Charcot-Marie-Tooth disease type 4 (CMT4) is a group of progressive neurological disorders resulting in demyelination of the motor and sensory axons. Myelin is the substance that covers nerve cells and provides protection for these cells. Also, myelin promotes the rapid transmission of nerve impulses. Patients with CMT4 have distal muscle weakness and atrophy associated with sensory loss and, frequently, pes cavus foot deformity. CMT4H is a sub type of CMT4 that is caused by mutations in the FGD4 gene.
[See: Lebanon > De Sandre-Giovannoli et al, 2005]
De Sandre-Giovannoli et al, 2005, studied seven patients belonging to a large consanguineous Lebanese family, as well as three brothers from a consanguineous Algerian family, with a severe form of autosomal recessive demyelinating Charcot-Marie-Tooth disease (CMT4H). The authors identified a new locus for CMT4H to a genetic interval of approximately 11.5 cM at chromosome 12p11.21-q13.11. Mutation analysis excluded peripherin (PRPH) and contactin-1 (CNTN1) as candidate genes.