GAS-CHROMATOGRAPHIC MASS-SPECTROMETRIC METABOLIC PROFILING OF PATIENTS WITH FATAL INFANTILE MITOCHONDRIAL MYOPATHY WITH DE TONI-FANCONI-DEBRE SYNDROME

The metabolic profiles of three patients with fatal infantile mitochon drial myopathy with de Toni-Fanconi-Debre syndrome were studied by sim ultaneous analysis, after urease treatment of urinary organic acids, c arbohydrates, polyols and amino acids using gas chromatography/mass sp ectrometry (GC/MS). All three patients persistently showed lactic acid uria, phosphaturia, glucosuria and generalized amino aciduria. This ab normal urinary metabolic profile was observed before the onset of any clinical symptoms, indicating that chemical diagnosis may be done pres ymptomatically. In one patient, the concentration of lactate increased in parallel with the severity of the clinical condition, whereas the urinary levels of 3-hydroxybutyrate, amino acids and glucose fluctuate d and showed only a general tendency to increase with the clinical cou rse. The above results suggest that simultaneous GC/MS analyses, witho ut fractionation, of urinary metabolites facilitate not only the early chemical diagnosis either before or after the first onset, but also f ollow-up studies, providing an important index for the evaluation of t he severity and clinical course in patients with this disorder.