The BEST3 gene gives cells instructions for a protein that helps move chloride, a charged salt particle, across cell membranes. This gene plays an important role in keeping fluid balance and electrical signaling steady in certain tissues, including smooth muscle. If it does not work as expected, those cell signals may become less stable, which could affect how some tissues function. Most BEST3 variants are not known to cause a clearly defined inherited condition, though some are being studied for possible links to blood pressure and heart rhythm.
What is a gene?
Genes are stretches of DNA that give your cells instructions to make molecules or regulate activities in the body. Some genes carry the directions for producing proteins, which are the parts of cells that do much of the work. Other genes mainly control when certain processes happen, where they take place, and how strongly they run. Taken together, genes affect how the body develops and functions, and they can also shape how you respond to food, stress, or medications. For a more detailed look at this topic, you can learn more in the LearnHub.
Overview
BEST3Gene function
What if the gene works
The BEST3 gene helps make a membrane protein that moves chloride ions in response to calcium signals. This supports normal smooth muscle cell activity and fluid balance.
Risk
What if the gene does not work
Changes in the BEST3 gene can range from milder to more severe and may reduce how well this cell membrane channel moves chloride and helps regulate electrical signaling. This can alter ion balance in smooth muscle and heart cells.
Treatment
What does that mean for your treatment
No BEST3-specific treatment or drug selection approach is currently established for people with a pathogenic or loss-of-function variant in the BEST3 gene.
Gene function
What if the gene works
Some of your body’s cells need to move charged particles and fluid in a controlled way to keep tissues working smoothly. The BEST3 gene helps make a channel protein that supports this movement, especially in smooth muscle cells. Understanding what the BEST3 gene does in the body helps show how cells keep their electrical balance steady during everyday activity.
The BEST3 gene helps cells move chloride, a charged salt particle, across their outer membrane. This supports the normal balance of fluid and electrical charge inside and around the cell.
Its protein opens in response to calcium, a signal many cells use to adjust activity from moment to moment. This lets the channel react when a cell needs close control of its electrical state.
Many studies place the BEST3 gene in smooth muscle, including muscle in blood vessel walls. By helping shape electrical signals there, it supports normal muscle tone and how these cells tighten or relax.
What is a variant?
A genetic variant is a small difference in the DNA sequence of a gene. These differences are common and are part of normal human diversity, including variations in appearance, metabolism, and how the body responds to environmental influences. Many have no noticeable effect and simply represent natural genetic variation. In some cases, though, a variant changes how a gene works more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Changes in the BEST3 gene may alter how the protein folds, joins with partner units, or reaches the cell membrane, which is central to how variants in the BEST3 gene affect function. Milder variants can leave some channel activity intact, while more disruptive variants may sharply reduce ion flow, destabilize the protein, or create a shortened protein that the cell breaks down. These effects can range from partial loss of activity to little or no working protein.
How variants are linked to conditions
Variants in the BEST3 gene do not yet have a broadly confirmed link to a specific health condition, so information about BEST3 gene variants and disease risk is still evolving. Anyone with a diagnosis involving the BEST3 gene should rely on guidance from their doctor or genetic counselor rather than general information.
A variant is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are widespread in the general population. Most do not directly affect health and instead reflect normal human diversity. For many genes, having a variant associated with a condition indicates a possible link rather than a confirmed diagnosis, especially when several genes and environmental factors are involved. In some situations, though, one well-characterized variant in a particular gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
There is not yet broadly confirmed evidence on specific factors that increase or reduce health risk related to the BEST3 gene. If a test shows a change in BEST3, a doctor or genetic counselor can explain what that result may mean in the context of your personal and family health history.
Inheritance of BEST3 variants
There is not yet a broadly confirmed disease inheritance pattern for BEST3, so how BEST3 gene variants are inherited in a condition-specific way is still being worked out. At this point, experts have not established a single well-supported autosomal dominant, autosomal recessive, or X-linked pattern for BEST3-related health effects. The BEST3 gene is located on chromosome 12, which is an autosome, so each person inherits one copy from each parent. This means any BEST3 variant can be passed through either side of the family.
What does my BEST3 result mean for my family?
There isn't yet a broadly confirmed inheritance pattern tied to a specific condition for BEST3, though this understanding can change as research develops. If you have a specific BEST3 result and questions about what it could mean for your family, a doctor or genetic counselor can explain it in the context of your personal and family history.
Genetic information
Genetic testing
How you find out about variants
Variants in the BEST3 gene are usually found through genetic testing, often as part of a multigene panel or broader DNA sequencing. A BEST3 genetic test uses a blood or saliva sample to read the gene's code and look for changes. Results may identify a variant, show no relevant change, or find a variant of uncertain significance.
When should I consider getting a genetic test?
There isn't yet a broadly established BEST3-specific clinical reason for testing. Testing decisions are best made with a doctor or genetic counselor, based on your symptoms and family history.
A genetic result is only one part of your health story
Genetic findings can be informative, but how much they reveal depends on the condition and on the type of variant involved. Lifestyle, environment, age, and medical history, among other factors, also shape how the body works over time. In some conditions, particularly those influenced by many genes, genetic information offers context rather than certainty and is best understood together with 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 people respond to medicines. Small differences in DNA can change how the body absorbs, breaks down, or responds to a drug. This helps explain why the same medication may work well for one person, seem less effective for another, or cause more side effects in someone else. These differences are common and are one part of why treatment response can vary from person to person.
What is Pharmacogenetics?
Pharmacogenetics examines how genetic differences affect the way people respond to medicines. By looking at links between genes and medications, it helps explain why the same treatment may work differently from one person to another. For many drugs, genes can influence both how strong a medicine’s effects are and how the body handles it. This information can support treatment decisions that are better informed and more individualized. More detail on this topic is available in the LearnHub.
Drugs influenced by the BEST3 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in how people respond to medicines, so general questions about side effects, medication choice, or dose changes are best discussed with your doctor or pharmacist.
History
The BEST3 gene entered research as scientists mapped and compared members of the bestrophin gene family in the early 2000s. Initially understood only through visible traits, later recognized as tied to a specific gene family, bestrophin research expanded from eye disease toward related genes with roles in other tissues. Building on this early work, scientists identified the BEST3 gene as a distinct family member and began studying where it is active in the body. Over time, descriptions became more precise as laboratory studies linked BEST3 to cell membrane ion movement, especially in muscle and blood vessel tissues. Unlike some better known genes, BEST3 has remained mainly a topic of specialist research rather than public attention, but it has helped broaden understanding of the bestrophin family as a whole.