Complementarily, a duplication on chromosome 17 results in the overexpression of PMP22 and causes Charcot–Marie–Tooth disease type 1A (CMT1A) (Lupski, 1992; Lupski et al, 1991; Raeymaekers et al, 1991; Timmerman et al, 1990). This evidence concerns the gene PMP22 and Charcot-Marie-Tooth disease type 1A.