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HelpTest Code LAB7468 Orotic Acid, Random, Urine
Additional Codes
OROT
Useful For
Evaluation of the differential diagnosis of hyperammonemia and hereditary orotic aciduria
Sensitive indicator of ornithine transcarbamylase (OTC) activity after administration of allopurinol or a protein load to identify OTC carriers
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
UrineNecessary Information
Patient's age is required.
Specimen Required
Supplies: Urine Tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 3 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative needed.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Frozen | 90 days |
Reference Values
≤6 years: ≤4 mmol/mol creatinine
7-18 years: ≤3 mmol/mol creatinine
≥19 years: 5 mmol/mol creatinine
Day(s) Performed
Tuesday, Thursday
CPT Code Information
83921
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| OROT | Orotic Acid, U | 17869-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 8905 | Orotic Acid, U | 17869-9 |
Interpretation
The value for the orotic acid concentration is reported. The interpretation of the result must be correlated with clinical and other laboratory findings.
Method Description
Diluted, filtered urine is mixed with an internal standard mixture and analyzed for orotic acid by liquid chromatography-tandem mass spectrometry. The ratio of the extracted peak area of orotic acid to the added internal standard is used to calculate the concentration present in the sample.(la Marca G, Casetta B, Malvagia S, et al. Implementing tandem mass spectrometry as a routine tool for characterizing the complete purine and pyrimidine metabolic profile in urine samples. J Mass Spectrom. 2006;41[11]:1442-1452; Monostori P, Klinke G, Hauke J, et al. Extended diagnosis of purine and pyrimidine disorders from urine: LC MS/MS assay development and clinical validation. PLoS One. 2019;14[2]:e0212458. doi:10.1371/journal.pone.0212458)
Report Available
3 to 7 daysSpecimen Retention Time
1 monthReject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.