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HelpTest ID: PIPU Pipecolic Acid, Urine
Reporting Name
Pipecolic Acid, UUseful For
Differentiating between disorders of peroxisomal biogenesis (eg, Zellweger syndrome) and disorders with loss of a single peroxisomal function
Detecting abnormal elevations of pipecolic acid in urine
Specimen Type
UrineNecessary Information
Patient's age is required.
Specimen Required
Supplies: Plastic, 10-mL urine tube (T068)
Container/Tube: Plastic, 10-mL urine tube (T068)
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Frozen (preferred) | 94 days | |
| Refrigerated | 14 days |
Special Instructions
Reference Values
≤31 days: ≤223.8 nmol/mg creatinine
32 days-5 months: ≤123.1 nmol/mg creatinine
6 months-11 months: ≤45.0 nmol/mg creatinine
≥1 year: ≤5.7 nmol/mg creatinine
Day(s) Performed
Thursday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
82542
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PIPU | Pipecolic Acid, U | 33659-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 81248 | Pipecolic Acid, U | 33659-4 |
| 29952 | Interpretation | 59462-2 |
| 29954 | Reviewed By | 18771-6 |
Clinical Information
Pipecolic acid (PA) is an intermediate of lysine metabolism and is oxidized in the peroxisomes by the enzyme L-pipecolate oxidase. In peroxisome biogenesis disorders (eg, Zellweger syndrome), the activity of this enzyme is lost, resulting in an increase in pipecolic acid levels. In contrast, in peroxisomal disorders involving single enzyme deficiencies such as D-bifunctional protein deficiency, PA is not elevated; therefore PA analysis is useful for differentiating between these 2 groups of disorders.
Increased pipecolic acid levels may also be seen in alpha-aminoadipic semialdehyde dehydrogenase deficiency (pyridoxine dependent epilepsy), hyperlysinemia types 1 and 2, and defects in proline metabolism.
Theoretically, a defect in L-pipecolate oxidase can exist and several cases of hyperpipecolic acidemia have been reported, but a specific enzyme deficiency has not been described in any of the patients.
Interpretation
Elevated pipecolic acid levels are seen in disorders of peroxisomal biogenesis; normal levels are seen in disorders with loss of a single peroxisomal function.
Abnormal levels of pipecolic acid should be interpreted together with the results of other biochemical markers of peroxisomal disorders, such as plasma C22-C26 very long-chain fatty acids, phytanic acid, pristanic acid (POX / Fatty Acid Profile, Peroxisomal [C22-C26], Serum); RBC plasmalogens; and bile acid intermediates.
Clinical Reference
1. Gould SJ, Raymond GV, Valle D: Chapter 129: The peroxisome biogenesis disorders. In Scriver's Online Metabolic and Molecular Bases of Inherited Disease. Edited by D Valle, AL Beaudet, B Vogelstein, et al. New York, McGraw-Hill Education. Accessed 06/30/17. Available at www.ommbid.com
2. Wanders RJA, Barth PG, Heymans HAS: Chapter 130: Single peroxisomal enzyme deficiencies. In Scriver's Online Metabolic and Molecular Bases of Inherited Disease. Edited by D Valle, AL Beaudet, B Vogelstein, et al. New York, McGraw-Hill Education. Accessed 06/30/17. Available at www.ommbid.com
3. Peduto A, Baumgartner MR, Verhoeven NM, et al: Hyperpipecolic acidaemia: a diagnostic tool for peroxisomal disorders. Mol Genet Metab 2004;82:224-230
4. Braverman N, Raymond G, Rizzo WB, et al: Peroxisome biogenesis disorders in the Zellweger spectrum: An overview of current diagnosis, clinical manifestations, and treatment guidelines. Mol Genet Metab 2016 Mar;117(3):313-321
Report Available
2 to 31 daysMethod Name
Gas Chromatography-Mass Spectrometry (GC-MS)
Testing Algorithm
See Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm in Special Instruction.
Forms
If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.
mml-biochemical