Novel missense mutation in the EDA1 gene identified in a family with hypohidrotic ectodermal dysplasia

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 (EDA1). We report the clinical and molecular analysis of a novel mutation in exon 1 affecting the transmembrane domain of the protein.

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 EDA1 gene from patients with XL-HED, carriers, and controls.

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 EDA1 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.

We found a novel missense mutation in exon 1 of the EDA1 gene in a putative Mayan family from México with XL-HED. We identified in this population some novel clinical signs of HED.