ABCC2 rs717620: What Your Genotype Means
The rs717620 variant is a common genetic change located in the promoter region of the ABCC2 gene. It has been studied for its potential influence on how the body processes certain medications, including methotrexate and tenofovir, though research findings remain mixed and often population-specific.
What each genotype means
Typical ABCC2 Transporter Function
You carry two copies of the common C allele (also known in literature as -24CC or wild-type) for the ABCC2 gene promoter. Research indicates typical biliary and renal efflux activity, though some studies suggest this genotype may carry a relatively higher risk of tenofovir-induced kidney tubular dysfunction compared to variant carriers. If you are taking tenofovir, methotrexate, or other medications handled by the ABCC2 transporter, consult your clinician or pharmacist about routine kidney function monitoring and dosing considerations.
Carried by approximately 60% to 75% of individuals globally, making it the most common genotype across most populations.
Moderately Altered Drug Clearance
You carry one copy of the -24T variant allele alongside one C allele in the promoter region of the ABCC2 gene. Published studies have linked the presence of the T allele to reduced promoter activity and altered clearance of certain therapeutics, including methotrexate and tenofovir. Because evidence on clinical toxicity and efficacy remains limited and sometimes inconsistent across study cohorts, discuss your medication regimen and any necessary dosing adjustments directly with your healthcare provider or pharmacist.
Carried by approximately 25% to 35% of people in European and South Asian populations, and slightly less frequently in East Asian cohorts.
Altered Transporter Expression
You carry two copies of the -24T promoter variant allele in the ABCC2 gene. Scientific literature associates this homozygous genotype with reduced transporter expression, which may lead to slower clearance of drugs like methotrexate and potentially lower risk of certain tenofovir-related kidney tubular toxicities. However, the overall clinical evidence remains limited and mixed across diverse populations, so you should speak with your physician or pharmacist regarding drug selection, dosing, and therapeutic monitoring.
Found in approximately 2% to 6% of individuals across global populations, being most common in European and South Asian ancestries.
Understanding the rs717620 Variant
The rs717620 variant, often referred to in scientific literature as the -24C>T polymorphism, is a single nucleotide polymorphism (SNP) located in the 5' untranslated region (UTR) of the ABCC2 gene. This region acts as a promoter, meaning it helps regulate how much of the ABCC2 protein is produced by the cell. Because this variant sits in a regulatory area, researchers have long hypothesized that it might alter the expression levels of the resulting protein. In genetic databases, the variant is typically described by the presence of either a cytosine (C) or a thymine (T) at this specific position on chromosome 10. Because it is a common variant, many individuals carry at least one copy of the T allele, making it a frequent subject of study in the field of pharmacogenomics, which examines how genetic differences influence individual responses to pharmaceutical treatments.
The Role of the ABCC2 Gene
The ABCC2 gene provides instructions for creating a protein known as multidrug resistance-associated protein 2 (MRP2). This protein functions as an efflux transporter, acting like a molecular pump that moves various substances—including bile acids, toxins, and certain medications—out of cells and into the bile or urine for excretion. By facilitating the removal of these compounds, MRP2 plays a critical role in protecting cells from the accumulation of potentially harmful substances. When the function of this transporter is altered, it can theoretically change the concentration of drugs within the body. For example, if MRP2 activity is reduced, drugs that rely on this pathway for clearance may remain in the bloodstream for longer periods, potentially increasing the risk of side effects or toxicity. Conversely, higher activity might lead to faster clearance, which could impact the overall effectiveness of a prescribed therapy.
Research Associations and Evidence Strength
Research into rs717620 has produced varied and sometimes conflicting results. Several studies have investigated whether the T allele is associated with altered pharmacokinetics—how the body absorbs, distributes, and eliminates drugs—specifically for medications like methotrexate and tenofovir. Some studies have suggested that carriers of the T allele may experience different drug clearance rates or a higher risk of toxicity, such as hepatotoxicity or nephrotoxicity. However, other large-scale studies have failed to replicate these findings, finding no significant difference in drug response based on this genotype. The evidence for this variant is currently considered limited and inconsistent. Furthermore, many of these associations appear to be highly dependent on the specific population being studied, suggesting that other genetic or environmental factors likely play a significant role in how an individual responds to these medications.
Population Frequency
The rs717620 variant is common across many global populations, with a reported minor allele frequency (MAF) typically ranging between 0.15 and 0.25. It is frequently observed in European and South Asian cohorts, though specific frequencies can vary significantly between different ethnic groups. Because the variant is common, it is not considered a rare mutation, but rather a normal variation in the human genetic landscape.
What This Information Means for You
If you have received information about your rs717620 genotype, it is important to understand that this variant is not a diagnostic tool. The current scientific evidence is not strong enough to support using this SNP to predict individual drug responses or to guide clinical dosing decisions in a routine setting. Genetic factors are only one piece of a much larger puzzle that includes your overall health, other medications you may be taking, and your unique physiology. You should never use genetic information to make changes to your prescribed medications or treatment plans. If you have concerns about how a medication is affecting you, or if you are curious about how your genetics might influence your treatment, the best course of action is to discuss these questions with your clinician or pharmacist. They can provide context based on your full medical history and current clinical guidelines.
How common is this variant?
The rs717620 variant is common globally, with a minor allele frequency typically between 0.15 and 0.25, and is frequently found in European and South Asian populations.
Frequently asked questions
Is rs717620 a cause of disease?
No, rs717620 is a common genetic variation and is not considered a disease-causing mutation. While it has been studied for its potential role in drug response, it is not a diagnostic marker for any specific condition.
Should I change my medication based on my rs717620 result?
Absolutely not. You should never alter your medication regimen based on genetic test results without consulting your doctor. Genetic variants like rs717620 are not currently used to guide clinical dosing.
Why do some studies show an effect and others do not?
Pharmacogenomic studies often show mixed results due to differences in study design, the specific populations analyzed, and the influence of other genetic or environmental factors. This is why the evidence for rs717620 is considered limited.
Does this variant affect all drugs?
No, this variant is only studied in the context of specific medications that are transported by the MRP2 protein, such as certain chemotherapies or antivirals. It does not affect the metabolism of all drugs.
Sources & further reading
Educational information only, last refreshed 10/18/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Functional 5-prime promoter polymorphism c.-24C>T in the ABCC2 (MRP2) transporter gene linked to altered methotrexate toxicity and tenofovir nephrotoxicity risk.
This variant is identified as pathogenic and associated with Dubin-Johnson syndrome.