Preferred Sample Type
Suitable Specimen Types
- Li Hep Plasma
Specimen Transport
Can transport at room temperatureSample Processing in Laboratory
UsualSample Preparation
Lithium heparin Sample
Heparinised blood is also acceptable.
Store frozen prior to sending.
Turnaround Time
3 weeksSample Stability
-20 ºCVery Long Chain Fatty Acids (VLCFA), Pristanic acid and phytanic acid
General Information
A very long chain fatty acid (VLCFA) is a fatty acid with aliphatic tails longer than 22 carbons. Unlike most fatty acids, VLCFAs are too long to be metabolized in the mitochondria, and must be metabolized in peroxisomes. Certain peroxisomal disorders, such as adrenoleukodystrophy, can be associated with an accumulation of VLCFAs.
The measurement of plasma very long chain fatty acids is used to detect defects of peroxisomal beta-oxidation of unsaturated fatty acids with chain lengths greater than C22:0 (docosanoic acid). The plasma concentrations of C26:0 (hexacosanoic acid) and C24:0 (tetracosanoic acid) and the ratios of C26:0 and C24:0 to C22:0 are increased in the majority of peroxisomal fatty acid beta-oxidation disorders. Pristanate and phytanate are also increased in some of the disorders and these results together with the ratio of pristanate to phytanate can help discriminate between them.
Patient Preparation
None
Notes
None Given
Reference Range
|
|
Age < 1 year |
Age >1 year |
All ages |
|
C22 (µmol/L) |
22.3-85.4 |
30.3-91.6 |
|
|
C24 (µmol/L) |
19.1-65.9 |
25.0-73.5 |
|
|
C26 (µmol/L) |
0.23-1.05 |
0.28-1.34 |
|
|
C24/C22 |
|
|
0.68-0.97 |
|
C26/C22 |
|
|
0.005-0.022 |
|
Pristanate (µmol/L) |
<0.7 |
<2.3 |
|
|
Phytanate (µmol/L) |
<5 |
<18 |
|
Reference ranges provided by reference laboratory.
Please note, new reference ranges applicable from 1st August 2015.
Specifications
- EQA Scheme?: Yes
- EQA Status: ERNDIM