CES1 rs2244613: What Your Genotype Means
The rs2244613 variant is a genetic change located within the CES1 gene, which provides instructions for making an enzyme involved in processing various substances in the body. Research has explored its potential association with how individuals metabolize certain medications, such as the anticoagulant dabigatran.
What each genotype means
Reduced dabigatran exposure
You carry two copies of the C allele (frequently designated as G in complementary strand reports). Research indicates this genotype is associated with decreased trough concentrations of the anticoagulant dabigatran and a reduced statistical risk of bleeding complications. Because genetic factors can alter drug activation and metabolism, consult your physician or pharmacist before starting or adjusting medications.
Found in approximately 10% to 15% of European populations, but reaches frequencies of 35% or higher in East Asian ancestries.
Moderately reduced dabigatran exposure
You carry one copy of the C allele and one copy of the common T allele. Studies observe that carrying one C allele is linked to moderately lower circulating trough levels of dabigatran and a lower likelihood of treatment-related bleeding compared to TT non-carriers. If you are prescribed dabigatran or other carboxylesterase-metabolized prodrugs, discuss your dosing regimen and monitoring plan with your doctor or pharmacist.
Carried by roughly 35% to 45% of individuals in European populations and nearly half of East Asian cohorts.
Typical carboxylesterase 1 activity
You have two copies of the T allele (often noted as AA in complementary strand studies), representing the baseline European genotype. Population studies associate this genotype with higher peak and trough concentrations of dabigatran compared to C allele carriers, along with a standard expected risk of bleeding. If you take dabigatran or other prodrug medications, always review proper dosing and monitoring with your healthcare provider.
Carried by approximately 40% to 50% of people of European descent, but less common in East Asian populations (around 15% to 20%).
Understanding the rs2244613 Variant
The rs2244613 variant is a single-nucleotide polymorphism (SNP) located within the CES1 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence. This specific variant is categorized as an intronic variant, meaning it is located in a non-coding region of the gene. While it does not directly change the protein sequence, researchers study such variants because they may influence how the gene is regulated or expressed. The CES1 gene is primarily active in the liver, where it plays a critical role in the hydrolysis of various esters, including those found in certain drugs and lipids. Because of its location and potential impact on enzyme activity, scientists have investigated whether this variant contributes to the observed differences in how people process medications that rely on CES1 for activation or breakdown.
The Role of the CES1 Gene
The CES1 gene encodes the carboxylesterase 1 enzyme. This enzyme is a member of a family of proteins responsible for breaking down (hydrolyzing) a wide range of compounds, including endogenous lipids and exogenous substances like medications. In the context of pharmacology, CES1 is particularly important for the activation of certain prodrugs—medications that are administered in an inactive form and must be converted into their active state by enzymes in the body. For example, the anticoagulant dabigatran etexilate requires conversion by CES1 to become the active drug dabigatran. Because the efficiency of this conversion can vary between individuals, researchers look at genetic variants like rs2244613 to see if they explain why some people experience different drug concentrations in their blood. Understanding these variations is a key focus of pharmacogenomics, the study of how genes affect a person's response to drugs.
Research Associations and Evidence
Scientific research has examined the association between rs2244613 and the pharmacokinetics of dabigatran. Some studies have suggested that carriers of the G allele may have lower trough concentrations of the active drug compared to those with the T allele, which has been statistically linked to a potentially lower risk of bleeding in some clinical cohorts. However, the evidence is considered limited and mixed. While some large-scale analyses have identified significant associations, other studies, particularly those involving different ancestral populations, have not always replicated these findings. Furthermore, the influence of this variant on other medications remains a subject of ongoing investigation. It is important to note that drug response is complex and influenced by many factors, including age, kidney function, diet, and other medications. Consequently, this genetic information is not currently used as a standalone diagnostic tool for clinical decision-making.
What You Can and Cannot Do
If you have received information about your rs2244613 genotype, it is important to interpret it within the context of current scientific limitations. This variant is not a definitive predictor of how you will respond to any specific medication. You cannot use this information to diagnose a health condition or to make independent decisions about your medical treatments. If you are prescribed a medication that is metabolized by CES1, such as dabigatran, you should discuss your genetic profile with your healthcare provider or pharmacist. They are the only ones qualified to evaluate your overall health, medical history, and other clinical factors to determine the most appropriate treatment plan for you. Never change your medication dosage or stop taking a prescribed drug based on genetic test results without consulting your clinical team first.
How common is this variant?
The frequency of the rs2244613 variant varies significantly by ancestry, with the G allele being more common in some Asian populations compared to European populations, where the minor allele frequency is approximately 0.35.
Frequently asked questions
Does the rs2244613 variant mean I will have a bad reaction to medication?
No, this variant does not guarantee a specific reaction. While research suggests it may influence how some drugs are processed, many other factors like your kidney function and overall health play a much larger role in how you respond to medication.
Should I get tested for the rs2244613 variant?
Genetic testing for this variant is not currently standard clinical practice. If you are concerned about how a specific medication might affect you, it is best to discuss your concerns and your medical history with your doctor.
Is rs2244613 the only variant that affects CES1?
No, the CES1 gene has many known variants. Researchers study several different SNPs and structural variations within this gene to understand how they collectively influence enzyme activity.
Can I change my genotype?
No, your genotype is determined at conception and cannot be changed. However, understanding your genetic predispositions can help you have more informed conversations with your healthcare providers.
Sources & further reading
Educational information only, last refreshed 9/12/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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