Among these variants, most HCM-associated variants were derived from MYBPC3 and MYH7; most ARVC-associated variants were derived from PKP2 and DSP; most LQTS-associated variants were derived from KCNQ1, KCNH2 and SCN5A; most BrS-associated variants were derived from SCN5A and CACNA1C; most CPVT-associated variants were derived from RYR2. The percentage of pathogenic/likely-pathogenic variants was high in LQTS and HCM, accounting for 51.9% and 45.5%, respectively (Fig 2). This evidence concerns the gene KCNQ1 and familial long QT syndrome.