Studies on the urinary acidic metabolites from three patients with methylmalonic aciduria.

By gas chromatographic mass spectrometric analysis, 2-methyl-3-oxovaleric acid, 3-oxovaleric acid, 3-hydroxyvaleric acid and 2-methyl-3-hydroxybutyric acid were identified in the urine from three patients with methylmalonic aciduria. The level of 2-methyl-3-oxovaleric acid increased with the increase of methylmalonic acid concentration and the level of 3-oxovaleric acid increased with the increase of ketone bodies. It was demonstrated that these metabolites are detectable from patients with propionic acidemia and methylmalonic aciduria when propionyl CoA accumulates in the cells of the patients either primarily or secondarily.