KCNJ2 and Ventricular arrhythmia: Short QT syndrome is a relatively recently-described cardiac channelopathy associated with a high risk of ventricular arrhythmia and sudden death (Priori et al., 2013), and mutations in KCNJ2 have recently been reported in patients with short QT syndrome and an autism–epilepsy phenotype (Ambrosini et al., 2014).