IGHMBP2 and Charcot-Marie-Tooth disease: CMT has an estimated prevalence of 1:2500, and its aetiology is related to more than 80 different genes.22 The diverse phenotypic and electrophysiological symptoms lead to the classification of CMT by type (type 1 and type 2).22, 23 In 2012, the Cottenie group discovered an IGHMBP2 mutation in two consanguineous English patients affected by CMT type 2S disease (CMT2S) through a combination of genome sequencing and linkage analysis.