L-2-Hydroxyglutaric aciduria: an inborn error of metabolism?

A 5-year-old boy, excreting large amounts of 2-hydroxyglutaric acid in the urine (3.3-7.6 mmol/l), is described. The patient presented with psychomotor retardation and dystrophy. His skeletal age was delayed. The EEG was not well differentiated; it resembled that observed in 2-year-old children. There was a severe anaemia, which reacted well to iron supplements. The 2-hydroxyglutaric acid was found to have the L-configuration, as analysed by capillary gas chromatography of the O-acetylated di-(-)-2-butyl ester derivative. The relation of L-2-hydroxyglutarate excretion to known metabolic pathways is discussed.