Understanding Your Laboratory Test: What It Is, Why It Is Done, and What the Results Mean for Your Health
A blood test that measures 2-methylcitrate levels to help diagnose and monitor inherited metabolic disorders affecting protein and fat metabolism.
{"2-Methylcitrate is a marker for propionic acidemia and methylmalonic acidemia","The test requires a simple blood draw from a vein","Abnormal results may indicate a metabolic disorder requiring treatment","Early diagnosis and monitoring are crucial for managing these conditions","This test is often part of newborn screening or follow-up testing"}
Key facts at a glance
- LOINC
- 12540-1
- Short code
- 2-MC
- Synonyms
- 2Me-citrate SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 0
- Ref high
- 0.5
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 82017 (Organic acids, quantitative, each)
- SNOMED
- 122269004
- Specimen volume
- 1.0-2.0 mL of serum minimum
- Stability
- Serum should be separated within 2 hours of collection. Store at 2-8°C if analyzing within 48 hours; for longer storage, freeze at -20°C or -70°C. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 72–168 hours
- Order
- routine
What is this test, and what exactly does it measure or look for in my body?
The 2-methylcitrate test measures the amount of 2-methylcitrate in your blood (serum or plasma). 2-Methylcitrate is a chemical byproduct (metabolite) that builds up in the blood when the body cannot properly break down certain amino acids and fatty acids. This test helps doctors identify inherited metabolic disorders, particularly propionic acidemia (PA) and methylmalonic acidemia (MMA).
Why might my doctor order this test for me, and what conditions can it help detect or monitor?
This test is performed to: 1) Screen newborns for certain metabolic disorders as part of routine newborn screening programs; 2) Diagnose suspected metabolic disorders when symptoms such as poor feeding, vomiting, lethargy, or developmental delays are present; 3) Monitor patients already diagnosed with propionic acidemia or methylmalonic acidemia to evaluate how well treatment is working; and 4) Help differentiate between different types of metabolic disorders.
How is this test performed, and what should I expect during the procedure step by step?
A healthcare professional will draw a small blood sample from a vein in your arm using a needle. The blood is collected into a special tube and sent to a laboratory for analysis. The test requires fasting (not eating) for several hours before the blood draw, as instructed by your doctor. For newborns, blood may be collected from a heel stick.
What do my test results mean, and how does my doctor interpret normal versus abnormal values?
Normal 2-methylcitrate levels vary by age and laboratory. Elevated levels typically suggest propionic acidemia or methylmalonic acidemia. Your doctor will interpret your results alongside other test results and your clinical symptoms. If you have been diagnosed with a metabolic disorder, your doctor will use the results to adjust your treatment plan, which may include dietary changes, medication, or other therapies.
Are there any risks, side effects, or complications I should be aware of before having this test?
The risks of this test are minimal and include slight pain or bruising at the needle site, dizziness, or very rarely, infection. These risks are the same as with any standard blood draw. The benefits of getting an accurate diagnosis or monitoring a serious condition far outweigh these minor risks.
Reference range
Reference range varies by laboratory and method. Typically: <0.5 μmol/L (may vary)N/A
No special preparation required. Inform laboratory of any medications or supplements. Collect as part of metabolic disorder workup when inherited metabolic disease is suspected.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated 2-methylcitrate in blood is primarily associated with propionic acidemia and methylmalonic acidemia, which are inherited metabolic disorders. In these conditions, the body lacks certain enzymes needed to process specific amino acids (isoleucine, valine, methionine, and threonine) and odd-chain fatty acids. Without proper treatment, toxic metabolites accumulate, potentially causing serious health problems including developmental delays, seizures, heart problems, and coma. Early detection through newborn screening allows for early intervention, which can significantly improve outcomes. The test is also used to monitor treatment effectiveness in patients already diagnosed with these disorders.
Frequently asked questions
Do I need to prepare for this test?
How long does it take to get results?
What happens if my results are abnormal?
Can this test diagnose other conditions?
Is this test only for children?
Sources
- 1
- 2
- 3
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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