Test Catalog

Test Id : PFAPC

Fatty Acid Profile, Comprehensive (C8-C26), Plasma

Useful For
Suggests clinical disorders or settings where the test may be helpful

Monitoring patients undergoing diet therapy for mitochondrial or peroxisomal disorders (possibly inducing essential fatty acid deficiency in response to restricted fat intake) using plasma specimens


Monitoring treatment of essential fatty acid deficiency


Monitoring the response to provocative tests (fasting tests, loading tests)


This test is a comprehensive profile that provides information regarding mitochondrial and peroxisomal fatty acid metabolism and the patient's nutritional status.

Method Name
A short description of the method used to perform the test

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

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Fatty Acid Profile, Comprehensive, P

Lists additional common names for a test, as an aid in searching

C8-C26, Fatty Acid Profile

Comprehensive Fatty Acids

Essential Fatty Acids

LCFA (Long-Chain Fatty Acids)

Long-Chain Fatty Acids (LCFA)

MCFA (Medium-Chain Fatty Acids)

Medium-Chain Fatty Acids (MCFA)

Omega 3

Omega 6

Omega 7

Omega 9

Polyunsaturated Fatty Acids

Very Long Chain Fatty Acids (VLCFA)

VLCFA (Very Long Chain Fatty Acids)

Octanoic Acid

Decenoic Acid

Decanoic Acid

Lauroleic Acid

Lauric Acid

Tetradecadienoic Acid

Myristoleic Acid

Myristic Acid

Hexadecadienoic Acid

Hexadecenoic Acid

Palmitoleic Acid

Palmitic Acid

Gamma-Linolenic Acid

Alpha-Linolenic Acid

Linoleic Acid

Oleic Acid

Vaccenic Acid

Stearic Acid

Eicosapentaenoic Acid

Arachidonic Acid

Mead Acid

Homo-Gamma-Linolenic Acid

Arachidic Acid

Docosahexaenoic Acid

Docosapentaenoic acid

Docosatetraenoic Acid

Docosenoic Acid

Docosanoic Acid

Nervonic Acid

Tetracosanoic Acid

Hexacosenoic Acid

Hexacosanoic Acid

Pristanic Acid

Phytanic Acid







































Triene:Tetraene Ratio

Specimen Type
Describes the specimen type validated for testing


Ordering Guidance

This test is not the recommended initial screening test for evaluating patients with possible peroxisomal disorders, single-enzyme defects of peroxisomal metabolism such as X-linked adrenoleukodystrophy, or peroxisomal biogenesis disorders (Zellweger syndrome spectrum). For these purposes, the preferred tests are either POXP / Fatty Acid Profile, Peroxisomal (C22-C26), Plasma or POX / Fatty Acid Profile, Peroxisomal (C22-C26), Serum.

Necessary Information

1. Patient's age is required.

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

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Patient Preparation:

1. For nutritional assessment, patient should fast overnight (12-14 hours); for patients with a suspected fatty acid oxidation disorder, collect prior to next feeding as fasting is contraindicated.

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

Collection Container/Tube:

Preferred: Green top (sodium heparin)

Acceptable: Lavender top (EDTA) or green top (lithium heparin)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot plasma into plastic vial.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

0.15 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis OK
Gross lipemia Reject
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Plasma Frozen (preferred) 92 days
Refrigerated 72 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Monitoring patients undergoing diet therapy for mitochondrial or peroxisomal disorders (possibly inducing essential fatty acid deficiency in response to restricted fat intake) using plasma specimens


Monitoring treatment of essential fatty acid deficiency


Monitoring the response to provocative tests (fasting tests, loading tests)

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Fatty Acid Deficiency/Excess:

Fats are important sources of energy for tissues and for the function and integrity of cellular membranes. Deficiencies are commonly caused by inadequate dietary intake of lipids due to an unbalanced diet, long-term parenteral nutrition, or by intestinal malabsorption. Linoleic acid, an omega-6 fatty acid, and alpha-linolenic acid, an omega-3 fatty acid, are considered essential fatty acids in that they cannot be made by the body and are essential components of the diet.


The major clinical manifestations associated with essential fatty acid deficiency (EFAD) include dermatitis, increased water permeability of the skin, increased susceptibility to infection, and impaired wound healing. Biochemical abnormalities may be detected before the onset of recognizable clinical manifestations. EFAD can be detected by diminished levels of the essential fatty acids, linoleic and alpha-linolenic acid, as well as by increases in the triene:tetraene ratio.


Excess dietary fatty acids have been linked to the onset of cardiovascular disease. Elevated levels of linoleic acid can contribute to overproduction of the proinflammatory 2-series local hormones. The Academy of Nutrition and Dietetics recommends that dietary fat for the healthy adult population should provide 20% to 35% of energy, with an increased consumption of n-3 polyunsaturated fatty acids and limited intake of saturated and trans fats.(1)


Fatty Acid Oxidation Disorders:

Mitochondrial beta-oxidation is the main source of energy to skeletal and heart muscle during periods of fasting. When the body's supply of glucose is depleted, fatty acids are mobilized from adipose tissue and converted to ketone bodies through a series of steps providing an alternate source of energy. Deficient enzymes at any step in this pathway prevent the production of energy during periods of physiologic stress such as fasting or intercurrent illness.


The major clinical manifestations associated with fatty acid oxidation (FAO) disorders include hypoketotic hypoglycemia, liver disease and failure, skeletal myopathy, dilated/hypertrophic cardiomyopathy, and sudden unexpected death in early life. Signs and symptoms may vary greatly in severity, combination, and age of presentation. Life-threatening episodes of metabolic decompensation frequently occur after periods of inadequate calorie intake or intercurrent illness. When properly diagnosed, patients with FAO disorders respond favorably to fasting avoidance, diet therapy, and aggressive treatment of intercurrent illnesses, with significant reduction of morbidity and mortality.


Disease-specific characteristic patterns of metabolites from FAO disorders are detectable in blood, bile, urine, and cultured fibroblasts of living and many deceased individuals. Quantitative determination of C8-C18 fatty acids is an important element of the workup and differential diagnosis of candidate patients. Fatty acid profiling can detect quantitatively modest, but nevertheless significant, abnormalities even when patients are asymptomatic and under dietary treatment. Confirmatory testing for many of the FAO disorders is also available. For more information see FAO / Fatty Acid Oxidation Probe Assay, Fibroblast Culture and HFAOP / Fatty Acid Oxidation Gene Panel, Varies.


Peroxisomal Disorders:

Peroxisomes are organelles present in all human cells except mature erythrocytes. They carry out essential metabolic functions including beta-oxidation of very long-chain fatty acids (VLCFA), alpha-oxidation of phytanic acid, and biosynthesis of plasmalogen and bile acids. Peroxisomal disorders include disorders of peroxisomal biogenesis with defective assembly of the entire organelle, and single peroxisomal enzyme/transporter defects where the organelle is intact but a specific function is disrupted. Peroxisomal beta-oxidation of VLCFA is impaired in all disorders of peroxisomal biogenesis and in selected single enzyme deficiencies, particularly X-linked adrenoleukodystrophy, resulting in elevated concentrations of VLCFA in serum or plasma. POXP / Fatty Acid Profile, Peroxisomal (C22-C26), Plasma or POX / Fatty Acid Profile, Peroxisomal (C22-C26), Serum is the preferred screening test for evaluating patients with possible peroxisomal disorders, single-enzyme defects of peroxisomal metabolism such as X-linked adrenoleukodystrophy, or peroxisomal biogenesis disorders (Zellweger syndrome spectrum). Confirmatory testing for X-linked adrenoleukodystrophy via molecular genetic analysis is available; see XALDZ / X-Linked Adrenoleukodystrophy, Full Gene Analysis, Varies.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Octanoic Acid, C8:0

<1 year: 7-63 nmol/mL

1-17 years: 9-41 nmol/mL

> or =18 years: 8-47 nmol/mL


Decenoic Acid, C10:1

<1 year: 0.8-4.8 nmol/mL

1-17 years: 1.6-6.6 nmol/mL

> or =18 years: 1.8-5.0 nmol/mL


Decanoic Acid, C10:0

<1 year: 2-62 nmol/mL

1-17 years: 3-25 nmol/mL

> or =18 years: 2-18 nmol/mL


Lauroleic Acid, C12:1

<1 year: 0.6-4.8 nmol/mL

1-17 years: 1.3-5.8 nmol/mL

> or =18 years: 1.4-6.6 nmol/mL


Lauric Acid, C12:0

<1 year: 6-190 nmol/mL

1-17 years: 5-80 nmol/mL

> or =18 years: 6-90 nmol/mL


Tetradecadienoic Acid, C14:2

<1 year: 0.3-6.5 nmol/mL

1-17 years: 0.2-5.8 nmol/mL

> or =18 years: 0.8-5.0 nmol/mL


Myristoleic Acid, C14:1

<1 year: 1-46 nmol/mL

1-17 years: 1-31 nmol/mL

> or =18 years: 3-64 nmol/mL


Myristic Acid, C14:0

<1 year: 30-320 nmol/mL

1-17 years: 40-290 nmol/mL

> or =18 years: 30-450 nmol/mL


Hexadecadienoic Acid, C16:2

<1 year: 4-27 nmol/mL

1-17 years: 3-29 nmol/mL

> or =18 years: 10-48 nmol/mL


Hexadecenoic Acid, C16:1w9

<1 year: 21-69 nmol/mL

1-17 years: 24-82 nmol/mL

> or =18 years: 25-105 nmol/mL


Palmitoleic Acid, C16:1w7

<1 year: 20-1,020 nmol/mL

1-17 years: 100-670 nmol/mL

> or =18 years: 110-1,130 nmol/mL


Palmitic Acid, C16:0

<1 year: 720-3,120 nmol/mL

1-17 years: 960-3,460 nmol/mL

> or =18 years: 1,480-3,730 nmol/mL


Gamma-Linolenic Acid, C18:3w6

<1 year: 6-110 nmol/mL

1-17 years: 9-130 nmol/mL

> or =18 years: 16-150 nmol/mL


Alpha-Linolenic Acid, C18:3w3

<1 year: 10-190 nmol/mL

1-17 years: 20-120 nmol/mL

> or =18 years: 50-130 nmol/mL


Linoleic Acid, C18:2w6

< or =31 days: 350-2,660 nmol/mL

32 days-11 months: 1,000-3,300 nmol/mL

1-17 years: 1,600-3,500 nmol/mL

> or =18 years: 2,270-3,850 nmol/mL


Oleic Acid, C18:1w9

<1 year: 250-3,500 nmol/mL

1-17 years: 350-3,500 nmol/mL

> or =18 years: 650-3,500 nmol/mL


Vaccenic Acid, C18:1w7

<1 year: 140-720 nmol/mL

1-17 years: 320-900 nmol/mL

> or =18 years: 280-740 nmol/mL


Stearic Acid, C18:0

<1 year: 270-1,140 nmol/mL

1-17 years: 280-1,170 nmol/mL

> or =18 years: 590-1,170 nmol/mL


EPA, C20:5w3

<1 year: 2-60 nmol/mL

1-17 years: 8-90 nmol/mL

> or =18 years: 14-100 nmol/mL


Arachidonic Acid, C20:4w6

<1 year: 110-1,110 nmol/mL

1-17 years: 350-1,030 nmol/mL

> or =18 years: 520-1,490 nmol/mL


Mead Acid, C20:3w9

< or =31 days: 8-60 nmol/mL

32 days-11 months: 3-24 nmol/mL

> or =1 year: 7-30 nmol/mL


Homo-Gamma-Linolenic Acid, C20:3w6

<1 year: 30-170 nmol/mL

1-17 years: 60-220 nmol/mL

> or =18 years: 50-250 nmol/mL


Arachidic Acid, C20:0

<1 year: 30-120 nmol/mL

1-17 years: 30-90 nmol/mL

> or =18 years: 50-90 nmol/mL


DHA, C22:6w3

<1 year: 10-220 nmol/mL

1-17 years: 30-160 nmol/mL

> or =18 years: 30-250 nmol/mL


DPA, C22:5w6

<1 year: 3-70 nmol/mL

1-17 years: 10-50 nmol/mL

> or =18 years: 10-70 nmol/mL


DPA, C22:5w3

<1 year: 6-110 nmol/mL

1-17 years: 30-270 nmol/mL

> or =18 years: 20-210 nmol/mL


DTA, C22:4w6

<1 year: 2-50 nmol/mL

1-17 years: 10-40 nmol/mL

> or =18 years: 10-80 nmol/mL


Docosenoic Acid, C22:1

<1 year: 2-20 nmol/mL

> or =1 year: 4-13 nmol/mL


Docosanoic Acid, C22:0

0.0-96.3 nmol/mL


Nervonic Acid, C24:1

<1 year: 30-150 nmol/mL

1-17 years: 50-130 nmol/mL

> or =18 years: 60-100 nmol/mL


Tetracosanoic Acid, C24:0

0.0-91.4 nmol/mL


Hexacosenoic Acid, C26:1

<1 year: 0.2-2.1 nmol/mL

> or =1 year: 0.3-0.7 nmol/mL


Hexacosanoic Acid, C26:0

0.00-1.30 nmol/mL


Pristanic Acid, C15:0(CH3)4

< or =4 months: 0.00-0.60 nmol/mL

5-8 months: 0.00-0.84 nmol/mL

9-12 months: 0.00-0.77 nmol/mL

13-23 months: 0.00-1.47 nmol/mL

> or =2 years: 0.00-2.98 nmol/mL


Phytanic Acid, C16:0(CH3)4

< or =4 months: 0.00-5.28 nmol/mL

5-8 months: 0.00-5.70 nmol/mL

9-12 months: 0.00-4.40 nmol/mL

13-23 months: 0.00-8.62 nmol/mL

> or =2 years: 0.00-9.88 nmol/mL


Triene/Tetraene Ratio

< or =31 days: 0.017-0.083

32 days-17 years: 0.013-0.050

> or =18 years: 0.010-0.038


Total Saturated Acid

<1 year: 1.2-4.6 mmol/L

1-17 years: 1.4-4.9 mmol/L

> or =18 years: 2.5-5.5 mmol/L


Total Monounsaturated Acid

<1 year: 0.3-4.6 mmol/L

1-17 years: 0.5-4.4 mmol/L

> or =18 years: 1.3-5.8 mmol/L


Total Polyunsaturated Acid

<1 year: 1.1-4.9 mmol/L

1-17 years: 1.7-5.3 mmol/L

> or =18 years: 3.2-5.8 mmol/L


Total w3

<1 year: 0.0-0.4 mmol/L

1-17 years: 0.1-0.5 mmol/L

> or =18 years: 0.2-0.5 mmol/L


Total w6

<1 year: 0.9-4.4 mmol/L

1-17 years: 1.6-4.7 mmol/L

> or =18 years: 3.0-5.4 mmol/L


Total Fatty Acids

<1 year: 3.3-14.0 mmol/L

1-17 years: 4.4-14.3 mmol/L

> or =18 years: 7.3-16.8 mmol/L

Provides information to assist in interpretation of the test results

An increased triene:tetraene ratio is consistent with essential fatty acid deficiency.


Fatty acid oxidation disorders are recognized on the basis of disease-specific patterns that are correlated to the results of other investigations in plasma (carnitine, acylcarnitines) and urine (organic acids, acylglycines).


Increased concentrations of very long-chain fatty acids (VLCFA) C24:0 and C26:0 are seen in peroxisomal disorders, X-linked adrenoleukodystrophy, adrenomyeloneuropathy, and Zellweger syndrome (cerebrohepatorenal syndrome).


Increased concentrations of phytanic acid (along with normal pristanic acid concentrations) are seen in Refsum disease (phytanase deficiency). Phytanic acid concentration also may be increased in other peroxisomal disorders and, when combined with the VLCFA, pristanic acid, and pipecolic acid, allows differential diagnosis of peroxisomal disorders.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

For nutritional assessment, a 12- to 14-hour fast is required; however, infants or persons suspected of having a fatty acid oxidation disorder should not fast before testing due to the possibility of acute metabolic decompensation. Instead, collect the specimen after the longest fast possible, just before feeding. In the case of a patient on total parenteral nutrition (TPN), specimen can be collected as normal.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Vannice G, Rasmussen H: Position of the Academy of Nutrition and Dietetics: Dietary fatty acids for healthy adults. J Acad Nutr Diet. 2014 Jan;114(1):136-153

2. Rinaldo P, Matern D, Bennett MJ: Fatty acid oxidation disorders. Annu Rev Physiol. 2002;64:477-502

3. Jeppesen PB, Christensen MS, Hoy CE, Mortensen PB: Essential fatty acid deficiency in patients with severe fat malabsorption. Am J Clin Nutr. 1997 Mar;65(3):837-843

4. VerHoeven NM, Jakobs C: Human metabolism of phytanic acid and pristanic acid. Prog Lipid Res. 2001 Nov;40(6):453-466

Method Description
Describes how the test is performed and provides a method-specific reference

Quantitation of fatty acids of specific chain lengths is performed as follows: a 2-step, acid-base hydrolysis is followed by hexane extraction and derivatization with pentafluorobenzyl bromide. Separation and detection are accomplished by capillary gas chromatography electron-capture negative ion-mass spectrometry. Quantitation is based on analysis in the selected ion-monitoring mode by using 13 stable isotope-labeled internal standards.(Lagerstedt SA, Hinrichs DR, Batt SM, Magera MJ, Rinaldo P, McConnell JP: Quantitative determination of plasma C8-C26 total fatty acids for the biochemical diagnosis of nutritional and metabolic disorders. Mol Genet Metab. 2001 May;73(1):38-45; Gramlich L, Ireton-Jones C, Miles JM, Morrison M, Pontes-Arruda A: Essential fatty acid requirements and intravenous lipid emulsions. JPEN J Parenter Enteral Nutr. 2019 Aug;43[6]:697-707)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

3 to 5 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

2 months

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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 US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
PFAPC Fatty Acid Profile, Comprehensive, P 43674-1
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
36595 Octanoic Acid, C8:0 35145-2
36596 Decenoic Acid, C10:1 35147-8
36597 Decanoic Acid, C10:0 35146-0
36598 Lauroleic Acid, C12:1 35151-0
36599 Lauric Acid, C12:0 35150-2
36600 Tetradecadienoic Acid, C14:2 35148-6
36601 Myristoleic Acid, C14:1 35158-5
36602 Myristic Acid, C14:0 35157-7
36603 Hexadecadienoic Acid, C16:2 35154-4
36604 Hexadecenoic Acid, C16:1w9 35155-1
36605 Palmitoleic Acid, C16:1w7 35162-7
36606 Palmitic Acid, C16:0 35161-9
36607 g-Linolenic Acid, C18:3w6 35163-5
36608 a-Linolenic Acid, C18:3w3 35164-3
36609 Linoleic Acid, C18:2w6 35165-0
36610 Oleic Acid, C18:1w9 35166-8
36611 Vaccenic Acid, C18:1w7 35167-6
36612 Stearic Acid, C18:0 35149-4
36613 EPA, C20:5w3 35173-4
36614 Arachidonic Acid, C20:4w6 35168-4
36615 Mead Acid, C20:3w9 35172-6
36616 h-g-Linolenic Acid, C20:3w6 35171-8
36617 Arachidic Acid, C20:0 35169-2
36618 DHA, C22:6w3 35174-2
36619 DPA, C22:5w6 35181-7
36620 DPA, C22:5w3 35180-9
36621 DTA, C22:4w6 35182-5
36622 Docosenoic Acid, C22:1 35160-1
36623 Docosanoic Acid, C22:0 30194-5
36624 Nervonic Acid, C24:1w9 35170-0
36625 Tetracosanoic Acid, C24:0 30195-2
36626 Hexacosenoic Acid, C26:1 33036-5
36627 Hexacosanoic Acid, C26:0 30197-8
36628 Pristanic Acid, C15:0(CH3)4 22761-1
36629 Phytanic Acid, C16:0(CH3)4 22671-2
36630 Triene Tetraene Ratio 35411-8
36631 Total Saturated 35175-9
36632 Total Monounsaturated 35176-7
36633 Total Polyunsaturated 35177-5
36634 Total w3 35178-3
36635 Total w6 35179-1
36636 Total Fatty Acids 24461-6
36637 Interpretation (PFAPC) 59462-2

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