SCN5A and cardiac arrhythmia: A recent systematic review of the genetics of SUDEP concluded that the most prominent and frequent gene variants identified across studies were associated with ion channels – which may be co-expressed in the heart and brain and are causally related to some epilepsies (e.g., DS and SCN1A) and cardiac disorders (e.g., Brugada Syndrome and SCN5A) – and genes linked to cardiac arrhythmia phenotypes (25).