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. This evidence concerns the gene KCNQ2 and Epileptic encephalopathy.