However, a recent line of evidence shows that some KCNQ2 mutations also cause early onset epileptic encephalopathies (EOEEs) or early infantile epileptic encephalopathies (EIEE), such as Ohtahara syndrome [8–12], which are associated with intractable seizures followed by profound psychomotor delay. The gene discussed is KCNQ2; the disease is early-infantile DEE.