Acylcarnitinepnlserpl
The acylcarnitine panel is a blood test that measures different types of acylcarnitines to help detect inherited metabolic disorders affecting how the body processes fats for energy.
{"Measures acylcarnitine levels in blood to screen for metabolic disorders","Helps diagnose conditions like fatty acid oxidation defects and organic acidemias","Abnormal results may indicate problems with converting fats into energy","Often used in newborn screening but also performed in children and adults with symptoms","The test involves drawing a small blood sample from a vein"}
Key facts at a glance
- LOINC
- 43433-2
- Short code
- ACARN
- Synonyms
- Acylcarnitine Pnl SerPl
- Category
- chemistry
- Sample
- serum
- Container
- EDTA plasma (lavender top) or serum separator tube (SST/gold top)
- Units
- N/A
- Ref low
- 25
- Ref high
- 60
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Tandem Mass Spectrometry (MS/MS)
- CPT
- 82017
- SNOMED
- 274279004
- Specimen volume
- 1-2 mL of serum or plasma minimum; 3-5 mL preferred for comprehensive panel
- Stability
- Room temperature: 24-48 hours; Refrigerated (2-8°C): 5-7 days; Frozen (-20°C or below): 2-3 weeks. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The acylcarnitine panel is a specialized blood test that measures the levels of various acylcarnitine compounds in your blood. Acylcarnitines are substances formed when fatty acids (the body's fat stores) combine with carnitine, a molecule that helps transport fatty acids into cells where they can be burned for energy. This test helps doctors evaluate how well your body is processing fats for energy.
Why is it ordered?
Doctors may order this test for several reasons: (1) Newborn screening - to detect inherited metabolic disorders early before symptoms appear; (2) Diagnostic testing - when a baby, child, or adult shows symptoms of a metabolic disorder such as vomiting, low blood sugar, muscle weakness, or developmental delays; (3) Family screening - to test siblings or other family members of someone diagnosed with a metabolic disorder; (4) Monitoring - to follow up on patients already diagnosed with a metabolic condition.
What do the results mean?
Results show the levels of different acylcarnitine species. Each type of acylcarnitine pattern is associated with specific metabolic disorders. For example, elevated medium-chain acylcarnitines may suggest Medium-Chain Acyl-CoA Dehydrogenase (MCAD) deficiency, while elevated long-chain acylcarnitines may indicate Long-Chain 3-Hydroxyacyl-CoA Dehydrogenase (LCHAD) deficiency or Carnitine Palmitoyltransferase (CPT) deficiencies. Your doctor will interpret the specific pattern of results in the context of your symptoms and medical history.
How is the test performed?
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 typically requires fasting (not eating for 8-12 hours) before the blood draw, as eating can affect the results. For newborns, the sample is usually collected from a heel stick. The sample may be transported to a specialized laboratory that performs this specialized testing.
Reference range
Reference ranges vary by specific acylcarnitine species measured. Typical reference ranges for common acylcarnitines: Free carnitine (C0): 25-60 μmol/L; Acetylcarnitine (C2): 5-15 μmol/L; Propionylcarnitine (C3): 0.5-5.0 μmol/L; Isovalerylcarnitine (C5): 0.1-0.5 μmol/L; Octanoylcarnitine (C8): 0.05-0.5 μmol/L; Palmitoylcarnitine (C16): 0.1-1.0 μmol/L. Reference ranges may differ by laboratory methodology and population. Interpretation should be performed by a metabolic specialist.N/A
No fasting required for routine testing. For evaluation of fatty acid oxidation disorders, fasting challenges may be performed under metabolic specialist supervision. Inform patient of any medications or supplements containing carnitine. Sample should be drawn prior to carnitine supplementation if assessing baseline levels.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is fasting required before the test?
Does this test hurt?
How long does it take to get results?
What happens if my results are abnormal?
Can this test diagnose all metabolic disorders?
Sources
- 1
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
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 14, 2026. · Read our editorial policy