SCN5A and sudden infant death syndrome: Ion channel genes such as KCNQ1, KCNH2, SCN5A, RYR2, and their molecular modifiers such as GPD1L and β-subunits account for ~10–15% of all SIDS cases, in which SCN5A variants account for approximately half of the channelopathic SIDS cases (Tan et al., 2010; Tester et al., 2018).