Molecular diagnosis of X-linked hypohidrotic ectodermal dysplasia families

Abstract

Objective To explore the mutations of EDA gene in 2 X-linked hypohidrotic ectodermal dysplasia(XLHED) pedigrees, and provide clues for the XLHED diagnosis, genetic counseling and treatment. Methods Polymerase chain reaction and direct sequencing were used to analyze the coding sequences and their flanking sequences of the EDA gene in the patients, suspicious carriers, normal family members in 2 families and non-relative control samples. Results In family 1, mutation c. 659_676del18, namely p. 220_225del(Gly-X-Y)6 which was located in(Gly-X-Y)19 collagen-like repeat domain, was found in the proband and other patient's EDA gene.In family 2, an insertion c. 118-119insT was found in the intracellular domain, which induces reading frame alteration from the 40th amino acid.The mutations found in the 2 families were consistent with the principle of mutation and phenotype co-separation, but these mutations were not found in the normal control samples.EDA gene analysis of fetal amniotic fluid sample from Ⅲ-1 in the family 1 was not found to have the same mutation as the proband, and the follow-up after birth proved normal for the baby. Conclusions EDA gene c. 118-119insT mutation found in the research is a novel mutation.Sequence analysis of EDA gene is an efficient method in XLHED diagnosis, and is beneficial for the genetic counseling and the genetic intervention of the disease in the affected families. Key words: Hypohidrotic ectodermal dysplasia; EDA gene; Molecular diagnosis