ESR1 rs104893956: Understanding This Rare Genetic Variant
The rs104893956 variant is a rare genetic change located within the ESR1 gene, which provides instructions for making the estrogen receptor alpha protein. Research has identified this specific variant as potentially altering the secondary structure of the protein, leading to investigations into its role in reproductive health conditions like polycystic ovary syndrome (PCOS).
What each genotype means
Typical ESR1 protein structure
This genotype represents the common form of the ESR1 gene in the population. Research indicates that individuals with this genotype do not carry the specific structural alteration associated with this variant, which has been studied for its potential impact on estrogen receptor protein stability and secondary structure.
This is the most common genotype observed in the general population.
Altered protein structure carrier
Carrying one copy of this variant may be associated with changes in the secondary structure of the estrogen receptor alpha protein. While some research suggests these structural changes could influence susceptibility to polycystic ovary syndrome (PCOS), the evidence remains limited and findings across different populations are inconsistent.
This genotype is rare in the general population.
Altered protein structure variant
Individuals with this genotype carry two copies of the variant, which has been linked in computational studies to changes in the secondary structure of the estrogen receptor alpha protein. Because the clinical significance of this structural change regarding PCOS susceptibility is currently based on limited evidence, it is not used for diagnostic purposes.
This genotype is very rare in the general population.
What is rs104893956?
The rs104893956 variant is a single nucleotide polymorphism (SNP) found within the ESR1 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence. This specific variant is classified as rare, meaning it is not commonly found in the general population. It is located in a region of the gene that codes for the estrogen receptor alpha protein, a critical component of the endocrine system. Because this variant is rare, it has not been as extensively studied as more common genetic markers, and its presence is often identified through specialized genomic sequencing efforts rather than routine screening.
The Role of the ESR1 Gene
The ESR1 gene encodes the estrogen receptor alpha (ERα), a nuclear receptor that acts as a transcription factor. When estrogen binds to this receptor, the complex regulates the expression of various genes involved in reproductive development, bone density, and cardiovascular health. Because ERα is essential for normal follicular development and ovulation, any structural change to the protein can theoretically impact how the body responds to estrogen. Disruptions in this signaling pathway are frequently studied in the context of reproductive disorders, as the receptor's ability to bind correctly to hormones is vital for maintaining hormonal balance and reproductive function.
Research and Evidence Strength
Current evidence linking rs104893956 to clinical outcomes is considered limited. Recent computational studies have suggested that this variant may significantly change the secondary structure of the estrogen receptor alpha protein. While these bioinformatics findings provide a theoretical basis for how the variant might affect protein function, they do not confirm a direct causal link to disease in humans. Other studies on ESR1 variants in relation to polycystic ovary syndrome (PCOS) have often yielded contradictory or population-specific results, highlighting the complexity of genetic associations. Because the evidence is preliminary, it is important to view these findings as an area of ongoing scientific inquiry rather than a definitive diagnostic marker for any specific condition.
Population Frequency
The rs104893956 variant is documented as a rare variant in human populations. Due to its low frequency, it is not typically captured in large-scale, common-variant association studies, which often focus on markers with a minor allele frequency of 5% or higher. Because of this rarity, there is insufficient data to establish clear frequency differences across diverse ancestral groups. Most information regarding this variant comes from targeted research studies rather than broad population-wide databases.
Interpreting Genetic Information
It is important to understand that having a rare variant like rs104893956 does not constitute a medical diagnosis. Genetic variants are only one piece of a much larger puzzle that includes environmental factors, lifestyle, and the interaction of thousands of other genes. If you have received information about this variant through genetic testing, it is best to discuss the results with a qualified healthcare provider or a genetic counselor. They can help place the finding in the context of your personal and family health history. Never use genetic data to make independent medical decisions or to alter any prescribed treatments without consulting your clinician.
How common is this variant?
The rs104893956 variant is classified as rare, with no significant frequency data available across major ancestral populations.
Frequently asked questions
Is rs104893956 a cause of PCOS?
No, rs104893956 is not considered a direct cause of PCOS. While some research suggests it may alter protein structure, the evidence linking it to the development of PCOS is limited and not definitive.
Should I be worried if I have this variant?
Genetic variants are common and do not necessarily indicate a health problem. You should discuss any concerns about your genetic results with a healthcare professional who can interpret them in the context of your overall health.
Can I change my ESR1 gene expression?
You cannot change your underlying DNA sequence. However, lifestyle factors and medical treatments can influence how your body manages hormones, which is something to discuss with your doctor.
Where can I find more information on ESR1 variants?
You can search databases like ClinVar or the GWAS Catalog for peer-reviewed research. Always prioritize information from reputable medical institutions and scientific journals.
Sources & further reading
Educational information only, last refreshed 11/2/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Rare regulatory variant in the ESR1 locus implicated in the modulation of reproductive hormone responsiveness and fertility.
Variant in the estrogen receptor 1 locus associated with reproductive traits and susceptibility to idiopathic infertility.
This variant in the estrogen receptor 1 gene is associated with human reproductive behavior and influences estrogen-responsive gene expression.
This variant in the estrogen receptor 1 gene is associated with an increased risk of endometriosis and may influence cognitive aging.
Estrogen receptor 1 variant associated with altered circulating estradiol levels, follicular maturation, and variability in age at natural menopause.
Variant in estrogen receptor 1 associated with variation in female reproductive timing, including age at menarche and natural menopause onset.