Keratin 17 Gene Mutation in a Pedigree with Pachyonychia Congenita typeⅡ / 中华皮肤科杂志

ABSTRACT

Objective To investigate the gene mutation in a pedigree with pachyonychia congenita typeⅡ(PC-Ⅱ)and to explore the relationship between the mutation and clinical manifestations.Methods The exon1of K17gene of genomic DNA from peripheral blood was amplified by PCR,and the PCR products were sequenced by automated sequencing system.Results In all the3patients of the pedigree with PC-Ⅱ(2patients presented as delayed-onset PC at4and15-16years of age respectively),the codon92(AAT)of K17gene was mutated as AGT,which caused missense mutation(N92S)in the1A domain of keratin17,but the2unaffected members of the pedigree and50unrelated controls had no such mutation.Conclusions Mutation of N92S in the1A domain of keratin17exists in this pedigree with PC-Ⅱ.Our results indicate that mutation in the1A domain of keratin17can present as delayed-onset pachyonychia congenita.Therefore,the site and type of keratin mutation are not the sole determinant of the age of onset for PC-Ⅱ,there may be other genetic and/or environmental factors that determine the age of onset of PC-Ⅱ.