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Acylcarnitinepatternserplimp

Published: August 9, 2026Updated: August 17, 2026

Acylcarnitine pattern testing measures specific substances in blood to help detect metabolic disorders that affect how the body processes fats for energy.

Quick summary

{"This blood test checks for abnormal levels of acylcarnitines, which can indicate metabolic diseases","It is commonly used to screen newborns for fatty acid oxidation disorders","The test helps doctors diagnose conditions that can cause low blood sugar, muscle weakness, or developmental delays","Abnormal results may require additional testing for confirmation","Early detection through newborn screening can prevent serious complications"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
46252-3
Short code
ACYPAT
Synonyms
Acylcarnitine pattern SerPl-Imp
Category
chemistry
Sample
serum
Container
EDTA plasma (lavender top) or Serum separator tube (SST)
Units
N/A
Ref low
0
Ref high
17
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Tandem Mass Spectrometry (MS/MS) with interpretation of acylcarnitine profile pattern
CPT
82017
SNOMED
314862001
Specimen volume
0.5-1 mL minimum, 2-3 mL preferred
Stability
Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
Hemolysis max
50
Lipemia max
100
Icterus max
20
TAT
72–168 hours
Order
routine

What is this test?

The acylcarnitine profile test is a blood test that measures the levels of different acylcarnitine compounds in your blood. Acylcarnitines are substances produced when your body breaks down fatty acids for energy. This test helps doctors detect abnormalities in how your body processes fats, which can indicate certain metabolic disorders.

Why is it done?

This test is primarily used as part of newborn screening programs to identify babies with fatty acid oxidation disorders and organic acidemias before symptoms appear. It may also be performed in older children and adults when doctors suspect a metabolic disorder causing symptoms such as low blood sugar, muscle weakness, heart problems, or developmental delays.

How is the sample collected?

A healthcare professional will draw a small blood sample from a vein in your arm or, for newborns, from a heel stick. The blood is collected on a special filter paper card and sent to a laboratory for analysis. The procedure is quick and generally causes minimal discomfort.

What do the results mean?

Results show the levels of different types of acylcarnitines. Abnormal levels of specific acylcarnitine compounds can indicate different metabolic disorders. Your doctor will interpret the pattern of results to determine if further testing is needed to confirm a diagnosis.

Reference range

NCBI: NSE 0-17 ng/mLN/A

Specimen: serum

No fasting required. Specimen should be collected prior to feeding in newborns. Inform laboratory of patient's clinical history including symptoms, family history of metabolic disorders, and current medications.

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?
For newborns, no fasting is required as the test is part of routine screening. For older children or adults, your doctor may recommend fasting for a specific period before the test, as fasting can affect acylcarnitine levels. Always follow your healthcare provider's instructions.
Is this test only for newborns?
While commonly used in newborn screening programs, this test can be performed at any age when a metabolic disorder is suspected. It is ordered for children or adults experiencing symptoms such as unexplained fatigue, low blood sugar, muscle pain, or developmental delays.
What happens if my baby's test is abnormal?
An abnormal result does not always mean your baby has a disorder. It means additional testing is needed to confirm or rule out a metabolic condition. Your doctor will contact you to discuss the results and recommend next steps, which may include repeat testing or more specialized tests.
Are there risks from this test?
The risks are minimal and include slight bruising at the blood draw site, rare infection, or fainting. For newborns, the heel stick may cause brief discomfort, but it is generally well-tolerated.
How long does it take to get results?
Results are typically available within a few days to a week, depending on the laboratory. Newborn screening results are usually sent to your pediatrician within 1-2 weeks.
  1. 1
    MedlinePlus - AcylcarnitineSource
  2. 2
    Mayo Clinic Laboratories - Acylcarnitine ProfileSource
  3. 3
    American College of Medical Genetics - Newborn ScreeningSource

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 17, 2026. · Read our editorial policy