Missense mutation (R15W) of the connexin32 gene in a family with X chromosomal Charcot-Marie-Tooth neuropathy with only female family members affected

Abstract

A small family with sensorimotor neuropathy of dominant inheritance was examined. All three affected members were female. They had unusually severe symptoms and pronounced reduction of motor nerve conduction velocities with absent sensory nerve action potentials. Molecular genetic analysis disclosed a missense mutation in the connexin32 gene in codon 15 (Arg15Trp) which predicts the replacement of a basic amino acid to a non-polar amino acid in the first cytoplasmic loop of the protein. This report illustrates that in small pedigrees in which only women are affected, and which show a severe clinical phenotype, X chromosomal Charcot-Marie-Tooth neuropathy should be considered as differential diagnosis.