[Keratin 17 mutation in pachyonychia congenita type 2 in a Chinese Han family]

To investigate the keratin 17 gene (KRT17) mutation in a pedigree with pachyonychia congenita type 2 (PC-II).

DNA was extracted from the blood samples of the patients, unaffected members of the pedigree, and 100 unrelated healthy controls. PCR was performed to amplify the hot spots in KRT17 gene. PCR products were directly sequenced to detect mutation.

A heterozygous 296T-->C mutation was found in all the affected members of this family, which resulted in the substitution of leucine by proline in codon 99 (L99P) in the 1A domain of the KRT17, but not in the healthy individuals from the family and the 100 unrelated controls.

The mutation of KRT17 may play a major role in the pathogenesis of this pedigree with pachyonychia congenita type 2.