--- Query Results ---

  
Program:Genetics and Genomics
 
Test Name:Amino Acids, urine (G&G South ACH)
Test Code:AA-U
Performing Site: Alberta Children's Hospital
Performing Dept:Biochemical Genetics
 
Availability:Test performed on a daily basis.
TAT:14 days
 
Preferred Tube/Container:Random specimen: plain urine container
Alternate:24 hour urine collection container (NO ADDITIVE)
 
Specimen Requirements:Random Urine Collection:
Collect 5-10 mL random urine.

24 hour Urine Collection:
Urine specimen MUST be kept FROZEN during entire collection and transport process (no preservative).
Instruct patient to ensure to place 24 hour urine collection container into freezer immediately after each void throughout the 24 hour collection period.
 
Min. Sample Required:1.0 mL random urine collection or 10.0 mL of 24hr urine collection
 
Specimen Processing:Random Urine Collection:
1.  If sample is transferred to a secondary aliquot tube or container, write "random urine" on label.
2.  Freeze.

24 hour Urine Collection:
1.  Thaw 24hr urine specimen.
2.  Measure total volume.
3.  Enter TVOL on requisiton.
4.  Send 10 mL aliquot of urine; write "24hr urine, Tvol #L" on the label.
5.  Freeze aliquot.
 
Specimen Handling:Transport frozen samples on ice. Samples must not thaw during transport.
 
Additional Information:Samples will be rejected if:
  • Aliquot received thawed
  • Sample type not written on aliquot tube label
    •  
    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:This test is considered specialty testing; this test will be cancelled if sufficient clinical justification is not provided.

    This test has limited clinical utility for investigating disorders of amino acid metabolism, and therefore Amino Acids - Plasma (ACH) is recommended.
     
    Indications:This test is for the specific investigation of disorders of amino acid transport (e.g., cystinuria, Hartnup disorder) and selected disorders of amino acid metabolism that require confirmation and/or additional metabolite identification/discrimination.
    This test should not be used as a frontline test for disorders of amino acid metabolism; recommend Amino Acids - Plasma (ACH) as a frontline test.
    Method:Amino acids are detected using an Amino Acid Analyzer with internal standard.
    Method Details:Primary Disorders Detectable by Urine Amino Acid Analysis*:
  • cystinuria
  • Hartnup disorder
  • beta-alaninemia
  • disorders of pyrimidine metabolism
  • alpha-aminoadipic aciduria
  • dibasic aminoaciduria
  • HHH syndrome
  • lysinuric protein intolerance
  • argininosuccinic aciduria (argininosuccinate lyase deficiency)
  • dicarboxylic aminoaciduria
  • carnosinemia
  • saccharopinuria
  • cystathionase deficiency
  • hyperlysinemia
  • hyperornithinemia
  • hyperprolinemia
  • hydroxyprolinuria
  • hypophosphatasia
  • familial renal iminoglycinuria
  • tryptophanuria

    Secondary Disorders Detectable by Urine Amino Acid Analysis*:
  • Fanconi syndrome
  • Vitamin D-dependent rickets

    *Further confirmatory testing is required for many of these conditions, as nonspecific findings and overlapping patterns may prevent definitive diagnosis in specific cases.

    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.
     
    Comments:Contact ACH Biochemical Genetics Laboratory (403-955-7379) for priority turn-around.
     
     
    Last Updated On:Thursday, August 31, 2017
    Date of Last Review:Jan 2 2018 12:00AM