Charcot-Marie-Tooth disease type 4J (CMT4J) is an autosomal recessive progressive neurologic disorder with a highly variable phenotype and onset ranging from early childhood to adulthood. Most patients have both proximal and distal asymmetric muscle weakness of the upper and lower limbs. There is significant motor dysfunction, followed by variably progressive sensory loss, which may be mild. Nerve conduction studies and nerve biopsies indicate demyelination as well as axonal loss (summary by Nicholson et al., 2011).
For a phenotypic description and a discussion of genetic heterogeneity of autosomal recessive demyelinating Charcot-Marie-Tooth disease, see CMT4A (214400). [from
OMIM]