Analysis of urinary markers for ornithine transcarbamylase deficiency by gas chromatography-mass spectrometry / 基础医学与临床

ABSTRACT

Objective To develope both qualitative and quantitative analytic method of the four urinary markers,i.e.lactate,uracil,orotate and hippurate,from ornithine transcarbamylase deficiency(OTCD) by Gas Chromatography-Mass Spectrometry(GC-MS).Methods Urea in urine samples was decomposed with urease,and heptadecanoiate was added as internal standard,then protein was denatured with ethanol and removed by centrifugation.After evaporation,the residue was derivatized trimethylsilylly by BSTFA/TMCS,and analyzed by GC-MS.ResultsThe markers can be separated in total ion current profiles,with indentifications confirmed by mass spectra.The significantly elevated levels of lactate,uracil and orotate in urine from OTCD patient were droped to normal or subnormal levels,together with large amount of hippurate excretion in the urine,after clinical therapeutic measures,including introduction of benzoic acid,were performed.Conclusion GC-MS analysis of the urinary markers is a valuable tool for the diagnosis and evaluation of the therapeutic outcome of OTCD.