KCNQ1 and familial long QT syndrome: He carried four rare variants: KCNQ1_p.Ala590Thr [previously reported as a cause of LQTS in HGMD (CM040442), classified as an LP by ACMG, and also as LP by ClinVar for LQTS], RyR2_p.Val93Metfs*29 (novel and classified as P), MYBPC3_p.Arg273Cys [classified in HGMD as potentially deleterious for hypertrophic cardiomyopathy (HCM), classified as VUS by ACMG, and also considered VUS by ClinVar for HCM], and TTN_p.Glu20374Lys -classified as VUS by ACMG and also predicted as VUS by ClinVar for dilated cardiomyopathy (DCM)-.