SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: The SCN1A gene encodes the alpha subunit Nav1.1 of the voltage-gated Na+ channel and plays a crucial role in the pathogenesis of several monogenic epilepsy syndromes, including genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome [21, 22].