In contrast, loss-of-function Scn1A mutations are associated with genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome, consistent with decreased activity of inhibitory GABAergic neurons (Escayg and Goldin, 2010; Ruffolo et al., 2018). Here, SCN1A is linked to encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.