Also, patients with the same electroclinical syndrome do not always share the same underlying cause (West syndrome, Lennox‐Gastaut syndrome, and epilepsy with CSWS), and the same etiologic factor may be associated with a range of epilepsy phenotype expression; for example, SCN1A mutations lead to GEFS + and Dravet syndrome.26 The gene discussed is SCN1A; the disease is developmental and/or epileptic encephalopathy with spike-wave activation in sleep.