SLCO1B1 rs4149310: Statin Response and Your Genetics
The rs4149310 variant is a genetic change located within the SLCO1B1 gene, which plays a critical role in how the liver processes statin medications. Research suggests this variant may influence the risk of experiencing muscle-related side effects when taking certain statins.
What each genotype means
Normal transporter function
This genotype is considered the wild-type or normal function profile for the SLCO1B1 gene. Individuals with this profile typically have standard hepatic uptake of statin medications, which is associated with a lower risk of statin-induced myopathy compared to those carrying the C allele. Please discuss your medication plan and any muscle-related symptoms with your healthcare provider.
This is the most common genotype in most global populations, though frequencies vary by ancestry.
Reduced transporter function
Carrying one copy of the C allele (also known as the Val174Ala variant) is associated with reduced activity of the OATP1B1 transporter, which may lead to higher levels of statins in the blood. Research indicates this may increase the risk of statin-induced muscle pain or injury compared to those without the variant. You should consult your clinician or pharmacist regarding your statin dosage and monitoring.
This genotype is found in a significant portion of the population, with the C allele frequency ranging from approximately 10% to 20% in many European and Asian populations.
Significantly reduced transporter function
Individuals with two copies of the C allele (often referred to as the *5/*5 genotype) have the highest risk of reduced OATP1B1 transporter function. Studies have shown this genotype is associated with a substantially increased risk of statin-induced myopathy, particularly when taking high doses of certain statins like simvastatin. It is important to discuss this genetic finding with your doctor to determine the most appropriate medication and dosage for your needs.
This is the least common of the three genotypes, occurring in a smaller percentage of the population depending on ethnic background.
Understanding the rs4149310 Variant
The rs4149310 variant is a single nucleotide polymorphism (SNP) found within the SLCO1B1 gene, located on chromosome 12. In genetics, a SNP represents a variation at a single position in the DNA sequence. This specific variant is categorized under pharmacogenomics, a field that studies how an individual's genetic makeup affects their response to drugs. Because the SLCO1B1 gene is responsible for creating proteins that act as 'gatekeepers' for substances entering the liver, changes in this gene's sequence can alter the efficiency of these transport processes. While many variants exist within the human genome, rs4149310 is of particular interest to researchers because of its potential to influence the pharmacokinetics—or the movement and concentration—of medications within the body. Understanding where this variant sits helps scientists map out how genetic diversity contributes to the wide range of individual responses observed in clinical settings when patients are prescribed cholesterol-lowering therapies.
The Role of the SLCO1B1 Gene
The SLCO1B1 gene provides instructions for making a protein called organic anion transporting polypeptide 1B1 (OATP1B1). This protein is primarily expressed in the liver, where it functions as a transporter, moving various compounds from the bloodstream into liver cells. These compounds include endogenous substances like bilirubin, as well as exogenous substances, most notably statin medications used to manage cholesterol. By facilitating the uptake of statins into the liver, OATP1B1 helps the body clear these drugs from the blood. When the function of this transporter is altered due to genetic variation, the concentration of statins in the bloodstream can increase. Higher levels of statins circulating in the blood, rather than being processed by the liver, are hypothesized to be a contributing factor to the development of statin-associated muscle symptoms, such as pain or weakness. Consequently, the SLCO1B1 gene is a primary focus for researchers studying why some individuals tolerate statins well while others experience adverse muscular effects.
Research and Evidence Strength
The association between SLCO1B1 variants and statin-induced myopathy has been a subject of extensive study, particularly following landmark genome-wide association studies. While some variants in this gene have shown strong, replicated associations with muscle symptoms, the evidence for rs4149310 specifically is considered limited in comparison to other well-characterized markers like rs4149056. Research in this field often involves comparing the frequency of specific genotypes in patients who have experienced muscle symptoms against those who have tolerated statin therapy without issue. While some studies suggest that variations in SLCO1B1 can influence the risk of muscle-related side effects, the clinical impact can vary depending on the specific statin used, the dosage, and the patient's overall genetic background. It is important to note that genetic factors are only one piece of the puzzle; other variables, such as drug-drug interactions, age, and underlying health conditions, also play significant roles in how a patient responds to statin treatment.
Population Frequency
The rs4149310 variant is considered common across various global populations. Genetic frequency can vary significantly between different ancestral groups, and researchers often look at these differences to understand how genetic risk factors are distributed worldwide. Because this variant is common, a large number of individuals carry at least one copy of the variant allele. However, having a common variant does not necessarily mean that every individual will experience the same clinical outcome. The prevalence of the variant highlights the importance of large-scale genomic studies to determine how these common genetic differences interact with environmental factors and medical treatments. In the context of pharmacogenomics, knowing that a variant is common underscores the potential for widespread clinical relevance, provided that the association with drug response is robustly validated across diverse populations.
Managing Your Genetic Information
If you are interested in your genetic profile regarding statin response, it is essential to approach this information as a tool for conversation rather than a medical diagnosis. Genetic testing can provide insights into your potential predisposition, but it cannot predict with certainty whether you will experience side effects or how you will respond to a specific medication. If you have concerns about your current statin therapy or are considering starting a new one, you should discuss your genetic information with your healthcare provider or a clinical pharmacist. They are best equipped to interpret these results in the context of your full medical history, current medications, and lifestyle factors. Never make changes to your prescribed medication regimen based on genetic test results without consulting a professional. Your clinician can help determine if a different dosage or an alternative medication is appropriate for your specific health needs, ensuring that your treatment plan is both safe and effective.
How common is this variant?
The rs4149310 variant is common across most major human populations, with the frequency of the variant allele varying by ancestry.
Frequently asked questions
Does having this variant mean I will get muscle pain from statins?
No, having this variant does not guarantee that you will experience muscle pain. While it is associated with an increased risk, many people with this variant take statins without any side effects.
Should I stop taking my statin if I have this variant?
You should never stop taking a prescribed medication without first consulting your doctor. If you are concerned about side effects, speak with your healthcare provider about your options.
Is this the only gene that affects statin response?
No, statin response is complex and influenced by many genes, including other transporters and enzymes, as well as non-genetic factors like diet and other medications.
Can I get tested for this variant?
Genetic tests for this variant are available, but they should be interpreted by a medical professional. Discuss with your doctor whether such testing is relevant to your specific health situation.
Sources & further reading
Educational information only, last refreshed 9/23/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs4149310?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in SLCO1B1
This variant is a clinically relevant marker in Asian populations often analyzed for its impact on drug transport and metabolic fitness.
The c.521T>C (p.Val174Ala, *5) missense variant impairs hepatic transporter uptake function, increasing systemic exposure and muscle toxicity risks for multiple statins including simvastatin and atorvastatin.
This missense variant (p.Pro155Thr) is associated with reduced OATP1B1 transporter function, which can lead to increased plasma concentrations of certain statins and higher risk of myopathy.
A regulatory variant in the SLCO1B1 gene influencing statin pharmacokinetics.
Defines the c.388A>G (p.Asn130Asp) variant, which is a component of the SLCO1B1*1B and *15 haplotypes, influencing hepatic statin uptake.
Non-synonymous coding polymorphism (p.Asn130Asp) defining the SLCO1B1*30 allele with modest alteration in hepatic statin uptake.