[The 521 T--> C mutation in the keratin 6A gene in a pedigree with pachyonychia congenita type I].

OBJECTIVE:To identify the mutation in the keratin 6A(K6A) gene in a pedigree with pachyonychia congenita type I (PC-I). METHODS:Blood samples were obtained from 2 affected, 3 unaffected members in this family, and 100 unrelated healthy individuals. Mutation detection was carried out by PCR amplification of the K6A gene and direct DNA sequencing. RESULTS:A heterozygous mutation of T--> C transition at position 521 in exon 1 of the K6A gene was found in the 2 affected, but not in the unaffected members and 100 unrelated healthy individuals. CONCLUSION:The mutation of 521T--> C in the K6A gene is the disease causing mutation in this PC-I family.