X-linked Charcot-Marie-Tooth disease: molecular analysis of interfamilial variability.

This report describes two families with type 1 Charcot-Marie-Tooth disease (CMTX), or hereditary motor sensory neuropathy type 1. Pedigree analysis is consistent with X-linked recessive inheritance in one family and X-linked dominant inheritance in the second. In the first family, a mutation in the connexin32 gene has been demonstrated and analyzed in family members. In the second family, linkage analysis is consistent with a mutation at the same locus. This report demonstrates the interfamilial variability in X-linked CMT and underscores the observation that regardless of the pattern of inheritance, X-linked CMT constitutes a single, variable disorder.