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Test Code POXP Fatty Acid Profile, Peroxisomal (C22-C26), Plasma

Useful For

Evaluating patients with possible peroxisomal disorders, including peroxisomal biogenesis disorders, X-linked adrenoleukodystrophy, and Refsum disease

 

An aid in the assessment of peroxisomal function

Method Name

Gas Chromatography-Mass Spectrometry (GC-MS) Stable Isotope Dilution Analysis

Reporting Name

Fatty Acid Profile, Peroxisomal,P

Specimen Type

Plasma


Specimen Required


Collection Container/Tube:

Preferred: Green top (sodium heparin)

Acceptable: EDTA or lithium heparin

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions:

1. Fasting-overnight (12-14 hours).

2. Patient must not consume any alcohol for 24 hours before the specimen is drawn.

3. Spin down within 45 minutes of draw.

Additional Information:

1. Patient's age and gender is required.

2. Include information regarding treatment, family history, and tentative diagnosis.


Specimen Minimum Volume

0.15 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Frozen (preferred) 92 days
  Refrigerated  15 days

Reference Values

C22:0

≤96.3 nmol/mL

 

C24:0

≤91.4 nmol/mL

 

C26:0

≤1.30 nmol/mL

 

C24:0/C22:0 RATIO

≤1.39

 

C26:0/C22:0 RATIO

≤0.023

 

PRISTANIC ACID

0-4 months: ≤0.60 nmol/mL

5-8 months: ≤0.84 nmol/mL

9-12 months: ≤0.77 nmol/mL

13-23 months: ≤1.47 nmol/mL

≥24 months: ≤2.98 nmol/mL

 

PHYTANIC ACID

0-4 months: ≤5.28 nmol/mL

5-8 months: ≤5.70 nmol/mL

9-12 months: ≤4.40 nmol/mL

13-23 months: ≤8.62 nmol/mL

≥24 months: ≤9.88 nmol/mL

 

PRISTANIC/PHYTANIC ACID RATIO

0-4 months: ≤0.35

5-8 months: ≤0.28

9-12 months: ≤0.23

13-23 months: ≤0.24

≥24 months: ≤0.39

Day(s) and Time(s) Performed

Monday through Friday; 7 a.m.

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

82726

LOINC Code Information

Test ID Test Order Name Order LOINC Value
POXP Fatty Acid Profile, Peroxisomal,P In Process

 

Result ID Test Result Name Result LOINC Value
36641 C22:0 30194-5
36642 C24:0 30195-2
36643 C26:0 30197-8
36644 C24:0/C22:0 30196-0
36645 C26:0/C22:0 30198-6
36646 Pristanic Acid 22761-1
36647 Phytanic Acid 22671-2
36648 Pristanic/Phytanic 30550-8
36649 Interpretation (POXP) 59462-2

Testing Algorithm

The following algorithms are available in Special Instructions:

-Newborn Screen Follow-up for X-Linked Adrenoleukodystrophy

-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm

 

For more information, see Newborn Screening Act Sheet X-linked Adrenoleukodystrophy: Increased Very Long Chain Fatty Acids in Special Instructions.

Forms

If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.