Developmental and Epileptic Encephalopathy 1, also known as epileptic encephalopathy, early infantile, 1, is related to developmental and epileptic encephalopathy 2 and intellectual developmental disorder, x-linked 29, and has symptoms including dyspnea, muscle spasticity and myoclonic seizures. An important gene associated with Developmental and Epileptic Encephalopathy 1 is ARX (Aristaless Related Homeobox), and among its related pathways/superpathways are Dopamine-DARPP32 Feedback onto cAMP Pathway and Neuroscience. Affiliated tissues include brain and eye, and related phenotypes are intellectual disability and spasticity