ClinVar

In Korean patients with X-linked CMT (302800), Choi et al. (2004) identified a 407T-C transition in the GJB1 gene, resulting in a val136-to-ala (V136A) substitution. (In the original publication, Choi et al. (2004) erroneously designated the nucleotide change as 408T-C.)

In a Korean girl with Dejerine-Sottas syndrome (145900), Chung et al. (2005) identified 2 mutations in 2 different genes: the V136A substitution in the GJB1 gene and an R359W mutation in the EGR2 gene (129010.0004). She inherited the EGR2 mutation from her father, who had Charcot-Marie-Tooth disease-1D (607678). The GJB1 gene was de novo. The father had pes cavus and developed difficulty walking at age 8 years, but had a milder phenotype than the daughter, who had experienced gait difficulties since infancy and facial weakness. She also had bilateral hand muscle weakness and atrophy and had sensory impairment of both upper and lower extremities. Chung et al. (2005) concluded that the more severe phenotype in the daughter was caused by an additive effect of the 2 mutations.