Three cases of LQTs carried a single pathogenic mutation of SCN5A p.R1880H (Clinic/ACMG = P/VUS, No.13, TdP and VF, ICD therapy), KCNH2 p.D161N (Clinic/ACMG = P/LP, No.21, VF, ICD therapy), and KCNQ1 p.R243S (Clinic/ACMG = P/LP, No.22, familial history of SCD, VF, ICD therapy), respectively (Table 2). Here, KCNQ1 is linked to Schnyder corneal dystrophy.