Acylcarnitineurmcnc
A urine test that measures acylcarnitine levels to help diagnose metabolic disorders affecting how the body breaks down fats.
{"Measures fatty acid metabolism byproducts in urine","Helps diagnose inherited metabolic disorders","Used for newborn screening follow-up and symptom evaluation","Involves collecting a simple urine sample","Results help doctors plan appropriate treatment"}
Key facts at a glance
- LOINC
- 9403-7
- Short code
- ACYU
- Synonyms
- Acylcarnitine Ur-mCnc
- Category
- chemistry
- Sample
- urine
- Container
- Sterile, clean-catch urine container (graded or plain)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Tandem mass spectrometry (MS/MS)
- CPT
- 82017
- SNOMED
- 314862001
- Specimen volume
- 5-10 mL minimum; 10-20 mL preferred
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 5-7 days; Frozen (-20°C or below): 2-3 weeks. Protect from light.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The urine acylcarnitine test measures the levels of acylcarnitines in your urine. Acylcarnitines are compounds produced when fatty acids bind to carnitine, a substance that helps transport fatty acids into cells for energy production. This test helps doctors evaluate how well your body processes fats for energy.
Why is this test done?
Doctors may order this test to: 1) Screen for or follow up on abnormal newborn screening results, 2) Investigate symptoms like unexplained fatigue, muscle weakness, or low blood sugar, 3) Diagnose fatty acid oxidation disorders and organic acidemias, and 4) Monitor patients already diagnosed with metabolic disorders.
How is the sample collected?
A clean-catch urine sample is collected. You will be given instructions to clean the genital area before urinating, then collect a mid-stream urine sample in a sterile container. The sample should be taken to the lab promptly for processing.
What do the results mean?
Abnormal acylcarnitine levels in urine may indicate a problem with fatty acid metabolism. Your doctor will interpret results based on your specific pattern of acylcarnitines, clinical symptoms, and other test results. Further testing may be needed to confirm a diagnosis.
Reference range
Reference ranges vary by specific acylcarnitine species measured. Results are typically reported as micromoles per mole of creatinine (μmol/mol Cr) or as absolute concentrations (μmol/L). Each acylcarnitine (free carnitine C0, acetylcarnitine C2, propionylcarnitine C3, isovalerylcarnitine C5, octanoylcarnitine C8, etc.) has age-specific reference intervals. Consult laboratory-specific reference ranges.N/A
No fasting required. Collect random urine sample in clean, sterile container. Inform laboratory of patient age, clinical history, and any medications. Avoid contamination with fecal material.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before this test?
Is this test only for children?
What happens if my results are abnormal?
How long does it take to get results?
Sources
- 1
- 2
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 16, 2026. · Read our editorial policy