In 28 of these 29 infants, a molecular screening for mutations in any of the LQTS genes KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, CAV3, and SCN4B, associated with the LQTS types 1–3, 5, 6, 9, and 10, respectively (Table 1), was performed. Here, SCN5A is linked to familial long QT syndrome.