SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: SCN1A variants are transmitted in an autosomal dominant pattern; however, incomplete penetrance and variable expressivity have been recorded, further adding to the great variability of phenotypes, the first of which is currently known as Dravet syndrome, previously SMEI, as described by the French neurologist Charlotte Dravet in 1978 [13].