A novel EDA gene mutation in a Spanish family with X-linked hypohidrotic ectodermal dysplasia.

X-linked hypohidrotic ectodermal dysplasia (XLHED) is characterized by abnormal development of the hair, teeth, and sweat glands. It is caused by mutations in the EDA gene, which maps to the X chromosome and encodes a protein called ectodysplasin-A, a member of the tumor necrosis factor-related ligand family. Affected males typically exhibit all the typical features of HED, but heterozygous carriers may show mild to moderate clinical manifestations. We describe the case of a Spanish family in which a novel heterozygous c.733_734insGA mutation at the EDA gene was identified. It was located in exon 5 and consisted of a frame-shift mutation at codon 245, which gave rise to an abnormal protein with a premature stop codon after 35 residues. Genetic analyses in families with XLHED are useful for checking carrier status, but they also provide information for genetic counseling and prenatal diagnosis.