SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: The SCN1A gene pathogenic variants are identified in the spectrum of disorders from the most severe non-Dravet DEEs (DEE6B, MIM 619317) Dravet syndrome (DRVT/DS, MIM 607208) to milder syndromes, such as generalized epilepsy with febrile seizures plus type 2 (GEFS+ 2/GEFSP2, MIM 604403).