Missense mutation of EDA1 gene in Japanese family with X-linked anhidrotic ectodermal dysplasia

Abstract X-linked anhidrotic ectodermal dysplasia (XLHED) is characterized by hypoplasia or absence of hair, teeth and sweat glands. In this study, the authors investigated the ectodysplasin-A1 (EDA1) gene was investigated in a Japanese family in which male member, a child, fulfilled the diagnostic for XLHED. The only affected male fulfils the diagnostic criteria for this disorder. His parents were not consanguineous and both of them were healthy. With informed consent, genomic DNA was isolated from oral buccal epithelial cells from all members of the family. Polymerase chain reaction fragments containing nine exons of the EDA1 gene were amplified. Amplified fragments from both the patient and the parents were directly sequenced. The sequence from the patient revealed a missense mutation (G643A) in exon 5 of the EDA1 gene, which changes codon 215 from glycine to arginine. Heterozygosity was demonstrated in the mother. The present results indicate that amino acid substitution occurs, disrupting the transmembrane domain, and strongly suggest that this was the disease-causing mutation in this family.