Deafness and CMT disease associated with a novel four amino acid deletion in the PMP22 gene.

The molecular basis for the clinically distinct entity of deafness with Charcot-Marie-Tooth disease has not been established with certainty. The authors report deafness associated with a demyelinating neuropathy in three individuals of a family in whom a novel four-amino acid deletion in the PMP22 gene was identified. The data and review of literature suggest that in the PMP22 gene, some point mutations and small deletions in the transmembrane domain that are in close proximity to the extracellular component of the protein result in this clinically distinct entity.