
MedGen UID:
860411
Concept ID:
C4011974
Disease or Syndrome
Coloboma is an ocular birth defect resulting from abnormal development of the eye during embryogenesis. It is defined as a congenital defect in any ocular tissue, typically presenting as absent tissue or a gap, at a site consistent with aberrant closure of the optic fissure. Failure of fusion can lead to coloboma of 1 or multiple regions of the inferior portion of the eye affecting any part of the globe traversed by the fissure, from the iris to the optic nerve, including the ciliary body, retina, and choroid. Coloboma is also frequently associated with small (microphthalmic) or absent (anophthalmic) eyes as part of an interrelated spectrum of developmental eye anomalies, and can affect either one or both eyes (summary by Kelberman et al., 2014). For a discussion of genetic heterogeneity of ocular coloboma, see 120200.
mental retardation with language impairment and with or without autistic features
MedGen UID:
862201
Concept ID:
C4013764
Disease or Syndrome
Mental retardation with language impairment and with or without autistic features is a neurodevelopmental disorder characterized by global developmental delay with moderate to severe speech delay that particularly affects expressive speech. Most patients have articulation defects, but frank verbal dyspraxia is not observed. Common dysmorphic features include broad forehead, downslanting palpebral fissures, short nose with broad tip, relative macrocephaly, frontal hair upsweep, and prominent digit pads. Gross motor skills are also delayed. Some patients have autistic features and/or behavioral problems. All reported cases have occurred de novo (review by Le Fevre et al., 2013).
spinocerebellar ataxia, autosomal recessive 16
MedGen UID:
862698
Concept ID:
C4014261
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-16 (SCAR16) is a progressive neurologic disorder characterized by truncal and limb ataxia, resulting in gait instability, associated with cerebellar atrophy on brain imaging. Most patients have onset in the teenage years, although earlier and later onset have been reported. Additional features may include dysarthria, nystagmus, hyperreflexia of the lower limbs, and mild peripheral sensory neuropathy. Some patients have gonadal dysfunction or hypogonadism and/or cognitive deficits. The phenotype represents a spectrum or continuum of neurodegenerative features that may overlap with those of SCA48 (summary by Shi et al., 2013 and Ravel et al., 2021).
short stature with microcephaly and distinctive facies
MedGen UID:
862776
Concept ID:
C4014339
Disease or Syndrome
Short stature with microcephaly and distinctive facies is characterized by pre- or postnatal growth retardation, frontal bossing, high forehead, sparse hair and eyebrows, and telecanthus. Patients also show skin dyspigmentation, with hyper- and/or hypopigmented areas (Leduc et al., 2016).
pontocerebellar hypoplasia, type 10
MedGen UID:
862784
Concept ID:
C4014347
Disease or Syndrome
Pontocerebellar hypoplasia type 10 is an autosomal recessive neurodevelopmental and neurodegenerative disorder characterized by severely delayed psychomotor development, progressive microcephaly, spasticity, seizures, and brain abnormalities, including brain atrophy and delayed myelination. Some patients have dysmorphic features and an axonal sensorimotor neuropathy (summary by Karaca et al., 2014 and Schaffer et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1 (607596).
mitochondrial complex iii deficiency, nuclear type 8
MedGen UID:
862877
Concept ID:
C4014440
Disease or Syndrome
Mitochondrial complex III deficiency, nuclear type 8, is an autosomal recessive disorder characterized by progressive neurodegeneration with onset in childhood. Affected individuals may have normal or delayed early development, and often have episodic acute neurologic decompensation and regression associated with febrile illnesses. The developmental regression results in variable intellectual disability and motor deficits, such as hypotonia, axial hypertonia, and spasticity; some patients may lose the ability to walk independently. Laboratory studies show increased serum lactate and isolated deficiency of mitochondrial complex III in skeletal muscle and fibroblasts. Brain imaging shows a characteristic pattern of multifocal small cystic lesions in the periventricular and deep cerebral white matter (summary by Dallabona et al., 2016). For a discussion of genetic heterogeneity of mitochondrial complex III deficiency, see MC3DN1 (124000).
microphthalmia/coloboma and skeletal dysplasia syndrome
MedGen UID:
862977
Concept ID:
C4014540
Disease or Syndrome
Colobomatous microphthalmia-rhizomelic dysplasia syndrome is a rare, genetic developmental defect during embryogenesis characterized by a range of developmental eye anomalies (including anophthalmia, microphthalmia, colobomas, microcornea, corectopia, cataract) and symmetric limb rhizomelia with short stature and contractures of large joints. Intellectual disability with autistic features, macrocephaly, dysmorphic features, urogenital anomalies (hypospadia, cryptorchidism), cutaneous syndactyly and precocious puberty may also be present.
leukoencephalopathy, progressive, with ovarian failure
MedGen UID:
863025
Concept ID:
C4014588
Disease or Syndrome
Progressive leukoencephalopathy with ovarian failure is an autosomal recessive neurodegenerative disorder characterized by loss of motor and cognitive skills, usually with onset in young adulthood. Some patients may have a history of delayed motor development or learning difficulties in early childhood. Neurologic decline is severe, usually resulting in gait difficulties, ataxia, spasticity, and cognitive decline and dementia. Most patients lose speech and become wheelchair-bound or bedridden. Brain MRI shows progressive white matter signal abnormalities in the deep white matter. Affected females develop premature ovarian failure (summary by Dallabona et al., 2014).
poretti-boltshauser syndrome
MedGen UID:
863258
Concept ID:
C4014821
Disease or Syndrome
Poretti-Boltshauser syndrome is an autosomal recessive disorder characterized by cerebellar dysplasia, cerebellar vermis hypoplasia, cerebellar cysts in most patients, high myopia, variable retinal dystrophy, and eye movement abnormalities. Affected individuals have delayed motor development and often have speech delay. Cognitive function can range from normal to intellectually disabled (summary by Aldinger et al., 2014).
cone-rod dystrophy 20
MedGen UID:
863293
Concept ID:
C4014856
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.\n\nThe 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).\n\nThere 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.
cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia
MedGen UID:
863379
Concept ID:
C4014942
Disease or Syndrome
CAGSSS, which comprises cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia, is an autosomal recessive multisystemic disorder with a highly variable phenotypic spectrum. Not all of these features are always present, and almost all the features may present at different times and/or become more apparent with age. The skeletal features are consistent with spondyloepimetaphyseal dysplasia (SEMD) (summary by Vona et al., 2018). One family had a distinctive presentation with infantile-onset intractable seizures and cortical abnormalities reminiscent of Leigh syndrome (see 256000). The correlation between genotype and phenotype remains unclear, but since the IARS2 gene is involved in mitochondrial function, heterogeneous manifestations can be expected (Takezawa et al., 2018).
primary autosomal recessive microcephaly 13
MedGen UID:
863517
Concept ID:
C4015080
Disease or Syndrome
episodic ataxia, type 8
MedGen UID:
863545
Concept ID:
C4015108
Disease or Syndrome
A rare hereditary ataxia characterized by recurrent episodes of ataxia with variable frequency and duration, associated with slurred speech, generalized muscle weakness and balance disturbance. Other symptoms may occur between episodes, including intention tremor, gait ataxia, mild dysarthria, myokymia, migraine and nystagmus.
perrault syndrome 5
MedGen UID:
863744
Concept ID:
C4015307
Disease or Syndrome
Perrault syndrome is characterized by sensorineural hearing loss (SNHL) in males and females and ovarian dysfunction in females. SNHL is bilateral and ranges from profound with prelingual (congenital) onset to moderate with early-childhood onset. When onset is in early childhood, hearing loss can be progressive. Ovarian dysfunction ranges from gonadal dysgenesis (absent or streak gonads) manifesting as primary amenorrhea to primary ovarian insufficiency (POI) defined as cessation of menses before age 40 years. Fertility in affected males is reported as normal (although the number of reported males is limited). Neurologic features described in some individuals with Perrault syndrome include learning difficulties and developmental delay, cerebellar ataxia, and motor and sensory peripheral neuropathy.
leukodystrophy, hypomyelinating, 9
MedGen UID:
863760
Concept ID:
C4015323
Disease or Syndrome
Hypomyelinating leukodystrophy-9 is an autosomal recessive neurologic disorder characterized by onset of delayed psychomotor development, spasticity, and nystagmus in the first year of life. Additional neurologic features such as ataxia and abnormal movements may also occur. Brain imaging shows diffuse hypomyelination affecting all regions of the brain (summary by Wolf et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of HLD, see 312080.
mental retardation, autosomal dominant 31
MedGen UID:
863794
Concept ID:
C4015357
Disease or Syndrome
PURA-related neurodevelopmental disorders include PURA syndrome, caused by a heterozygous pathogenic sequence variant in PURA, and 5q31.3 deletion syndrome, caused by a genomic 5q31.3 deletion encompassing all or part of PURA. PURA-related neurodevelopmental disorders are characterized by moderate-to-severe neurodevelopmental delay with absence of speech in most and lack of independent ambulation in many. Early-onset problems can include hypotonia, hypothermia, hypersomnolence, feeding difficulties, excessive hiccups, recurrent central and obstructive apneas, epileptic seizures, abnormal nonepileptic movements (dystonia, dyskinesia, and dysconjugate eye movements), and abnormal vision. Congenital heart defects, urogenital malformations, skeletal abnormalities, and endocrine disorders occur, but are less common.
spinocerebellar ataxia, autosomal recessive 18
MedGen UID:
863942
Concept ID:
C4015505
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-18 is a neurologic disorder characterized by delayed psychomotor development, severely impaired gait due to cerebellar ataxia, ocular movement abnormalities, and intellectual disability. Brain imaging shows progressive cerebellar atrophy (summary by Hills et al., 2013).
combined oxidative phosphorylation deficiency 24
MedGen UID:
864080
Concept ID:
C4015643
Disease or Syndrome
Combined oxidative phosphorylation deficiency-24 (COXPD24) is an autosomal recessive mitochondrial disorder with wide phenotypic variability. Most patients present in infancy with delayed neurodevelopment, refractory seizures, hypotonia, and hearing impairment due to auditory neuropathy. Less common features may include cortical blindness, renal dysfunction, and/or liver involvement, suggestive of Alpers syndrome (MTDPS4A; 203700). Patients with the severe phenotype tend to have brain abnormalities on imaging, including cerebral atrophy and hyperintensities in the basal ganglia and brainstem, consistent with Leigh syndrome. Laboratory values may be normal or show increased lactate and evidence of mitochondrial respiratory chain defects, particularly in muscle. Some patients achieve little developmental milestones and may die in infancy or early childhood. However, some patients have a less severe phenotype manifest only by myopathy (summary by Sofou et al., 2015, Vanlander et al., 2015, and Mizuguchi et al., 2017). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).
congenital stationary night blindness, type 2b
MedGen UID:
874422
Concept ID:
C4041558
Disease or Syndrome
Congenital nonprogressive cone-rod synaptic disorder is characterized by stable low vision, nystagmus, photophobia, a normal or near-normal fundus appearance, and no night blindness. Electroretinography shows an electronegative waveform response to scotopic bright flash, near-normal to subnormal rod function, and delayed and/or decreased to nonrecordable cone responses (Traboulsi, 2013; Khan, 2014).
joubert syndrome 24
MedGen UID:
905319
Concept ID:
C4084841
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 26
MedGen UID:
900415
Concept ID:
C4084843
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.
leukodystrophy, hypomyelinating, 13
MedGen UID:
896545
Concept ID:
C4225170
Disease or Syndrome
Hypomyelinating leukodystrophy-13 is an autosomal recessive neurodegenerative disorder characterized by infantile onset of delayed psychomotor development, axial hypotonia, and spasticity associated with delayed myelination and periventricular white matter abnormalities on brain imaging. More variable neurologic deficits, such as visual impairment, may also occur. Some patients may experience cardiac failure during acute illness (summary by Edvardson et al., 2016). For a general phenotypic description and a discussion of genetic heterogeneity of HLD, see 312080.
spasticity, childhood-onset, with hyperglycinemia
MedGen UID:
905660
Concept ID:
C4225178
Disease or Syndrome
Childhood-onset spasticity with hyperglycinemia is an autosomal recessive disorder characterized by onset of slowly progressive spasticity that results in impaired gait in the first decade of life. Imaging of the central nervous system shows leukodystrophy and/or lesions in the upper spinal cord. More variable features include visual defects and mild learning disabilities. Serum glycine is increased, but CSF glycine is only mildly increased or normal; serum lactate is normal. The disorder represents a form of 'variant' nonketotic hyperglycinemia and is distinct from classic nonketotic hyperglycinemia (NKH, or GCE; 605899), which is characterized by significantly increased CSF glycine. Several forms of 'variant' NKH, including SPAHGC, appear to result from defects of mitochondrial lipoate biosynthesis (summary by Baker et al., 2014).
hypotonia, infantile, with psychomotor retardation and characteristic facies 2
MedGen UID:
907651
Concept ID:
C4225203
Disease or Syndrome
UNC80 deficiency is characterized by hypotonia, strabismus, oral motor dysfunction, postnatal growth deficiency, and developmental delay. The majority of individuals do not learn to walk. All individuals lack expressive language; however, many have expressive body language, and a few have used signs to communicate. Seizures may develop during infancy or childhood. Additional features can include nystagmus, extremity hypertonia, a high-pitched cry, repetitive and self-stimulatory behaviors, constipation, clubfeet, joint contractures, and scoliosis. For most individuals the UNC80 deficiency syndrome is not progressive. Individuals have slow acquisition of skills and do not have a loss of skills suggestive of neurodegeneration.
leukodystrophy and acquired microcephaly with or without dystonia
MedGen UID:
908888
Concept ID:
C4225213
Disease or Syndrome
optic atrophy 10 with or without ataxia, mental retardation, and seizures
MedGen UID:
905727
Concept ID:
C4225227
Disease or Syndrome
slc39a8-cdg
MedGen UID:
899837
Concept ID:
C4225234
Disease or Syndrome
Congenital disorder of glycosylation type IIn (CDG2N) is an autosomal recessive severe multisystem developmental disorder characterized by delayed psychomotor development apparent from infancy, hypotonia, and variable additional features, such as short stature, seizures, visual impairment, and cerebellar atrophy. Serum transferrin analysis shows a CDG type II pattern (summary by Boycott et al., 2015 and Park et al., 2015). For a discussion of genetic heterogeneity of CDG type II, see CDG2A (212066).
spastic paraplegia 75, autosomal recessive
MedGen UID:
896387
Concept ID:
C4225250
Disease or Syndrome
Spastic paraplegia-75 is an autosomal recessive, slowly progressive neurodegenerative disorder characterized by onset of spastic paraplegia and cognitive impairment in childhood (summary by Lossos et al., 2015). For a discussion of genetic heterogeneity of autosomal recessive SPG, see SPG5A (270800).
senior-loken syndrome 9
MedGen UID:
899086
Concept ID:
C4225263
Disease or Syndrome
Senior-Loken syndrome-9 is an autosomal recessive disorder characterized by early-onset nephronophthisis and pigmentary retinopathy. Additional more variable features can include liver defects, skeletal anomalies, and obesity (summary by Bizet et al., 2015). For a phenotypic description and a discussion of genetic heterogeneity of Senior-Loken syndrome, see 266900.
epilepsy, hearing loss, and mental retardation syndrome
MedGen UID:
895574
Concept ID:
C4225276
Disease or Syndrome
Epilepsy, hearing loss, and mental retardation syndrome is an autosomal recessive disorder characterized by severe neurologic impairment including intellectual disability, intractable epilepsy, microcephaly, abnormal muscle tone, and sensorineural hearing loss. Most affected individuals are nonambulatory, cannot sit unassisted, and have no speech development. More variable features include feeding difficulties, poor growth, cortical visual impairment, spasticity, scoliosis, immunodeficiency, and thrombocytopenia (summary by Tanaka et al., 2015).
short stature, microcephaly, and endocrine dysfunction
MedGen UID:
895448
Concept ID:
C4225288
Disease or Syndrome
In patients with SSMED, short stature and microcephaly are apparent at birth, and there is progressive postnatal growth failure. Endocrine dysfunction, including hypergonadotropic hypogonadism, multinodular goiter, and diabetes mellitus, is present in affected adults. Progressive ataxia has been reported in some patients, with onset ranging from the second to fifth decade of life. In addition, a few patients have developed tumors, suggesting that there may be a predisposition to tumorigenesis. In contrast to syndromes involving defects in other components of the nonhomologous end-joining (NHEJ) complex (see, e.g., 606593), no clinically overt immunodeficiency has been observed in SSMED, although laboratory analysis has revealed lymphopenia or borderline leukopenia in some patients (Murray et al., 2015; Bee et al., 2015; de Bruin et al., 2015; Guo et al., 2015).
achromatopsia 7
MedGen UID:
904646
Concept ID:
C4225297
Disease or Syndrome
Achromatopsia is characterized by reduced visual acuity, pendular nystagmus, increased sensitivity to light (photophobia), a small central scotoma, eccentric fixation, and reduced or complete loss of color discrimination. All individuals with achromatopsia (achromats) have impaired color discrimination along all three axes of color vision corresponding to the three cone classes: the protan or long-wavelength-sensitive cone axis (red), the deutan or middle-wavelength-sensitive cone axis (green), and the tritan or short-wavelength-sensitive cone axis (blue). Most individuals have complete achromatopsia, with total lack of function of all three types of cones. Rarely, individuals have incomplete achromatopsia, in which one or more cone types may be partially functioning. The manifestations are similar to those of individuals with complete achromatopsia, but generally less severe. Hyperopia is common in achromatopsia. Nystagmus develops during the first few weeks after birth followed by increased sensitivity to bright light. Best visual acuity varies with severity of the disease; it is 20/200 or less in complete achromatopsia and may be as high as 20/80 in incomplete achromatopsia. Visual acuity is usually stable over time; both nystagmus and sensitivity to bright light may improve slightly. Although the fundus is usually normal, macular changes (which may show early signs of progression) and vessel narrowing may be present in some affected individuals. Defects in the macula are visible on optical coherence tomography.
neuropathy, hereditary motor and sensory, type 6b
MedGen UID:
895482
Concept ID:
C4225302
Disease or Syndrome
Hereditary motor and sensory neuropathy type VIB is an autosomal recessive complex progressive neurologic disorder characterized mainly by early-onset optic atrophy resulting in progressive visual loss and peripheral axonal sensorimotor neuropathy with highly variable age at onset and severity. Affected individuals may also have cerebellar or pontocerebellar atrophy on brain imaging, and they may show abnormal movements such as ataxia, dysmetria, and myoclonus (summary by Abrams et al., 2015). For a general phenotypic description and a discussion of genetic heterogeneity of HMSN6, see HMSN6A (601152).
leukodystrophy, hypomyelinating, 10
MedGen UID:
904191
Concept ID:
C4225332
Disease or Syndrome
Hypomyelinating leukodystrophy-10 is an autosomal recessive neurologic disorder characterized by postnatal progressive microcephaly, severely delayed psychomotor development, and hypomyelination on brain imaging (summary by Nakayama et al., 2015). For a general phenotypic description and a discussion of genetic heterogeneity of HLD, see 312080.
multiple mitochondrial dysfunctions syndrome 4
MedGen UID:
899010
Concept ID:
C4225348
Disease or Syndrome
Infants with ISCA2-related mitochondrial disorder (IRMD) typically attain normal development in the first months of life. At age three to seven months, affected individuals usually present with a triad of neurodevelopmental regression, nystagmus with optic atrophy, and diffuse white matter disease. As the disease progresses, global psychomotor regression continues at a variable pace and seizures may develop. Affected children become vegetative within one to two years. During their vegetative state, which may persist for years, affected individuals are prone to recurrent chest infections that may require ventilator support. Most affected individuals die during early childhood.
spinocerebellar ataxia, autosomal recessive 20
MedGen UID:
903867
Concept ID:
C4225355
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-20 is a neurodevelopmental disorder characterized by severely delayed psychomotor development with poor or absent speech, wide-based or absent gait, coarse facies, and cerebellar atrophy (summary by Thomas et al., 2014).
epileptic encephalopathy, early infantile, 29
MedGen UID:
908570
Concept ID:
C4225361
Disease or Syndrome
Developmental and epileptic encephalopathy-29 (DEE29) is an autosomal recessive neurologic disorder characterized by the onset of refractory myoclonic seizures in the first months of life. Affected individuals have poor overall growth, congenital microcephaly with cerebral atrophy and impaired myelination on brain imaging, spasticity with abnormal movements, peripheral neuropathy, and poor visual fixation (summary by Simons et al., 2015). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
microcephaly and chorioretinopathy, autosomal recessive, 3
MedGen UID:
902924
Concept ID:
C4225362
Disease or Syndrome
lichtenstein-knorr syndrome
MedGen UID:
898996
Concept ID:
C4225383
Disease or Syndrome
Lichtenstein-Knorr syndrome is an autosomal recessive neurologic disorder characterized by postnatal onset of severe progressive sensorineural hearing loss and progressive cerebellar ataxia. Features usually develop in childhood or young adulthood (summary by Guissart et al., 2015). Some patients with SLC9A1 mutations may not have deafness (Iwama et al., 2018)
mitochondrial short-chain enoyl-coa hydratase 1 deficiency
MedGen UID:
902729
Concept ID:
C4225391
Disease or Syndrome
Mitochondrial short-chain enoyl-CoA hydratase 1 deficiency (ECHS1D) represents a clinical spectrum in which several phenotypes have been described: The most common phenotype presents in the neonatal period with severe encephalopathy and lactic acidosis and later manifests Leigh-like signs and symptoms. Those with presentation in the neonatal period typically have severe hypotonia, encephalopathy, or neonatal seizures within the first few days of life. Signs and symptoms typically progress quickly and the affected individual ultimately succumbs to central apnea or arrhythmia. A second group of affected individuals present in infancy with developmental regression resulting in severe developmental delay. A third group of affected individuals have normal development with isolated paroxysmal dystonia that may be exacerbated by illness or exertion. Across all three groups, T2 hyperintensity in the basal ganglia is very common, and may affect any part of the basal ganglia.
spondyloocular syndrome, autosomal recessive
MedGen UID:
900371
Concept ID:
C4225412
Disease or Syndrome
Spondylo-ocular syndrome is a very rare association of spinal and ocular manifestations that is characterized by dense cataracts, and retinal detachment along with generalized osteoporosis and platyspondyly. Mild craniofacial dysphormism has been reported including short neck, large head and prominent eyebrows.
mental retardation, x-linked, syndromic 33
MedGen UID:
895979
Concept ID:
C4225418
Disease or Syndrome
X-linked syndromic mental retardation-33 is an X-linked recessive neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, and characteristic facial features (summary by O'Rawe et al., 2015).
linear skin defects with multiple congenital anomalies 3
MedGen UID:
906997
Concept ID:
C4225421
Disease or Syndrome
Microphthalmia with linear skin defects (MLS) syndrome is characterized by unilateral or bilateral microphthalmia and/or anophthalmia and linear skin defects, usually involving the face and neck, which are present at birth and heal with age, leaving minimal residual scarring. Other findings can include a wide variety of other ocular abnormalities (e.g., corneal anomalies, orbital cysts, cataracts), central nervous system involvement (e.g., structural anomalies, developmental delay, infantile seizures), cardiac concerns (e.g., hypertrophic or oncocytic cardiomyopathy, atrial or ventricular septal defects, arrhythmias), short stature, diaphragmatic hernia, nail dystrophy, hearing impairment, and genitourinary malformations. Inter- and intrafamilial variability is described.
colobomatous optic disc-macular atrophy-chorioretinopathy syndrome
MedGen UID:
894574
Concept ID:
C4225424
Disease or Syndrome
sialidosis type 2
MedGen UID:
924303
Concept ID:
C4282398
Disease or Syndrome
Sialidosis is an autosomal recessive disorder characterized by the progressive lysosomal storage of sialylated glycopeptides and oligosaccharides caused by a deficiency of the enzyme neuraminidase. Common to the sialidoses is the accumulation and/or excretion of sialic acid (N-acetylneuraminic acid) covalently linked ('bound') to a variety of oligosaccharides and/or glycoproteins (summary by Lowden and O'Brien, 1979). The sialidoses are distinct from the sialurias in which there is storage and excretion of 'free' sialic acid, rather than 'bound' sialic acid; neuraminidase activity in sialuria is normal or elevated. Salla disease (604369) is a form of 'free' sialic acid disease. Classification Lowden and O'Brien (1979) provided a logical nosology of neuraminidase deficiency into sialidosis type I and type II. Type I is the milder form, also known as the 'normosomatic' type or the cherry red spot-myoclonus syndrome. Sialidosis type II is the more severe form with an earlier onset, and is also known as the 'dysmorphic' type. Type II has been subdivided into juvenile and infantile forms. Other terms for sialidosis type II are mucolipidosis I and lipomucopolysaccharidosis.
spastic paraplegia, intellectual disability, nystagmus, and obesity
MedGen UID:
924883
Concept ID:
C4284592
Disease or Syndrome
Spastic paraplegia, intellectual disability, nystagmus, and obesity (SINO) is an autosomal dominant neurologic disorder characterized by rapid growth in infancy, global developmental delay, spastic paraplegia, variable ophthalmologic defects, and dysmorphic facial features (summary by Josifova et al., 2016).
mucopolysaccharidosis-plus syndrome
MedGen UID:
934594
Concept ID:
C4310627
Disease or Syndrome
MPSPS is an autosomal recessive inborn error of metabolism resulting in a multisystem disorder with features of the mucopolysaccharidosis lysosomal storage diseases (see, e.g., 607016). Patients present in infancy or early childhood with respiratory difficulties, cardiac problems, anemia, dysostosis multiplex, renal involvement, coarse facies, and delayed psychomotor development. Most patients die of cardiorespiratory failure in the first years of life (summary by Kondo et al., 2017).
dystonia, childhood-onset, with optic atrophy and basal ganglia abnormalities
MedGen UID:
934601
Concept ID:
C4310634
Disease or Syndrome
MECR-related neurologic disorder is characterized by a progressive childhood-onset movement disorder and optic atrophy; intellect is often – but not always – preserved. The movement disorder typically presents between ages one and 6.5 years and is mainly dystonia that can be accompanied by chorea and/or ataxia. Over time some affected individuals require assistive devices for mobility. Speech fluency and intelligibility are progressively impaired due to dysarthria. Optic atrophy typically develops between ages four and 12 years and manifests as reduced visual acuity, which can include functional blindness (also known as legal blindness) in adulthood. Because only 13 affected individuals are known to the authors, and because nearly half of them were diagnosed retrospectively as adults, the natural history of disease progression and other aspects of the phenotype have not yet been completely defined.
neurodevelopmental disorder with hypotonia, seizures, and absent language
MedGen UID:
934610
Concept ID:
C4310643
Disease or Syndrome
myasthenic syndrome, congenital, 21, presynaptic
MedGen UID:
934621
Concept ID:
C4310654
Disease or Syndrome
myoclonus, intractable, neonatal
MedGen UID:
934625
Concept ID:
C4310658
Disease or Syndrome
Neonatal intractable myoclonus is a severe neurologic disorder characterized by the onset of intractable myoclonic seizures soon after birth. Affected infants have intermittent apnea, abnormal eye movements, pallor of the optic nerve, and lack of developmental progress. Brain imaging shows a progressive leukoencephalopathy. Some patients may die in infancy. There is phenotypic and biochemical evidence of mitochondrial dysfunction (summary by Duis et al., 2016).
spastic paraplegia 78, autosomal recessive
MedGen UID:
934629
Concept ID:
C4310662
Disease or Syndrome
Autosomal recessive spastic paraplegia-78 is an adult-onset neurodegenerative disorder characterized predominantly by spasticity and muscle weakness of the lower limbs, resulting in gait difficulties and loss of ambulation in some patients. Affected individuals also have cerebellar signs, such as dysarthria, oculomotor disturbances, and limb and gait ataxia; brain imaging shows cerebellar atrophy. Some patients may have mild cognitive impairment or frank dementia. The phenotype is highly variable (summary by Estrada-Cuzcano et al., 2017). Biallelic mutation in the ATP13A2 gene also causes Kufor-Rakeb syndrome (KRS; 606693), a neurodegenerative disorder with overlapping features. Patients with KRS have earlier onset and prominent parkinsonism. Loss of ATP13A2 function results in a multidimensional spectrum of neurologic features reflecting various regions of the brain and nervous system, including cortical, pyramidal, extrapyramidal, brainstem, cerebellar, and peripheral (summary by Estrada-Cuzcano et al., 2017).
encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy 1
MedGen UID:
934642
Concept ID:
C4310675
Disease or Syndrome
Early-onset progressive encephalopathy with brain edema and/or leukoencephalopathy-1 (PEBEL1) is an autosomal recessive severe neurometabolic disorder characterized by rapidly progressive neurologic deterioration that is usually associated with a febrile illness. Affected infants tend to show normal early development followed by acute psychomotor regression with ataxia, hypotonia, respiratory insufficiency, and seizures, resulting in coma and death in the first years of life. Brain imaging shows multiple abnormalities, including brain edema and signal abnormalities in the cortical and subcortical regions (summary by Kremer et al., 2016). Genetic Heterogeneity of PEBEL See also PEBEL2 (618321), caused by mutation in the NAXD gene (615910) on chromosome 13q34.
harel-yoon syndrome
MedGen UID:
934644
Concept ID:
C4310677
Disease or Syndrome
Harel-Yoon syndrome is a syndromic neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, truncal hypotonia, spasticity, and peripheral neuropathy. Other more variable features such as optic atrophy may also occur. Laboratory studies in some patients show evidence of mitochondrial dysfunction (summary by Harel et al., 2016).
intellectual developmental disorder with cardiac arrhythmia
MedGen UID:
934649
Concept ID:
C4310682
Disease or Syndrome
Intellectual developmental disorder with cardiac arrhythmia is an autosomal recessive multisystem disorder characterized by delayed psychomotor development, severe intellectual disability with poor or absent speech, and bradycardia and/or cardiac sinus arrhythmias. Additional features include visual abnormalities, seizures, hypotonia, and gastric reflux (summary by Lodder et al., 2016).
neurodegeneration with ataxia, dystonia, and gaze palsy, childhood-onset
MedGen UID:
934660
Concept ID:
C4310693
Disease or Syndrome
Childhood-onset neurodegeneration with ataxia, dystonia, and gaze palsy is an autosomal recessive progressive disorder characterized by onset of gait ataxia, cognitive decline, and gaze palsy in the first or second decades. Additional features include dysarthria, dystonia, and athetoid movements. Some patients may become wheelchair-bound as young adults (summary by Haack et al., 2016).
spinocerebellar ataxia, autosomal recessive 24
MedGen UID:
934666
Concept ID:
C4310699
Disease or Syndrome
joubert syndrome 28
MedGen UID:
934672
Concept ID:
C4310705
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 27
MedGen UID:
934673
Concept ID:
C4310706
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.
epileptic encephalopathy, early infantile, 42
MedGen UID:
934683
Concept ID:
C4310716
Disease or Syndrome
Developmental and epileptic encephalopathy-42 (DEE42) is a neurologic disorder characterized by the onset of various types of seizures in the first hours or days of life, although rare patients may have onset in the first weeks of life. The seizures tend to be refractory and associated with EEG abnormalities, including multifocal spikes and generalized spike-wave complexes. Affected infants show global developmental delay with severely impaired intellectual development. Other features may include axial hypotonia, peripheral hypertonia with hyperreflexia, tremor, ataxia, and abnormal eye movements (summary by the Epi4K Consortium, 2016). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
hermansky-pudlak syndrome 10
MedGen UID:
934713
Concept ID:
C4310746
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
spinocerebellar ataxia 43
MedGen UID:
934730
Concept ID:
C4310763
Disease or Syndrome
Spinocerebellar ataxia-43 is an autosomal dominant, slowly progressive neurologic disorder characterized by adult-onset gait and limb ataxia and often associated with peripheral neuropathy mainly affecting the motor system, although some patients may have distal sensory impairment (summary by Depondt et al., 2016). For a general discussion of autosomal dominant spinocerebellar ataxia, see SCA1 (164400).
cerebral palsy, spastic quadriplegic, 3
MedGen UID:
934734
Concept ID:
C4310767
Disease or Syndrome
epileptic encephalopathy, early infantile, 37
MedGen UID:
934737
Concept ID:
C4310770
Disease or Syndrome
Developmental and epileptic encephalopathy-37 (DEE37) is an autosomal recessive epileptic-dyskinetic neurologic disorder characterized by the onset of intractable seizures or abnormal movements in the first months or years of life. Patients typically have normal or only mildly delayed development in early infancy, but then show developmental regression and stagnation after the onset of seizures, which can occur between about 6 months to 2 years of age. In addition to epileptic encephalopathy, affected individuals also manifest a hyperkinetic movement disorder with choreoathetosis, spasticity, and rigidity. There is severely impaired intellectual development and function, loss of verbal skills with absent speech, and impaired volitional movements (summary by Madeo et al., 2016). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
mental retardation, autosomal dominant 42
MedGen UID:
934741
Concept ID:
C4310774
Disease or Syndrome
GNB1 encephalopathy (GNB1-E) is characterized by moderate-to-severe developmental delay / intellectual disability, structural brain abnormalities, and often infantile hypotonia and seizures. Other less common findings include dystonia, reduced vision, behavior issues, growth delay, gastrointestinal (GI) problems, genitourinary (GU) abnormalities in males, and cutaneous mastocytosis.
spinocerebellar ataxia, autosomal recessive 22
MedGen UID:
934748
Concept ID:
C4310781
Disease or Syndrome
trichothiodystrophy 6, nonphotosensitive
MedGen UID:
934752
Concept ID:
C4310785
Disease or Syndrome
spastic paraplegia 76, autosomal recessive
MedGen UID:
934767
Concept ID:
C4310800
Disease or Syndrome
Spastic paraplegia-76 is an autosomal recessive neurologic disorder characterized by young-adult onset of slowly progressive spasticity of the lower limbs resulting in gait difficulties. Most affected individuals have upper limb involvement and additional features such as foot deformities and dysarthria. Cognition is unaffected (summary by Gan-Or et al., 2016). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive spastic paraplegia, see SPG5A (270800).
witteveen-kolk syndrome
MedGen UID:
934771
Concept ID:
C4310804
Disease or Syndrome
15q24 microdeletion is a chromosomal change in which a small piece of chromosome 15 is deleted in each cell. The deletion occurs on the long (q) arm of the chromosome at a position designated q24.\n\n15q24 microdeletion is associated with mild to moderate intellectual disability and delayed speech development. Other common signs and symptoms include short stature, weak muscle tone (hypotonia), and skeletal abnormalities including loose (lax) joints. Affected males may have genital abnormalities, which can include an unusually small penis (micropenis) and the opening of the urethra on the underside of the penis (hypospadias). Affected individuals also have distinctive facial features such as a high front hairline, broad eyebrows, widely set eyes (hypertelorism), outside corners of the eyes that point downward (downslanting palpebral fissures), a broad nasal bridge, a full lower lip, and a long, smooth space between the upper lip and nose (philtrum).
mental retardation, x-linked 104
MedGen UID:
934784
Concept ID:
C4310817
Disease or Syndrome
congenital disorder of glycosylation type 1q
MedGen UID:
1392124
Concept ID:
C4317224
Disease or Syndrome
A rare, non X-linked congenital disorder of glycosylation due to steroid 5 alpha reductase type 3 deficiency with a highly variable phenotype. The disease typically presents with severe visual impairment, variable ocular anomalies (such as optic nerve hypoplasia/atrophy, iris and optic nerve coloboma, congenital cataract, glaucoma), intellectual disability, cerebellar abnormalities, nystagmus, hypotonia, ataxia, and/or ichthyosiform skin lesions. Other reported manifestations include retinitis pigmentosa, kyphosis, congenital heart defects, hypertrichosis and abnormal coagulation. Caused by homozygous or compound heterozygous mutation in the SRD5A3 gene on chromosome 4q12.
intellectual disability, x-linked 106
MedGen UID:
1389156
Concept ID:
C4478379
Mental or Behavioral Dysfunction
congenital heart defects and ectodermal dysplasia
MedGen UID:
1387409
Concept ID:
C4479250
Disease or Syndrome
peroxisome biogenesis disorder 10b
MedGen UID:
1379481
Concept ID:
C4479254
Disease or Syndrome
hyperphenylalaninemia, mild, non-bh4-deficient
MedGen UID:
1391882
Concept ID:
C4479270
Disease or Syndrome
Mild non-BH4-deficient hyperphenylalaninemia (HPANBH4) is an autosomal recessive disorder characterized by increased serum phenylalanine (HPA) usually detected by newborn screening and associated with highly variable neurologic defects, including movement abnormalities, such as dystonia, and variably impaired intellectual development. Laboratory analysis shows dopamine and serotonin deficiencies in the cerebrospinal fluid, and normal tetrahydrobiopterin (BH4) metabolism. Evidence suggests that treatment with BH4 and neurotransmitter precursors can lead to clinical improvement or even prevent the neurologic defects if started in infancy (summary by Anikster et al., 2017). The phenotype is highly variable: some patients may present with later onset of juvenile or young adult nonprogressive dopa-responsive parkinsonism reminiscent of early-onset Parkinson disease (168600). These patients benefit from treatment with L-dopa (summary by Straniero et al., 2017). In a review of HPA, Blau et al. (2018) noted that molecular screening for DNAJC12 mutations should be mandatory in patients in whom deficiencies of PAH (612349) and BH4 metabolism have been excluded.
autosomal recessive cutis laxa type 2c
MedGen UID:
1385755
Concept ID:
C4479387
Disease or Syndrome
Autosomal recessive cutis laxa type IIC (ARCL2C) is characterized by generalized skin wrinkling with sparse subcutaneous fat and dysmorphic progeroid facial features. Most patients also exhibit severe hypotonia as well as cardiovascular involvement (summary by Van Damme et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal recessive cutis laxa, see ARCL1A (219100).
stankiewicz-isidor syndrome
MedGen UID:
1375936
Concept ID:
C4479599
Disease or Syndrome
Stankiewicz-Isidor syndrome (STISS) is a neurodevelopmental disorder characterized by delayed psychomotor development, intellectual disability, behavioral disorders, mild craniofacial anomalies, and variable congenital defects of the cardiac and/or urogenital systems (summary by Kury et al., 2017).
neurodevelopmental disorder with midbrain and hindbrain malformations
MedGen UID:
1385580
Concept ID:
C4479613
Disease or Syndrome
neurodevelopmental disorder with progressive microcephaly, spasticity, and brain anomalies
MedGen UID:
1380260
Concept ID:
C4479631
Disease or Syndrome
NDMSBA is an autosomal recessive neurodevelopmental disorder characterized by infantile onset of progressive microcephaly and spasticity and severe global developmental delay resulting in profound mental retardation and severely impaired or absent motor function. More variable features include seizures and optic atrophy. Brain imaging may show myelinating abnormalities and white matter lesions consistent with a leukoencephalopathy, as well as structural anomalies, including thin corpus callosum, gyral abnormalities, and cerebral or cerebellar atrophy. Some patients die in early childhood (summary by Falik Zaccai et al., 2017 and Hall et al., 2017).
spastic ataxia 8, autosomal recessive, with hypomyelinating leukodystrophy
MedGen UID:
1382553
Concept ID:
C4479653
Disease or Syndrome
NKX6-2-related disorder is characterized by a spectrum of progressive neurologic manifestations resulting from diffuse central nervous system hypomyelination. At the severe end of the spectrum is neonatal-onset nystagmus, severe spastic tetraplegia with joint contractures and scoliosis, and visual and hearing impairment, all of which rapidly progress resulting in death in early childhood. At the milder end of the spectrum is normal achievement of early motor milestones in the first year of life followed by slowly progressive complex spastic ataxia with pyramidal findings (spasticity with increased muscle tone and difficulty with gait and fine motor coordination) and cerebellar findings (nystagmus, extraocular movement disorder, dysarthria, titubation, and ataxia) with loss of developmental milestones. To date NKX6-2-related disorder has been reported in 25 individuals from 13 families.
spinocerebellar ataxia 38
MedGen UID:
1379865
Concept ID:
C4518337
Disease or Syndrome
Spinocerebellar ataxia type 38 (SCA38) is characterized as a pure cerebellar ataxia with symptoms typically manifesting in the fourth decade of life. The most common presenting features are nystagmus and slowly progressive gait ataxia. As the disease progresses, cerebellar symptoms (limb ataxia, dysarthria, dysphagia, diplopia on the horizontal line) may emerge, and affected individuals may experience sensory loss. In the later stages of the condition, ophthalmoparesis followed by ophthalmoplegia may occur. Features that distinguish SCA38 from other spinocerebellar ataxias include pes cavus without paresis, hyposmia, hearing loss, and anxiety disorder. Dementia and extrapyramidal signs are not common features of SCA38. Brain imaging typically demonstrates cerebellar atrophy mainly affecting the vermis without atrophy of the cerebral cortex and a normal appearance of the brain stem. With disease progression, nerve conduction velocities and electromyography demonstrate a sensory and motor axonal polyneuropathy in all four extremities. Life span is apparently not decreased.
auditory neuropathy-optic atrophy syndrome
MedGen UID:
1623572
Concept ID:
C4521678
Disease or Syndrome
ANOA is an autosomal recessive neurologic disorder characterized by onset of visual and hearing impairment in the first or second decades (summary by Paul et al., 2017).
syringomyelia, isolated
MedGen UID:
1622554
Concept ID:
C4538540
Disease or Syndrome
Syringomyelia (Greek: 'syrinx,' pipe, and 'myelos,' marrow) is a tubular cavity in the spinal cord. It can occur sporadically in association with spinal cord tumors, inflammatory arachnoiditis, or posttraumatically. It is rarely idiopathic (less than 1% of cases). The vast majority of cases of syringomyelia are cervical, noncommunicating, and associated with an abnormality at the foramen magnum, particularly the Chiari malformation type I (CM1; 118420), as well as basilar impression (109500) and Dandy-Walker malformation (220200) (Speer et al., 2003; Levine, 2004); these cases have shown familial segregation. The form of syringomyelia discussed here is 'noncommunicating' with the fourth ventricle, but may communicate with the subarachnoid space. In contrast, 'communicating' syringomyelia, or 'hydromelia,' opens rostrally into the fourth ventricle and almost always occurs in children with hydrocephalus, Chiari malformation type II (CM2; 207950), and spina bifida (see 182940) (Levine, 2004).
galloway-mowat syndrome 2, x-linked
MedGen UID:
1625619
Concept ID:
C4538784
Disease or Syndrome
Galloway-Mowat syndrome is a renal-neurologic disease characterized by early-onset nephrotic syndrome associated with microcephaly, gyral abnormalities of the brain, and delayed psychomotor development. Most patients have dysmorphic facial features, often including hypertelorism, ear abnormalities, and micrognathia. Other features, such as arachnodactyly and visual impairment, are more variable. Most patients die in the first years of life (summary by Braun et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of GAMOS, see GAMOS1 (251300).
exudative vitreoretinopathy 7
MedGen UID:
1626650
Concept ID:
C4539767
Disease or Syndrome
spinocerebellar ataxia, autosomal recessive 25
MedGen UID:
1618081
Concept ID:
C4539808
Disease or Syndrome
spinocerebellar ataxia, autosomal recessive 26
MedGen UID:
1617917
Concept ID:
C4539948
Disease or Syndrome
combined oxidative phosphorylation deficiency 32
MedGen UID:
1617600
Concept ID:
C4540029
Disease or Syndrome
Combined oxidative phosphorylation deficiency-32 is an autosomal recessive neurodegenerative disorder characterized by onset of delayed psychomotor development and developmental regression in infancy. Affected individuals have multiple variable symptoms, including poor or absent speech, inability to walk, and abnormal movements. Brain imaging shows T2-weighted abnormalities in the basal ganglia and brainstem consistent with Leigh syndrome (256000). Patient cells showed decreased activities of mitochondrial respiratory chain complexes, I, III, and IV, as well as impaired mitochondrial translation (summary by Lake et al., 2017). For a discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).
neurodevelopmental disorder, mitochondrial, with abnormal movements and lactic acidosis, with or without seizures
MedGen UID:
1619876
Concept ID:
C4540192
Disease or Syndrome
NEMMLAS is an autosomal recessive multisystemic disorder characterized by delayed psychomotor development, intellectual disability, and abnormal motor function, including hypotonia, dystonia, ataxia, and spasticity. Patient tissues may show deficiencies in one or more of the mitochondrial oxidative phosphorylation (OXPHOS) enzymes, but this is not a constant finding (summary by Wortmann et al., 2017).
joubert syndrome 32
MedGen UID:
1626697
Concept ID:
C4540342
Disease or Syndrome
JBTS32 is an autosomal recessive developmental disorder characterized by delayed psychomotor development, intellectual disability, dysmorphic facial features, and postaxial polydactyly. Brain imaging shows cerebellar abnormalities consistent with the molar tooth sign (MTS) (summary by De Mori et al., 2017). For discussion of genetic heterogeneity of Joubert syndrome, see JBTS1 (213300).
joubert syndrome 31
MedGen UID:
1618082
Concept ID:
C4540355
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.
retinitis pigmentosa-hearing loss-premature aging-short stature-facial dysmorphism syndrome
MedGen UID:
1615526
Concept ID:
C4540367
Disease or Syndrome
SHRF is an autosomal recessive disorder characterized by short stature, brachydactyly, dysmorphic facial features, hearing loss, and visual impairment. Onset of the hearing and visual abnormalities, including retinitis pigmentosa, varies from birth to the second decade. Patients have mild intellectual disability and mild cerebellar atrophy with myelination defects on brain imaging (summary by Di Donato et al., 2016).
spinocerebellar ataxia 45
MedGen UID:
1622156
Concept ID:
C4540400
Disease or Syndrome
spinocerebellar ataxia 46
MedGen UID:
1624251
Concept ID:
C4540404
Disease or Syndrome
neurodevelopmental disorder with ataxic gait, absent speech, and decreased cortical white matter
MedGen UID:
1621102
Concept ID:
C4540498
Disease or Syndrome
NDAGSCW is a neurodevelopmental disorder characterized by severely delayed psychomotor development apparent from infancy. Affected individuals have delayed and difficulty walking, intellectual disability, absent speech, and variable additional features, including hip dysplasia, tapering fingers, and seizures. Brain imaging shows decreased cortical white matter, often with decreased cerebellar white matter, thin corpus callosum, and thin brainstem (summary by Lamers et al., 2017).
glycosylphosphatidylinositol biosynthesis defect 15
MedGen UID:
1615160
Concept ID:
C4540520
Disease or Syndrome
GPIBD15 is an autosomal recessive disorder characterized by delayed psychomotor development, variable intellectual disability, hypotonia, early-onset seizures in most patients, and cerebellar atrophy, resulting in cerebellar signs including gait ataxia and dysarthria. The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis (summary by Nguyen et al., 2017). For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
sotos syndrome 1
MedGen UID:
1634368
Concept ID:
C4551477
Disease or Syndrome
Sotos syndrome is characterized by a distinctive facial appearance (broad and prominent forehead with a dolichocephalic head shape, sparse frontotemporal hair, downslanting palpebral fissures, malar flushing, long and narrow face, long chin); learning disability (early developmental delay, mild-to-severe intellectual impairment); and overgrowth (height and/or head circumference =2 SD above the mean). These three clinical features are considered the cardinal features of Sotos syndrome. Major features of Sotos syndrome include behavioral problems (most notably autistic spectrum disorder), advanced bone age, cardiac anomalies, cranial MRI/CT abnormalities, joint hyperlaxity with or without pes planus, maternal preeclampsia, neonatal complications, renal anomalies, scoliosis, and seizures.
sclerosteosis 1
MedGen UID:
1642815
Concept ID:
C4551483
Disease or Syndrome
SOST-related sclerosing bone dysplasias include sclerosteosis and van Buchem disease, both disorders of progressive bone overgrowth due to increased bone formation. The major clinical features of sclerosteosis are progressive skeletal overgrowth, most pronounced in the skull and mandible, and variable syndactyly, usually of the second (index) and third (middle) fingers. Affected individuals appear normal at birth except for syndactyly. Facial distortion due to bossing of the forehead and mandibular overgrowth is seen in nearly all individuals and becomes apparent in early childhood with progression into adulthood. Hyperostosis of the skull results in narrowing of the foramina, causing entrapment of the seventh cranial nerve (leading to facial palsy) with other, less common nerve entrapment syndromes including visual loss (2nd cranial nerve), neuralgia or anosmia (5th cranial nerve), and sensory hearing loss (8th cranial nerve). In sclerosteosis, hyperostosis of the calvarium reduces intracranial volume, increasing the risk for potentially lethal elevation of intracranial pressure. Survival of individuals with sclerosteosis into old age is unusual, but not unprecedented. The manifestations of van Buchem disease are generally milder than sclerosteosis and syndactyly is absent; life span appears to be normal.
tyrosinase-negative oculocutaneous albinism
MedGen UID:
1643910
Concept ID:
C4551504
Disease or Syndrome
Oculocutaneous albinism is a group of conditions that affect coloring (pigmentation) of the skin, hair, and eyes. Affected individuals typically have very fair skin and white or light-colored hair. Long-term sun exposure greatly increases the risk of skin damage and skin cancers, including an aggressive form of skin cancer called melanoma, in people with this condition. Oculocutaneous albinism also reduces pigmentation of the colored part of the eye (the iris) and the light-sensitive tissue at the back of the eye (the retina). People with this condition usually have vision problems such as reduced sharpness; rapid, involuntary eye movements (nystagmus); and increased sensitivity to light (photophobia).\n\nSeveral additional types of this disorder have been proposed, each affecting one or a few families.\n\nResearchers have identified multiple types of oculocutaneous albinism, which are distinguished by their specific skin, hair, and eye color changes and by their genetic cause. Oculocutaneous albinism type 1 is characterized by white hair, very pale skin, and light-colored irises. Type 2 is typically less severe than type 1; the skin is usually a creamy white color and hair may be light yellow, blond, or light brown. Type 3 includes a form of albinism called rufous oculocutaneous albinism, which usually affects dark-skinned people. Affected individuals have reddish-brown skin, ginger or red hair, and hazel or brown irises. Type 3 is often associated with milder vision abnormalities than the other forms of oculocutaneous albinism. Type 4 has signs and symptoms similar to those seen with type 2.
wolfram syndrome 1
MedGen UID:
1641635
Concept ID:
C4551693
Disease or Syndrome
WFS1 Wolfram syndrome spectrum disorder (WFS1-WSSD) is a progressive neurodegenerative disorder characterized by onset of diabetes mellitus (DM) and optic atrophy (OA) before age 16 years, and typically associated with other endocrine abnormalities, sensorineural hearing loss, and progressive neurologic abnormalities (cerebellar ataxia, peripheral neuropathy, dementia, psychiatric illness, and urinary tract atony). Although DM is mostly insulin-dependent, overall the course is milder (with lower prevalence of microvascular disease) than that seen in isolated DM. OA typically results in significantly reduced visual acuity in the first decade. Sensorineural hearing impairment ranges from congenital deafness to milder, sometimes progressive, hearing impairment.
perrault syndrome 1
MedGen UID:
1640257
Concept ID:
C4551721
Disease or Syndrome
Perrault syndrome is characterized by sensorineural hearing loss (SNHL) in males and females and ovarian dysfunction in females. SNHL is bilateral and ranges from profound with prelingual (congenital) onset to moderate with early-childhood onset. When onset is in early childhood, hearing loss can be progressive. Ovarian dysfunction ranges from gonadal dysgenesis (absent or streak gonads) manifesting as primary amenorrhea to primary ovarian insufficiency (POI) defined as cessation of menses before age 40 years. Fertility in affected males is reported as normal (although the number of reported males is limited). Neurologic features described in some individuals with Perrault syndrome include learning difficulties and developmental delay, cerebellar ataxia, and motor and sensory peripheral neuropathy.
galloway-mowat syndrome 1
MedGen UID:
1634188
Concept ID:
C4551772
Disease or Syndrome
knobloch syndrome 1
MedGen UID:
1642123
Concept ID:
C4551775
Disease or Syndrome
Knobloch syndrome is an autosomal recessive developmental disorder primarily characterized by typical eye abnormalities, including high myopia, cataracts, dislocated lens, vitreoretinal degeneration, and retinal detachment, with occipital skull defects, which can range from occipital encephalocele to occult cutis aplasia (summary by Aldahmesh et al., 2011).
cornelia de lange syndrome 1
MedGen UID:
1645760
Concept ID:
C4551851
Disease or Syndrome
Cornelia de Lange syndrome (CdLS) encompasses a spectrum of findings from mild to severe. Severe (classic) CdLS is characterized by distinctive facial features, growth restriction (prenatal onset; <5th centile throughout life), hypertrichosis, and upper-limb reduction defects that range from subtle phalangeal abnormalities to oligodactyly (missing digits). Craniofacial features include synophrys, highly arched and/or thick eyebrows, long eyelashes, short nasal bridge with anteverted nares, small widely spaced teeth, and microcephaly. Individuals with a milder phenotype have less severe growth, cognitive, and limb involvement, but often have facial features consistent with CdLS. Across the CdLS spectrum IQ ranges from below 30 to 102 (mean: 53). Many individuals demonstrate autistic and self-destructive tendencies. Other frequent findings include cardiac septal defects, gastrointestinal dysfunction, hearing loss, myopia, and cryptorchidism or hypoplastic genitalia.
lissencephaly, x-linked
MedGen UID:
1644310
Concept ID:
C4551968
Disease or Syndrome
DCX-related disorders include the neuronal migration disorders: Classic thick lissencephaly (more severe anteriorly), usually in males. Subcortical band heterotopia (SBH), primarily in females. Males with classic DCX-related lissencephaly typically have early and profound cognitive and language impairment, cerebral palsy, and epileptic seizures. The clinical phenotype in females with SBH varies widely with cognitive abilities that range from average or mild cognitive impairment to severe intellectual disability and language impairment. Seizures, which frequently are refractory to antiepileptic medication, may be either focal or generalized and behavioral problems may also be observed. In DCX-related lissencephaly and SBH the severity of the clinical manifestation correlates roughly with the degree of the underlying brain malformation as observed in cerebral imaging.
pseudo-torch syndrome 1
MedGen UID:
1639355
Concept ID:
C4552078
Disease or Syndrome
developmental and epileptic encephalopathy, 58
MedGen UID:
1646861
Concept ID:
C4693367
Disease or Syndrome
Developmental and epileptic encephalopathy-58 (DEE58) is a severe neurodevelopmental disorder characterized by the onset of infantile spasms and refractory seizures in the first days or months of life. Affected individuals have global developmental delay with impaired intellectual development, usually with absent speech and inability to walk. Additional features include optic atrophy with poor or absent visual fixation, hypotonia, feeding difficulties, and spasticity (summary by Hamdan et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
neurodevelopmental disorder with microcephaly, epilepsy, and brain atrophy
MedGen UID:
1637443
Concept ID:
C4693390
Disease or Syndrome
NEDMEBA is an autosomal recessive neurodegenerative disorder characterized by global developmental delay, severe intellectual disability with poor or absent speech and autistic stereotypic behaviors, microcephaly, early-onset generalized seizures, and hypotonia (summary by Marin-Valencia et al., 2018).
neurodevelopmental disorder with or without seizures and gait abnormalities
MedGen UID:
1645968
Concept ID:
C4693391
Disease or Syndrome
NEDSGA is an autosomal dominant disorder characterized by global developmental delay apparent from infancy or early childhood, resulting in variable intellectual disability that can range from profound with absent speech to mild with an ability to attend special schools. Most affected individuals show irritability, stiffness, and hypertonia early in life, which progresses to spasticity and impaired gait later. Some patients may develop seizures of variable severity early in life (summary by Martin et al., 2017).
charcot-marie-tooth disease, dominant intermediate g
MedGen UID:
1642893
Concept ID:
C4693509
Disease or Syndrome
CMTDIG is an autosomal dominant neurologic disorder with a highly variable phenotype. Most affected individuals have onset in the first or second decades of slowly progressive distal motor weakness and atrophy, resulting in gait instability and distal upper limb impairment, as well as distal sensory impairment. More severely affected individuals may have pes cavus and claw hands and become wheelchair-bound, whereas other affected individuals have later onset with a milder disease course. Electrophysiologic studies tend to show median motor nerve conduction velocities (NCV) in the 'intermediate' range, between 25 and 45 m/s (summary by Berciano et al., 2017). In a review of intermediate CMT, Berciano et al. (2017) noted that advanced axonal degeneration may induce secondary demyelinating changes resulting in decreased NCV and attenuated compound muscle action potential (CMAP) in median nerve conduction studies. They thus suggested that testing the upper arm, axilla to elbow, may provide more accurate assessment of NCV and CMAP and reveal an intermediate phenotype (review by Berciano et al., 2017). For a discussion of genetic heterogeneity of CMTDI, see 606482.
neurodegeneration with brain iron accumulation 7
MedGen UID:
1647672
Concept ID:
C4693583
Disease or Syndrome
Neurodegeneration with brain iron accumulation-7 (NBIA7) is characterized by iron accumulation in the basal ganglia and manifests as a progressive extrapyramidal syndrome with dystonia, rigidity, and choreoathetosis. Severity and rate of progression are variable (Drecourt et al., 2018).
leukodystrophy, hypomyelinating, 15
MedGen UID:
1633653
Concept ID:
C4693733
Disease or Syndrome
Hypomyelinating leukodystrophy-15 is an autosomal recessive neurodegenerative disorder characterized by onset of motor and cognitive impairment in the first or second decade of life. Features include dystonia, ataxia, spasticity, and dysphagia. Most patients develop severe optic atrophy, and some have hearing loss. Brain imaging shows hypomyelinating leukodystrophy with thin corpus callosum. The severity of the disorder is variable (summary by Mendes et al., 2018) For a discussion of genetic heterogeneity of HLD, see 312080.
leukodystrophy, hypomyelinating, 16
MedGen UID:
1631337
Concept ID:
C4693779
Disease or Syndrome
Hypomyelinating leukodystrophy-16 is an autosomal dominant neurologic disorder characterized by onset of hypotonia, nystagmus, and mildly delayed motor development in infancy. Affected individuals have motor disabilities, including ataxic or broad-based gait, hyperreflexia, intention tremor, dysmetria, and a mild pyramidal syndrome. Some patients have cognitive impairment, whereas others may have normal cognition or mild intellectual disability with speech difficulties. Brain imaging typically shows hypomyelination, leukodystrophy, and thin corpus callosum (summary by Simons et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of hypomyelinating leukodystrophy, see 312080.
developmental delay, intellectual disability, obesity, and dysmorphic features
MedGen UID:
1641154
Concept ID:
C4693860
Disease or Syndrome
Chung-Jansen syndrome (CHUJANS) is characterized by global developmental delay apparent from infancy, impaired intellectual development or learning difficulties, behavioral abnormalities, dysmorphic features, and obesity. The severity of the phenotype and additional features are variable (summary by Jansen et al., 2018).
alacrima, achalasia, and mental retardation syndrome
MedGen UID:
1640947
Concept ID:
C4706563
Disease or Syndrome
Alacrima, achalasia, and mental retardation syndrome (AAMR) is an autosomal recessive disorder characterized by onset of these 3 main features at birth or in early infancy. More variable features include hypotonia, gait abnormalities, anisocoria, and visual or hearing deficits. The disorder shows similarity to the triple A syndrome (231550), but patients with AAMR do not have adrenal insufficiency (summary by Koehler et al., 2013). See also 300858 for a phenotypically similar disorder that shows X-linked inheritance.
peroxisome biogenesis disorder 1a (zellweger)
MedGen UID:
1648474
Concept ID:
C4721541
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 defect in one of the ZSD-PEX genes 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 the 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.
cataract 2, multiple types
MedGen UID:
1648415
Concept ID:
C4721890
Disease or Syndrome
Mutations in the CRYGC gene have been found to cause several types of cataract, which have been described as Coppock-like; embryonic, fetal, infantile nuclear; zonular pulverulent; and lamellar. Some patients also exhibit microcornea. Before it was known that mutations in the CRYGC gene cause several types of cataract, this entry was titled 'Cataract, Coppock-like,' with the symbol CCL.
hypomagnesemia 5, renal, with ocular involvement
MedGen UID:
1648449
Concept ID:
C4721891
Disease or Syndrome
HOMG5 is an autosomal recessive disorder characterized by severe renal magnesium wasting, progressive renal failure, nephrocalcinosis, and severe visual impairment (Konrad et al., 2006). Amelogenesis imperfecta may also be present in some patients (Yamaguti et al., 2017). For a discussion of genetic heterogeneity of renal hypomagnesemia, see 602014.
mitochondrial complex 1 deficiency, nuclear type 12
MedGen UID:
1648278
Concept ID:
C4746984
Disease or Syndrome
neurodevelopmental disorder with cerebellar atrophy and with or without seizures
MedGen UID:
1648373
Concept ID:
C4748032
Disease or Syndrome
intellectual developmental disorder with or without epilepsy or cerebellar ataxia
MedGen UID:
1648354
Concept ID:
C4748041
Disease or Syndrome
pontocerebellar hypoplasia, type 1d
MedGen UID:
1648387
Concept ID:
C4748058
Disease or Syndrome
Pontocerebellar hypoplasia type 1D is a severe autosomal recessive neurologic disorder characterized by severe hypotonia and a motor neuronopathy apparent at birth or in infancy. Patients have respiratory insufficiency, feeding difficulties, and severely delayed or minimal gross motor development. Other features may include eye movement abnormalities, poor overall growth, contractures. Brain imaging shows progressive cerebellar atrophy with relative sparing of the brainstem (summary by Burns et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of PCH, see PCH1A (607596).
developmental and epileptic encephalopathy, 66
MedGen UID:
1648486
Concept ID:
C4748070
Disease or Syndrome
Developmental and epileptic encephalopathy-66 (DEE66) is a neurologic disorder characterized by the onset of various types of seizures in the first days or weeks of life. Most seizures have focal origins; secondary generalization is common. Seizure control is difficult at first, but may become easier with time. Affected individuals show global developmental delay with hypotonia, behavioral abnormalities, and dysmorphic features or ophthalmologic defects. Brain imaging often shows cerebellar dysgenesis. A subset of patients have extraneurologic manifestations, including hematologic and distal limb abnormalities (summary by Olson et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
neurodevelopmental disorder with regression, abnormal movements, loss of speech, and seizures
MedGen UID:
1648345
Concept ID:
C4748127
Disease or Syndrome
glycosylphosphatidylinositol biosynthesis defect 18
MedGen UID:
1648478
Concept ID:
C4748357
Disease or Syndrome
DEE95 is a severe autosomal recessive developmental disorder characterized by severely impaired global development, hypotonia, weakness, ataxia, coarse facial features, and intractable seizures. More variable features may include abnormalities of the hands and feet, inguinal hernia, and feeding difficulties. The disorder is part of a group of similar neurologic disorders resulting from biochemical defects in the glycosylphosphatidylinositol (GPI) biosynthetic pathway (summary by Nguyen et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350. For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
neurodegeneration, childhood-onset, stress-induced, with variable ataxia and seizures
MedGen UID:
1648391
Concept ID:
C4748527
Disease or Syndrome
Stress-induced childhood-onset neurodegeneration with variable ataxia and seizures (CONDSIAS) is an autosomal recessive neurodegenerative disorder with onset in the first years of life following normal early development. Patient have cyclic episodic deterioration in response to stress, such as infection or febrile illness. The severity is highly variable: some patients develop seizures early in life that are associated with loss of developmental milestones and early sudden death in childhood, whereas others present at a later age with muscle weakness, gait ataxia, impaired speech, more subtle clinical deterioration, and cognitive decline. Neurologic involvement includes gait ataxia, cerebellar signs associated with cerebellar atrophy, generalized brain atrophy, impaired intellectual development, hearing loss, and peripheral neuropathy (summary by Ghosh et al., 2018).
myasthenic syndrome, congenital, 24, presynaptic
MedGen UID:
1648337
Concept ID:
C4748684
Disease or Syndrome
infantile hypotonia-oculomotor anomalies-hyperkinetic movements-developmental delay syndrome
MedGen UID:
1648431
Concept ID:
C4748715
Disease or Syndrome
Baker-Gordon syndrome (BAGOS) is a neurodevelopmental disorder characterized by infantile hypotonia, ophthalmic abnormalities, moderate to profound global developmental delay, poor or absent speech, behavioral abnormalities, hyperkinetic movements, and EEG abnormalities in the absence of overt seizures (summary by Baker et al., 2018).
mitochondrial complex 1 deficiency, nuclear type 2
MedGen UID:
1648466
Concept ID:
C4748737
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 5
MedGen UID:
1648292
Concept ID:
C4748754
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 6
MedGen UID:
1648496
Concept ID:
C4748759
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 7
MedGen UID:
1648484
Concept ID:
C4748760
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 9
MedGen UID:
1648447
Concept ID:
C4748767
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 10
MedGen UID:
1648426
Concept ID:
C4748768
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 14
MedGen UID:
1648440
Concept ID:
C4748777
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 15
MedGen UID:
1648320
Concept ID:
C4748778
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 16
MedGen UID:
1648351
Concept ID:
C4748785
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 21
MedGen UID:
1648383
Concept ID:
C4748792
Disease or Syndrome
mitochondrial complex 1 deficiency, nuclear type 31
MedGen UID:
1648395
Concept ID:
C4748838
Disease or Syndrome
neurodegeneration, childhood-onset, with cerebellar atrophy
MedGen UID:
1648286
Concept ID:
C4748934
Disease or Syndrome
Childhood-onset neurodegeneration with cerebellar atrophy is a severe autosomal recessive neurodevelopmental disorder affecting the central and peripheral nervous system. Patients present in the first year of life with global developmental delay, impaired intellectual development, poor or absent speech, and motor abnormalities. Brain imaging shows cerebellar atrophy. The severity is variable, but death in childhood may occur (summary by Shashi et al., 2018).
developmental and epileptic encephalopathy, 69
MedGen UID:
1648381
Concept ID:
C4748988
Disease or Syndrome
Developmental and epileptic encephalopathy-69 (DEE69) is an autosomal dominant severe neurodevelopmental encephalopathic disorder characterized by early-onset refractory seizures, hypotonia, and profoundly impaired development often associated with macrocephaly, hyperkinetic movements, and contractures. The disorder can sometimes result in early death. Some patients may have a favorable seizure response to topiramate medication (summary by Helbig et al., 2018). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
cone-rod dystrophy and hearing loss 1
MedGen UID:
1682048
Concept ID:
C5193018
Disease or Syndrome
CRDHL1 is characterized by cone-rod dystrophy and sensorineural hearing loss, with relatively late onset of both ocular and hearing impairment. The funduscopic findings are characteristic, showing ring-shaped atrophy along the major vascular arcades that manifests on fundus autofluorescence as a hypoautofluorescent band along the vascular arcades surrounded by hyperautofluorescent borders (Namburi et al., 2016). Genetic Heterogeneity of Cone-Rod Dystrophy and Hearing Loss CRDHL2 (618358) is caused by mutation in the CEP250 gene (609689) on chromosome 20q11.
congenital disorder of glycosylation with defective fucosylation 2
MedGen UID:
1676187
Concept ID:
C5193028
Disease or Syndrome
spinocerebellar ataxia, autosomal recessive 27
MedGen UID:
1672866
Concept ID:
C5193058
Disease or Syndrome
Autosomal recessive spinocerebellar ataxia-27 (SCAR27) is an adult-onset neurologic disorder characterized by gait difficulties and other cerebellar signs, such as eye movement abnormalities, dysarthria, and difficulty writing. The disorder is progressive, and some patients may lose independent ambulation. Additional features include spasticity of the lower limbs and cognitive impairment. Brain imaging shows cerebellar atrophy (summary by Eidhof et al., 2018).
facial dysmorphism, hypertrichosis, epilepsy, intellectual/developmental delay, and gingival overgrowth syndrome
MedGen UID:
1679105
Concept ID:
C5193066
Disease or Syndrome
developmental and epileptic encephalopathy, 74
MedGen UID:
1680535
Concept ID:
C5193074
Disease or Syndrome
Developmental and epileptic encephalopathy-74 (DEE74) is neurologic disorder characterized by the onset of refractory seizures in the first months of life. Seizure types are variable and include infantile spasms, myoclonic, tonic, atonic, and absence, often with secondary generalization. Affected individuals have severe global developmental delay with hypotonia, severe motor impairment, roving eye movements, and absent language (summary by Shen et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
leukodystrophy, hypomyelinating, 18
MedGen UID:
1680067
Concept ID:
C5193078
Disease or Syndrome
Hypomyelinating leukodystrophy-18 (HLD18) is an autosomal recessive neurologic disorder characterized by onset of global developmental delay usually in early infancy. Affected individuals have very poor psychomotor development, including inability to sit or walk independently in the more severe cases, as well as poor or absent speech, dystonia, and spasticity. A subset of patients may develop seizures. Brain imaging shows hypomyelinating leukodystrophy affecting various brain regions; some patients may also have progressive atrophy of the corpus callosum, thalami, and cerebellum (summary by Pant et al., 2019). For a general phenotypic description and a discussion of genetic heterogeneity of hypomyelinating leukodystrophy, see 312080.
khan-khan-katsanis syndrome
MedGen UID:
1682553
Concept ID:
C5193110
Disease or Syndrome
Khan-Khan-Katsanis syndrome (3KS) is an autosomal recessive neurodevelopmental disorder with variable involvement of the ocular, renal, skeletal, and sometimes cardiac systems. Affected individuals present at birth with multiple congenital anomalies, defects in urogenital and limb morphogenesis, poor overall growth with microcephaly, and global developmental delay (summary by Khan et al., 2019).
neurodevelopmental disorder with seizures and nonepileptic hyperkinetic movements
MedGen UID:
1678038
Concept ID:
C5193128
Disease or Syndrome
Neurodevelopmental disorder with seizures and nonepileptic hyperkinetic movements (NEDNEH) is an autosomal recessive severe neurologic disorder characterized by delayed psychomotor development with inability to walk or speak, early-onset refractory seizures, and nonepileptic hyperkinetic movement disorders, including myoclonus dystonia and dyskinesias. Patients require tube feeding and may die of respiratory failure in childhood or in the second decade (summary by Gorman et al., 2019).
cerebellar atrophy with seizures and variable developmental delay
MedGen UID:
1683734
Concept ID:
C5193132
Disease or Syndrome
Cerebellar atrophy with seizures and variable developmental delay (CASVDD) is an autosomal recessive neurologic disorder characterized by cerebellar ataxia associated with atrophy of the cerebellar vermis on brain imaging. Most patients also have onset of severe refractory seizures in the first year of life and show global developmental delay, compatible with epileptic encephalopathy (summary by Edvardson et al., 2013). However, at least 1 patient with normal cognitive development and only 1 febrile seizure has been reported (Valence et al., 2019), suggesting significant clinical variability of this disorder.
leber congenital amaurosis 19
MedGen UID:
1679297
Concept ID:
C5193139
Disease or Syndrome
Leber congenital amaurosis-19 (LCA19) is characterized by reduced vision in early childhood and severely reduced responses of both rods and cones on electroretinography (Yi et al., 2019). For a general description and a discussion of genetic heterogeneity of LCA, see 204000.
neurodevelopmental disorder with visual defects and brain anomalies
MedGen UID:
1684774
Concept ID:
C5231404
Disease or Syndrome
Neurodevelopmental disorder with visual defects and brain anomalies (NEDVIBA) is characterized by global developmental delay with impaired intellectual development and speech delay, variable visual defects, including retinitis pigmentosa and optic atrophy, hypotonia or hypertonia, and variable structural brain abnormalities. Other nonspecific features may be found (summary by Okur et al., 2019).
glycosylphosphatidylinositol biosynthesis defect 21
MedGen UID:
1684749
Concept ID:
C5231419
Disease or Syndrome
Neurodevelopmental disorder with brain anomalies, seizures, and scoliosis (NEDBSS) is an autosomal recessive disorder characterized by severely impaired psychomotor development, hypotonia, seizures, and structural brain anomalies, including thin corpus callosum and cerebellar atrophy. Other features include scoliosis, dysmorphic facies, and visual impairment. Affected individuals are usually unable to walk or speak and may require tube feeding in severe cases. The disorder is caused by a defect in glycosylphosphatidylinositol (GPI) biosynthesis (summary by Knaus et al., 2019). For a discussion of genetic heterogeneity of GPI biosynthesis defects, see GPIBD1 (610293).
intellectual developmental disorder with speech delay, autism, and dysmorphic facies
MedGen UID:
1684848
Concept ID:
C5231456
Disease or Syndrome
neurodevelopmental disorder with behavioral abnormalities, absent speech, and hypotonia
MedGen UID:
1684663
Concept ID:
C5231471
Disease or Syndrome
Neurodevelopmental disorder with behavioral abnormalities, absent speech, and hypotonia (NEDBASH) is an autosomal recessive disorder characterized by severely impaired intellectual and motor development, axial and peripheral hypotonia usually with inability to walk, and significant behavioral abnormalities consistent with autism spectrum disorder and reminiscent of Rett syndrome (RTT; 312750), such as poor communication, stereotypic or repetitive behaviors, hand-wringing, bruxism, and sleep disturbances. Other features include poor overall growth, and joint hypermobility. Rare features include seizures, dystonia, spasticity, and nonspecific brain abnormalities (summary by Abu-Libdeh et al., 2019 and Dias et al., 2019).
ectodermal dysplasia with facial dysmorphism and acral, ocular, and brain anomalies
MedGen UID:
1684719
Concept ID:
C5231477
Disease or Syndrome
EDFAOB is characterized by linear hypopigmentation and craniofacial asymmetry in association with ocular, dental, and acral anomalies. Brain imaging has revealed some abnormalities, including diffuse cystic leukoencephalopathy and mildly enlarged lateral ventricles, but patients show no intellectual or neurologic impairment (Vabres et al., 2019).
liang-wang syndrome
MedGen UID:
1684847
Concept ID:
C5231479
Disease or Syndrome
Liang-Wang syndrome (LIWAS) is a polymalformation syndrome apparent from birth that shows large phenotypic variability and severity. However, all patients have some degree of neurologic dysfunction. The most severely affected individuals have severe global developmental delay with impaired intellectual development and poor or absent speech, marked craniofacial dysmorphism, and visceral and connective tissue abnormalities affecting the bones and vessels. The least severely affected individuals lack seizures, significant dysmorphism, and visceral involvement; they come to attention for neurologic signs and symptoms, including developmental delay with speech delay, strabismus, and/or ataxia. About half of patients have brain imaging anomalies, notably cerebral and cerebellar atrophy and thin corpus callosum, whereas the other half have normal brain imaging (summary by Liang et al., 2019).
neurodevelopmental disorder with brain anomalies and with or without vertebral or cardiac anomalies
MedGen UID:
1684772
Concept ID:
C5231481
Disease or Syndrome
developmental and epileptic encephalopathy, 83
MedGen UID:
1684784
Concept ID:
C5231487
Disease or Syndrome
Developmental and epileptic encephalopathy-83 (DEE83) is a severe autosomal recessive neurodevelopmental disorder characterized by onset of frequent seizures in the first days to months of life that are usually refractory to medical treatment and are associated with significant EEG abnormalities. Affected individuals have profoundly impaired development, with no motor or language skill acquisition, poor or absent visual tracking, and poor oromotor function necessitating tube feeding. Many patients die in the first years of life (summary by Perenthaler et al., 2020). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
intellectual disability, autosomal dominant 9
MedGen UID:
1714250
Concept ID:
C5393830
Disease or Syndrome
NESCAV syndrome (NESCAVS) is a neurodegenerative disorder characterized by onset of features in infancy or early childhood. Affected individuals show global developmental delay with delayed walking or difficulty walking due to progressive spasticity mainly affecting the lower limbs and often leading to loss of independent ambulation. There is variably impaired intellectual development, speech delay, and learning disabilities and/or behavioral abnormalities. Additional features may include cortical visual impairment, often associated with optic atrophy, axonal peripheral neuropathy, seizures, dysautonomia, ataxia, and dystonia. Brain imaging often shows progressive cerebellar atrophy and thin corpus callosum. Some patients may show developmental regression, particularly of motor skills. The phenotype and presentation are highly variable (summary by Nemani et al., 2020).
spastic paraplegia 82, autosomal recessive
MedGen UID:
1710411
Concept ID:
C5394037
Disease or Syndrome
Autosomal recessive spastic paraplegia-82 (SPG82) is a progressive neurologic disorder characterized by global developmental delay apparent from infancy, significant motor impairment, and progressive spasticity mainly affecting the lower limbs. Some patients never achieve walking, whereas others lose the ability to walk or walk with an unsteady gait. Additional features include variably impaired intellectual development with language difficulties, ocular anomalies, such as nystagmus and visual impairment, and seizures. Brain imaging shows progressive cerebral and cerebellar atrophy, as well as white matter hyperintensities. Based on the additional abnormalities, the disorder can be classified as a type of complicated SPG (summary by Vaz et al., 2019). For a discussion of genetic heterogeneity of autosomal recessive spastic paraplegia, see SPG5A (270800).
cebalid syndrome
MedGen UID:
1710973
Concept ID:
C5394044
Disease or Syndrome
Individuals with MN1 C-terminal truncation (MCTT) syndrome have mild-to-moderate intellectual disability, severe expressive language delay, dysmorphic facial features (midface hypoplasia, downslanting palpebral fissures, hypertelorism, exophthalmia, short upturned nose, and small low-set ears), and distinctive findings on brain imaging (including perisylvian polymicrogyria and atypical rhombencephalosynapsis). Mild-to-moderate prelingual hearing loss (usually bilateral, conductive, and/or sensorineural) is common. Generalized seizures (observed in the minority of individuals) are responsive to antiepileptic drugs. There is an increased risk for craniosynostosis and, thus, increased intracranial pressure. To date, 25 individuals with MCTT syndrome have been identified.
beck-fahrner syndrome
MedGen UID:
1711894
Concept ID:
C5394097
Disease or Syndrome
Beck-Fahrner syndrome (BEFAHRS) is a developmental disorder characterized by global developmental delay with variably impaired intellectual development. Affected individuals often have behavioral abnormalities, such as autistic features or attention deficit-hyperactivity disorder (ADHD), as well as learning disabilities. Most patients have hypotonia and dysmorphic facies. Some may have growth abnormalities, including overgrowth or poor growth, poor feeding, and rarely, seizures. Although both monoallelic and biallelic mutations have been reported, some heterozygous carriers in autosomal recessive families may have milder symptoms; thus, both groups are included in this entry (summary by Beck et al., 2020).
basal ganglia calcification, idiopathic, 8, autosomal recessive
MedGen UID:
1713414
Concept ID:
C5394199
Disease or Syndrome
Autosomal recessive idiopathic basal ganglia calcification-8 (IBGC8) is a progressive neurologic disorder with insidious onset of motor symptoms in adulthood. Affected individuals develop gait difficulties, parkinsonism, pyramidal signs, and dysarthria. Some may demonstrate cognitive decline or memory impairment. Brain imaging shows extensive calcifications in various brain regions including the basal ganglia, thalamus, and cerebellum. Because serum calcium and phosphate are normal, the disorder is thought to result from defects in the integrity of the neurovascular unit in the brain (summary by Schottlaender et al., 2020). For a phenotypic description and a discussion of genetic heterogeneity of IBGC, see IBGC1 (213600).
combined oxidative phosphorylation deficiency 44
MedGen UID:
1718899
Concept ID:
C5394293
Disease or Syndrome
Combined oxidative phosphorylation deficiency-44 (COXPD44) is an autosomal recessive mitochondrial disorder with multisystemic manifestations. Most affected individuals present in infancy or early childhood with global developmental delay, hypotonia, and abnormal movements. Most patients develop seizures, often associated with status epilepticus, and some patients may have optic atrophy. One patient with hypertrophic cardiomyopathy has been reported. Serum lactate may be increased, although that finding is inconsistent. Detailed biochemical analysis shows variable combined deficiencies of mitochondrial oxidative complexes that appear to be tissue-specific (summary by Wei et al., 2020). For discussion of genetic heterogeneity of combined oxidative phosphorylation deficiency, see COXPD1 (609060).
congenital disorder of glycosylation, type iit
MedGen UID:
1709627
Concept ID:
C5394387
Disease or Syndrome
Congenital disorder of glycosylation type IIt (CDG2t) is an autosomal recessive multisystemic metabolic disorder characterized by global developmental delay, poor overall growth, severely impaired intellectual development with absent language, and behavioral abnormalities. Most patients develop early-onset seizures; brain imaging tends to show white matter abnormalities. Variable dysmorphic features, including long face, almond-shaped eyes, protruding maxilla, and short philtrum, are also present. The disorder, which is associated with low levels of HDL cholesterol, results from defective posttranslational O-linked glycosylation of certain plasma lipids and proteins (summary by Zilmer et al., 2020). For an overview of congenital disorders of glycosylation, see CDG1A (212065) and CDG2A (212066).
episodic ataxia type 9
MedGen UID:
1714171
Concept ID:
C5394520
Disease or Syndrome
Episodic ataxia type 9 (EA9) is a neurologic disorder characterized by onset of ataxic episodes in the first years of life. Features may include difficulty walking, dizziness, slurred speech, headache, vomiting, and pain. The ataxic episodes vary in frequency and duration; most tend to occur every few weeks or months and last minutes to hours. Prior to the EA, most patients have neonatal- or infantile-onset tonic or generalized tonic-clonic (GTC) seizures that may be severe and refractory to medication, but remit later in infancy or early childhood, either spontaneously or concurrently with medication. Some patients have mildly delayed development with speech delay and/or autistic features or mildly impaired intellectual development. However, others show normal psychomotor development. Treatment of the ataxic episodes with acetazolamide is effective in about 50% of patients (summary by Schwarz et al., 2019). For a phenotypic description and discussion of genetic heterogeneity of episodic ataxia, see EA1 (160120).
joubert syndrome with hepatic defect
MedGen UID:
1769861
Concept ID:
C5435651
Disease or Syndrome
COACH syndrome is an autosomal recessive disorder characterized by impaired intellectual development, ataxia due to cerebellar hypoplasia, and hepatic fibrosis. Other features, such as coloboma and renal cysts, may be variable. COACH syndrome is considered by some to be a subtype of Joubert syndrome (JBTS; see 213300) with congenital hepatic fibrosis. Identification of liver disease in these patients is critical because some may develop complications such as portal hypertension with fatal variceal bleeding (Brancati et al., 2009; Doherty et al., 2010). Genetic Heterogeneity of COACH Syndrome Also see COACH syndrome-2 (COACH2; 619111), caused by mutation in in the CC2D2A gene (612013), and COACH syndrome-3 (COACH3; 619113), caused by mutation the RPGRIP1L gene (610937). Most cases of COACH syndrome are caused by mutation in the TMEM67 gene.
cone-rod synaptic disorder syndrome, congenital nonprogressive
MedGen UID:
1773574
Concept ID:
C5436505
Disease or Syndrome
Congenital nonprogressive cone-rod synaptic disorder syndrome (CRSDS) is characterized by retinal and neurodevelopmental disease as well as occasional anomalies of glucose homeostasis. Patients exhibit low vision, photophobia, and nystagmus, and show an electronegative waveform in response to bright flash under dark adaptation on electroretinography, with severely reduced and delayed light-adapted responses. Neurodevelopmental features include poor to no language and autistic behaviors (Mechaussier et al., 2020).
neurodegeneration, infantile-onset, biotin-responsive
MedGen UID:
1771692
Concept ID:
C5436520
Disease or Syndrome
Infantile-onset biotin-responsive neurodegeneration (NERIB) is an autosomal recessive disorder characterized by onset of developmental regression with loss of early motor and cognitive milestones in the first year or so of life. Some patients may have normal early development before the onset of symptoms. Affected individuals show growth retardation with decreasing head circumference and poor feeding. More variable features may include seizures, ataxia, spasticity, peripheral neuropathy, immune defects, and osteopenia. Brain imaging shows cerebral, cerebellar, and brainstem atrophy and thin corpus callosum. Treatment with biotin, pantothenic acid, and alpha-lipoic acid has been shown to result in clinical improvement (summary by Byrne et al., 2019).
neurodevelopmental disorder with progressive spasticity and brain white matter abnormalities
MedGen UID:
1736667
Concept ID:
C5436628
Disease or Syndrome
Neurodevelopmental disorder with progressive spasticity and brain white matter abnormalities (NEDSWMA) is an autosomal recessive disorder characterized by impaired psychomotor development apparent in infancy. Affected individuals show poor overall growth, progressive microcephaly, and axial hypotonia, with later onset of spasticity. The disorder is progressive. Some patients show normal early development, but later have regression of motor, cognitive, and language skills. More variable features include seizures, joint contractures, ocular disturbances, episodic respiratory failure, and nonspecific dysmorphic facial features. The intellectual impairment is variable, ranging from poor visual contact with inability to walk or speak to milder intellectual disability with the ability to say some words. Brain imaging shows variable white matter abnormalities, including thin corpus callosum and poor myelination (summary by Husain et al., 2020).
mitochondrial complex 4 deficiency, nuclear type 3
MedGen UID:
1764816
Concept ID:
C5436682
Disease or Syndrome
combined oxidative phosphorylation deficiency 51
MedGen UID:
1757992
Concept ID:
C5436703
Disease or Syndrome
oculocutaneous albinism, type 8
MedGen UID:
1754121
Concept ID:
C5436929
Disease or Syndrome
Oculocutaneous albinism type VIII (OCA8) is characterized by mild hair and skin hypopigmentation, associated with ocular features including nystagmus, reduced visual acuity, iris transillumination, and hypopigmentation of the retina (Pennamen et al., 2021).
hermansky-pudlak syndrome 11
MedGen UID:
1727728
Concept ID:
C5436936
Disease or Syndrome
Hermansky-Pudlak syndrome (HPS) is characterized by oculocutaneous albinism, a bleeding diathesis, and, in some individuals, pulmonary fibrosis, granulomatous colitis, or immunodeficiency. Ocular findings include reduced iris pigment with iris transillumination, reduced retinal pigment, foveal hypoplasia with significant reduction in visual acuity (usually in the range of 20/50 to 20/400), nystagmus, and increased crossing of the optic nerve fibers. Hair color ranges from white to brown; skin color ranges from white to olive and is usually a shade lighter than that of other family members. The bleeding diathesis can result in variable bruising, epistaxis, gingival bleeding, postpartum hemorrhage, colonic bleeding, and prolonged bleeding with menses or after tooth extraction, circumcision, and other surgeries. Pulmonary fibrosis, a restrictive lung disease, typically causes symptoms in the early thirties and can progress to death within a decade. Granulomatous colitis is severe in about 15% of affected individuals. Neutropenia and/or immune defects occur primarily in individuals with pathogenic variants in AP3B1 and AP3D1.
optic atrophy 6
MedGen UID:
338012
Concept ID:
C1850281
Disease or Syndrome
dilution, pigmentary
MedGen UID:
406294
Concept ID:
C1876214
Disease or Syndrome

Recent clinical studies

Etiology

Volk AE, Hedergott A, Preising M, Rading S, Fricke J, Herkenrath P, Nürnberg P, Altmüller J, von Ameln S, Lorenz B, Neugebauer A, Karsak M, Kubisch C
Hum Genet 2021 Aug;140(8):1157-1168. Epub 2021 May 6 doi: 10.1007/s00439-021-02285-0. PMID: 33959807
Kong TH, Song MH, Shim DB
Otol Neurotol 2021 Apr 1;42(4):585-591. doi: 10.1097/MAO.0000000000003026. PMID: 33710997
Lee J, Choi B, Noh H, Jeong H, Shin JE, Kim CH
Neurol Sci 2021 Jan;42(1):193-198. Epub 2020 Jun 26 doi: 10.1007/s10072-020-04536-w. PMID: 32592105
Lee H, Kim HA
J Vestib Res 2020;30(2):95-100. doi: 10.3233/VES-200696. PMID: 32310200
Wang FB
Strabismus 2020 Mar;28(1):17-19. Epub 2019 Sep 30 doi: 10.1080/09273972.2019.1668028. PMID: 31566469

Diagnosis

Mouelhi A, Ben Slama A, Marrakchi J, Trabelsi H, Sayadi M, Labidi S
Comput Methods Biomech Biomed Engin 2021 Mar;24(4):400-418. Epub 2020 Oct 12 doi: 10.1080/10255842.2020.1830972. PMID: 33043702
Lee J, Choi B, Noh H, Jeong H, Shin JE, Kim CH
Neurol Sci 2021 Jan;42(1):193-198. Epub 2020 Jun 26 doi: 10.1007/s10072-020-04536-w. PMID: 32592105
Nomura Y, Toi T, Ogawa Y, Oshima T, Saito Y
BMC Neurol 2020 Nov 30;20(1):435. doi: 10.1186/s12883-020-02009-3. PMID: 33256636Free PMC Article
Jorge A, Martins AI, Gouveia A, Lemos J
Cerebellum 2020 Aug;19(4):611-615. doi: 10.1007/s12311-020-01140-8. PMID: 32410095
Rosengren W, Nyström M, Hammar B, Rahne M, Sjödahl L, Stridh M
Behav Res Methods 2020 Aug;52(4):1729-1743. doi: 10.3758/s13428-020-01346-y. PMID: 32314183Free PMC Article

Therapy

Nomura Y, Toi T, Ogawa Y, Oshima T, Saito Y
BMC Neurol 2020 Nov 30;20(1):435. doi: 10.1186/s12883-020-02009-3. PMID: 33256636Free PMC Article
Gómez-Mariscal M, Hernández-Martínez P, Rodríguez-Del Valle JM, Ruiz-Guerrero M, Márquez-González C, Rodríguez-Sánchez JM
Graefes Arch Clin Exp Ophthalmol 2020 Jul;258(7):1549-1554. Epub 2020 Apr 20 doi: 10.1007/s00417-020-04686-9. PMID: 32307586
Kuwano A, Arai K, Aihara Y, Kawamata T
World Neurosurg 2020 Feb;134:577-579. Epub 2019 Nov 29 doi: 10.1016/j.wneu.2019.11.140. PMID: 31790839
Hong H, Lyu IJ
BMC Ophthalmol 2019 Dec 16;19(1):257. doi: 10.1186/s12886-019-1270-3. PMID: 31842796Free PMC Article
Estrada M, Kelly JP, Wright J, Phillips JO, Weiss A
Pediatr Neurol 2019 Aug;97:30-37. Epub 2019 Mar 28 doi: 10.1016/j.pediatrneurol.2019.03.021. PMID: 31113715

Prognosis

Lee J, Choi B, Noh H, Jeong H, Shin JE, Kim CH
Neurol Sci 2021 Jan;42(1):193-198. Epub 2020 Jun 26 doi: 10.1007/s10072-020-04536-w. PMID: 32592105
Lou Y, Xu L, Wang Y, Zhao Z, Liu X, Li Y
Am J Otolaryngol 2020 Jul - Aug;41(4):102472. Epub 2020 Apr 1 doi: 10.1016/j.amjoto.2020.102472. PMID: 32276733
Skipper C, Knight R, Cane D
Int J Audiol 2020 May;59(5):333-340. Epub 2019 Dec 19 doi: 10.1080/14992027.2019.1703046. PMID: 31855087
Kuwano A, Arai K, Aihara Y, Kawamata T
World Neurosurg 2020 Feb;134:577-579. Epub 2019 Nov 29 doi: 10.1016/j.wneu.2019.11.140. PMID: 31790839
Wang FB
Strabismus 2020 Mar;28(1):17-19. Epub 2019 Sep 30 doi: 10.1080/09273972.2019.1668028. PMID: 31566469

Clinical prediction guides

Lee SU, Kim HJ, Lee ES, Choi JH, Choi JY, Kim JS
J Neurol 2021 Aug;268(8):2851-2857. Epub 2021 Feb 18 doi: 10.1007/s00415-021-10435-7. PMID: 33599814
Lee J, Choi B, Noh H, Jeong H, Shin JE, Kim CH
Neurol Sci 2021 Jan;42(1):193-198. Epub 2020 Jun 26 doi: 10.1007/s10072-020-04536-w. PMID: 32592105
Nomura Y, Toi T, Ogawa Y, Oshima T, Saito Y
BMC Neurol 2020 Nov 30;20(1):435. doi: 10.1186/s12883-020-02009-3. PMID: 33256636Free PMC Article
Rosengren W, Nyström M, Hammar B, Rahne M, Sjödahl L, Stridh M
Behav Res Methods 2020 Aug;52(4):1729-1743. doi: 10.3758/s13428-020-01346-y. PMID: 32314183Free PMC Article
Skipper C, Knight R, Cane D
Int J Audiol 2020 May;59(5):333-340. Epub 2019 Dec 19 doi: 10.1080/14992027.2019.1703046. PMID: 31855087

Recent systematic reviews

Cham KM, Abel LA, Busija L, Kowal L, Bachar Zipori A, Downie LE
Cochrane Database Syst Rev 2021 Feb 18;2:CD013390. doi: 10.1002/14651858.CD013390.pub2. PMID: 33598911Free PMC Article
Waissbluth S, Sepúlveda V
Otol Neurotol 2021 Jun 1;42(5):646-658. doi: 10.1097/MAO.0000000000003022. PMID: 33492062
De Clercq H, Naude A, Bornman J
S Afr Med J 2017 Oct 31;107(11):957-964. doi: 10.7196/SAMJ.2017.v107i11.12472. PMID: 29262937
van den Broek EM, van der Zaag-Loonen HJ, Bruintjes TD
Otolaryngol Head Neck Surg 2014 Jun;150(6):933-8. Epub 2014 Mar 13 doi: 10.1177/0194599814525919. PMID: 24627409
Alvarenga GA, Barbosa MA, Porto CC
Braz J Otorhinolaryngol 2011 Nov-Dec;77(6):799-804. PMID: 22183288

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