Test ID: PIPU Pipecolic Acid, Random, 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: Urine tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL urine tube
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 |
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
Tuesday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US 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 |
Genetics Test Information
Pipecolic acid is not detected by conventional organic acid analysis of urine.
In the newborn period, pipecolic acid levels are more likely to be abnormal in urine than in plasma or serum. 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, red blood cell plasmalogens, and bile acid intermediates.
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 serum C22-C26 very long-chain fatty acids, phytanic acid, pristanic acid (POX / Fatty Acid Profile, Peroxisomal [C22-C26], Serum); red blood cell plasmalogens (PGRBC / Plasmalogens, Blood); and bile acid intermediates (BAIPD / Bile Acids for Peroxisomal Disorders, Serum).
Clinical Reference
1. Gartner J, Rosewich H, Thoms S. The peroxisome biogenesis disorders. In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill Medical; 2019. Accessed November 02, 2023. Available at https://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=22554226
2. Wanders RJA, Barth PG, Heymans HAS. Single peroxisomal enzyme deficiencies. In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill Medical; 2019. Accessed November 02, 2023. Available at https://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=225542524
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;117(3):313-321
Report Available
3 to 9 daysMethod Name
Gas Chromatography Mass Spectrometry (GC-MS)
Testing Algorithm
For more information see Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm.
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
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