Use of proton nuclear magnetic resonance spectroscopy in detection and study of organic acidurias.

We used high-resolution proton nuclear magnetic resonance spectroscopy to detect, identify, and study the major normal and abnormal organic acid metabolites in urine from patients with propionic acidemia, methylmalonic aciduria, branched-chain ketoaciduria, isovaleric acidemia, and glutaric aciduria type I. Characteristic and diagnostic spectra were obtained at 400 MHz for each disorder in all the patients studied and neutral and basic compounds, including amino acids and acylcarnitines, were also detected. The technique is rapid (10 min) and requires small samples (0.5 mL) and no preliminary extraction or derivative preparation. We believe that it is particularly suitable for the rapid and acute diagnosis of inborn errors of metabolism, especially the organic acidurias, and for acute pediatric clinical care, when rapid monitoring of major metabolic alterations is required in a time scale suitable to influence directly and immediately the therapy of the patients concerned.