ED-syndactyly syndrome 1 (EDSS1; OMIM#613573) is a rare type of ED caused by biallelic mutations in the NECTIN4 gene (previously known as poliovirus-like receptor 4, PVRL4) located on chromosome 1 (1q23.1–3) [4]. Here, NECTIN4 is linked to ectodermal dysplasia-syndactyly syndrome.