Some authors calculated the contribution of Charcot-Marie-Toute disease 4C (CMT4C), taking into account all patients with CMT (Nagappa et al., 2023), all CMT1 patients (Rudnik-Schöneborn et al., 2016; Yuan et al., 2018; Sun et al., 2022), while other studies selected patients with CMT1 who do not have a duplication of the PMP22 gene (Laššuthová et al., 2011; Piscosquito et al., 2016; Kontogeorgiou et al., 2019). Here, PMP22 is linked to Charcot-Marie-Tooth disease type 1.