In models of Dravet syndrome, abnormal dendritic arborization is a pathological manifestation of Scn1a−/− deletion and has been hypothesized to contribute to loss of GABAergic tone in regions of the brain most affected by Dravet syndrome (Table 1). Here, SCN1A is linked to encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.