5-oxoprolinuria: biochemical observations and case report.

We have studied a patient with 5-oxoprolinuria who presented with hemolysis and metabolic acidosis as a neonate; he has had normal growth and development to one year of age. Compensated hemolytic anemia persists, and he requires alkalinizing agents for correction of acidosis. Biochemical studies have confirmed that a deficiency of glutathione synthetase is responsible for the 5-oxoprolinuria. Genetic heterogeneity was apparent on comparative study of glutathione synthetase kinetics in cells from two patients with this disorder. The consequences of the deficiency of glutathione synthetase, decreased intracellular glutathione, and overproduction of 5-oxoproline are discussed with reference to the possible cellular roles of these compounds.