SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: The vast majority of Dravet syndrome cases are caused by a LoF mutation in one allele of the SCN1A gene, resulting in voltage-gated sodium channels with a non-functional NaV1.1 subunit primarily in inhibitory GABAergic neurons, leading to hyperexcitability and seizures associated with high risk of sudden infant death (Samanta, 2020).