SCN8A mutations in mice result in ataxia, tremor, and dystonia; in humans, SCN8A haploinsufficiency is associated with intellectual disability, while hyperactivity can contribute to pathogenesis of epileptic encephalopathy (O'Brien and Meisler, 2013; Meisler, 2019). The gene discussed is SCN8A; the disease is Epileptic encephalopathy.