A new truncating MPZ mutation associated with a very mild CMT1 B phenotype.

We have investigated a 34-year-old female who had mild clinical and electrophysiological features of demyelinating peripheral neuropathy. She presented a novel frameshift mutation (V160fsX3) in the exon 4 of the Myelin Protein Zero (MPZ) gene. Clinical and genetic studies performed on her family revealed the same mutation in her oligosymptomatic mother and sister. Our report expands the number of MPZ mutations and indicates that mutations in exon 4 may cause a mild Charcot-Marie-Tooth type 1B phenotype.