ESR1 rs1799988: Understanding the PvuII Polymorphism
The rs1799988 variant is a common genetic polymorphism located within the ESR1 gene, which encodes the estrogen receptor alpha protein. Research has investigated its potential associations with various reproductive health conditions, including endometriosis and age at menarche.
What each genotype means
Typical reproductive risk profile
You carry two copies of the C allele for the intronic ESR1 PvuII variant, historically designated as the uppercase P allele. Published studies have evaluated this genotype for subtle associations with reproductive traits like age at menarche, uterine fibroids, and endometriosis, but findings across populations remain mixed and inconclusive. Carrying this genotype does not cause reproductive conditions, nor does it replace clinical screenings.
Carried by approximately 20% to 26% of individuals across European and East Asian populations.
Intermediate reproductive risk profile
You carry one C allele and one T allele for this ESR1 intronic variant, sometimes referred to as the Pp genotype in older restriction fragment length polymorphism research. Scientific research indicates this genotype reflects an average genetic background for estrogen receptor-related traits with no definitive clinical outcome. Evidence linking this heterozygous profile to variations in reproductive timing or conditions like endometriosis is weak and conflicting.
Carried by roughly 45% to 51% of people across diverse global ancestries.
Modestly altered estrogen trait association
You have two copies of the T allele for this ESR1 variant, historically annotated as the lowercase p allele. Some observational studies and meta-analyses have reported weak, ancestry-specific associations with reproductive parameters including age at menarche and hormone-sensitive conditions, though large genome-wide association studies show little to no causal impact. This genotype does not predict disease or fertility outcomes on an individual level.
Carried by approximately 25% to 32% of individuals globally.
What is rs1799988?
The variant rs1799988, historically referred to as the PvuII polymorphism, is a single nucleotide polymorphism (SNP) situated within the ESR1 gene on chromosome 6. Specifically, it is an intronic variant, meaning it resides in a non-coding region of the gene that does not directly provide instructions for building the protein. Despite being located in an intron, researchers study this site because such variants can sometimes influence how a gene is regulated, spliced, or expressed. In the context of the PvuII polymorphism, the variation involves a change between the C and T alleles. Because it is a common variant, it has been the subject of numerous genetic association studies aiming to understand how subtle differences in DNA sequence might contribute to complex biological traits or susceptibility to specific health conditions.
The Role of the ESR1 Gene
The ESR1 gene provides the blueprint for estrogen receptor alpha, a protein that plays a critical role in the body's response to estrogen. Estrogen is a primary sex hormone that influences the development and function of the reproductive system, as well as bone health, cardiovascular function, and metabolism. When estrogen binds to the estrogen receptor alpha, the receptor acts as a transcription factor, entering the cell nucleus to turn specific genes on or off. Because this receptor is so central to hormone signaling, variations in the ESR1 gene are frequently studied to see if they alter the sensitivity or efficiency of these pathways. By modulating how cells respond to estrogen, genetic variants in ESR1 may theoretically influence a wide range of physiological processes, particularly those sensitive to hormonal fluctuations throughout a person's life.
Research and Associations
Scientific literature has explored the potential link between rs1799988 and various reproductive health outcomes, most notably endometriosis. Meta-analyses have examined whether this variant influences the risk of developing endometriosis, with some studies suggesting that the association may be dependent on the stage of the disease or specific population backgrounds. However, the evidence remains limited and sometimes conflicting; while some studies report a statistical correlation, others find no significant difference in risk. Furthermore, the ESR1 region is known to be complex, with multiple independent SNPs contributing to disease risk, making it difficult to isolate the effect of any single variant. It is important to note that these findings are based on statistical associations observed in large groups and do not imply a direct cause-and-effect relationship for any individual.
Interpreting Your Information
Understanding your genotype for rs1799988 provides a glimpse into your genetic makeup, but it is not a diagnostic tool. Because the evidence linking this variant to specific health outcomes is limited and often inconsistent across different populations, it cannot be used to predict your personal risk for conditions like endometriosis or uterine fibroids. Genetic factors are only one piece of a much larger puzzle that includes environmental influences, lifestyle, and other genetic markers. If you have concerns about your reproductive health or family history, the most effective approach is to consult with a healthcare professional or a genetic counselor. They can help you interpret your health history in a clinical context and guide you toward appropriate screenings or care, rather than relying on individual SNP data.
How common is this variant?
The rs1799988 variant is common, with the C and T alleles typically appearing at frequencies between 0.40 and 0.55 across many global populations.
Frequently asked questions
Is rs1799988 a diagnostic test for endometriosis?
No, rs1799988 is not a diagnostic test. While some research has explored its association with endometriosis, the evidence is limited and not strong enough to be used for clinical diagnosis.
Does my genotype mean I will have reproductive health issues?
No. Genetic variants like rs1799988 are only one small factor in complex health conditions. Having a specific genotype does not guarantee or prevent the development of any health condition.
What should I do if I am worried about my ESR1 results?
If you have concerns about your reproductive health, you should discuss them with your doctor or a qualified healthcare provider. They can evaluate your symptoms and family history to provide appropriate medical advice.
Why do different studies show different results for this SNP?
Genetic association studies can vary due to differences in study design, the size of the population studied, and the genetic background of the participants. This is why scientific consensus often requires many large-scale studies to confirm an association.
Sources & further reading
Educational information only, last refreshed 10/19/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs1799988?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in ESR1
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.
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.