Charcot-Marie-Tooth disease: study of a large kinship with an intermediate form.

A clinical, genetic, electrophysiological and ultrastructural study of a large kinship with peroneal muscular atrophy is reported. There was a noteworthy homogeneity in the phenotype as well as in the electrophysiological characteristics encountered in 15 affected members aged between 7 and 72 years. The symptoms appeared first in the second decade of life and stabilized by the fourth decade. There was no evidence of linkage of the neuropathy gene to the Duffy blood group locus on chromosome 1. The electrophysiological data in this family as well as the ultrastructural findings confirm that there is heterogeneity in hereditary motor and sensory neuropathy type I, and support the concept of an intermediate form of Charcot-Marie-Tooth disease.