ESR1 rs2303557: What Your Genotype Means
The rs2303557 variant is a genetic change located within the ESR1 gene, which encodes the estrogen receptor alpha protein. Research has investigated this variant for potential associations with ovarian responsiveness and fertilization rates in the context of assisted reproductive technology.
What each genotype means
Typical estrogen receptor activity
This genotype represents the most common form of the ESR1 gene variant. Research into this specific variant is limited, but it is generally considered the baseline against which other variations are compared in studies of ovarian responsiveness and reproductive health.
This genotype is common, occurring in approximately 40% of individuals of European ancestry based on the reported minor allele frequency.
Intermediate reproductive profile
Carriers of this genotype possess one copy of the variant allele, which has been studied for its potential association with ovarian response during assisted reproductive technology. Evidence remains limited and mixed, so this result should not be used to predict individual fertility outcomes or clinical success.
This heterozygous genotype is found in roughly 45% of individuals of European ancestry.
Variant reproductive profile
This genotype contains two copies of the variant allele, which has been investigated in the context of ovarian stimulation response and reproductive hormone regulation. Because the evidence strength for this association is limited, it is unclear how this genotype influences individual physiology; please consult with a fertility specialist to discuss your specific clinical context.
This genotype is present in approximately 15% of individuals of European ancestry.
Understanding the rs2303557 Variant
The rs2303557 variant is a single-nucleotide polymorphism (SNP) found within the ESR1 gene. In genomics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is located in a region of the gene that may influence how the estrogen receptor is regulated or expressed. Because the ESR1 gene is large and complex, variants like rs2303557 are often studied to determine if they alter the function of the resulting protein or the timing and amount of protein produced in specific tissues. While many SNPs have no observable effect on health, researchers track them to see if they correlate with specific biological traits or clinical outcomes, particularly in systems where estrogen signaling is critical.
The Role of the ESR1 Gene
The ESR1 gene provides instructions for making the estrogen receptor alpha protein. This protein acts as a ligand-activated transcription factor, meaning it binds to estrogen and then travels to the cell nucleus to turn specific genes on or off. This process is fundamental to many physiological functions, including growth, metabolism, sexual development, and the maintenance of the reproductive system. Because estrogen signaling is vital for the development of ovarian follicles and the maturation of eggs, the ESR1 gene is a primary candidate for studies regarding female fertility. When the estrogen receptor functions optimally, it helps coordinate the complex hormonal signals required for successful reproduction. Variations in this gene are therefore of significant interest to reproductive biologists and clinicians working in fertility medicine.
Research and Evidence Strength
Current scientific evidence linking rs2303557 to specific reproductive outcomes is considered limited. While some studies have explored the role of ESR1 variants in ovarian responsiveness to hormonal stimulation during assisted reproductive technology (ART), the findings are often mixed or require larger, more diverse cohorts to confirm. It is important to note that reproductive success is a multifactorial process influenced by many genes, environmental factors, and clinical variables. Consequently, a single SNP like rs2303557 is unlikely to be a sole determinant of fertility or treatment response. The scientific community continues to investigate these associations, but current data does not support using this variant as a standalone diagnostic tool for predicting fertility outcomes or clinical success in IVF cycles.
Population Frequency
The rs2303557 variant is relatively common, with a minor allele frequency (MAF) of approximately 0.35 in European populations. This means that a significant portion of the population carries at least one copy of the variant allele. Frequency can vary across different ancestral groups, and researchers often look at these differences to understand the evolutionary history of the gene and its potential impact on health across diverse populations. Because the variant is common, it is considered a normal part of human genetic variation rather than a rare mutation. Understanding these frequencies helps scientists design better studies and interpret how genetic background might influence the results of reproductive health research.
What This Information Means for You
If you have received information about your rs2303557 genotype, it is important to view it in the proper context. This variant is not a diagnostic marker, and it cannot predict your personal fertility or the outcome of any medical procedure. Genetic associations are statistical observations made across large groups of people and do not necessarily apply to any single individual. You cannot use this information to make medical decisions or change your health habits. If you have questions about your reproductive health, fertility treatments, or how your genetic background might relate to your care, please discuss these topics with a qualified clinician or a reproductive endocrinologist. They can provide personalized guidance based on your full medical history and clinical testing, rather than isolated genetic data.
How common is this variant?
The rs2303557 variant is common, with a minor allele frequency of approximately 0.35 in European populations.
Frequently asked questions
Can rs2303557 predict my fertility?
No, rs2303557 cannot predict your fertility. Fertility is a complex trait influenced by many genetic and environmental factors, and current evidence for this variant is limited and not sufficient for clinical prediction.
Is rs2303557 a mutation that causes disease?
No, rs2303557 is a common genetic variant, not a disease-causing mutation. It is a normal variation in the human genome that has been studied for its potential influence on reproductive physiology.
Should I change my fertility treatment based on this SNP?
You should never change your medical treatment based on a single genetic variant. Always consult with your fertility specialist or reproductive endocrinologist regarding your treatment plan.
Where can I find more information on ESR1?
You can find authoritative information on the ESR1 gene through the NCBI Gene database or the Genetics Home Reference section of MedlinePlus. These resources provide comprehensive summaries of gene function and related research.
Sources & further reading
Educational information only, last refreshed 9/20/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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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.
Common polymorphism in estrogen receptor alpha (ESR1) affecting target tissue responsiveness to estrogen, recurrent pregnancy loss risk, and bone-reproductive axis interactions.
Estrogen receptor 1 regulatory variant associated with variation in timing of menarche and bone density response to sex hormones.
ESR1 variant linked to variation in age at natural menopause.