Novel missense mutation in the EDA 1 gene identified in a family with hypohidrotic ectodermal dysplasia

Background Hypohidrotic ectodermal dysplasia ( HED ) is a human genetic disorder that affects structures of ectodermal origin such as hair, teeth, and sweat glands. Although there are autosomal recessive and dominant forms, X‐linked ( XL ) is the most frequent form of the disease. This XL ‐ HED phenotype is associated with mutations in the gene encoding the transmembrane protein ectodysplasin‐1 ( EDA 1). We report the clinical and molecular analysis of a novel mutation in exon 1 affecting the transmembrane domain of the protein. Methods We have screened 20 members of a family from Yucatán, México, nine men and 11 women, searching clinical and histopathological signs of HED . We searched mutations in EDA 1 gene from patients with XL ‐ HED , carriers, and controls. Results We identified seven men with clinical characteristics of HED showing short toes and plantar hyperkeratosis not reported previously in patients with HED . A mutational study of the EDA 1 gene showed that all seven patients with HED carry a novel missense mutation of the nucleotide 409 (c.409T>C) in exon 1, which changes p.Leu56‐Pro in the protein amino acid sequence; five women are heterozygous compatible with carrier status. Conclusions We found a novel missense mutation in exon 1 of the EDA 1 gene in a putative Mayan family from México with XL ‐ HED . We identified in this population some novel clinical signs of HED .