SCN5A and familial long QT syndrome: Over 3 decades later, in 1995, the first genes thought to underlie the pathophysiology of LQTS were discovered by Mark Keating’s research team.4,5 Their identification of rare genetic variants in the KCNH2-encoded Kv11.1 potassium channel and the SCN5A-encoded Nav1.5 sodium channel in families with LQTS was revolutionary in our understanding of not only this condition but also all inherited arrhythmia syndromes.