ANK2 and catecholaminergic polymorphic ventricular tachycardia: Variations in genes implicated in cardiac calcium signaling have been shown to cause a number of arrhythmia syndromes, including long-QT syndrome 4 (ANK2) and 8 (CACNA1C), Brugada syndrome (CACNA1C) and catecholaminergic polymorphic ventricular tachycardia (RyR2).