Since the study cohort was selected from a consecutive series of 251 CMT pedigrees and we did not find any NEFL or GDAP1 mutations among the index patients (data not shown), the mutation frequencies for CMT in our population were 2.4% (6/251) for NEFL, 2.0% (5/251) for MFN2, and 0.4% (1/251) for each of AARS, HSPB1 and GDAP1. This evidence concerns the gene HSPB1 and Charcot-Marie-Tooth disease.