Organic acidemias.

Inherited organic acidemias are a group of metabolic disorders currently being described and investigated as gas-liquid chromatography is applied to unexplained diseases of infancy and childhood. Common clinical presentations include attacks of ketoacidosis, unexplained metabolic acidosis, failure of normal development, seizures, and other neurologic abnormalities. Hyperglycinemia, hyperammonemia, and hypoglycemia are other laboratory findings frequently present. Diagnosis depends on examination of urine, and sometimes blood, by gas-liquid chromatography to measure concentrations of organic acids and organic acid derivatives. Prognosis in many cases is excellent if diagnosis is made promptly and the metabolic acidosis can be reversed. Recovery from neurologic deficits has frequently been seen. Long-term therapy is generally dependent on restricting precursors of the toxic organic acid which builds up as a consequence of the enzyme deficiency. If there is some enzyme activity retained or if alternate metabolic pathways exist, success with therapy is likely.