Dysarthria, and Split hand

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}.

• Generalized hypotonia
• Hearing impairment
• Ataxia
• Nystagmus
• Muscle weakness

SOURCES: OMIM MENDELIAN

Vocal cord and pharyngeal distal myopathy (VCPDM) is a rare autosomal dominant distal myopathy characterized by adult onset of muscle weakness in the feet and hands (slowly progressing to involve proximal limb muscles) combined with vocal or swallowing dysfunction and frequent respiratory muscle involvement in later stages. Normal to mildly elevated creatine kinase (CK) serum levels and rimmed-vacuolated dystrophic muscle fiber changes are associated laboratory and pathologic findings.

VOCAL CORD AND PHARYNGEAL DISTAL MYOPATHY Is also known as mpd2, formerly|myopathy, distal, 2, formerly|vocal cord and pharyngeal dysfunction with distal myopathy, formerly|matr3-related distal myopathy|distal myopathy with vocal cord weakness|vcpdm, formerly|vcpdm

• Muscle weakness
• Spasticity
• Cognitive impairment
• Hyperreflexia
• Dysarthria

SOURCES: OMIM ORPHANET MENDELIAN

Charcot-Marie-Tooth disease type 2Z (CMT2Z) is an autosomal dominant peripheral neuropathy characterized by onset, usually in the first decade, of distal lower limb muscle weakness and sensory impairment. The disorder is progressive, and affected individuals tend to develop upper limb and proximal muscle involvement in an asymmetric pattern, resulting in severe disability late in adulthood (summary by Sevilla et al., 2016).For a phenotypic description and a discussion of genetic heterogeneity of axonal CMT, see CMT2A1 (OMIM ).

AUTOSOMAL DOMINANT CHARCOT-MARIE-TOOTH DISEASE TYPE 2Z Is also known as autosomal dominant charcot-marie-tooth disease type 2 due to morc2 mutation|cmt2z|charcot-marie-tooth disease, axonal, autosomal dominant, type 2z|charcot-marie-tooth neuropathy, type 2z

• Global developmental delay
• Generalized hypotonia
• Hearing impairment
• Scoliosis
• Muscle weakness

SOURCES: ORPHANET OMIM MENDELIAN

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 (OMIM ).

• Generalized hypotonia
• Hearing impairment
• Scoliosis
• Ataxia
• Nystagmus

SOURCES: OMIM MENDELIAN

Van der Woude syndrome (VWS) is a dominantly inherited developmental disorder characterized by pits and/or sinuses of the lower lip, and cleft lip and/or cleft palate (CL/P, CP). It is the most common cleft syndrome. Genetic Heterogeneity of van der Woude SyndromeAlso see VWS2 (OMIM ), caused by mutation in the GRHL3 gene (OMIM ) on chromosome 1p36.

VAN DER WOUDE SYNDROME 1; VWS1 Is also known as cleft lip and/or palate with mucous cysts of lower lip|pit|lps|lip-pit syndrome|vdws

• Scoliosis
• Micrognathia
• Cleft palate
• Cryptorchidism
• Flexion contracture

SOURCES: OMIM MENDELIAN

Najm type X-linked intellectual deficit is a rare cerebellar dysgenesis syndrome characterized by variable clinical manifestations ranging from mild intellectual deficit with or without congenital nystagmus, to severe cognitive impairment associated with cerebellar and pontine hypoplasia/atrophy and abnormalities of cortical development.

X-LINKED INTELLECTUAL DISABILITY, NAJM TYPE Is also known as fgs1|keller syndrome|fg syndrome|fgs|x-linked intellectual disability-microcephaly-pontocerebellar hypoplasia syndrome|mental retardation, large head, imperforate anus, congenital hypotonia, and partial agenesis of corpus callosum|fg syndrome 1|micpch

• Intellectual disability
• Seizures
• Global developmental delay
• Short stature
• Generalized hypotonia

SOURCES: OMIM ORPHANET MENDELIAN

The Sanfilippo syndrome, or mucopolysaccharidosis III, is an autosomal recessive lysosomal storage disease due to impaired degradation of heparan sulfate (Esposito et al., 2000). The disorder is characterized by severe central nervous system degeneration, but only mild somatic disease. Onset of clinical features usually occurs between 2 and 6 years; severe neurologic degeneration occurs in most patients between 6 and 10 years of age, and death occurs typically during the second or third decade of life. Type A has been reported (van de Kamp et al., 1981) to be the most severe, with earlier onset and rapid progression of symptoms and shorter survival. Genetic Heterogeneity of Mucopolysaccharidosis Type IIIMPS III includes 4 types, each due to the deficiency of a different enzyme: heparan N-sulfatase (type A); alpha-N-acetylglucosaminidase (type B; {252920}); acetyl CoA:alpha-glucosaminide acetyltransferase (type C; {252930}); and N-acetylglucosamine 6-sulfatase (type D; {252940}).

MUCOPOLYSACCHARIDOSIS, TYPE IIIA; MPS3A Is also known as mps iiia|sulfamidase deficiency|sanfilippo syndrome a|heparan sulfate sulfatase deficiency

• Intellectual disability
• Seizures
• Global developmental delay
• Hearing impairment
• Ataxia

SOURCES: OMIM MENDELIAN

Congenital Cataracts Facial Dysmorphism Neuropathy (CCFDN) syndrome is a complex developmental disorder of autosomal recessive inheritance.

CONGENITAL CATARACTS-FACIAL DYSMORPHISM-NEUROPATHY SYNDROME Is also known as ccfdn|cataract, congenital, with facial dysmorphism and neuropathy

• Intellectual disability
• Global developmental delay
• Short stature
• Hearing impairment
• Scoliosis

SOURCES: OMIM MESH ORPHANET MENDELIAN

Mucopolysaccharidosis II is a rare X-linked recessive disorder caused by deficiency of the lysosomal enzyme iduronate sulfatase, leading to progressive accumulation of glycosaminoglucans in nearly all cell types, tissues, and organs. Patients with MPS II excrete excessive amounts of chondroitin sulfate B (dermatan sulfate) and heparitin sulfate (heparan sulfate) in the urine (McKusick, 1972; Wraith et al., 2008).

MUCOPOLYSACCHARIDOSIS, TYPE II; MPS2 Is also known as hunter syndrome|sulfoiduronate sulfatase deficiency|sids deficiency|mps ii|ids deficiency|iduronate 2-sulfatase deficiency

• Intellectual disability
• Seizures
• Global developmental delay
• Hearing impairment
• Ptosis

SOURCES: OMIM MENDELIAN

Mucopolysaccharidosis type VI is an autosomal recessive lysosomal storage disorder resulting from a deficiency of arylsulfatase B. Clinical features and severity are variable, but usually include short stature, hepatosplenomegaly, dysostosis multiplex, stiff joints, corneal clouding, cardiac abnormalities, and facial dysmorphism. Intelligence is usually normal (Azevedo et al., 2004).

MUCOPOLYSACCHARIDOSIS, TYPE VI; MPS6 Is also known as maroteaux-lamy syndrome|mps vi|n-acetylgalactosamine-4-sulfatase deficiency|arsb deficiency|arylsulfatase b deficiency

• Intellectual disability
• Short stature
• Hearing impairment
• Abnormal facial shape
• Flexion contracture

SOURCES: OMIM MENDELIAN