--- Query Results ---

Program:Genetics and Genomics
Test Name:Amino Acids, plasma (G&G South ACH)
Test Code:AA-P
Performing Site: Alberta Children's Hospital
Performing Dept:Biochemical Genetics
Availability:Test performed on a daily basis.
TAT:7 days
Preferred Tube/Container:Sodium heparin (dark green - NOT PST)
Alternate:Lithium heparin (dark green - NOT PST)
Specimen Requirements:1.  Collect 1 x 4.0 mL sodium heparin tube (or alternate tube type).
2.  Collect following a minimum four-hour fast; or just before next feed for newborns.
3.  Indicate length of fast, or time of last feeding on the requisition (with collection time).
4.  Physician test requests from known metabolic patients (non-fasting) are also acceptable.
Min. Sample Required:0.25 mL plasma
Specimen Processing:At ACH only
The primary heparinized tube can be put on ice (ensure not to freeze sample) or refrigerated for routine pick-ups between 8:30 am – 2:30 pm, Monday through Friday.

For all other collections
1. Centrifuge.
2. Transfer plasma or serum to aliquot tube.
3. Write "NaHep" or "LiHep" on the aliquot tube label.
4. Freeze.
Specimen Handling:Transport frozen samples on ice. Samples must not thaw during transport.
Additional Information:Samples will be rejected if:
  • Primary tube not refrigerated
  • Aliquot tube received thawed
  • Tube type not written on aliquot tube label
  • Serum is submitted
    Requisition/Form:Submit request using Biochemical Genetics Laboratory Requisition.
    Please ensure all required information, including patient's clinical history/indication, is provided on the requisition.
    Order Restrictions:None
    Indications:This test is for the investigation of disorders of amino acid metabolism.
    This test may also be ordered to rule out the possibility of these disorders in a patient being assessed for the ketogenic diet.
    This test may also be used to monitor known patients with certain amino acid disorders that are on diet-modified treatment.
    Method:Amino acids detected using Amino Acid Analyzer with internal standard.
    Method Details:Amino acid analysis enables the diagnosis of specific disorders of amino acid metabolism, as relevant primary enzyme deficiencies result in either the accumulation or reduced synthesis of specific amino acids.

    Disorders Detectable by Amino Acid Analysis*:
  • maple syrup urine disease (MSUD)
  • propionic Acidemia (PA)
  • isovaleric Acidemia (IVA)
  • methylmalonic Acidemia (MMA)
  • nonketotic Hyperglycinemia (NKH)
  • disorders of phenylalanine and tyrosine metabolism
  • hypermethioninemias
  • histidinemia
  • hypertryptophanemia
  • hyperlysinemias
  • aminoadipic aciduria
  • serine biosynthesis disorders
  • disorders of ornithine and proline metabolism
  • urea cycle disorders and inherited hyperammonemias
  • mitochondrial energy metabolism disorders (i.e., primary lactic acidemias)
  • beta-alaninemia
  • cystathionase deficiency
  • glutamic acidemia
  • glutamine synthase deficiency

    Metabolites reported:
  • phosphoserine, taurine, phosphoethanolamine, aspartic acid, hydroxyproline, threonine, serine, asparagine, glutamic acid, glutamine, sarcosine, alpha-aminoadipic acid, proline, glycine, alanine, citrulline, alpha-aminobutyric acid, valine, cystine, methionine, cystathionine, isoleucine, leucine, tyrosine, beta-alanine, phenylalanine, beta-aminoisobutyric acid, homocystine, gamma-aminobutyric acid, ethanolamine, hydroxylysine, ornithine, lysine, 1-methylhistidine, histidine, tryptophan, 3-methylhistidine, anserine, carnosine, arginine.

    This test is not a reliable method for detecting and quantitating homocystine, as levels can be altered depending on the length of time between sample collection and analysis, as well as the presence of an interfering peak that falsely suggests elevated homocystine. Recommend ordering Homocysteine, Total - Blood (ACH) or Homocysteine, Total - Urine (ACH) for evaluation of homocytine levels.

    Similarly, various medications can lead to ninhydrin-positive peaks that interfere with the identification and quantitation of certain amino acids. It is recommend that all current medications being take at the time of specimen collection be provided in the reason for referral.
    Reference Interval:Provided on test report, based on patient age.
    Comments:Contact ACH Biochemical Genetics Laboratory (403-955-7379) for priority turn-around.
    Last Updated On:Tuesday, July 17, 2018
    Date of Last Review:Jan 2 2018 12:00AM