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Acylcarnitinebldql

Published: August 9, 2026Updated: August 16, 2026

Acylcarnitine testing is a blood test that checks for specific metabolic substances to help diagnose inherited fatty acid oxidation disorders and organic acidemias.

Quick summary

{"This test measures acylcarnitine levels in blood to detect metabolic disorders","It is commonly used in newborn screening programs","Abnormal results may indicate problems with how the body converts fat into energy","Early detection helps prevent serious health complications","The test requires a simple blood draw"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
43715-2
Short code
ACYL
Synonyms
Acylcarnitine Bld Ql
Category
chemistry
Sample
whole-blood
Container
Dried Blood Spot (DBS) card (filter paper) or EDTA (lavender top) whole blood tube
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Tandem Mass Spectrometry (MS/MS) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
CPT
82017
SNOMED
313334005
Specimen volume
DBS: One full spot (approximately 50-100 μL blood); Whole blood: 1-3 mL in EDTA tube
Stability
DBS: Stable at room temperature (15-25°C) for 7-10 days, refrigerated (2-8°C) for 2-3 weeks, frozen (-20°C or below) for longer; Whole blood: Refrigerate within 24 hours, stable 72 hours at 2-8°C
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
24–72 hours
Order
routine

What is this test?

The acylcarnitine test is a blood test that measures the presence and amount of acylcarnitines in your blood. Acylcarnitines are substances produced when your body breaks down fatty acids for energy. This test helps doctors detect certain inherited metabolic disorders that affect how the body processes fats.

Why is this test performed?

Doctors order this test primarily to: (1) Screen newborns for metabolic disorders as part of routine newborn screening programs, (2) Diagnose suspected metabolic disorders when symptoms such as muscle weakness, low blood sugar, or developmental delays are present, (3) Monitor patients already diagnosed with fatty acid oxidation disorders, and (4) Evaluate family members of individuals with known metabolic conditions.

How is the test done?

A healthcare professional will collect a small blood sample from a vein in your arm or, for newborns, from a heel stick. The blood is then sent to a laboratory where special equipment measures the different types of acylcarnitines present. The test is safe and takes only a few minutes to collect the sample.

What do the results mean?

Normal results mean no abnormal levels of acylcarnitines were detected. Abnormal results may indicate a metabolic disorder such as Medium-chain acyl-CoA dehydrogenase deficiency (MCAD), Carnitine palmitoyltransferase (CPT) deficiency, or various organic acidemias. Your doctor will interpret the specific patterns of acylcarnitine elevation to determine which condition, if any, may be present.

Reference range

Not detected / Negative - Normal acylcarnitine profileN/A

Specimen: whole-blood

No special preparation required. Inform the laboratory of any medications, supplements, or nutritional status as these may affect results. For newborns, specimen should be collected prior to feeding or at any routine time.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is fasting required before this test?
Fasting is generally not required for the acylcarnitine test, especially for newborn screening. However, your doctor may provide specific instructions based on your situation. For infants, the test is often done along with other routine newborn screening tests before hospital discharge.
Are there any risks with this test?
The risks are minimal and similar to any routine blood draw. You may experience slight bruising, soreness, or dizziness. For newborns, the heel stick may cause brief discomfort, but it is generally well-tolerated.
How long does it take to get results?
Results typically take a few days to a week, depending on the laboratory. Newborn screening results are usually available within 1-2 weeks. If the test is done for diagnostic purposes, results may take longer due to more detailed analysis.
What happens if my results are abnormal?
If results are abnormal, your doctor will likely refer you or your child to a metabolic specialist for further testing and evaluation. Additional tests may include genetic testing, urine tests, and repeat blood tests to confirm the diagnosis. Early diagnosis is important for starting appropriate treatment and management.
Can adults have this test?
Yes, while this test is commonly used in newborn screening, it can also be performed on adults who show symptoms of metabolic disorders or have a family history of these conditions. Adults may develop symptoms later in life or may be diagnosed through family screening.
  1. 1
    MedlinePlus - Newborn ScreeningSource
  2. 2
    Mayo Clinic - Metabolic DisordersSource
  3. 3
    American College of Medical Genetics and GenomicsSource

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.

Medical Disclaimer

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