Relationship between Ion Channel Genes KCNQ1, KCNH2 and Familial Sudden Death

Objective To ascertain the relation of ion channel genes KCNQ1 and KCNH2 to familial sudden death (FSD), so as to explore the molecular genetic mechanism by which such disease might occur.Methods In a large family affected with sudden death, PCR DNA direct sequencing was performed to screen all exons and their flanking introns of genes KCNQ1 and KCNH2 for mutations.Results In this family, 4 mutations were identified in gene KCNQ1, 3 of those were located in exons, but they all were nonsense mutation; and the other one, in introns. Incidentally, no mutation was observed in gene KCNH2.Conclusion Genes KCNQ1 and KCNH2 may not be responsible for FSD, although there exist polymorphisms in ion channel gene KCNQ1. A certain gene or more other than KCNQ1 and KCNH2 genes might contribute to FSD.