UGT1A1 Genotyping – MC062
🧬 Genetic Test (Pharmacogenomics)Report: 15-16th Working Day
Sample Type: Blood (EDTA)
Test Code: MC062
UGT1A1 Genotyping is a genetic test that analyzes variations in the UGT1A1 gene. This gene is responsible for producing an enzyme that helps break down and clear bilirubin (a substance that causes jaundice) and certain medications from the body.
✔ Helps diagnose inherited conditions like Gilbert's Syndrome and Crigler-Najjar Syndrome.
✔ Crucial in pharmacogenomics to predict a patient's risk of severe side effects from chemotherapy drugs like Irinotecan.
✔ Allows oncologists to personalize chemotherapy doses for better safety and efficacy.
✔ A simple one-time blood test provides lifelong genetic information.
UGT1A1: A Gene with a Dual Role in Health
The UGT1A1 gene holds the blueprint for an important enzyme called UDP-glucuronosyltransferase 1A1. This enzyme plays a vital housekeeping role in the liver by converting toxic substances into water-soluble forms that can be easily excreted from the body. This process is called glucuronidation. The UGT1A1 enzyme is primarily responsible for processing two key things: bilirubin and certain drugs.
This genetic test analyzes your specific version of the UGT1A1 gene to look for common variations (polymorphisms) that can reduce the enzyme's efficiency. The results have important implications in two distinct areas of medicine.
1. Diagnosing Inherited Bilirubin Disorders
Bilirubin is a yellow pigment produced during the normal breakdown of old red blood cells. The UGT1A1 enzyme is essential for processing bilirubin so it can be eliminated. Variations in the UGT1A1 gene that reduce the enzyme's function lead to a buildup of bilirubin in the blood, causing jaundice (yellowing of the skin and eyes).
- Gilbert's Syndrome: This is a very common and harmless genetic condition caused by a mild reduction in UGT1A1 enzyme activity. People with Gilbert's Syndrome may experience episodes of mild jaundice during times of stress, illness, or fasting, but it does not cause serious health problems. UGT1A1 genotyping can definitively confirm this diagnosis.
- Crigler-Najjar Syndrome: This is a much rarer and more severe disorder where the UGT1A1 enzyme is severely deficient or completely absent, leading to dangerously high bilirubin levels from birth.
2. Personalized Medicine: Pharmacogenomics and Chemotherapy
The most critical application of this test is in oncology. The UGT1A1 enzyme is also the primary way the body breaks down the active metabolite of Irinotecan, a chemotherapy drug used to treat colorectal, pancreatic, and other cancers. Patients with certain UGT1A1 gene variations produce a less efficient enzyme. When they receive a standard dose of Irinotecan, their bodies cannot clear the drug effectively. This leads to a toxic buildup, dramatically increasing the risk of severe, life-threatening side effects like neutropenia (dangerously low white blood cell count) and severe diarrhea.
By performing UGT1A1 genotyping before starting treatment, an oncologist can identify at-risk patients and proactively adjust the Irinotecan dose. This is a cornerstone of personalized medicine, moving away from a "one-size-fits-all" approach to a treatment plan tailored to your unique genetic makeup, maximizing safety and effectiveness.
Frequently Asked Questions (FAQ)
Your doctor may have ordered this test for two main reasons: 1) To confirm a diagnosis of a hereditary condition like Gilbert's Syndrome if you have persistently high bilirubin levels, or 2) If you are scheduled to receive chemotherapy with the drug Irinotecan, to check if you are at a higher risk for side effects.
No. An LFT measures the current levels of enzymes and proteins (including bilirubin) in your blood to assess liver health. UGT1A1 Genotyping is a genetic test that analyzes your DNA to look for inherited variations in a specific gene. It explains why your bilirubin might be high, rather than just measuring its level.
No, fasting is not required for this genetic test. It is a simple blood draw.
Genetic testing (genotyping) is a highly complex and specialized process. It involves extracting DNA from your blood cells, amplifying the specific UGT1A1 gene region, and then analyzing its sequence. This multi-step process requires significant time and expertise.
No. Your genes do not change. The result of this test is valid for your entire life and does not need to be repeated.