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N-Acetyllalanine/Creatinine Ratio, Urine

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

A specialized urine test that measures N-acetyllalanine relative to creatinine. It may help evaluate certain rare inherited metabolic disorders.

Quick summary

["This urine ratio can provide evidence of abnormal metabolism, but it 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
104697-8
Short code
N-acetyl-L-alanine/Creat Ur-sRto
Synonyms
N-acetyl-L-alanine/Creat Ur-sRto
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 test measures N-acetyllalanine, a small molecule related to amino acid metabolism, in your urine. The result compares the amount of N-acetyllalanine with the amount of creatinine in the same urine sample.

Why might I need this test?

This is a specialized test that may be ordered to investigate suspected inherited disorders of amino acid or organic acid metabolism. It is usually interpreted along with other urine and blood tests, medical history, and sometimes genetic testing.

How is the test performed?

A urine specimen is tested for N-acetyllalanine and creatinine, and the laboratory calculates their ratio. Depending on the ordering laboratory, this may use a single urine sample or a timed collection.

How do I prepare for the test?

Follow the laboratory's collection instructions and tell your clinician about medicines, vitamins, supplements, and your diet. Do not fast or stop prescribed medicines unless your healthcare professional specifically instructs you to do so.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated ratio means that more N-acetyllalanine is being excreted in the urine relative to creatinine. This may occur in certain rare inherited metabolic disorders, but diet, supplements, medicines, kidney function, and urine collection factors can also affect the result. A single abnormal result does not establish a diagnosis and should be reviewed by a clinician or metabolic specialist.

Short name

Urinary N-acetyllalanine ratio

Frequently asked questions

What does this urine test measure?
It measures the ratio of N-acetyllalanine to creatinine in urine. This provides information about the amount of N-acetyllalanine being excreted.
Why is creatinine included in the result?
Creatinine is commonly used to account for differences in urine concentration. Using the ratio makes results easier to compare between samples.
Does an abnormal result confirm a metabolic disorder?
No. An abnormal result may support further evaluation, but diagnosis usually requires additional laboratory tests, clinical information, and sometimes genetic testing.
  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