MedGen

Autosomal dominant intellectual developmental disorder-72 (MRD72) is characterized by developmental delay, predominant speech delay, autistic or attention-deficit/hyperactivity disorder features, overfriendliness, generalized hypotonia, overweight/obesity, and dysmorphic features (Cuinat et al., 2022). [from OMIM]

Autosomal dominant intellectual developmental disorder-68 (MRD68) is characterized by developmental delay/intellectual disability, microcephaly, poor growth, feeding difficulties, and dysmorphic features. Some patients may have autism spectrum disorder or attention deficit-hyperactivity disorder (ADHD) (Cif et al., 2020). [from OMIM]

Nephrotic syndrome type 24 (NPHS24) is an autosomal recessive renal disorder characterized by onset of proteinuria and hypoalbuminemia in early childhood, although onset in the second decade has been reported. Additional features include edema and hyperlipidemia. The disorder is slowly progressive, and most patients eventually develop end-stage renal disease. Renal biopsy shows focal segmental glomerulosclerosis (FSGS) (summary by Schneider et al., 2020). For a general phenotypic description and a discussion of genetic heterogeneity of nephrotic syndrome, see NPHS1 (256300). [from OMIM]

Retinitis pigmentosa-89 (RP89) is characterized by classic features of RP as well as features of ciliopathy, including postaxial polydactyly and renal and hepatic disease. Onset of symptoms is within the first decade of life (Cogne et al., 2020). For a general phenotypic description and discussion of genetic heterogeneity of RP, see 268000. [from OMIM]

Hennekam lymphangiectasia-lymphedema syndrome-3 (HKKLLS3) is characterized by widespread congenital edema that is more severe in more dependent areas of the body. Associated features include facial dysmorphism and protein-losing enteropathy of variable severity (Brouillard et al., 2017). For a discussion of genetic heterogeneity of Hennekam lymphangiectasia-lymphedema syndrome, see HKLLS1 (235510). [from OMIM]

Blepharocheilodontic (BCD) syndrome is a disorder that is present at birth. It mainly affects the eyelids (blepharo-), upper lip (-cheilo-), and teeth (-dontic).

People with BCD syndrome have lower eyelids that turn out so that the inner surface is exposed (ectropion). The outside of the lower lid may sag away from the eye (euryblepharon), and the eyelids may not be able to close completely (lagophthalmia). There can be extra eyelashes (distichiasis) on the upper eyelids, ranging from a few extra eyelashes to a full extra set. These eyelashes do not grow along the edge of the eyelid with the normal lashes, but out of its inner lining. When the abnormal eyelashes touch the eyeball, they can cause damage to the clear covering of the eye (cornea). Affected individuals may also have widely spaced eyes (hypertelorism), a flat face, and a high forehead.

Other features of BCD syndrome usually include openings on both sides of the upper lip (bilateral cleft lip) and an opening in the roof of the mouth (cleft palate). Affected individuals may have fewer teeth than normal (oligodontia) and their teeth are often smaller than usual and cone-shaped. The dental abnormalities affect both primary teeth (sometimes called "baby teeth") and secondary (permanent) teeth. Other frequent features include sparse, fine hair and abnormal nails.

Occasionally people with BCD syndrome have additional features, including an obstruction of the anal opening (imperforate anus); malformation or absence of the butterfly-shaped gland in the lower neck called the thyroid, resulting in lack of thyroid gland function; or fused fingers or toes (syndactyly). Very rarely, affected individuals have incompletely formed arms or legs (limb reduction defects) or a spinal cord abnormality known as spina bifida. [from MedlinePlus Genetics]

KMT2B-related dystonia (DYT-KMT2B) is a complex childhood-onset (mean age 7 years) movement disorder described to date in 39 individuals. It is characterized by a progressive disease course evolving commonly from lower-limb focal dystonia into generalized dystonia with prominent cervical, cranial, and laryngeal involvement. Communication difficulties, secondary to articulation difficulties and low speech volume, are common. Bulbar dysfunction leads to impaired swallowing. Intellectual disability (ID) / developmental delay (DD) are commonly reported. Additional findings can include eye movement abnormalities, skin changes, psychiatric comorbidities (attention-deficit/hyperactivity disorder, anxiety, depression, and obsessive-compulsive disorder), myoclonus, seizures, spasticity, and sensorineural hearing loss. Many affected individuals follow a similar disease course, though milder and atypical findings have been described. [from GeneReviews]

Webb-Dattani syndrome is an autosomal recessive disorder characterized by frontotemporal hypoplasia, globally delayed development, and pituitary and hypothalamic insufficiency due to hypoplastic development of these brain regions. Patients present soon after birth with multiple pituitary hormonal deficiencies and subsequently develop microcephaly, seizures, and spasticity. Other features include postretinal blindness and renal abnormalities (summary by Webb et al., 2013). [from OMIM]

Developmental delay with autism spectrum disorder and gait instability is a rare, genetic, neurological disorder characterized by infant hypotonia and feeding difficulties, global development delay, mild to moderated intellectual disability, delayed independent ambulation, broad-based gait with arms upheld and flexed at the elbow with brisk walking or running, and limited language skills. Behavior patterns are highly variable and range from sociable and affectionate to autistic behavior. [from ORDO]

Advanced sleep phase syndrome is characterized by very early sleep onset and offset (summary by Jones et al., 1999). Genetic Heterogeneity of Advanced Sleep Phase Syndrome See also FASPS2 (615224), caused by mutation in the CSNK1D gene (600864) on chromosome 17q25, and FASPS3 (616882), caused by mutation in the PER3 gene (603427) on chromosome 1p36. [from OMIM]

Central hypothyroidism and testicular enlargement (CHTE) is characterized by central hypothyroidism, delayed pubertal testosterone rise, adult macroorchidism, variable prolactin deficiency, and occasional transient partial GH deficiency. Some carrier females also exhibit central hypothyroidism and mild prolactin deficiency. Inter- and intrafamilial variability has been observed (summary by Joustra et al., 2016). [from OMIM]

Chromosome 20q11-q12 deletion syndrome is characterized by global developmental delay, poor overall growth, sometimes with severe feeding difficulties, facial dysmorphism, and distal skeletal anomalies. Some patients may have hearing impairment, retinopathy, or cardiac defects. It is a multisystemic disorder with variable features (summary by Loddo et al., 2018). [from OMIM]

Hereditary sensory and autonomic neuropathy type II (HSAN2) is characterized by progressively reduced sensation to pain, temperature, and touch. Onset can be at birth and is often before puberty. The sensory deficit is predominantly distal with the lower limbs more severely affected than the upper limbs. Over time sensory function becomes severely reduced. Unnoticed injuries and neuropathic skin promote ulcerations and infections that result in spontaneous amputation of digits or the need for surgical amputation. Osteomyelitis is common. Painless fractures can complicate the disease. Autonomic disturbances are variable and can include hyperhidrosis, tonic pupils, and urinary incontinence in those with more advanced disease. [from GeneReviews]

Genetic Heterogeneity of Variation in Skin/Hair/Eye Pigmentation Multiple genes influence normal human skin, hair, and/or eye pigmentation. Pigmentation phenotypes influenced by variation in the OCA2 gene are termed SHEP1. The SHEP2 association (266300) is determined by variation at the MC1R locus (155555) and describes a phenotype predominantly characterized by red hair and fair skin. SHEP3 (601800) encompasses pigment variation influenced by the TYR gene (606933); SHEP4 (113750), that influenced by the SLC24A5 gene (609802). Variation in the SLC45A2 (606202) and SLC24A4 (609840) genes result in the phenotypic associations SHEP5 (227240) and SHEP6 (210750), respectively. Sequence variation thought to affect expression of KITLG (184745) results in the SHEP7 (611664) phenotypic association. SHEP8 (611724) is associated with variation in the IRF4 gene (601900). Polymorphism in the 3-prime untranslated region of the ASIP gene (600201) influences the SHEP9 association (611742). The SHEP10 association (612267) comprises variation in the TPCN2 gene (612163), and SHEP11 (612271) is associated with polymorphism near the TYRP1 gene (115501). [from OMIM]

A hereditary demyelinating motor and sensory neuropathy with characteristics of slowed nerve conduction velocities in the absence of clinically apparent neurological deficits, gait abnormalities or muscular atrophy, associated with a germline mutation in the ARGHEF10 gene. [from SNOMEDCT_US]

Pseudohypoaldosteronism type II (PHAII) is characterized by hyperkalemia despite normal glomerular filtration rate (GFR) and frequently by hypertension. Other associated findings in both children and adults include hyperchloremia, metabolic acidosis, and suppressed plasma renin levels. Aldosterone levels are variable, but are relatively low given the degree of hyperkalemia (elevated serum potassium is a potent stimulus for aldosterone secretion). Hypercalciuria is well described. [from GeneReviews]