--- Query Results --- | ||||||||||
| 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: | Homocysteine, Total, Urine, 24 Hour (Synonyms: Homocysteine, Reduced) | |||||||||
| Clinical Indications: | Total homocysteine can be elevated in the following enzyme deficiencies: Disorders Detectable by Elevated Plasma/Urine Total Homocysteine
This test is not recommended for the investigation of nutritional vitamin B12 deficiency, as total homocysteine is not a sensitive marker for this purpose, nor for assessing carrier status of the common methylene tetrahydrofolate reductase (MTHFR) polymorphisms. This test is also available on random urines, refer to Homocysteine, Total, Urine, Random. | |||||||||
| Ordering Alert: | This test is considered specialty testing; this test will be cancelled if sufficient clinical justification is not provided. | |||||||||
| LABID (Connect Care): | LAB4023B | |||||||||
| Test Code: |
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| Specimen Type: | Urine | |||||||||
| Primary Container: | 24 hour urine, plain bottle (NO ADDITIVE) | |||||||||
| Minimum Collection Volume: | 10 mL of the 24 hour urine collection | |||||||||
| Specimen Collection Requirements: | Urine specimen MUST be kept FROZEN during entire collection and transport process. 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:
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| Stability and Storage: | Frozen | |||||||||
| Processing: | 1. Thaw 24hr urine specimen. 2. Measure total volume (TVOL). 3. Connect Care users, enter TVOL in Connect Care. All other users, write the TVOL amount on the requisition. 4. Aliquot 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 aliquots can be submitted. Write “urine” on all secondary aliquot tubes. Freeze container and/or tubes. | |||||||||
| Transportation: | Transport frozen specimens on dry ice. Samples must not thaw during transport. Transport to Biochemical Genetics at Alberta Children’s Hospital. | |||||||||
| Method: | LC-MS/MS | |||||||||
| Method and Interpretation of Results: | Total homocysteine is detected following reduction using liquid chromatography, electrospray-ionization tandem mass spectrometry (LC-MS/MS) with a deuterium-labelled internal standard. | |||||||||
| Routine Turn Around Time: | 30 days | |||||||||
| Testing Schedule: | Monthly | |||||||||
| Reference Interval: |
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| Testing Area: | Biochemical Genetics | |||||||||
| Performing Site: | Alberta Children's Hospital | |||||||||
| Additional Test Information: | For priority turn-around contact Biochemical Genetics South Laboratory. | |||||||||
| Contact Comments: | Biochemical Genetics 403-955-7379 | |||||||||
| Last Updated On: | Wednesday, November 23, 2022 | |||||||||
