Research progress in HERG potassium channel and long QT syndrome

The human ether-a-go-go-related gene(HERG) channel,a member of the family of voltage-gated potassium(K+) channels,plays a critical role in repolarization of the cardiac action potential.Reduction in HERG channel activity resulted from genetic mutations or drug blocking effects may cause congenital or acquired long QT syndrome(LQTS) and potentially leads to torsades de pointes(TdP).Congenital LQTS exemplifies one of the best understood inherited cardiac disorders so far.Nearly 300 HERG mutations are linked to LQT-2.In the last decade,drug-induced QT interval prolongation has become the major safety issue in the development of pharmaceuticals,superseding liver injury in the primary causes of drug withdrawals.Thus,HERG channels are closely related with arrhythmia.This review summarized the recent progress of structure and functions of HERG channel,HERG-related congenital or acquired LQTS,TdP and HERG-mediated evaluation of cardiac toxicity.