This syndrome is generally due to a cerebral anomaly (brain malformations, brain lesions, etc.)or genetic abnormalities (trisomy 21, mutation of the ARX or STK9 gene) [5, 6]; The second, called Lennox-gastant syndrome is a severe form of epileptic encephalopathy that affects 2 to 6 year-old children, this condition is characterized by psychomotor retardation accompanied by different types of frequent crises (tonic, axial, diurnal and nocturnal crises, etc.)[7]. The gene discussed is ARX; the disease is Epileptic encephalopathy.