SLCO1B1 rs4149036: What Your Genotype Means
The rs4149036 variant is a common genetic change in the SLCO1B1 gene that results in an amino acid substitution. It is primarily studied for its role in defining specific haplotypes that influence how the liver takes up and clears certain medications, including statins.
What each genotype means
Normal transporter function
This genotype represents the reference sequence for this position, often associated with the SLCO1B1*1A haplotype. Research suggests this configuration typically results in standard hepatic uptake of certain medications, such as statins. Please discuss your medication response and dosing with your clinician or pharmacist.
This genotype is common globally, though its frequency varies significantly depending on ancestral background.
Increased transporter activity
This heterozygous genotype includes one copy of the G allele, which is a component of the SLCO1B1*1B haplotype. Some studies indicate this variant may be associated with increased hepatic uptake of certain drugs, potentially influencing how your body processes medications like atorvastatin. Please discuss your medication response and dosing with your clinician or pharmacist.
This genotype is widespread and frequently observed across many global populations.
Enhanced transporter activity
This homozygous genotype consists of two copies of the G allele, which is associated with the SLCO1B1*1B haplotype. Evidence suggests this may lead to enhanced hepatic transporter activity compared to the reference, which can influence the pharmacokinetics of specific statins. Please discuss your medication response and dosing with your clinician or pharmacist.
This genotype is common in many populations, with particularly high prevalence in individuals of African ancestry.
Understanding the rs4149036 Variant
The rs4149036 variant is a single nucleotide polymorphism (SNP) located within the SLCO1B1 gene. At the molecular level, this variant involves a change from adenine (A) to guanine (G) at a specific position in the DNA sequence, often referred to as c.388A>G. This change leads to a non-synonymous substitution where the amino acid asparagine is replaced by aspartic acid at position 130 (p.Asn130Asp) in the resulting protein. This SNP is a critical component in defining specific SLCO1B1 haplotypes, such as *1B and *15, which are used by researchers to categorize how the SLCO1B1 protein functions. Because it is a common variant, it is frequently analyzed alongside other SNPs in the same gene to understand the overall genetic architecture of drug transport in the liver.
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 found in the liver, where it acts as a gatekeeper, facilitating the transport of various substances from the blood into liver cells for processing and eventual elimination. OATP1B1 is responsible for the uptake of endogenous compounds, such as bilirubin, as well as many exogenous substances, including various statin medications used to lower cholesterol. When the function of this transporter is altered, it can change the systemic concentration of these drugs in the bloodstream. While some variants in this gene are associated with significant changes in transporter activity, the functional impact of rs4149036 is often studied in the context of how it interacts with other variants to influence drug clearance.
Research and Clinical Associations
Research into rs4149036 often focuses on its contribution to statin response and lipid-lowering efficacy. Studies have observed that individuals carrying different genotypes at this position may show variations in how their LDL cholesterol levels respond to statin therapy. However, the evidence regarding the clinical impact of this specific variant is considered limited compared to other, more potent variants in the same gene, such as rs4149056. While some research suggests that rs4149036 influences the therapeutic efficacy of drugs like atorvastatin, findings can be mixed or dependent on the specific population studied. It is important to note that genetic associations are statistical in nature and do not guarantee a specific clinical outcome. Because the evidence is not definitive, this variant is generally not used in isolation to make clinical prescribing decisions.
What This Information Means for You
If you have received information about your rs4149036 genotype, it is important to view it as one small piece of a much larger biological puzzle. Genetic variants like this are common and are found in a large portion of the global population. They do not act in a vacuum; your actual response to any medication is influenced by a complex interplay of your overall genetic profile, your age, your diet, other medications you may be taking, and your underlying health status. You should never use this information to start, stop, or change the dosage of any prescribed medication. If you have questions about how your genetics might relate to your treatment plan, the best course of action is to discuss these results with your clinician or a pharmacist, who can interpret them within the context of your complete medical history.
How common is this variant?
The rs4149036 variant is widespread globally, with minor allele frequencies ranging from 35% to 80% depending on the ancestral background of the population.
Frequently asked questions
Is rs4149036 the same as the 'statin gene' test?
While rs4149036 is located in the SLCO1B1 gene, which is involved in statin transport, it is not the only variant tested. Most clinical pharmacogenetic tests focus on more impactful variants like rs4149056, which has a stronger, well-documented link to statin-induced side effects.
Can I use this result to predict if I will have side effects from statins?
No. The evidence for rs4149036 as a predictor of statin side effects is limited and inconsistent. Statin intolerance is complex and influenced by many factors beyond a single genetic variant.
Should I change my medication based on this SNP?
Absolutely not. You should never alter your medication regimen based on genetic test results without consulting your doctor. Only a healthcare professional can determine if a change is appropriate based on your full clinical picture.
How common is the G allele?
The G allele is very common, with frequencies varying significantly by ancestry. It is found in a large percentage of the global population, making it a normal variation rather than a rare mutation.
Sources & further reading
Educational information only, last refreshed 10/13/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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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.
Non-synonymous coding polymorphism (p.Asn130Asp) defining the SLCO1B1*30 allele with modest alteration in hepatic statin uptake.
This variant (c.521T>C) is strongly associated with decreased function of the OATP1B1 transporter, significantly increasing the risk of statin-induced myopathy.
Known as SLCO1B1*1b (p.Asn130Asp), this variant alters hepatic transporter activity and modulates statin exposure and pharmacokinetic clearance.
Defines the SLCO1B1*14 haplotype (p.Gly488Ala) associated with altered hepatic uptake transporter activity and statin pharmacokinetics.