UGT1A1 rs72552760: What Your Genotype Means
The rs72552760 variant is a genetic alteration located within the UGT1A1 gene, which plays a critical role in how the body processes certain medications and bilirubin. This variant is studied for its potential to reduce the body's glucuronidation capacity, which may influence susceptibility to side effects from specific chemotherapy drugs like irinotecan.
What each genotype means
Typical enzyme activity
This genotype represents the most common form of the UGT1A1 gene in most populations. Individuals with this profile are generally expected to have standard glucuronidation capacity for medications processed by this enzyme. Please discuss any medication dosing, particularly regarding irinotecan, with your clinician or pharmacist.
This is the most common genotype globally, found in the vast majority of individuals across all major ancestral groups.
Reduced enzyme activity
This genotype includes one copy of the variant allele, which is associated with reduced UGT1A1 enzyme function. Research suggests this may lead to a decreased ability to process certain substances, potentially increasing the risk of side effects from drugs like irinotecan or mild elevations in bilirubin. You should consult with your healthcare provider or pharmacist before starting any medication metabolized by this enzyme to determine if dose adjustments are necessary.
This genotype is observed at a low frequency, with the minor allele appearing in approximately 2% of East Asian cohorts and varying in other populations.
Decreased enzyme activity
This genotype consists of two copies of the variant allele, which is linked to a more pronounced reduction in UGT1A1 enzyme activity. Carriers may have a higher susceptibility to hyperbilirubinemia and an increased risk of toxicity when taking specific medications such as irinotecan. It is important to discuss this genetic profile with your clinician or pharmacist to ensure appropriate clinical management and medication dosing.
This genotype is rare, occurring at a very low frequency in the general population, with higher prevalence noted specifically in certain East Asian cohorts.
Understanding the rs72552760 Variant
The rs72552760 variant is a single nucleotide polymorphism (SNP) found within the UGT1A1 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is categorized as a missense alteration, meaning the change in the DNA sequence results in a different amino acid being incorporated into the protein structure. Because proteins are the functional building blocks of the body, changes in their sequence can sometimes alter their efficiency or stability. Researchers track these variants to understand how they contribute to biological diversity and individual differences in health outcomes. While rs72552760 is documented in genomic databases, it is important to note that its functional impact is still being characterized by the scientific community, and it is often studied alongside other more common UGT1A1 variants that are known to affect enzyme activity.
The Role of the UGT1A1 Gene
The UGT1A1 gene provides instructions for making an enzyme called UDP-glucuronosyltransferase 1A1. This enzyme is primarily responsible for a process called glucuronidation, which is a chemical reaction that makes substances more water-soluble so they can be easily excreted from the body. One of the most important substances processed by this enzyme is bilirubin, a yellow pigment produced during the normal breakdown of red blood cells. When UGT1A1 activity is reduced, bilirubin can accumulate in the blood, potentially leading to jaundice or conditions like Gilbert syndrome. Beyond bilirubin, this enzyme is also essential for metabolizing various drugs, including the chemotherapy agent irinotecan. By converting these substances into inactive forms, the UGT1A1 enzyme helps prevent the buildup of toxic compounds in the body. Variations in this gene can therefore lead to differences in how efficiently a person clears these substances from their system.
Research and Clinical Associations
Scientific research into UGT1A1 has largely focused on how genetic variations influence the metabolism of irinotecan, a drug used to treat certain types of cancer. Reduced enzyme activity is associated with an increased risk of severe side effects, such as neutropenia and diarrhea, because the body cannot clear the drug as effectively. While variants like UGT1A1*28 are well-established in clinical guidelines, the evidence for rs72552760 is considered limited. Current studies are working to determine the exact extent to which this specific variant contributes to reduced glucuronidation capacity compared to better-known markers. Because the evidence is not yet definitive, clinicians often look at a patient's entire genetic profile rather than a single variant when making treatment decisions. It is essential to recognize that genetic associations are statistical in nature and do not guarantee that a specific individual will experience a particular drug reaction.
Population Frequency and Distribution
Genetic variants are distributed unevenly across different human populations, and rs72552760 is no exception. According to current genomic data, the minor allele frequency for this variant is approximately 0.02 in East Asian cohorts. This means that the variant is relatively uncommon in these populations, though it is present. Frequencies can vary significantly when comparing different ancestral groups, which is a common theme in pharmacogenomics. Understanding these frequency differences is vital for researchers who aim to develop personalized medicine strategies that are equitable and accurate across diverse global populations. Because the frequency is low, many individuals will carry the common, or reference, version of the gene. If you are curious about your own genetic makeup, it is important to remember that population-level statistics describe groups, not individuals, and your personal health is influenced by a complex interplay of genetics, environment, and lifestyle.
Navigating Genetic Information
Accessing information about your genetic variants can be empowering, but it is important to use this data responsibly. If you have received a report mentioning rs72552760, it is crucial to understand that this information is not a medical diagnosis. Genetic variants are only one piece of a much larger puzzle that includes your medical history, current medications, and overall health status. You should never make changes to your prescribed medications or treatment plans based on genetic test results without first consulting your healthcare provider or a clinical pharmacist. These professionals are trained to interpret genetic data in the context of your specific clinical needs. They can help determine if a particular variant is relevant to your care and whether any adjustments to your treatment are necessary. Always prioritize professional medical advice over self-interpretation of genetic data.
How common is this variant?
The rs72552760 variant is relatively rare, with a minor allele frequency of approximately 0.02 in East Asian cohorts.
Frequently asked questions
What is the UGT1A1 gene?
The UGT1A1 gene provides instructions for an enzyme that helps the body process bilirubin and certain medications. It is a key player in the liver's detoxification pathways.
Does this variant cause Gilbert syndrome?
Gilbert syndrome is often associated with specific UGT1A1 promoter variants. While rs72552760 affects the same gene, its specific role in causing Gilbert syndrome is not as well-established as other common variants.
Should I change my medication if I have this variant?
No. You should never change your medication based on genetic results without consulting your doctor. Your physician will consider your entire clinical picture before making any adjustments.
Is this variant common?
The variant is considered rare in many populations, with a minor allele frequency of about 0.02 in East Asian groups. Most people carry the common, or reference, version of the gene.
Where can I get tested for this?
Genetic testing for UGT1A1 is typically ordered by oncologists or specialists when planning specific chemotherapy treatments. It is not a standard test for the general public.
Sources & further reading
Educational information only, last refreshed 9/17/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Missense variant corresponding to the functional UGT1A1*27 allele associated with reduced glucuronidation and elevated irinotecan toxicity risk.
Variant allele in UGT1A1 promoter region associated with altered glucuronidation and risk of irinotecan-induced toxicity.
This variant in the UGT1A gene cluster is associated with serum total bilirubin levels and susceptibility to Gilbert syndrome.
This variant (UGT1A1*6) is a decreased-function allele associated with reduced glucuronidation capacity, impacting the metabolism of drugs like irinotecan and influencing neonatal hyperbilirubinemia risk.
This variant is a key marker for defining UGT1A1 star alleles (*1, *28, *36, *37) which influence the metabolism of drugs like irinotecan and the risk of hyperbilirubinemia.
This variant is associated with hyperbilirubinaemia (Gilbert's syndrome) and is used to guide irinotecan dosage.