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Maple Syrup Urine Disease (MSUD) Newborn Screen — Comment

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

A newborn screening blood test that checks for signs of maple syrup urine disease, an inherited disorder that can affect brain development and metabolism.

Quick summary

["This newborn screen looks for evidence of maple syrup urine disease and may be followed by confirmatory testing if the result is abnormal."]

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

Key facts at a glance

LOINC
58230-4
Short code
MSUD NBS comment
Synonyms
MSUD NBS comment
Category
urine
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?

This test is part of newborn screening for maple syrup urine disease, also called MSUD. It measures markers in a blood sample that can suggest an inherited problem with breaking down certain amino acids.

Why might I need this test?

Newborn screening can detect MSUD before symptoms appear. Early diagnosis and treatment help reduce the risk of serious health and developmental complications.

How is the test performed?

A few drops of blood are usually collected from the newborn's heel and placed on a filter-paper card. The laboratory analyzes the dried blood sample, often using tandem mass spectrometry, to look for MSUD-related markers.

How do I prepare for the test?

No special preparation is usually needed. The sample is generally collected during routine newborn screening, and the healthcare team will arrange repeat or confirmatory testing if the result is abnormal or the sample is inadequate.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An abnormal result may indicate elevated markers associated with MSUD, but it does not by itself confirm the diagnosis. A positive screen is generally followed by more specific testing and evaluation by a healthcare professional. Results should be interpreted together with the newborn's clinical findings and medical history.

Short name

MSUD newborn screen

Frequently asked questions

Does this test diagnose maple syrup urine disease?
No. It is a screening test. An abnormal result requires confirmatory testing before a diagnosis can be made.
What does MSUD mean?
MSUD stands for maple syrup urine disease, a rare inherited condition in which the body has difficulty processing certain amino acids.
What happens if the newborn screen is abnormal?
The healthcare team may request a repeat sample or more specific blood and urine tests. Early evaluation can help determine whether treatment is needed.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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