BEST1 rs28936684: What Your Genotype Means
The rs28936684 variant is a rare genetic change in the BEST1 gene that results in a Thr6Arg (T6R) amino acid substitution. This specific variant is associated with autosomal dominant Best vitelliform macular dystrophy, an inherited condition that affects the retina.
What each genotype means
Typical BEST1 profile
This genotype represents the most common sequence found in the general population for this location in the BEST1 gene. It does not carry the specific Thr6Arg (T6R) missense change associated with autosomal dominant Best vitelliform macular dystrophy. Individuals with this genotype are not expected to have the specific retinal risks linked to this variant.
This is the predominant genotype, carried by the vast majority of the global population.
Increased risk of vitelliform dystrophy
This genotype includes one copy of the Thr6Arg (T6R) variant, which is associated with autosomal dominant Best vitelliform macular dystrophy. Because this condition is inherited in an autosomal dominant manner, carrying a single copy of this variant may be sufficient to increase the risk of developing retinal changes. You should discuss these findings with an ophthalmologist or a genetic counselor to understand your specific clinical risk.
This genotype is extremely rare, with the variant allele frequency reported at less than 0.0001 in general population databases.
High risk of bestrophinopathy
This genotype indicates the presence of two copies of the Thr6Arg (T6R) variant. While this variant is typically associated with autosomal dominant conditions, the presence of two copies may lead to more severe or complex retinal phenotypes, sometimes referred to as bestrophinopathies. Clinical evaluation by a retinal specialist is recommended to assess your ocular health.
This genotype is exceptionally rare and is not typically observed in general population cohorts.
Understanding the rs28936684 Variant
The rs28936684 variant is a single nucleotide polymorphism (SNP) located within the BEST1 gene. In genetic terms, this variant represents a missense mutation, meaning it causes a change in the protein's building blocks—specifically, replacing the amino acid threonine with arginine at position 6 of the protein sequence. This change is often referred to as T6R. Because this variant is located in a gene critical for retinal function, researchers study it to understand how small alterations in DNA can lead to significant changes in cellular behavior. It is classified as a rare variant, meaning it is not commonly found in the general population, and its presence is typically investigated in the context of inherited eye disorders.
The Role of the BEST1 Gene
The BEST1 gene provides instructions for making a protein called bestrophin-1. This protein is primarily found in the retinal pigment epithelium (RPE), a layer of cells that supports the light-sensing cells of the retina. Bestrophin-1 functions as a channel that transports chloride ions across cell membranes, which is essential for maintaining the proper ionic balance and health of the retina. When the BEST1 gene is altered, the resulting protein may not function correctly, leading to the accumulation of fluid or deposits under the retina. This disruption can interfere with the normal visual cycle and the health of photoreceptor cells, which are the cells responsible for capturing light and sending visual signals to the brain.
Clinical Associations and Evidence
Research associates the rs28936684 variant with Best vitelliform macular dystrophy (BVMD), an autosomal dominant condition. In this context, 'autosomal dominant' means that inheriting a single copy of the altered gene from one parent is typically sufficient to manifest the condition. The evidence linking this specific variant to the disease is based on clinical observations of individuals presenting with characteristic retinal findings, such as vitelliform lesions—yellowish deposits that resemble an egg yolk—in the macula. While over 250 variants in the BEST1 gene have been linked to various 'bestrophinopathies,' the strength of evidence for any single variant can vary. It is important to note that the presence of this variant does not guarantee a specific clinical outcome, as the expression of retinal diseases can be influenced by other genetic and environmental factors.
Population Frequency
The rs28936684 variant is extremely rare in the general population. According to large-scale genomic databases like gnomAD, the allele frequency is reported to be less than 0.0001. This low frequency confirms that the variant is not a common polymorphism found in the general public but is instead a rare genetic finding typically identified through clinical genetic testing in individuals or families with a history of retinal dystrophy.
Navigating Genetic Information
If you have received information about this variant, it is important to understand that genetic data is complex and should be interpreted by a qualified healthcare professional, such as a genetic counselor or an ophthalmologist specializing in retinal diseases. A genetic finding is not a medical diagnosis; it is one piece of information that must be considered alongside a comprehensive clinical eye examination, family history, and functional testing like an electro-oculogram (EOG). You cannot 'treat' a genetic variant itself, but understanding your genetic status can help you and your doctor monitor your eye health more effectively. Always discuss any concerns about your vision or genetic results with a clinician who can provide personalized medical guidance based on your specific health profile.
How common is this variant?
The rs28936684 variant is extremely rare in general population databases, with an allele frequency of less than 0.0001.
Frequently asked questions
What is Best vitelliform macular dystrophy?
Best vitelliform macular dystrophy is an inherited eye condition that causes the buildup of yellowish, egg-yolk-like deposits in the macula, the part of the retina responsible for sharp central vision. It is caused by mutations in the BEST1 gene.
Is rs28936684 the same as Best disease?
The rs28936684 variant is a specific genetic change within the BEST1 gene that is associated with Best disease. While the variant is linked to the condition, it is just one of many possible mutations in the gene that can lead to the diagnosis.
How is this variant inherited?
This variant is associated with an autosomal dominant pattern of inheritance. This means that an individual only needs to inherit one copy of the altered gene from one parent to be at risk for the associated retinal condition.
Should I get tested for this variant?
Genetic testing is typically recommended by an ophthalmologist or genetic counselor if there is a clinical suspicion of an inherited retinal dystrophy. It is not a routine test for the general population.
Sources & further reading
Educational information only, last refreshed 9/28/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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A missense alteration in bestrophin-1 linked to Best vitelliform macular dystrophy and central visual impairment.
Pathogenic missense variant in BEST1 (p.Ala146Thr) linked to autosomal dominant Best vitelliform macular dystrophy causing progressive loss of central vision.
Missense mutation in BEST1 causing classical Best vitelliform macular dystrophy type 2.
A pathogenic missense variant (p.Tyr227Asn) in BEST1 associated with Best vitelliform macular dystrophy.
Pathogenic missense mutation (p.Arg218Cys) in bestrophin-1 causing Best vitelliform macular dystrophy with subretinal egg-yolk-like lesions.
Pathogenic missense variant (p.Thr6Arg) in BEST1 altering the bestrophin-1 channel causing autosomal dominant Best vitelliform macular dystrophy.