GJB2 and keratoderma hereditarium mutilans: All syndromic PLP missense variants can be associated with deafness and skin pathologies, often with overlapping clinical phenotypes and varying penetrance: deafness with PPK (OMIM #148350), KID syndrome (OMIM #148210), overlapping with hystrix-like ichthyosis with deafness (OMIM #602540), Vohwinkel syndrome (OMIM #124500), and Bart–Pumphrey syndrome (OMIM #149200).