HOXC13 and scalp-ear-nipple syndrome: Within the last years, many genetic causes of rare EDs were reported as e.g. mutations in the HOXC13 gene (MIM 142976) [1], a member of the HOX family of transcription factors, causing pure hair and nail ectodermal dysplasia (PHNED; MIM 614931), mutations in the KCTD1 gene (MIM 613420) [2] for scalp-ear-nipple syndrome (SENS; MIM 181270) and recently pathogenic variants in GRHL2 gene causing an autosomal-recessive ectodermal dysplasia syndrome [3].