The SLCO1B3 gene gives liver cells instructions for a transporter that moves bilirubin, bile-related substances, and some medicines from the blood into the liver. This gene plays an important role in helping your body clear these substances in a controlled way. If it does not work well, bilirubin handling can be affected, which may contribute to jaundice, and your body may process some drugs differently. In medicine, SLCO1B3 is best known for its role in inherited bilirubin conditions and in how certain treatments move through the body.
What is a gene?
A gene is a section of DNA that carries instructions your cells use to make molecules or manage processes in the body. Some genes hold the information needed to produce proteins, the working parts of cells. Other genes mainly help control when certain processes happen, where they take place, and how strongly they operate. Taken together, genes influence how the body develops and functions, and they can shape how you respond to food, stress, or medications. For a more in depth look at this topic, you can find more in the LearnHub.
Overview
SLCO1B3Gene function
What if the gene works
The SLCO1B3 gene helps liver cells take up bilirubin, bile salts, and some medicines from the blood. This supports normal bile handling and helps the body process and clear certain substances.
Risk
What if the gene does not work
Milder variants in the SLCO1B3 gene may mainly change how the liver takes up bilirubin and some medicines. More severe variants, especially alongside loss of the related SLCO1B1 gene, can cause Rotor syndrome with lifelong mild jaundice.
Treatment
What does that mean for your treatment
No treatment or management approach based specifically on pathogenic or loss-of-function variants in the SLCO1B3 gene is currently established. The SLCO1B3 gene is being studied as a marker of drug handling and as a possible cancer biomarker, but this has not yet led to guideline-based treatment choices.
Conditions associated with SLCO1B3
Gene function
What if the gene works
Your liver depends on the SLCO1B3 gene to move selected substances from the blood into liver cells. This steady transport supports normal handling of bilirubin, bile acids, and some medicines. When this system is working well, the liver can process and clear these substances in an orderly way.
The SLCO1B3 gene helps liver cells pull selected substances out of the bloodstream. Its protein sits on the surface of these cells that faces the blood and acts like an entry gate.
It helps move bilirubin, a yellow pigment made when old red blood cells are broken down, into liver cells. This is part of how the SLCO1B3 gene helps the liver clear bilirubin from the blood.
The transporter also carries bile acids into liver cells. This supports the liver's daily work of reusing these digestive chemicals and sending them back into bile.
It also moves some medicines from the blood into liver cells. This transport is part of normal liver processing and can shape how certain drugs are handled in the body.
What is a variant?
A genetic variant is a minor change in the DNA sequence within a gene. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, and how the body responds to environmental influences. Many variants do not cause any noticeable effects and simply represent natural genetic variation. In some situations, however, a variant can change how a gene functions more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Changes in the SLCO1B3 gene can alter the shape, stability, or placement of its transporter protein, so liver cells take up certain compounds less effectively. How SLCO1B3 gene variants affect transporter function depends on the change: some mildly reduce activity, while more severe variants can disrupt folding, shorten the protein, or keep it from reaching the cell membrane. When both gene copies are strongly affected, transport loss is usually greater.
How variants are linked to conditions
Variants in the SLCO1B3 gene are most clearly linked to Rotor syndrome, a rare inherited condition that causes mild ongoing jaundice from higher bilirubin levels. This link between SLCO1B3 gene variants and Rotor syndrome usually involves disease-causing variants affecting both the SLCO1B3 gene and the nearby SLCO1B1 gene, which can confirm the diagnosis. Common SLCO1B3 variants have also been studied for links to bilirubin levels, but these do not by themselves diagnose a disease.
A variant is not necessarily a diagnosis
Genetic variants are common in the general population and are a normal feature of human biology. Most do not have a direct effect on health and simply contribute to natural human diversity. For many genes, carrying a variant associated with a condition indicates a possible link rather than a definite diagnosis, especially when multiple genes and environmental factors play a role. In some situations, however, a single well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
There isn't yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the SLCO1B3 gene outside of its role in how the body handles certain medicines. Anyone with concerns about personal risk should speak with a doctor or genetic counselor.
Inheritance of SLCO1B3 variants
There is not yet a single, broadly confirmed Mendelian pattern that explains how SLCO1B3 gene variants are inherited on their own for one specific SLCO1B3 related condition. In practice, how SLCO1B3 gene variants are inherited depends on the health issue being considered, and some findings involving this gene are part of a more complex, multi gene picture rather than a simple dominant or recessive pattern. The SLCO1B3 gene is located on chromosome 12, which is an autosome, so you inherit one copy from your mother and one copy from your father.
What does my SLCO1B3 result mean for my family?
There is not yet a broadly confirmed single-gene inheritance pattern tied to a specific health condition for the SLCO1B3 gene. Most SLCO1B3 results are used to understand how the body handles certain medicines rather than to diagnose an inherited condition in relatives. If you have a specific SLCO1B3 result and questions about your family, a doctor or genetic counselor can explain what it may or may not mean in your situation.
Genetic information
Genetic testing
How you find out about variants
Variants in the SLCO1B3 gene are usually found with a blood sample, saliva sample, or cheek swab. Genetic testing for SLCO1B3 variants reads the DNA code in a lab to look for changes in this gene and reports whether a variant was found.
When should I consider getting a genetic test?
Genetic testing for the SLCO1B3 gene may be worth considering if someone has lifelong, unexplained yellowing of the eyes or skin, especially when close relatives have had the same pattern. It is mainly used as part of testing for Rotor syndrome, a rare inherited condition that affects how the liver handles bilirubin.
A genetic result is only one part of your health story
A genetic result can provide useful insight, but how informative it is depends on the condition and the kind of variant involved. Many factors, including lifestyle, environment, age, and medical history, influence how the body functions over time. In some conditions, especially those shaped by many genes, genetic information offers context rather than certainty and is most helpful when viewed alongside other parts of care. In other situations, a genetic result may give a clear answer. In areas like medication response, genetic results can help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body responds to medicines. This helps explain why the same treatment may work well for one person, feel too strong for another, or seem to do very little in someone else. Differences in how the body absorbs, moves, and breaks down a drug are common, and they can influence both benefit and side effects.
What is Pharmacogenetics?
Pharmacogenetics is the area of study focused on how differences in genes affect the way people respond to medications. It examines links between genes and drugs to help explain why the same treatment can work differently from one person to another. With many medicines, genes can influence how powerfully a drug works or how the body handles it. This information can support more informed, personalized treatment choices. More detailed information on this topic is available in the LearnHub.
Drugs influenced by the SLCO1B3 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding routine medication choices, so general questions about side effects, new symptoms, or how well a treatment is working are best discussed with your doctor. Research on the SLCO1B3 gene has explored whether it may affect how the liver handles some medicines, including certain cancer treatments, but this is not part of standard care.