Understanding Your Laboratory Test: What It Is, Why It Is Ordered, and What Your Results Mean
A genetic blood test that looks for mutations in the ABCD1 gene to diagnose X-linked adrenoleukodystrophy (X-ALD), a rare inherited disorder affecting the adrenal glands and nervous system.
{"The test analyzes your DNA from a blood sample to find changes (mutations) in the ABCD1 gene","It helps confirm diagnosis of X-linked adrenoleukodystrophy, a genetic disorder affecting adrenal function and brain white matter","Results typically take 2-4 weeks as the sample is sent to a specialized genetics laboratory","This test is recommended if you have symptoms or family history of X-ALD","Genetic counseling is often recommended before and after testing to understand results"}
Key facts at a glance
- LOINC
- 53836-3
- Short code
- ABCD1 MUT
- Synonyms
- ABCD1 gene Mut Anl Bld/T
- Category
- chemistry
- Sample
- whole-blood
- Container
- EDTA tube (purple top) for whole blood
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- molgen
- CPT
- 81401
- SNOMED
- 129688006
- Specimen volume
- 3-5 mL
- Stability
- Room temperature: 72 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): acceptable for extended storage
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 336–1008 hours
- Order
- routine
What is this test and what does it measure?
The ABCD1 gene targeted mutation analysis is a specialized genetic test that examines your DNA to find specific changes (mutations) in the ABCD1 gene. This gene provides instructions for making a protein that is essential for breaking down very long-chain fatty acids (VLCFAs). When the ABCD1 gene has a mutation, these fatty acids build up in the body, causing damage to the adrenal glands and the protective covering (myelin) of nerve cells in the brain.
Why might my healthcare provider order this test for me?
Your healthcare provider may order this test if you show symptoms suggestive of X-linked adrenoleukodystrophy (X-ALD), such as adrenal insufficiency (Addison's disease), progressive neurological problems including difficulty walking, vision loss, or cognitive changes. It may also be recommended if you have a family history of X-ALD, even if you don't have symptoms yet. Additionally, this test can be used for prenatal diagnosis or to confirm carrier status in women who might pass the gene to their children.
How is this test performed, and what can I expect during the procedure?
A healthcare professional will collect a blood sample from a vein in your arm using a small needle. The collection process only takes a few minutes and may cause minor discomfort or bruising at the puncture site. The blood sample is then sent to a specialized laboratory that performs molecular genetic testing. Technicians will extract DNA from your blood cells and analyze the ABCD1 gene for specific mutations known to cause X-ALD. The analysis uses techniques like polymerase chain reaction (PCR) and DNA sequencing to identify any genetic changes.
What do my test results mean, and how will my doctor interpret them?
A positive result means a mutation was found in the ABCD1 gene, confirming a diagnosis of X-linked adrenoleukodystrophy. This result helps guide treatment decisions and allows family members to understand their genetic risk. A negative result means no known disease-causing mutation was found; however, this does not completely rule out X-ALD if you have symptoms, as there may be rare mutations not detected by this specific test. Your healthcare provider and a genetic counselor will help you interpret your specific results in the context of your symptoms and family history.
Are there any risks, side effects, or limitations I should be aware of?
The blood draw itself carries minimal risks, including slight pain, bruising, or rare infection at the puncture site. The genetic test has some limitations: it may not detect all possible mutations in the ABCD1 gene, and sometimes variants of uncertain significance (VUS) are found whose effect on health is unknown. Results can also have implications for family members, which may cause emotional or psychological concerns. This is why genetic counseling is strongly recommended before and after testing.
Reference range
No pathogenic variant detected in ABCD1 geneN/A
No special preparation required. Informed consent may be required per institutional policy. Clinical indication and family history should be provided.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
The ABCD1 gene mutation test is critical for diagnosing X-linked adrenoleukodystrophy, a peroxisomal disorder characterized by impaired breakdown of very long-chain fatty acids (VLCFAs). Elevated VLCFA levels cause progressive demyelination of neural white matter and adrenal insufficiency. Early diagnosis allows for timely intervention with adrenal hormone replacement therapy, dietary modifications (such as Lorenzo's oil), and monitoring for potentially life-threatening cerebral ALD. In affected males, the test confirms the diagnosis and guides family planning, while identifying female carriers has implications for offspring inheritance patterns. The specific mutation identified can sometimes provide prognostic information about disease severity and progression.
Frequently asked questions
How long does it take to get results?
Do I need to fast before this test?
Can women have this test?
Will my insurance cover this genetic test?
What happens if my test is positive?
Sources
- 1
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy