KCNH2 and familial long QT syndrome: Zhao et al. in 2009 determined that p.G572S causes a dominant negative trafficking defect.44 KCNH2:p.F627L was first identified by Splawski et al. in 2000 as part of his LQTS screen of 262 probands45 and later was reported to be the cause of LQTS with foetal onset of atrioventricular block and ventricular tachycardia.46