ABCB1 rs11983225: What Your Genotype Means
The rs11983225 variant is a single nucleotide polymorphism located within the ABCB1 gene, which encodes the P-glycoprotein transporter. This protein acts as an efflux pump that regulates the movement of various substances, including certain medications, across the blood-brain barrier.
What each genotype means
Typical transporter activity
This genotype represents the most common form of the ABCB1 gene at this location. Research into this variant is ongoing, and current evidence does not suggest a significant impact on drug transport or clinical outcomes. Please discuss any concerns regarding medication efficacy or dosing with your healthcare provider or pharmacist.
This is the most common genotype, found in the majority of individuals across most global populations.
Typical transporter activity
Carrying one copy of the T allele is common and generally not associated with significant changes in P-glycoprotein function. While this gene is involved in drug transport, current scientific literature does not support using this specific variant to guide clinical treatment decisions. Always consult your clinician before making changes to your medication regimen.
This genotype is observed in a significant portion of the population, consistent with the reported minor allele frequency of approximately 13%.
Typical transporter activity
This genotype is the less common variant at this position, but it is not definitively linked to altered drug transport or clinical side effects in current research. Because the evidence for this specific variant is limited, it is not currently used to adjust medication dosages. Please consult your pharmacist or doctor if you have questions about how your medications are working for you.
This genotype is the least common of the three, occurring in a smaller percentage of the population compared to the CC and CT genotypes.
Understanding the ABCB1 Gene
The ABCB1 gene, also historically referred to as the MDR1 (multidrug resistance 1) gene, provides instructions for creating a protein called P-glycoprotein. This protein is a member of the ATP-binding cassette (ABC) transporter superfamily. P-glycoprotein functions as an energy-dependent efflux pump, meaning it uses energy from ATP to move molecules out of cells. It is widely expressed throughout the body, including in the liver, kidneys, intestines, and crucially, the blood-brain barrier. By pumping substances out of cells, P-glycoprotein plays a significant role in protecting the brain from toxins and regulating the concentration of various therapeutic drugs within the central nervous system. Because of its broad substrate specificity, variations in the ABCB1 gene can potentially influence how effectively certain medications are absorbed, distributed, or cleared from the body.
What is the rs11983225 Variant?
The rs11983225 variant is a specific genetic change, or single nucleotide polymorphism (SNP), found within the ABCB1 gene. Located on chromosome 7, this variant represents a point where the DNA sequence can differ between individuals. In the context of pharmacogenomics, researchers study such variants to determine if they correlate with differences in how people respond to specific medications. The rs11983225 variant is often studied alongside other SNPs in the same region because they are frequently inherited together in a block, a phenomenon known as linkage disequilibrium. This means that the presence of one variant can often predict the presence of others nearby. While the biological impact of this specific SNP is a subject of ongoing research, its location within a gene critical for drug transport makes it a target of interest for scientists investigating why individuals may experience different drug efficacy or side-effect profiles.
Research and Clinical Evidence
Scientific research into rs11983225 has primarily focused on its potential association with drug response, particularly for medications that cross the blood-brain barrier, such as antidepressants. The hypothesis is that variations in P-glycoprotein function could alter the amount of drug that reaches the brain, potentially affecting clinical outcomes. However, the evidence remains mixed and inconclusive. While some studies have suggested a link between ABCB1 variants and treatment response, others have found no significant correlation. A review of the literature indicates that findings are often inconsistent, with some reports showing clinical effects and others showing none. Because of these conflicting results, the clinical utility of using this variant to guide medication choices is currently limited. It is important to note that drug response is a complex trait influenced by many factors, including other genes, environmental influences, and the specific medication being used.
Interpreting Your Genetic Information
If you have information about your rs11983225 genotype, it is essential to understand that this data does not provide a definitive prediction of how you will respond to any medication. Genetic associations are statistical observations made across large populations and do not necessarily apply to an individual's unique biology. You cannot use this information to diagnose a condition or to make decisions about starting, stopping, or changing the dosage of any prescribed medication. If you are concerned about how a medication is affecting you, or if you are interested in how your genetics might influence your treatment, the most appropriate step is to consult with your healthcare provider or a pharmacist. They can evaluate your clinical history, current medications, and other relevant factors to provide personalized medical guidance that is far more reliable than any single genetic marker.
How common is this variant?
The rs11983225 variant has a Global Minor Allele Frequency (GMAF) of approximately 0.1318, though frequencies can vary significantly across different ancestral populations.
Frequently asked questions
Can I use rs11983225 to predict my antidepressant response?
No. While some research has investigated this, the evidence is inconsistent and not strong enough to be used for clinical decision-making. Medication response is influenced by many factors beyond a single genetic variant.
What does the ABCB1 gene do?
The ABCB1 gene encodes P-glycoprotein, a protein that acts as a pump to move various substances, including drugs, out of cells. It is particularly important for regulating drug levels in the brain.
Should I change my medication based on my ABCB1 genotype?
Absolutely not. You should never change your medication or dosage based on genetic test results without consulting your doctor. Only a healthcare professional can safely manage your treatment plan.
Is rs11983225 a dangerous mutation?
No, rs11983225 is a common genetic variant, not a disease-causing mutation. It is a normal variation in the human genome that researchers study to understand differences in drug metabolism.
Sources & further reading
Educational information only, last refreshed 9/27/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This SNP is located in the ABCB1 gene and is associated with the regulation of drug efflux pumps that influence intracerebral drug concentrations.
Synonymous variant (c.3435C>T) in ABCB1 linked to altered P-glycoprotein expression and multi-drug transporter pharmacokinetics.
Carriers of the ancestral homozygous genotype (GG) show significantly worse progression-free survival in breast carcinoma patients compared to those with the non-ancestral allele.
A variant associated with potential differences in drug absorption and clinical outcomes in patients undergoing specific pharmacological therapies.
This SNP is linked to variations in the pharmacokinetics of drugs that are substrates for the ABCB1 transporter protein.
Nonsynonymous variant (Ala893Ser/Thr) in ABCB1/MDR1 altering P-glycoprotein transporter kinetics and plasma concentrations of drugs such as digoxin, fexofenadine, and tacrolimus.