Test ID POX Fatty Acid Profile, Peroxisomal (C22-C26), Serum
Useful For
Evaluating patients with possible peroxisomal disorders, single-enzyme defects of peroxisomal metabolism, such as X-linked adrenoleukodystrophy or peroxisomal biogenesis disorders (Zellweger syndrome spectrum) using serum specimens
Aiding in the assessment of peroxisomal function
Highlights
This test analyzes very long-chain fatty acids as well as pristanic and phytanic acid to aid in diagnosis of peroxisomal biogenesis disorders, X-linked adrenoleukodystrophy (X-ALD), and Refsum disease.
This test is also appropriate for follow-up of an abnormal newborn screen for X-ALD.
Reports include concentrations of C22:0, C24:0, C26:0 species, phytanic and pristanic acid, and calculated C24:0/C22:0, C26:0/C22:0 and phytanic acid/pristanic acid ratios.
Special Instructions
Method Name
Gas Chromatography Mass Spectrometry (GC-MS)
Reporting Name
Fatty Acid Profile, Peroxisomal, SSpecimen Type
SerumNecessary Information
1. Patient's age and sex is required.
2. Biochemical Genetics Patient Information (T602) is recommended, but not required, to be filled out and sent with the specimen to aid in the interpretation of test results.Specimen Required
Patient Preparation: Fasting 12 hours or more. (Collect specimens from infants and small children just before next feeding)
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial.
Specimen Minimum Volume
0.15 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Frozen (preferred) | 92 days | |
Refrigerated | 15 days |
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) Performed
Monday through Friday
Performing Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
82726
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
POX | Fatty Acid Profile, Peroxisomal, S | 43677-4 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
81369 | C22:0 | 30194-5 |
7143 | C24:0 | 30195-2 |
7137 | C26:0 | 30197-8 |
7138 | C24:0/C22:0 | 30196-0 |
7139 | C26:0/C22:0 | 30198-6 |
7140 | Pristanic Acid | 22761-1 |
7141 | Phytanic Acid | 22671-2 |
7142 | Pristanic/Phytanic | 30550-8 |
7144 | Comment | 48767-8 |
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.Report Available
3 to 5 daysNY State Approved
YesTesting Algorithm
For more information see:
-Newborn Screen Follow-up for X-Linked Adrenoleukodystrophy
-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm
-Newborn Screening Act Sheet X-Linked Adrenoleukodystrophy: Increased Very Long Chain Fatty Acids
Forms
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.