According to a study by Wang et al. [46] of 274 cases of sudden unexplained death in neonates (141 cases) and non-neonates (133 cases), LQTS-associated mutations were detected in 13.4% of infant cases, with the SCN5A gene representing the most common genetic alteration; however, SIDS-related mutations were also detected in the KCNQ1, KCNH2, KCNE2 genes. This evidence concerns the gene KCNH2 and familial long QT syndrome.