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Test ID FAPM Fatty Acid Profile, Mitochondrial (C8-C18), 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 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: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.

Useful For

Biochemical diagnosis of inborn errors of mitochondrial fatty acid oxidation, including deficiencies of medium-chain acyl-Co-A dehydrogenase, long-chain 3-hydroxyacyl-Co-A dehydrogenase, very long-chain acyl-Co-A dehydrogenase, and glutaric acidemia type 2

Genetics Test Information

This test can be ordered to screen patients with a suspected mitochondrial fatty acid oxidation (FAO) disorder.

Method Name

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

Reporting Name

Fatty Acid Profile, Mitochondrial,S

Specimen Type


Specimen 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

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


Reference Values

Octanoic Acid, C8:0

<1 year: 7-63 nmol/mL

1-17 years: 9-41 nmol/mL

≥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

≥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

≥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

≥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

≥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

≥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

≥18 years: 3-64 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


Hexadecadienoic Acid, C16:2

<1 year: 4-27 nmol/mL

1-17 years: 3-29 nmol/mL

≥18 years: 10-48 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


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


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


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


For nutritional assessment, a 12- to 14-hour fast is required; however, patients 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. Rinaldo P, Matern D, Bennett MJ: Fatty acid oxidation disorders. Ann Rev Physiol. 2002;64:477-502

2. Kang E, Kim YM, Kang, M, et al: Clinical and genetic characteristics of patients with fatty acid oxidation disorders identified by newborn screening. BMC Pediatr. 2018 Mar 8;18(1):103

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 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)

Day(s) Performed

Monday through Friday

Report Available

3 to 5 days

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 US Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
FAPM Fatty Acid Profile, Mitochondrial,S 43675-8


Result ID Test Result Name Result LOINC Value
17007 Octanoic Acid, C8:0 35145-2
17008 Decenoic Acid, C10:1 35147-8
17009 Decanoic Acid, C10:0 35146-0
17010 Lauroleic Acid, C12:1 35151-0
17011 Lauric Acid, C12:0 35150-2
17012 Tetradecadienoic Acid, C14:2 35148-6
17013 Myristoleic Acid, C14:1 35158-5
17014 Myristic Acid, C14:0 35157-7
17015 Hexadecadienoic Acid, C16:2 35154-4
17016 Palmitoleic Acid, C16:1w7 35162-7
17017 Palmitic Acid, C16:0 35161-9
17018 Linoleic Acid, C18:2w6 35165-0
17019 Oleic Acid, C18:1w9 35166-8
17020 Stearic Acid, C18:0 35149-4
17055 Interpretation 59462-2