1H-NMR spectroscopy of body fluids: inborn errors of purine and pyrimidine metabolism.

BACKGROUND The diagnosis of inborn errors of purine and pyrimidine metabolism is often difficult. We examined the potential of 1H-NMR as a tool in evaluation of patients with these disorders. METHODS We performed 1H-NMR spectroscopy on 500 and 600 MHz instruments with a standardized sample volume of 500 microL. We studied body fluids from 25 patients with nine inborn errors of purine and pyrimidine metabolism. RESULTS Characteristic abnormalities could be demonstrated in the 1H-NMR spectra of urine samples of all patients with diseases in the pyrimidine metabolism. In most urine samples from patients with defects in the purine metabolism, the 1H-NMR spectrum pointed to the specific diagnosis in a straightforward manner. The only exception was a urine from a case of adenine phosphoribosyl transferase deficiency in which the accumulating metabolite, 2,8-dihydroxyadenine, was not seen under the operating conditions used. Similarly, uric acid was not measured. We provide the 1H-NMR spectral characteristics of many intermediates in purine and pyrimidine metabolism that may be relevant for future studies in this field. CONCLUSION The overview of metabolism that is provided by 1H-NMR spectroscopy makes the technique a valuable screening tool in the detection of inborn errors of purine and pyrimidine metabolism.