SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: We found that early postnatal induction (P2) of Scn1a haploinsufficiency recapitulated phenotypes of classic Dravet syndrome models and that, similarly, P30- and P60-induced mice displayed seizures and SUDEP, accompanied with GABAergic interneurons dysfunction that was evident in all three groups of mice at their specific symptom onset.