GJB2 and KID syndrome: Currently it is known that several missense point mutation in Cx26 – G12R, N14K, N14Y, A40V, G45E, D50N, D50A and A88V do form leaky HCs and induce both skin and hearing disorders, which together are known as keratitis-ichthyosis-deafness (KID) syndrome (Stong et al., 2006; Gerido et al., 2007; Lee et al., 2009; García et al., 2013; Mhaske et al., 2013; Meigh et al., 2014; Sanchez et al., 2014).