The screening of inborn errors of metabolism in sick Chinese infants by tandem mass spectrometry and gas chromatography/mass spectrometry.

ABSTRACT

BACKGROUND: Analyses of amino acid/acylcarnitines in dried blood spots (DBS) and organic acids in urine are the primary tests for inborn errors of metabolism (IEMs). Automated tandem mass spectrometry (MS/MS) and gas chromatography/mass spectrometry (GC/MS) can rapidly and simultaneously detect numerous metabolic compounds with high precision and sensitivity. METHODS: Three thousand four hundred and twenty-nine DBSs and 2781 urine samples were collected from our hospital patients with suspected IEMs, and analyzed for amino acid/acylcarnitines and organic acids by MS/MS and GC/MS, respectively. The results were used in a coincidental survey to determine the efficacy of these methods for the diagnosis of IEMs. RESULTS: Nineteen different types of IEMs were detected in 121 affected cases (1.95% of 6210 samples). There were 66.12% amino acid disorders, 29.75% organic acid disorders and 4.13% with fatty acid oxidation disorders. CONCLUSIONS: the sick infants tested in this study had high prevalence rates of neonatal intrahepatic cholestasis, methylmalonic acidemia, hyperphenylalaninemia, tyrosinemia type I, and urea cycle disorders. CONCLUSION: The combined use of MS/MS and GC/MS is an appropriate tool for screening of IEMs in sick infants.