Although the genetic of CMT is featured by a strong genetic heterogeneity, most of the patients carry 17p CNV of PMP22. Among this CNV, almost all cases carry the whole gene duplication of PMP22. The prevalence of the duplication varies among populations, ranging from 15% in Norwegian studies, up to more than 50% in Italy and Spain (Abe et al., 2011; Saporta et al., 2011; Murphy et al., 2012; Østern et al., 2013; Sivera et al., 2013; Høyer et al., 2014). Here, PMP22 is linked to Charcot-Marie-Tooth disease.