Any early infantile epileptic encephalopathy in which the cause of the disease is a mutation in the SPTAN1 gene. The disease is developmental and epileptic encephalopathy, 5 (Monarch Disease Ontology identifier MONDO_0013277). Also known as: DEE5, EIEE5, SPTAN1 early infantile epileptic encephalopathy, developmental and epileptic encephalopathy 5, early infantile epileptic encephalopathy caused by mutation in SPTAN1, epileptic encephalopathy, early infantile, 5, epileptic encephalopathy, early infantile, type 5.