In our study, causal findings in either KCNQ1, KCNH2, or SCN5A were detected in 75% of the index patients, which corresponds to the reported worldwide estimates [51], and the vast majority (25/29, 86.2%) of these findings are established LQTS-causing variants, previously described by reputable sources. This evidence concerns the gene KCNQ1 and familial long QT syndrome.