Acylcarnitine, Urine (Referred Out) - Saskatoon
Discipline
Biochemistry
Overview
Description
- If clinically feasible, discontinue L-carnitine supplementation at least 72 hours before specimen collection
Test ordering requirements
Forms required
- Requisitions must have specific test indicated
- Miscellaneous Specimen Requisition Form #101878 or SHR Laboratory Medicine Community Laboratory Requisition Form #101064 or Acute Care Phlebotomy Requisition Form #101062
Alias
Specimen Information
Specimen types accepted
- Random urine
Specimen collection container
- Preferred collection container: Sterile Wide Mouth Screw Cap Container (Pink Top)
Required volume
- Optimal volume: 5 mL urine
- Minimum volume/pediatric volume: 1 mL urine
(Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory/reflex testing. In some situations, a minimum volume may require a second collection)
Transport and stability
- Freeze immediately upon receipt in the lab
- Send to SPH on an ice pack
- Store and ship frozen to referral laboratory
- Stable 24 hours when refrigerated, 7 days when frozen
Rejection criteria
- Specimens received where the proper collection protocols were not followed
- Pathology and Laboratory Medicine Acceptance and Rejection Criteria
Testing Information
Relevant clinical history
- Family History
- Must include diagnosis and/or patient symptoms on the requisition
- Relevant Recent Medication History - A recent medication list is relevant for clinical interpretation of results
Clinical interpretation
- Almost all patients with isobutyryl-CoA dehydrogenase deficiency excrete an abnormal amount of iso-/butryrylcarnitine (C4) in their urine. Some, but not all, affected individuals also excrete elevated levels of isobutyrulglycine. Conversely, patients with short-chain acyl-CoA dehydrogenase deficiency can have a normal excretion of C4
- Result interpretation should be correlated with clinical and other laboratory findings
- If patient is receiving L-carnitine supplementation, the result of this urine acylcarnitine test will not be informative
Performance
Methodology
- Flow injection Analysis-Tandem Mass Spectrometry (FIA-MS/MS)
Days/times performed
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Maximum laboratory time
- 5 day turnaround time by referral laboratory
Other information
Last Updated: September 30, 2024