Lab Test

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Very Long Chain Fatty Acids

Fatty Acid Profile, Peroxisomal (C22-C26), Serum, Fatty Acid Profile, Peroxisomal, Serum, VLCFA,X-ALD, Fatty Acid, Peroxisomal Disorders

Test Codes

EPIC: LAB1232095, Beaker: Fatty Acid P, Quest: 90559

Department

Send Outs

Instructions

  • Fasting required (overnight fast). No alcohol consumption for 24 hours prior to draw.
  • For pediatric patients, fasting is not required, but sample collection should occur prior to the next meal or scheduled feeding.

Specimen Collection Criteria

Collect: One plain Red-top tube

Do not use Serum Separator Tubes (SST).

Physician Office/Draw Specimen Preparation

Centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below).

Preparation for Courier Transport

Transport: 1.0 serum, frozen (-20°C/-4°F or below). (Minimum: 0.2 mL)

Rejection Criteria

  • Hemolysis.
  • Lipemia.
  • Serum separator tube (SST).
  • Non-fasting samples.
  • Specimens not collected and processed as indicated.

In-Lab Processing

Centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below).

Transport: 1.0 mL serum, frozen (-20°C/-4°F or below). (Minimum: 0.2 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 28 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Tuesday, Thursday, Saturday.
Results available within 5-7 days.

Reference Range

By report.

Test Methodology

Gas Chromatography / Tandem Mass Spectrometry

Interpretation

By report.

Clinical Utility

Very Long Chain Fatty Acids - Peroxisomes play a vital role in several metabolic pathways, including the synthesis of plasmalogens and bile acids. They are also involved in the catabolism of Very Long Chain Fatty Acids (VLCFAs), phytanic acid, and pristanic acid. Defects in these pathways usually result in the accumulation in tissues and body fluids of one or more metabolites derived from the blocked metabolic steps. Specific accumulations are used for the differential biochemical diagnosis of numerous peroxisomal disorders. These disorders include (A) Zellweger spectrum disorders of peroxisomal biogenesis, (B) X-linked adrenoleukodystrophy (X-ALD) and its adult form X-linked adrenomyeloneuropathy (X-AMN), (C) Refsum disease (Phytanoyl-CoA hydroxylase Deficiency), and (D) 2-methylacyl-CoA racemase deficiency.

CPT Codes

82726

Contacts

Last Updated

12/17/2025

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