SCN8A and developmental and epileptic encephalopathy, 13: Missense mutations of SCN8A accounting for 1% of EE are associated with a wide-spectrum phenotype of heterogenous epilepsy, and SCN8A missense mutations are recently recognized to be associated with early infantile epileptic encephalopathy type 13, ref. [15–18] which displays multiple seizure types, including focal seizures, generalized seizures (tonic, myoclonic, absence) and epileptic spasms.