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Methinine-to-Creatinine Ratio, Urine

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

A urine test that compares methionine with creatinine to help evaluate methionine metabolism, especially in children with suspected inherited metabolic disorders.

Quick summary

["This ratio helps assess how much methionine is being excreted in the urine relative to creatinine."]

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

Key facts at a glance

LOINC
13772-9
Short code
Methionine/Creat Ur
Synonyms
Methionine/Creat Ur
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This urine test measures methionine relative to creatinine, a substance used to account for urine concentration. It can help evaluate methionine metabolism.

Why might I need this test?

It may be used when an inherited methionine metabolism disorder is suspected, particularly in a child with developmental concerns, liver problems, or other symptoms. The results are interpreted alongside other tests and clinical findings.

How is the test performed?

A urine sample is analyzed for methionine and creatinine, and the results are used to calculate their ratio. The laboratory may require a random urine sample or a collection over a specified period, depending on the testing protocol.

How do I prepare for the test?

Follow the laboratory's instructions for urine collection, including any specified collection time. Tell the healthcare team about medicines, supplements, diet changes, or vitamin supplements that could affect the results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine Methionine-to-Creatinine Ratio

Frequently asked questions

What does the methionine-to-creatinine ratio measure?
It compares the amount of methionine in urine with the amount of creatinine. Creatinine helps account for differences in urine concentration.
Why is this test sometimes collected from young children?
Young children may be unable to provide a reliable timed urine collection, so a urine methionine-to-creatinine ratio may be used for initial screening. Confirmatory testing may still be needed.
Can diet or supplements affect the result?
Yes. Dietary methionine, protein intake, vitamin supplementation, and certain medicines may influence methionine levels. Follow any preparation instructions provided by your healthcare team.
  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