Sign in →

Test ID HFAOP Fatty Acid Oxidation Gene Panel, Varies

Ordering Guidance

The recommended first-tier tests to screen for fatty acid oxidation disorders include acylcarnitine profile in plasma (ACRN / Acylcarnitines, Quantitative, Plasma) and urine organic acids (OAU / Organic Acids Screen, Urine)

Shipping Instructions

Specimen preferred to arrive within 96 hours of collection.

Specimen Required

Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

Specimen Type: Whole blood


Preferred: Lavender top (EDTA) or yellow top (ACD)

Acceptable: Any anticoagulant

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

Specimen Stability Information: Ambient (preferred)/Refrigerated


1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing (Spanish) (T826)

2. Molecular Genetics: Biochemical Disorders Patient Information (T527) in Special Instructions

Useful For

Follow up for abnormal biochemical results suggestive of a fatty acid oxidation disorder


Establishing a molecular diagnosis for patients with a fatty acid oxidation disorder


Identifying variants within genes known to be associated with a fatty acid oxidation disorder, allowing for predictive testing of at-risk family members

Method Name

Custom Sequence Capture and Targeted Next-Generation Sequencing followed by Polymerase Chain Reaction (PCR) and Sanger Sequencing

Reporting Name

Fatty Acid Oxidation Gene Panel

Specimen Type


Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Clinical Information

Mitochondrial fatty acid beta-oxidation plays an important role in energy production, particularly in skeletal and heart muscle, and in hepatic ketone body formation. Disorders of fatty acid oxidation (FAO) are characterized by hypoglycemia, hepatic dysfunction, encephalopathy, skeletal myopathy, and cardiomyopathy. Most FAO disorders have a similar presentation and their biochemical diagnosis can, at times, be difficult. Commonly used metabolite screens such as urine organic acids, plasma acylcarnitines, and fatty acids are influenced by dietary factors and the clinical status of the patient. This often leads to incomplete diagnostic information or even false-negative results. Enzyme assays are limited to one enzyme per assay, which doesn't allow for comprehensive testing for all FAO disorders.


A comprehensive gene panel is a helpful tool to establish a diagnosis for patients with suggestive clinical and biochemical features, given the broad clinical spectrum and genetic heterogeneity of FAO disorders.


Acylcarnitine profile in plasma (ACRN / Acylcarnitines, Quantitative, Plasma) and urine organic acids (OAU / Organic Acids Screen, Random, Urine) are the recommended first-tier tests to assess individuals for a FAO disorder. Additional testing includes an assay in fibroblasts (FAO / Fatty Acid Oxidation Probe Assay, Fibroblast Culture), which is useful following molecular testing to determine whether variants of uncertain significance are pathogenic. The purpose of the in vitro probe assay is to offer screening for several defects of FAO and organic acid metabolism under controlled laboratory conditions using fibroblast cultures.

Reference Values

An interpretive report will be provided.


All detected alterations are evaluated according to American College of Medical Genetics and Genomics (ACMG) recommendations.(1) Variants are classified based on known, predicted, or possible pathogenicity and reported with interpretive comments detailing their potential or known significance.

Clinical Reference

1. Richards S, Aziz N, Bale S, et al: Standards and guidelines for the interpretation of sequence variants: a joint consensus recommendation of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology. Genet Med. 2015 May;17(5):405-424

2. Vockley J, Bennett MJ, Gillingham MB: Mitochondrial fatty acid oxidation disorders. In: Valle D, Antonarakis S, Ballabio A, Beaudet A, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill Education; 2019. Accessed October 28, 2020. Available at

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.

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HFAOP Fatty Acid Oxidation Gene Panel In Process


Result ID Test Result Name Result LOINC Value
608740 Test Description 62364-5
608741 Specimen 31208-2
608742 Source 31208-2
608743 Result Summary 50397-9
608744 Result 82939-0
608745 Interpretation 69047-9
608746 Resources 99622-3
608747 Additional Information 48767-8
608748 Method 85069-3
608749 Genes Analyzed 48018-6
608750 Disclaimer 62364-5
608751 Released By 18771-6

Day(s) Performed


Report Available

3 to 4 weeks

CPT Code Information