The Second Deletion Mutation in Exon 8 of EDA Gene in an XLHED Pedigree

Abstract

Background: X-linked hypohidrotic ectodermal dysplasia (XLHED) is characterized by hypodontia, hypohidrosis, sparse hair and characteristic facial features and is caused by mutation in the ectodysplasin A (EDA) gene. Objective: In this study we report on a large Chinese XLHED family and investigate the molecular genetics of the defect. Methods: All individuals of the family were examined by clinical and radiographic examinations. The EDA gene was sequenced in the whole family and in 150 controls. Results: Three male patients had classic XLHED phenotype. A novel one-nucleotide deletion mutation (c.855delG) in exon 8 which caused premature termination of the polypeptide at amino acid 307 was confirmed. The mutant lost parts of the TNF domain may prevent transmission of the intracellular downstream signal. This was the second deletion mutation in exon 8 that was reported in a Chinese individual. Conclusions: Our findings suggested deletion mutations in exon 8 might be specific to the Chinese population.