KCNH2 and familial long QT syndrome: Loss‐of‐function mutations in hERG are associated with the LQT2 form of the Long QT Syndrome (LQTS; Modell and Lehmann 2006), while gain‐of‐function hERG mutations are associated with the SQT1 variant of the short QT syndrome (SQTS; Brugada et al. 2004; Sun et al. 2011).