Sudden unexpected death in epilepsy (SUDEP) is known to occur, possibly because of lethal cardiac arrhythmias following severe seizures in Scn1a knock-in R1407X DS mouse model (Auerbach et al., 2013) and Scn1a+/− knock-out DS mouse model (Kalume et al., 2013). The gene discussed is SCN1A; the disease is cardiac arrhythmia.