Genetic and clinical advances in congenital long QT syndrome

Congenital long QT syndrome (LQTS) is an inherited arrhythmia syndrome characterized by a prolonged QT interval on the 12-lead ECG, torsades de pointes and a higher chance of sudden cardiac death. LQTS segregates in a Mendelian fashion, which includes Romano-Ward syndrome with an autosomal dominant pattern as well as a rare autosomal recessive pattern (Jervell and Lange-Nielsen syndrome). Since 1957 when Jervell and Lange-Nielsen reported the first familial LQTS with congenital deafness, progress in understanding the genetic and electrophysiological mechanisms of LQTS has tremendously improved diagnostic methods and treatments. In the meantime, it has become evident that LQTS may not always be explained by a single gene mutation, but seems to follow a more complex genetic model intertwined with genetic common polymorphisms that have a mild to moderate effect on disease expression. In this review, we summarize the characteristics of LQTS (mainly LQT1-3) and briefly describe the most recent advances in LQTS clinical diagnostics as well as genetics.