The BEST1 gene gives instructions for a protein in the back of the eye that helps move charged particles and balance fluid in the retina. This gene plays an important role in keeping the light sensing part of the eye working normally. If the gene does not work properly, waste material can build up under the retina and cause inherited eye conditions such as Best disease. People with certain BEST1 variants may notice blurred or distorted central vision, often starting in childhood or adulthood.
What is a gene?
Genes are stretches of DNA that carry instructions your cells can use to make molecules or regulate processes in the body. Some genes hold the instructions for making proteins, the parts of cells that do 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 shape how you respond to food, stress, or medications. You can explore this topic further in the LearnHub.
Overview
BEST1Gene function
What if the gene works
The BEST1 gene helps cells under the retina move chloride and other ions. This supports fluid balance in the macula and helps keep central vision clear.
Risk
What if the gene does not work
Variants in the BEST1 gene can disrupt the retina’s support cells, leading to inherited retinal conditions such as Best disease. Central vision changes can range from mild findings in adulthood to earlier, more marked retinal disease.
Treatment
What does that mean for your treatment
No BEST1-specific treatment or drug choice is currently established in clinical guidelines for pathogenic or loss-of-function variants in the BEST1 gene. Research is exploring gene therapy and other retina-directed approaches for BEST1-related conditions, but these remain investigational.
Conditions associated with BEST1
Gene function
What if the gene works
At the back of your eye, the BEST1 gene helps a support layer under the retina keep its surroundings balanced. Much of BEST1 gene function in the retina involves moving small charged particles and helping control fluid and acidity. This steady support helps light sensing cells work smoothly in everyday vision.
The BEST1 gene makes a channel in support cells under the retina. This channel lets chloride and bicarbonate move across the cell membrane when calcium signals tell it to open.
By moving these charged particles, the BEST1 gene helps guide water movement across the same tissue. This helps keep the space around the retina stable during normal eye function.
BEST1 activity helps control acidity, which means how acidic or alkaline the local fluid is. That balance supports the cells that nourish and protect the retina.
Calcium inside the cell helps adjust how active the BEST1 channel is. This allows retinal support cells to fine tune ion flow as the eye's needs change.
What is a variant?
A genetic variant is a minor change in the DNA sequence of a gene. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, or the way the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. In some cases, though, 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
Variants in the BEST1 gene can change the shape, stability, or cell placement of the bestrophin-1 protein, which may weaken channel activity or disrupt how protein units fit together. Some BEST1 gene variants leave partial function, while more disruptive variants can markedly reduce activity or keep the protein from reaching the cell surface. This range in effect helps explain why BEST1 related eye conditions can begin earlier in some people and remain milder in others.
How variants are linked to conditions
Pathogenic variants in the BEST1 gene cause several inherited eye conditions, most often Best vitelliform macular dystrophy and autosomal recessive bestrophinopathy. They are also linked to other forms of BEST1-related retinal disease, including adult-onset vitelliform macular dystrophy and autosomal dominant vitreoretinochoroidopathy. These conditions can affect central vision and may cause blurred vision, distortion, or changes seen on an eye exam, with severity varying from person to person.
A variant is not necessarily a diagnosis
Genetic variants are a natural part of being human, and they are common throughout the general population. Most do not have a direct effect on health and simply reflect normal human diversity. For many genes, having a variant associated with a condition suggests a possible link rather than a definite diagnosis, especially when several genes and environmental factors also play a part. In some situations, though, a single well-characterized variant in a particular gene can be enough to confirm a diagnosis.
Are there things that can increase or change my risk?
For BEST1, risk is usually driven mainly by whether you inherited a disease-causing gene change, and the specific change can affect how likely eye problems are and how severe they become. There is not yet broadly confirmed evidence that lifestyle or environmental factors clearly increase or reduce BEST1-related risk.
Inheritance of BEST1 variants
The inheritance pattern for the BEST1 gene can differ depending on the eye condition linked to the variant. Many BEST1-related conditions, including classic Best disease, follow an autosomal dominant pattern, which means a parent carrying the variant has a 50% chance of passing it to each child. Other BEST1-related conditions, especially autosomal recessive bestrophinopathy, usually appear only when a child inherits one altered copy from each parent. This is why the BEST1 inheritance pattern depends on the specific condition and variant involved.
What does my BEST1 result mean for my family?
BEST1 results can have different meanings for relatives because this gene is linked to both dominant and recessive eye conditions. In some families, a parent, child, brother, or sister may also carry the same change and could have similar retinal findings, even if symptoms are mild. In other families, relatives may be healthy carriers and only children who inherit two changed copies develop the condition. The family impact depends on the exact BEST1 result and which BEST1-related eye condition it is tied to.
Genetic information
Genetic testing
How you find out about variants
Variants in the BEST1 gene are found with genetic testing, usually using a blood sample or saliva. BEST1 genetic testing for inherited retinal disease reads the gene’s DNA code to look for changes that may explain certain eye conditions and can show whether relatives carry the same variant.
When should I consider getting a genetic test?
Consider genetic testing for the BEST1 gene if you or your child have signs of an inherited eye condition affecting the retina, especially central vision, or if close relatives have had similar vision loss. A BEST1 result can help confirm the cause and clarify family risk.
A genetic result is only one part of your health story
A genetic result can provide meaningful insight, but how much it explains depends on the condition and the type of variant involved. Many factors, including lifestyle, environment, age, and medical history, also influence how the body functions over time. In some conditions, especially those shaped by many genes, genetic information provides context rather than certainty and is best viewed alongside other parts of care. In other situations, a genetic result may offer a clear answer. In areas such as medication response, genetic results can also help put individual experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how people respond to medicines. This helps explain why the same treatment works well for one person, has little effect in another, or causes more side effects in someone else. Small differences in the genes involved in handling medicines can change how the body absorbs, breaks down, or responds to a drug. These differences are common and can influence both how well a treatment works and how sensitive a person may be to it.
What is Pharmacogenetics?
Pharmacogenetics looks at how genetic differences can affect a person’s response to medications. It studies links between genes and drugs to help explain why the same treatment can work differently from one person to another. For many medicines, genes influence either how strongly a drug works or how the body processes it. Understanding this can support treatment decisions that are more informed and more personalized. You can read more about this topic in the LearnHub.
Drugs influenced by the BEST1 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in predicting how medicines will work, so questions about medications, side effects, or your overall health are best discussed with your doctor.
History
BEST1 entered medical history through Best vitelliform macular dystrophy, an inherited eye condition first described by Friedrich Best in 1905. For many years, doctors recognized the condition by its distinctive retinal changes seen during eye exams, long before the responsible gene was identified. Initially understood only through visible traits, later recognized as tied to a specific gene, it was mapped in the 1990s and then identified in 1998. Researchers first named it VMD2 after the eye condition and later renamed it the BEST1 gene as knowledge broadened. Over time, descriptions became more precise. This shift helped doctors connect several related inherited retinal conditions to changes in the same gene.