Several CDH3/P-cadherin germline mutations have been shown to cause P-cadherin functional inactivation, leading to developmental defects associated with hypotrichosis with juvenile macular dystrophy (HJMD) [26–28] and ectodermal dysplasia, ectrodactyly, and macular dystrophy (EEM syndrome) [29, 30]. This evidence concerns the gene CDH3 and ectodermal dysplasia syndrome.