Fatty Acid Profile, Peroxisomal (C22-C26), Plasma
Use
This test is primarily used for evaluating patients with suspected peroxisomal disorders, including peroxisomal biogenesis disorders, X-linked adrenoleukodystrophy (X-ALD), and Refsum disease. It aids in the assessment of peroxisomal function. The test analyzes very long-chain fatty acids and pristanic and phytanic acids which are crucial for diagnosing peroxisomal biogenesis disorders, X-ALD, and Refsum disease. It is also used to follow up on abnormal newborn screenings for X-ALD.
Special Instructions
The test is useful for follow-up of an abnormal newborn screen for X-ALD. Patients' age and sex are required for processing, and the completion of the Biochemical Genetics Patient Information form is recommended to aid interpretation.
Limitations
In rare instances, patients with X-linked adrenoleukodystrophy may only have minimally elevated values. About 15% to 20% of women heterozygous for X-ALD have normal plasma very long-chain fatty acid levels. False-positive results may occur if specimens are not fasted.
New York Approved
Methodology
Mass Spectrometry (GC-MS)
Biomarkers
LOINC Codes
- 43677-4
- 30194-5
- 30195-2
- 30197-8
- 30196-0
- 30198-6
- 22761-1
- 22671-2
- 30550-8
- 59462-2
Result Turnaround Time
3-5 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
0.5 mL
Minimum Volume
0.15 mL
Container
Plastic vial, preferred Green top (sodium heparin), acceptable Lavender top (EDTA) or green top (lithium heparin)
Collection Instructions
Centrifuge and aliquot plasma into a plastic vial. The patient must fast for 12 hours before collection; infants should have the specimen collected before next feeding. The patient must not consume alcohol for 24 hours before the specimen is collected.
Patient Preparation
Fasting for 12 hours is required.
Causes for Rejection
Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 15 days |
| Frozen | 92 days |