Any early infantile epileptic encephalopathy in which the cause of the disease is a mutation in the MDH2 gene. The disease is MONDO_0015025 (developmental and epileptic encephalopathy, 51). Also known as: DEE51, EIEE51, MDH2 early infantile epileptic encephalopathy, developmental and epileptic encephalopathy 51, early infantile epileptic encephalopathy caused by mutation in MDH2, epileptic encephalopathy, early infantile, 51, epileptic encephalopathy, early infantile, 51; EIEE51, epileptic encephalopathy, early infantile, type 51.