A novel mutation of KRT9 gene in a Chinese Han pedigree with epidermolytic palmoplantar keratoderma.

BACKGROUND: Mutations of keratin 9 (KRT9) gene is a hot research area of epidermolytic palmoplantar keratoderma (EPPK).

AIMS: To identify the genes caused the EPPK of a Chinese family.

PATIENTS/METHODS: Three cases of lesions were collected for pathological examination. Genomic DNA was extracted from peripheral blood samples of six patients and five healthy individuals and 100 unrelated individuals. Polymerase chain reaction (PCR) was used to amplify exons 1 of KRT9 gene. PCR products were sequenced to identify potential mutations.

RESULTS: The lesion pathology of the proband and two ill relatives diagnosed EPPK. A new heterozygous missense mutation (488G>T) was identified in the 488 site of exon 1 of KRT9 gene in all six patients, which resulted in substitution of thymine for guanine, and substitution of leucine acid for arginine acid at position 163 of the KRT9 protein. The same mutation was not found in the five healthy individuals of the family and 100 unrelated individuals.

CONCLUSIONS: The new heterozygous missense mutation (488G>T) of KRT9 gene is probably the cause of EPPK in this Chinese family.