SCN1A and Dravet syndrome: Pathogenic alterations in SCN1A (associated with Dravet syndrome, a genetic epileptic encephalopathy in which a SCN1A loss-of-function mutation is found in 80% of cases) or in SCN8A (associated with early-infantile encephalopathy) are examples of variants co-expressed in both brain and heart that increase the risk of SUDEP [38].