A novel homozygous mutation in PVRL4 causes ectodermal dysplasia-syndactyly syndrome 1

Ectodermal dysplasias (EDs) are a group of hereditary disorders defined by alterations in two or more ectodermal structures. One recently described rare entity is the autosomal recessive inherited ectodermal dysplasia-syndactyly syndrome 1 (EDSS1). Homozygous and compound heterozygous missense and nonsense mutations in the poliovirus receptor related-4 (PVRL4) gene, encoding cell adhesion molecule nectin-4, have been identified as causal for EDSS1. We here report a consanguineous family with a 2-year-old girl featuring EDSS1, including slowly progressive alopecia on the head, pili torti-like twisted hairs in trichoscopy, widely spaced, peg-shaped and conical teeth, proximal syndactyly with fusion of the 2nd to 4th toes, and generalized dry skin. There was no palmoplantar hyperkeratosis and sweating appeared normal to slightly enhanced, especially on the head. Using exome sequencing, we identified the novel homozygous nonsense mutation c.229C>T (p.Gln77Ter) in PVRL4.