In the previously reported study of CMT subtype samples, including CMT1A and 11 other subtypes (31 out of the total 75 patient samples were CMT1A),19 the combined data for all subtypes also showed NfL increased with age (r 0.7 controls) and with CMTES (r 0.41) after age correction and so significant correlation was found with CMAP. This evidence concerns the gene NEFL and Charcot-Marie-Tooth disease.