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Order Code LAB937 Orotic Acid, Random, Urine

Additional Codes

Mayo Test Code: OROT

Reporting Name

Orotic Acid, U

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

Urine


Necessary 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

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)

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)