SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: Dravet syndrome is one of the most serious epilepsy syndromes in early childhood and is usually characterized by febrile epileptic status with a high childhood mortality rate (up to 15%).[32] In 70–80% of individuals with Dravet syndrome, its pathogenesis is related to a mutation in the sodium channel alpha 1 subunit gene (SCN1A).[33]