Mutations in SCN1A, the gene that encodes the α subunit of voltage-gated sodium channel Nav1.1, can cause epilepsies with wide ranges of clinical phenotypes, from the relatively benign genetic epilepsy with febrile seizures plus to the more severe Dravet syndrome.1, 2, 3, 4 Some of these epilepsies, such as Dravet syndrome,5 are therapy resistant, and the treatment of the rest is relied mainly on antiepileptic drugs. The gene discussed is SCN1A; the disease is encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy.