OMIM
:
58
Congenital hypomyelinating neuropathy-2 is an autosomal dominant neurologic disorder characterized by early-onset hypotonia, severely delayed motor development, muscle weakness with areflexia, and severely decreased nerve conduction velocities (NCV) resulting from improper myelination of axons. The severity is variable: some patients may present at birth with contractures and respiratory insufficiency, whereas others may achieve walking (summary by Warner et al., 1996).
CHN shows significant phenotypic overlap with Dejerine-Sottas syndrome (DSS; 145900), which is also a neuropathy with early onset. Some classify the disorders differently, noting that CHN is characterized by hypo- or amyelination resulting from a congenital defect in myelin formation, whereas DSS has features of continuous myelin breakdown, with demyelination and remyelination (summary by Smit et al., 2008).
For a discussion of genetic heterogeneity of CHN, see CHN1 (605253).
(618184)
MalaCards based summary
:
Neuropathy, Congenital Hypomyelinating, 2, also known as
hypomyelinating neuropathy, congenital, 2, is related to
schizophrenia and
kuru. An important gene associated with Neuropathy, Congenital Hypomyelinating, 2 is
MPZ (Myelin Protein Zero).
UniProtKB/Swiss-Prot
:
76
Neuropathy, congenital hypomyelinating, 2: A form of congenital hypomyelinating neuropathy, a neurologic disorder characterized by early-onset hypotonia, areflexia, distal muscle weakness, and very slow nerve conduction velocities (NCV) resulting from improper myelination of axons. In its extreme form, it may present with severe joint contractures or arthrogryposis multiplex congenita and respiratory insufficiency. In less severe cases patients may achieve walking. Patients lack both active myelin breakdown and well-organized onion bulbs on sural nerve biopsies, have absence of inflammation, and show hypomyelination of most or all fibers. CHN2 inheritance is autosomal dominant.
