KCNQ1 and catecholaminergic polymorphic ventricular tachycardia: In total, 5 of the 105 (5%) identified mutations had occurred de novo in the index patient (four LQTS mutations and one CPVT mutation, KCNQ1 p.T169R, KCNH2 p.E95G, KCNH2 p.Q61R, SCN5A p.V411M, and RYR2 p.S2246L, see Table 2).