DPP6 and cardiac arrhythmia: The inherited arrhythmia syndromes most strongly associated with mental stress-induced arrhythmias and SCA are long QT syndrome type 2 (LQTS2) (45), catecholaminergic ventricular tachycardia (CPVT) (46) and an idiopathic VF syndrome linked to a risk haplotype that contains the DPP6 gene (5).