Alberta Precision Laboratories

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Organization:

Alberta Precision Laboratories

Message Alert:

PLEASE NOTE: This Test Directory is in an interim state and due to changes pertaining to the DynaLIFE transition, performing site for routing has not been updated. Please refer to Laboratory Information System for appropriate routing.

Test Name/Synonym:

Amino Acids Quantitation, Urine, 24 Hour

Clinical 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 is also available on random urines, refer to Amino Acids Quantitation, Urine, Random.

Test Includes:

Metabolites reported from both BCG North and BCG South:

alanine	alpha-aminobutyric acid	arginine
aspartic acid	cystine	glutamic acid
glutamine	glycine	histidine
isoleucine	leucine	lysine
methionine	ornithine	phenylalanine
serine	taurine	threonine
tryptophan	tyrosine	valine

Additional metabolites reported from BCG North:

alloisoleucine

argininosuccinic acid

homocitrulline

Additional metabolites reported from BCG South:

1-methylhistidine	3-methylhistidine	alpha-aminoadipic acid
anserine	asparagine	beta-alanine
beta-aminoisobutyric acid	carnosine	citrulline
cystathionine	ethanolamine	gamma-aminobutyric acid
homocystine	hydroxylysine	hydroxyproline
phosphoethanolamine	phosphoserine	proline
sarcosine

Ordering Alert:

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 should not be used as a frontline test for these disorders. Amino Acids Quantitation, Plasma is recommended as a frontline test.

LABID (Connect Care):

LAB4358A

Test Code:

CALGARY ZONE	BGLNON; IN BLG NON-BLOOD TEST NAME FIELD ENTERE AMINO ACIDS 24UR
CENTRAL ZONE	AAUR
EDMONTON ZONE	UAAQ
GENETICS AND GENOMICS	AA-U
NORTH ZONE	AAUR
SOUTH ZONE	AAQT

Specimen Type:

Urine

Primary Container:

24 hour urine collection container (NO ADDITIVE)

Minimum Collection Volume:

1 mL of 24 hour urine collection

Specimen Collection Requirements:

Urine specimen MUST be kept FROZEN during entire collection and transport process (no preservative).

Refer to 24 Hour Urine General Collection - Patient Instructions for detailed instructions. Instruct patient to ensure the 24 hour urine collection container is placed into freezer immediately after each void throughout the 24 hour collection period

Test Resources:

Submit request using the applicable requisition or Connect Care online order entry:

Biochemical Genetics Laboratory Requisition

Please ensure all required information, including patient's clinical history/indication, is provided on the requisition.

Stability and Storage:

Frozen

Processing:

1. Thaw 24hr urine specimen.
2. Measure total volume (TVOL).
3.Connect Care users, eEnter TVOL in Connect Care. All other users, write the TVOL amount on requisition.
4. Aliquot minimum 10.0 mL of urine.
5. Write "TVOL #" on the aliquot label.
6. Freeze aliquot.

This test requires creatinine determination for result reporting. For sites using EPIC, a separate aliquot should be removed at the time of initial specimen receipt and sent to the EPIC-designated lab for creatinine testing.

One aliquot with primary container, or two separate aliquot can be submitted. Write "urine" on all secondary aliquot tubes. Freeze conatiner and/or tubes.

Transportation:

Transport frozen specimens on dry ice.
Samples must not thaw during transport.

Method:

Ion exchange liquid chromatography

Method and Interpretation of Results:

Amino acids are detected using an Amino Acid Analyzer with internal standard.

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.

Primary Disorders Detectable by Urine Amino Acid Analysis:

alpha-aminoadipic aciduria	argininosuccinic aciduria (argininosuccinate lyase deficiency)
beta-alaninemia	carnosinemia
cystathionase deficiency	cystinuria
dibasic aminoaciduria	dicarboxylic aminoaciduria
disorders of pyrimidine metabolism	familial renal iminoglycinuria
Hartnup disorder	HHH syndrome
hydroxyprolinuria	hyperlysinemia
hyperornithinemia	hyperprolinemia
hypophosphatasia	lysinuric protein intolerance
saccharopinuria	tryptophanuria

Secondary Disorders Detectable by Urine Amino Acid Analysis:

Fanconi syndrome

Vitamin D-dependent rickets

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 (for pediatric patients, less than 16 years of age) or Homocysteine, Total - Urine 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.

Routine Turn Around Time:

14 days

Testing Schedule:

Daily

Reference Interval:

Reference Intervals are age-dependent and normalized by creatinine, and will be provided on the report.

For determination of per day total excretion of specific amino acids (e.g., cystine), the molar concentration can be calculated by multiplying the normalized concentration with the creatinine concentration and the total reported volume.

Testing Area:

Biochemical Genetics

Performing Site:

University of Alberta Hospital or Alberta Children’s Hospital

Additional Test Information:

For priority turn-around contact Biochemical Genetics Laboratory.

Contact Comments:

Biochemical Genetics North	Biochemical Genetics South
780-407-8820	403-955-7379

Last Updated On:

Wednesday, November 23, 2022

Date of Last Review:

Aug 1 2022 12:00AM