SCN2A and Dravet syndrome: Ever since the first case of SCN2A mutation-induced benign (familial) neonatal/infantile seizure was discovered and confirmed in 2001, the epilepsy spectrum as provoked by SCN2A mutations has continuously expanded to include OS syndrome, infantile spasms, EIMFS, DS, myoclonic-atonic epilepsy, LGS, GEFS+, and other unclassified severe EE (15, 16).