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Acylcarnitinenbscomment

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

Acylcarnitine newborn screening is a blood test performed on newborns to detect rare metabolic disorders that affect how the body breaks down fats for energy.

Quick summary

{"The test uses a small blood sample from your baby's heel to screen for metabolic diseases","It measures different types of acylcarnitines in the blood that may indicate inherited disorders","Early detection allows for prompt treatment before symptoms become severe","Abnormal results do not always mean your baby has a disease - follow-up testing is needed","This screening is part of routine newborn care in most hospitals"}

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

Key facts at a glance

LOINC
58093-6
Short code
Acylcarnitine NBS comment
Synonyms
Acylcarnitine NBS comment
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

The acylcarnitine newborn screening is a blood test that checks for certain rare inherited metabolic disorders. These disorders affect how the body converts food into energy, particularly how it breaks down fatty acids. The test measures levels of different acylcarnitines, which are substances that help transport fatty acids into cells where they can be used for energy.

How is the test done?

A healthcare provider will prick your baby's heel to collect a few drops of blood. This is usually done 24-48 hours after birth, often before your baby leaves the hospital. The blood is placed on a special filter paper and sent to a laboratory for analysis. The test is part of the routine newborn screening panel and is generally safe with minimal discomfort for your baby.

What conditions can this test detect?

This screening can detect several metabolic disorders including medium-chain acyl-CoA dehydrogenase deficiency (MCAD), short-chain acyl-CoA dehydrogenase deficiency (SCAD), multiple acyl-CoA dehydrogenase deficiency (MADD), and various organic acidemias. These conditions are genetic and are usually inherited when both parents carry a gene mutation.

What do the results mean?

If the screening shows abnormal acylcarnitine levels, it does not automatically mean your baby has a disorder. Abnormal results indicate that additional diagnostic testing is needed. Your healthcare provider will contact you if follow-up testing is required. It's important to remember that early detection through newborn screening allows for early intervention, which can prevent serious health complications.

Is treatment available if a disorder is found?

Yes, if a metabolic disorder is confirmed, treatment is available. Treatment typically includes a special diet, medications, and careful management of fasting periods. With early detection and proper treatment, many children with these disorders can live healthy lives. Your doctor will refer you to a metabolic specialist who will create a personalized treatment plan for your baby.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is the acylcarnitine test mandatory?
Newborn screening requirements vary by country and state. In many places, this test is mandatory because the benefits of early detection far outweigh the risks. However, parents can usually opt out for religious or personal reasons after being fully informed of the potential consequences.
Will my baby need more blood tests if the first result is abnormal?
If the initial screening shows abnormal results, your healthcare provider will contact you to arrange follow-up testing. This typically involves repeating the acylcarnitine test and may include additional blood tests, urine tests, or genetic testing to confirm or rule out a diagnosis.
Can these metabolic disorders be prevented?
These disorders are genetic and cannot be prevented. However, newborn screening allows for early detection, and with proper management from birth, many complications can be avoided. If you have a family history of metabolic disorders, you may want to discuss genetic counseling with your doctor before or during pregnancy.
Are false positives common with this test?
False positives can occur with newborn screening tests. Some babies may have abnormal initial results but have normal follow-up testing. This is why confirmatory testing is always performed before making a diagnosis. The benefits of catching true cases early far outweigh the concern over occasional false positives.
  1. 1
    Mayo Clinic - Newborn Screening TestsSource
  2. 2
    Baby's First Test - Newborn ScreeningSource
  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