[2-Methyl-3-oxovaleric acid: a characteristic metabolite in propionic acidemia].

Urine samples from 9 patients with propionic acidemis were analyzed with respect to secondary propionyl-CoA metabolites by means of gas chromatography-mass spectrometry. A wide range of variation was observed. The presence of methylcitric and 2-methyl-3-oxovaleric acids, however, was demonstrable in all urines investigated in considerable amounts. For laboratories analyzing urinary organic acids as their methyl esters, 2-methyl-3-oxovaleric acid is considered to be of diagnostic value. In addition to the usual metabolites, the excretion of N-2-methylbutyrylglycine has been demonstrated in the urine of one patient with propionic acidemia.