Genetic Test for UGT1A1 Gene Variant (Specifically p.Pro229Gln)
This test checks for a specific genetic change in the UGT1A1 gene, which may affect how your body processes certain medications or contribute to conditions like Gilbert’s syndrome or certain cancers.
["A genetic test to identify a rare variant linked to medication metabolism or potential health risks."]
Key facts at a glance
- LOINC
- 104286-0
- Short code
- UGT1A1 gene.p.P229Q Bld/T Ql
- Synonyms
- UGT1A1 gene.p.P229Q Bld/T Ql
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have a family history of conditions related to UGT1A1 gene variants, are considering certain medications that interact with this gene, or if symptoms like jaundice, fatigue, or unusual bruising are present.
What the Test Measures
The test detects a specific amino acid change (from proline to glutamine) at position 229 in the UGT1A1 gene. This variant may influence how your liver processes drugs or certain toxins.
Common Uses and Considerations
This test is primarily used for genetic screening or carrier testing, especially in cases where family history or clinical suspicion of UGT1A1-related conditions exists. It is not a routine screening test for most individuals.
What to Expect Before the Test
No special preparation is needed. A small blood sample (whole blood) will be taken, similar to a regular blood draw. If testing is done on saliva, you may need to fast or avoid certain foods for a specified period, but this is rare for this test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
UGT1A1 Gene Mutation Test
Frequently asked questions
UGT1A1 encodes an enzyme involved in the metabolism of drugs and toxins. The p.Pro229Gln variant may affect enzyme function, potentially altering how your body processes medications like irinotecan (used in cancer treatment) or contributing to conditions like Gilbert’s syndrome (mild jaundice). However, the clinical impact varies widely among individuals.
No, this test specifically checks for a genetic variant in the UGT1A1 gene. Gilbert’s syndrome is diagnosed through liver function tests or clinical symptoms, not solely by genetic testing.
Possibly. Some medications metabolized by UGT1A1 may require dose adjustments if you carry this variant, especially if they are used for cancer treatment or other serious conditions. Always discuss potential risks and benefits with your doctor.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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