KCNQ1 and Prolonged QT interval: These included the KCNQ1 NM_000218.3:c.1552 C > T, p.(Arg518Ter) Swedish founder mutation.; associated with a milder long-QT syndrome phenotype20, and the PKP2 NM_004572.3:c.2146-1 G > C variant; associated with incomplete segregation in families affect by arrhythmogenic right-ventricular cardiomyopathy21.