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Fatty Acids, Very Long Chain , Saturated plus Phytanic acid

Item Value
Approval req'd? No
Available Stat? No
Test code VLCF
Performed by KNDY
Sendout? Yes
Method Capillary gas chromatography / massspectroscopy of pentafluorobenzyl bromide fatty acid esters
Patient Preparation An 8 hour fast before specimen collection is required.
Container type Lavender top
Amount to Collect 6 mL blood
Sample type EDTA plasma
Preferred volume 3 mL plasma
Min. Volume 1 mL plasma
Processing notes Separate and freeze plasma at -20C until sent at room temperature by Federal Express for next day delivery.

Ship to: Peroxisomal Diseases Laboratory, Kennedy Krieger Institute, 707 N. Broadway, rm 421, Baltimore, MD 21205, (888)554-2080, fax (410)502-8279
mosera@kennedykrieger.org www.genetics.kennedykrieger.org)
Units µg/mL
Normal range
Normal X-linked ALD hemizygote X-linked ALD Heterozygote Zellweger Syndrome
C26:0 µg/mL 0.24 (0.14) 1.30 (0.45) 0.68 (0.29) 3.93 (1.50)
C26:1 µg/mL 0.11 (0.04) 0.34 (0.16) 0.23 (0.10) 4.08 (2.30)
Phytanic acid µg/mL 0.54 (0.29) 0.57 (0.46) 0.45 (0.22) 0.40 (0.28)
Pristanic acid µg/mL 0.05 (0.04) 0.06 (0.06) 0.06 (0.03) 0.09 (0.16)
C22:0 µg/mL 29.76 (6.45) 18.50 (5.10) 19.41 (4.08) 8.66 (4.97)
C24:0 µg/mL 22.88 (4.88) 32.25 (8.20) 24.89 (5.42) 17.51 (8.64)
C22:1 (n-9) µg/mL 1.61 (0.45) 1.19 (0.66) 1.33 (0.41) 1.73 (0.65)
Erucic acid
C24/C22 µg/mL 0.78 (0.10) 1.71 (0.23) 1.30 (0.19) 2.07 (0.28)
C26/C22 µg/mL 0.01 (0.003) 0.07 (0.03) 0.04 (0.02) 0.50 (0.16)
Synonyms Long chain fatty acids; VLC-FA; phytanic acid; Refsum's disease; Peroxisomal disease
Turn around times 2 weeks
Additional information This test is restricted to the Neurology/Pediatric Neurology Services.

Includes Phytanic and Pristanic and Erucic Acid.

For the diagnosis of most peroxisomal disorders of lipid oxidation, including X-linked or neonatal adrenoleukodystrophy, "infantile" and "adult" Refsum's disease, Zellweger syndrome and rhizomelic chondrodysplasia punctata.

Erucic acid is the active ingredient of Lorenzo's Oil, used in the treatment of X-linked adrenoleukodystrophy. In the presence of a plasma level of erucicacid > 5 µg/mL, the assay for very long chain fatty acids may give false-negative results. As phytanic acid comes from the diet, levels in the newborn period may not be diagnostic. Pristanic acid levels aid in the differential diagnosis of these disorders.
CPT coding 82726-90
LOINC code 34169-3
Last Updated 10/2/2010 11:51:51 AM
Entry Number 375
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