Pilot study of gas chromatographic-mass spectrometric screening of newborn urine for inborn errors of metabolism after treatment with urease

J Chromatogr B Biomed Sci Appl. 1999 Aug 6;731(1):141-7. doi: 10.1016/s0378-4347(99)00205-4.


Gas chromatographic-mass spectrometric (GC-MS) techniques for urinary organic acid profiling have been applied to high-risk screening for a wide range of diseases, mainly for inborn errors of metabolism (IEM), rather than to low-risk screening or mass screening. Using a simplified procedure with urease-pretreatment and the GC-MS technique, which allows simultaneous determination of organic acids, amino acids, sugars and sugar acids, we performed a pilot study of the application of this procedure to neonatal urine screening for 22 IEM. Out of 16,246 newborns screened, 11 cases of metabolic disorders were chemically diagnosed: two each of methylmalonic aciduria and glyceroluria, four of cystinuria, and one each of Hartnup disease, citrullinemia and alpha-aminoadipic aciduria/alpha-ketoadipic aciduria. The incidence of IEM was thus one per 1477, which was higher than the one per 3000 obtained in the USA in a study targeting amino acids and acylcarnitines in newborn blood spots by tandem mass spectrometry. Also, 227 cases were found to have transient metabolic abnormalities: 108 cases with neonatal tyrosinuria, 99 cases with neonatal galactosuria, and 20 cases with other transient metabolic disorders. Two hundred and thirty-eight cases out of 16,246 neonates (approximately 1/68) were thus diagnosed using this procedure as having either persistent or transient metabolic abnormalities.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gas Chromatography-Mass Spectrometry / methods*
  • Humans
  • Infant, Newborn
  • Metabolism, Inborn Errors / urine*
  • Neonatal Screening / methods*
  • Pilot Projects
  • Urease / metabolism*


  • Urease