Very Long-Chain and Branched-Chain Fatty Acids Profile
Ordering Recommendation

Initial test to screen for disorders of peroxisomal biogenesis and/or function, including X-linked adrenoleukodystrophy and Zellweger syndrome.

Liquid Chromatography-Tandem Mass Spectrometry
2-9 days
New York DOH Approval Status
This test is New York DOH approved.
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Adults: Fasting specimen preferred.
Infants and children: Draw specimen prior to feeding or 2-3 hours after a meal. 
Green (sodium or lithium heparin) or lavender (EDTA). 
Specimen Preparation
Separate plasma from cells. Transfer 0.5 mL plasma to an ARUP Standard Transport Tube and freeze immediately. (Min: 0.2 mL) 
Storage/Transport Temperature
CRITICAL FROZEN. Separate specimens must be submitted when multiple tests are ordered. 
Unacceptable Conditions
Room temperature specimens greater than 24 hours. Refrigerated specimens greater than 48 hours. Specimens exposed to more than one freeze/thaw cycle. 
Clinical information is needed for appropriate interpretation. Additional required information includes age, gender, diet (e.g.TPN therapy), drug therapy, and family history. Biochemical Genetics Patient History Form is available on the ARUP Web site at or by contacting ARUP Client Services. 
After separation from cells: Ambient: 24 hours; Refrigerated: 72 hours; Frozen: 1 month 
Reference Interval
Available SeparatelyComponent
0-11 months
1 year to 2 years
3 years to 6 years
7 years and older
NoPristanic AcidLess than 0.31 µmol/LLess than 0.55 µmol/LLess than 0.46 µmol/LLess than 0.26 µmol/L
NoPhytanic Acid0.03-2.13 µmol/L0.23-5.03 µmol/L0.33-2.53 µmol/L0.25- 2.07 µmol/L
NoRatio Pristanic Acid to Phytanic AcidLess than 0.91Less than 0.28Less than 0.28Less than 0.28
NoC22:0 Behenic Acid28.94-93.50 µmol/L28.94-93.50 µmol/L28.94-93.50 µmol/L28.94-93.50 µmol/L
NoC24:0 Tetracosanoic Acid24.25-77.75 µmol/L24.25-77.75 µmol/L24.25-77.75 µmol/L24.25-77.75 µmol/L
NoC26:0 Hexacosanoic Acid0.17-0.73 µmol/L0.17-0.73 µmol/L0.17-0.73 µmol/L0.17-0.73 µmol/L
NoRatio C24:0 to C22:00.64-1.020.64-1.020.64-1.020.64-1.02
NoRatio C26:0 to C22:00.003-0.0150.003-0.0150.003-0.0150.003-0.015

Interpretive Data
Refer to report.

Compliance Statement B: This test was developed and its performance characteristics determined by ARUP Laboratories. The U.S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

CPT Code(s)
Component Test Code*Component Chart NameLOINC
2004251Fatty Acids Profile Interpretation49263-7
2004252Pristanic Acid22761-1
2004253Phytanic Acid22671-2
2004256C22:0 Behenic Acid30194-5
2004257C24:0 Tetracosanoic Acid30195-2
2004259C26:0 Hexacosanoic Acid30197-8
2004260Ratio Pristanic to Phytanic30550-8
2004261Ratio C24:0 to C22:030196-0
2004262Ratio C26:0 to C22:030198-6
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • VLCFA and BCFA