[Mutation analysis and prenatal diagnosis of keratin 9 gene in a large Chinese family with epidermolytic palmoplantar keratoderma]

Abstract

Objective: To analyze potential mutation in keration 9 (KRT9) gene in a large Chinese family with epidermolytic palmoplantar keratoderma (EPPK) and to perform prenatal diagnosis on the fetus at 10th gestational week.

Methods: Peripheral venous blood samples were obtained from 5 affected and 8 unaffected individuals of the family. Fifty unrelated healthy individuals were also recruited as controls. PCR was used to amplify exons 1 and 6 of KRT9 gene, and the products were sequenced directly. After the mutation was confirmed, prenatal diagnosis was performed on the fetus during the first trimester of pregnancy.

Results: A heterozygous missense mutation c.482A to G in the KRT9 gene, which has led to substitution of Asparaginate by Serine at codon 161 (p.N161S), was detected in all patients but not in other individuals of the family and the 50 healthy controls. The fetus was found to have carried the p.N161S mutation too. Following selected abortion, analysis of fetal tissue was consistent with prenatal diagnosis.

Conclusion: The missense mutation c.482A to G (p.N161S), which has been shown previously to cause EPPK, is found in the KRT9 gene of patients in this family. Gene mutation analysis for prenatal diagnosis is efficient to facilitate detection of affected fetus in time.