GJB1 and Charcot-Marie-Tooth disease type 1B: Myelin is fundamental for axonal integrity and fast axon potential propagation, and damages to the myelin have been associated with Charcot–Marie–Tooth disease, where mutations to the PMP22, P0, and gap junction beta 1 (coding for connexin 32) are responsible for CMT1A, CMT1B and X-linked CMT1 disease, respectively [46].