A novel mutation of myelin protein zero associated with late-onset predominantly axonal Charcot-Marie-Tooth disease

We report a case of late-onset predominantly axonal Charcot-Marie-Tooth disease resulting from a novel mutation in the MPZ gene encoding myelin protein zero (P0). Neurological examination, electrophysiological examination and genetic testing were performed on three members of a Finnish family (family A) and one member of a German family (family B). Three other members of the Finnish family were interviewed and genetically tested. Genetic testing was also performed on 95 healthy Finnish controls. Three members in two generations of family A and the member of family B were affected with late-onset axonal more than demyelinating, motor and sensory polyneuropathy. Heterozygous c.316C>T mutation in MPZ leading to p.Arg106Cys in P0 was found in all the affected subjects, but not in the three unaffected members of the Finnish family. None of 95 healthy Finnish controls harbored the mutation. The findings of this study indicate that p.Arg106Cys allele in MPZ causes late-onset predominantly axonal sensory and motor neuropathy.