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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, which helps account for differences in urine concentration.

Quick summary

["The result can provide information about amino acid metabolism and, in some settings, vitamin B6 status."]

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

Key facts at a glance

LOINC
28590-8
Short code
A-Aminobutyr/Creat Ur-Rto
Synonyms
A-Aminobutyr/Creat Ur-Rto
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-related substance, in urine. The result is divided by the urine creatinine level to form a ratio, making it less affected by how concentrated or dilute the urine is.

Why might I need this test?

A clinician may use this test as part of an evaluation of unusual symptoms, suspected inherited metabolic conditions, or possible vitamin B6-related problems. It is usually interpreted together with other laboratory and clinical findings.

How is the test performed?

A urine specimen is collected and analyzed in the laboratory for alpha-aminobutyric acid and creatinine. The laboratory then calculates their ratio.

How do I prepare for the test?

For a routine urine collection, follow the instructions provided by the laboratory or clinician. Special preparation may be needed if this test is being used with a medication challenge or another standardized metabolic evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated urine ratio may occur with vitamin B6 deficiency or impaired vitamin B6 metabolism and can also be seen with some liver or inherited metabolic disorders. Results are not diagnostic by themselves and must be interpreted in the context of symptoms, medications, diet, and other tests.

Short name

Urine alpha-aminobutyric acid ratio

Frequently asked questions

Is this the same as a serum amino acid test?
No. This test measures alpha-aminobutyric acid in urine and compares it with urine creatinine. A serum amino acid profile measures different substances in blood.
Why is creatinine included in the result?
Creatinine helps account for variations in urine concentration. Using a ratio makes the alpha-aminobutyric acid result more comparable between samples.
Does an abnormal result confirm a specific condition?
No. An abnormal result can suggest several possible metabolic or nutritional issues. Your clinician will interpret it with your medical history and other laboratory results.
  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