Amino acid analysis is one of the most frequently requested tests in the selective screening of inherited metabolic disease. To date, at least 57 primary defects of amino acid catabolism/biosynthesis are known, most of these associated with clinical symptoms. The differential diagnosis of the aminoacidopathies requires the quantitative analysis of not only the 20 physiological amino acids, but also more than 50 unusual amino acids, which may be of key diagnostic importance. Historically, the amino acid analysis was developed using cation-exchange liquid chromatography with lithium citrate buffers as eluents and post-column ninhydrin reaction with photometric detection (amino acid analyzer). This technique is widespread in use. High-performance liquid chromatography with pre-column derivatisation is versatile and cost-effective, but has some limitations. The recently introduced tandem mass spectrometry approach is a promising technique which may prove to be superior on the long run. Knowledge of the nutritional state, age of the patient, potentially interfering drugs and other secondary changes is summarized in this chapter as an aid in the diagnosis of primary inherited defects of amino acid metabolism.
KeywordsPipecolic Acid Tyrosinemia Type Lysinuric Protein Intolerance Ornithine Carbamoyltransferase Plasma Amino Acid Level
Unable to display preview. Download preview PDF.
- 1.Blau N, Duran M, Blaskovics ME, Gibson KM (2003) Physician’s Guide to the Laboratory Diagnosis of Metabolic Diseases. Springer Verlag, Berlin, pp 1–716Google Scholar
- 2.Bremer HJ, Duran M, Kamerling JP, Przyrembel H, Wadman SK (1981) Disturbances of Amino Acid Metabolism: Clinical Chemistry and Diagnosis. Urban Schwarzenberg, München, pp 1–525Google Scholar
- 3.Clarke JTR (2006) A Clinical Guide to Inherited Metabolic Diseases. Cambridge University Press, Cambridge, UK, pp 1–338Google Scholar
- 4.Fernandes J, Saudubray JM, Van den Berghe G, Walter J (2006) Inborn Metabolic Diseases. Springer Verlag, Berlin, pp 1–438Google Scholar
- 8.Piraud M, Vianey-Saban C, Bourdin C, Acquavica-Bourdain C, Boyer S, Elfakir C, Bouchu D (2005) A new reversed-phase liquid chromatographic/tandem mass spectrometric method for analysis of underivatized amino acids: evaluation for the diagnosis and the management of inherited disorders of amino acid metabolism. Rapid Commun Mass Spectrom 19:3287–3297PubMedCrossRefGoogle Scholar
- 10.Scriver CR, Beaudet AL, Sly WS, Valle D, Childs B (2001) The Metabolic and Molecular Basis of Inherited Disease. McGraw-Hill, New York, pp 1–6338Google Scholar
- 12.Zschocke J, Hoffmann GF (2004) Vademecum Metabolicum. Schattauer, Milupa, Friedrichsdorf, pp 1–164Google Scholar