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Alpha-Aminobutyric Acid/Creatinine Ratio, Urine

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

This urine test measures alpha-aminobutyric acid relative to creatinine, helping assess urinary amino acid excretion and adjust for urine concentration.

Quick summary

["The result can help identify increased urinary amino acid loss but must be interpreted with other clinical and laboratory findings."]

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

Key facts at a glance

LOINC
26919-1
Short code
A-Aminobutyr/Creat Ur-sRto
Synonyms
A-Aminobutyr/Creat Ur-sRto
Category
liver
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 test measures alpha-aminobutyric acid, an amino acid, in urine and compares it with creatinine, a waste product commonly used to account for differences in urine concentration. The result is reported as a ratio.

Why might I need this test?

It may be ordered as part of an evaluation for a suspected inherited amino acid metabolism or transport disorder. It can also help clinicians assess amino acid loss in the urine while considering kidney function and other laboratory results.

How is the test performed?

A urine specimen is collected according to the instructions provided by the healthcare professional or laboratory. The laboratory measures alpha-aminobutyric acid and creatinine in the sample and calculates their ratio.

How do I prepare for the test?

Follow the collection instructions exactly, including any fasting or timed-collection requirements. If a 24-hour collection is requested, collect all urine for the specified period and follow the laboratory's storage and transport guidance.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A higher-than-expected ratio may indicate increased urinary amino acid excretion, which can occur with some inherited metabolism or transport disorders and may be influenced by urine concentration and kidney function. Results should be interpreted using the laboratory's reference information, collection method, age, medications, and other relevant findings. This ratio alone does not establish a specific diagnosis.

Short name

Urine alpha-aminobutyric acid/creatinine ratio

Frequently asked questions

What does an elevated alpha-aminobutyric acid/creatinine ratio mean?
It may mean that more alpha-aminobutyric acid is being excreted in the urine than expected for the urine concentration. Causes can include inherited metabolic or transport conditions, so the result must be reviewed with other tests and clinical findings.
Why is the result reported as a ratio?
Urine concentration can vary with fluid intake and other factors. Comparing alpha-aminobutyric acid with creatinine helps reduce the effect of these variations.
Do I need to collect urine for 24 hours?
Only if your clinician or laboratory specifically requests it. Otherwise, follow the collection type stated in your test instructions, which may include fasting or other timing requirements.
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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