Common KCNH2 Polymorphism (K897T) as a genetic modifier of congenital long QT syndrome

Abstract

in none of 34 controls. None of these mutations was found in the 200 normal alleles. Mutations in SCN5A were found in 8/16 (50%) SIDS cases, in KCNH2 in 6/16 (37%) cases and in KCNQ1 in 2/16 (13%) cases. The conclusions of this still ongoing study have to take into account the fact that 35-40% of patients unquestionably affected by LQTS still escape identification of the responsible mutation. Thus, the present findings strongly suggest that LQTS accounts for 12-15% of SIDS victims. As sudden death due to LQTS can be effectively prevented, early identification and proper therapy of the affected infants becomes imperative. This requires the performance of an ECG during the first month of life.