For example, the gain-of-function T226M mutation in Scn1a has been found in children with developmental and epileptic encephalopathy (Berecki et al., 2019) and gain-of-function mutations in Scn2a have been shown to elicit seizures, behavioral arrest, and behavioral abnormalities in mice (Kearney et al., 2001). The gene discussed is SCN2A; the disease is Epileptic encephalopathy.