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HelpMayo Test ID FAPEP Fatty Acid Profile, Essential, Serum
Necessary Information
1. Patient's age is required.
2. Include information regarding treatment, family history, and tentative diagnosis.
Specimen Required
Patient Preparation:
1. For nutritional assessment, patient should fast overnight (12-14 hours); for patients with a suspected fatty acid oxidation disorder, collect immediately before next feeding as fasting is contraindicated.
2. Patient must not consume any alcohol for 24 hours before the specimen collection.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial.
Useful For
Evaluating the nutritional intake and intestinal absorption of essential fatty acids using serum specimens
Identifying deficiency of essential and other nutritionally beneficial fatty acids
Monitoring treatment of patients with essential fatty acid deficiencies who are receiving linoleic acid (C18:2w6) and alpha-linolenic acid (C18:3w3)
Method Name
Gas Chromatography Mass Spectrometry (GC-MS) Stable Isotope Dilution Analysis
Reporting Name
Fatty Acid Profile, Essential, SSpecimen Type
SerumSpecimen Minimum Volume
0.15 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 92 days | |
| Refrigerated | 72 hours |
Reject Due To
| Gross hemolysis | OK |
| Gross lipemia | Reject |
| Gross icterus | OK |
Clinical Information
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)
Reference Values
Lauric Acid, C12:0
<1 year: 6-190 nmol/mL
1-17 years: 5-80 nmol/mL
≥18 years: 6-90 nmol/mL
Myristic Acid, C14:0
<1 year: 30-320 nmol/mL
1-17 years: 40-290 nmol/mL
≥18 years: 30-450 nmol/mL
Hexadecenoic Acid, C16:1w9
<1 year: 21-69 nmol/mL
1-17 years: 24-82 nmol/mL
≥18 years: 25-105 nmol/mL
Palmitoleic Acid, C16:1w7
<1 year: 20-1,020 nmol/mL
1-17 years: 100-670 nmol/mL
≥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
≥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
≥18 years: 16-150 nmol/mL
Alpha-Linolenic Acid, C18:3w3
<1 year: 10-190 nmol/mL
1-17 years: 20-120 nmol/mL
≥18 years: 50-130 nmol/mL
Linoleic Acid, C18:2w6
≤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
≥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
≥18 years: 650-3,500 nmol/mL
Vaccenic Acid, C18:1w7
<1 year: 140-720 nmol/mL
1-17 years: 320-900 nmol/mL
≥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
≥18 years: 590-1,170 nmol/mL
EPA, C20:5w3
<1 year: 2-60 nmol/mL
1-17 years: 8-90 nmol/mL
≥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
≥18 years: 520-1,490 nmol/mL
Mead Acid, C20:3w9
≤31 days: 8-60 nmol/mL
32 days-11 months: 3-24 nmol/mL
1-17 years: 7-30 nmol/mL
≥18 years: 7-30 nmol/mL
Homo-Gamma-Linolenic C20:3w6
<1 year: 30-170 nmol/mL
1-17 years: 60-220 nmol/mL
≥18 years: 50-250 nmol/mL
Arachidic Acid, C20:0
<1 year: 30-120 nmol/mL
1-17 years: 30-90 nmol/mL
≥18 years: 50-90 nmol/mL
DHA, C22:6w3
<1 year: 10-220 nmol/mL
1-17 years: 30-160 nmol/mL
≥18 years: 30-250 nmol/mL
DPA, C22:5w6
<1 year: 3-70 nmol/mL
1-17 years: 10-50 nmol/mL
≥18 years: 10-70 nmol/mL
DPA, C22:5w3
<1 year: 6-110 nmol/mL
1-17 years: 30-270 nmol/mL
≥18 years: 20-210 nmol/mL
DTA, C22:4w6
<1 year: 2-50 nmol/mL
1-17 years: 10-40 nmol/mL
≥18 years: 10-80 nmol/mL
Docosenoic Acid, C22:1
<1 year: 2-20 nmol/mL
1-17 years: 4-13 nmol/mL
≥18 years: 4-13 nmol/mL
Nervonic Acid, C24:1w9
<1 year: 30-150 nmol/mL
1-17 years: 50-130 nmol/mL
≥18 years: 60-100 nmol/mL
Triene/Tetraene Ratio
≤31 days: 0.017-0.083
32 days-17 years: 0.013-0.050
≥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
≥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
≥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
≥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
≥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
≥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
≥18 years: 7.3-16.8 mmol/L
Interpretation
Concentrations below the stated reference ranges are consistent with fatty acid deficiencies.
An increased triene:tetraene ratio is consistent with essential fatty acid deficiency.
Cautions
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, specimen can be collected as normal.
Clinical Reference
1. Vannice G, Rasmussen H. Position of the Academy of Nutrition and Dietetics: Dietary fatty acids for healthy adults. J Acad Nutr Diet. 2014;1(114):136-153
2. Jeppesen PB, Chistensen MS, Hoy CE, Mortensen PB. Essential fatty acid deficiency in patients with severe fat malabsorption. Am J Clin Nutr. 1997;65(3):837-843
3. Spector AA, Kim HY. Discovery of essential fatty acids. J. Lipid Res. 2015;56(1):11-21
4. Luszczki E, Boakye F, Zielinska M, Deren K, et al. Vegan diet: nutritional components, implementation, and effects on adults' health. Front Nutr. 2023;10:1294497. doi:10.3389/fnut.2023.1294497
Method Description
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;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;43[6]:697-707)
Day(s) Performed
Monday through Friday
Report Available
3 to 5 daysSpecimen Retention Time
2 monthsPerforming 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. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82725
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| FAPEP | Fatty Acid Profile, Essential, S | 43676-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 17021 | Lauric Acid, C12:0 | 35150-2 |
| 17022 | Myristic Acid, C14:0 | 35157-7 |
| 17023 | Hexadecenoic Acid, C16:1w9 | 35155-1 |
| 17024 | Palmitoleic Acid, C16:1w7 | 35162-7 |
| 17025 | Palmitic Acid, C16:0 | 35161-9 |
| 17026 | g-Linolenic Acid, C18:3w6 | 35163-5 |
| 17027 | a-Linolenic Acid, C18:3w3 | 35164-3 |
| 17028 | Linoleic Acid, C18:2w6 | 35165-0 |
| 17029 | Oleic Acid, C18:1w9 | 35166-8 |
| 17030 | Vaccenic Acid, C18:1w7 | 35167-6 |
| 17031 | Stearic Acid, C18:0 | 35149-4 |
| 17032 | EPA, C20:5w3 | 35173-4 |
| 17033 | Arachidonic Acid, C20:4w6 | 35168-4 |
| 17034 | Mead Acid, C20:3w9 | 35172-6 |
| 17035 | h-g-Linolenic, C20:3w6 | 35171-8 |
| 17036 | Arachidic Acid, C20:0 | 35169-2 |
| 17037 | DHA, C22:6w3 | 35174-2 |
| 17038 | DPA, C22:5w6 | 35181-7 |
| 17039 | DPA, C22:5w3 | 35180-9 |
| 17040 | DTA, C22:4w6 | 35182-5 |
| 17041 | Docosenoic Acid, C22:1 | 35160-1 |
| 17042 | Nervonic Acid, C24:1w9 | 35170-0 |
| 17043 | Triene Tetraene Ratio | 35411-8 |
| 17044 | Total Saturated Acid | 35175-9 |
| 17045 | Total Monounsaturated Acid | 35176-7 |
| 17046 | Total Polyunsaturated Acid | 35177-5 |
| 17047 | Total w3 | 35178-3 |
| 17048 | Total w6 | 35179-1 |
| 17049 | Total Fatty Acids | 24461-6 |
| 17054 | Interpretation | 59462-2 |