One individual was heterozygous for the MYBPC3 p.Gly531Arg pathogenic variant associated with hypertrophic cardiomyopathy (HCM), and two individuals were heterozygous for the KCNQ1 p.Arg397Trp (LP) variant implicated in long QT syndrome (LQTS). The gene discussed is MYBPC3; the disease is Prolonged QT interval.