Orotic Acid, Urine
Quantitative urinary orotic acid analysis is used in the evaluation of patients with hyperammonemia and a suspected urea cycle defect (UCD). It is typically ordered in conjunction with plasma amino acids and urine organic acids. Urine orotic acid is also used in conjunction with plasma amino acids when monitoring patients with UCD. This test can also detect rare inherited orotic acidurias with pyrimidine defects. Orotic acid is measured by gas chromatography and mass spectrometry (GC/MS) method.
- Urine: 5-10 mL (random or preferably morning first void) in a clean container without preservatives, then freeze