Dravet syndrome (DRVT) is a rare form of neurodevelopmental disorder with a high risk of sudden unexpected death in epilepsy (SUDEP), caused mainly (>80% cases) by mutations in the SCN1A gene, coding the Nav1.1 protein (alfa-subunit of voltage-sensitive sodium channel). The gene discussed is SCN1A; the disease is encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.