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HelpTest Code POXP Fatty Acid Profile, Peroxisomal (C22-C26), Plasma
Useful For
Evaluating patients with possible peroxisomal disorders, including peroxisomal biogenesis disorders, X-linked adrenoleukodystrophy, and Refsum disease
An aid in the assessment of peroxisomal function
Method Name
Gas Chromatography-Mass Spectrometry (GC-MS) Stable Isotope Dilution Analysis
Reporting Name
Fatty Acid Profile, Peroxisomal,PSpecimen Type
PlasmaSpecimen Required
Collection Container/Tube:
Preferred: Green top (sodium heparin)
Acceptable: EDTA or lithium heparin
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Fasting-overnight (12-14 hours).
2. Patient must not consume any alcohol for 24 hours before the specimen is drawn.
3. Spin down within 45 minutes of draw.
Additional Information:
1. Patient's age and gender is required.
2. Include information regarding treatment, family history, and tentative diagnosis.
Specimen Minimum Volume
0.15 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Plasma | Frozen (preferred) | 92 days | |
| Refrigerated | 15 days |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | Reject |
| Gross icterus | OK |
Reference Values
C22:0
≤96.3 nmol/mL
C24:0
≤91.4 nmol/mL
C26:0
≤1.30 nmol/mL
C24:0/C22:0 RATIO
≤1.39
C26:0/C22:0 RATIO
≤0.023
PRISTANIC ACID
0-4 months: ≤0.60 nmol/mL
5-8 months: ≤0.84 nmol/mL
9-12 months: ≤0.77 nmol/mL
13-23 months: ≤1.47 nmol/mL
≥24 months: ≤2.98 nmol/mL
PHYTANIC ACID
0-4 months: ≤5.28 nmol/mL
5-8 months: ≤5.70 nmol/mL
9-12 months: ≤4.40 nmol/mL
13-23 months: ≤8.62 nmol/mL
≥24 months: ≤9.88 nmol/mL
PRISTANIC/PHYTANIC ACID RATIO
0-4 months: ≤0.35
5-8 months: ≤0.28
9-12 months: ≤0.23
13-23 months: ≤0.24
≥24 months: ≤0.39
Day(s) and Time(s) Performed
Monday through Friday; 7 a.m.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
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
82726
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| POXP | Fatty Acid Profile, Peroxisomal,P | 43677-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 36641 | C22:0 | 30194-5 |
| 36642 | C24:0 | 30195-2 |
| 36643 | C26:0 | 30197-8 |
| 36644 | C24:0/C22:0 | 30196-0 |
| 36645 | C26:0/C22:0 | 30198-6 |
| 36646 | Pristanic Acid | 22761-1 |
| 36647 | Phytanic Acid | 22671-2 |
| 36648 | Pristanic/Phytanic | 30550-8 |
| 36649 | Interpretation (POXP) | 59462-2 |
Testing Algorithm
The following algorithms are available in Special Instructions:
-Newborn Screen Follow-up for X-Linked Adrenoleukodystrophy
-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm
For more information, see Newborn Screening Act Sheet X-linked Adrenoleukodystrophy: Increased Very Long Chain Fatty Acids in Special Instructions.
Special Instructions
Forms
If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.