CYP19A1 rs11225154: What Your Genotype Means
The rs11225154 variant is a common genetic change located within the CYP19A1 gene, which provides instructions for making the aromatase enzyme. This variant is studied for its potential associations with circulating estradiol levels and the timing of natural menopause.
What each genotype means
Typical baseline estradiol levels
You carry two copies of the common C allele near the CYP19A1 gene. Research indicates this genotype is associated with baseline circulating estradiol concentrations and typical timing for natural menopause. Because evidence linking this regulatory marker to hormonal phenotypes remains limited, this genetic variation alone does not predict personal hormone health or reproductive lifespan.
Found in approximately 50% to 55% of individuals of European ancestry, representing the most common genotype in this population.
Modestly altered estradiol association
You carry one copy of the T allele near the CYP19A1 gene, which encodes the aromatase enzyme responsible for estrogen production. In population studies, the T allele has shown limited statistical associations with minor shifts in circulating estradiol levels and slight differences in natural menopause timing. However, individual hormonal profiles are strongly shaped by lifestyle, environment, and complex polygenic factors rather than this single marker.
Carried by approximately 35% to 40% of people of European ancestry.
Altered hormone regulation marker
You carry two copies of the T allele near the CYP19A1 aromatase gene. In genetic studies, carriage of two T alleles has been tied to small differences in circulating estradiol concentrations and timing of menopause compared to common genotypes. Current evidence remains limited and observational, meaning this genotype does not diagnose hormone imbalances or guarantee a specific age of menopause.
Occurs in roughly 6% to 8% of individuals of European ancestry and is generally less frequent in East Asian populations.
Understanding the rs11225154 Variant
The rs11225154 variant is a single nucleotide polymorphism (SNP) situated within the CYP19A1 gene. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. This specific variant is categorized as a regulatory SNP, meaning it is located in a region of the gene that may influence how much of the aromatase enzyme is produced or when it is expressed, rather than changing the structure of the protein itself. Because it sits within the regulatory architecture of the gene, researchers investigate it to see if it correlates with physiological differences in hormone production across different life stages.
The Role of the CYP19A1 Gene
The CYP19A1 gene encodes the aromatase enzyme, which is a critical component of the cytochrome P450 system. Aromatase is responsible for the final step in the biosynthesis of estrogens, specifically converting androgens like testosterone and androstenedione into estrogens like estradiol and estrone. This process is essential for reproductive health, bone density maintenance, and cardiovascular function. Because aromatase is the primary enzyme responsible for estrogen production in both men and women, variations in the CYP19A1 gene are frequently studied to understand how genetic differences might lead to natural variations in hormone levels, which in turn can influence various health outcomes related to the endocrine system.
Research and Evidence Strength
Research into CYP19A1 variants, including rs11225154, often focuses on their association with circulating sex hormone levels and reproductive milestones. While the GWAS Catalog and various studies have identified associations between CYP19A1 variants and traits like the timing of menopause or bone mineral density, the evidence strength for any single variant like rs11225154 is generally considered moderate. It is important to note that hormone levels are complex traits influenced by a combination of many genetic factors, environmental influences, and lifestyle choices. Consequently, while statistical associations are observed in large population studies, these findings do not imply a direct cause-and-effect relationship for an individual. The scientific community continues to explore how these regulatory variants interact with other genes and external factors to shape human physiology.
Population Frequency and Interpretation
The rs11225154 variant is recognized as a common polymorphism, meaning it is found at significant frequencies across diverse global populations. Because it is common, it is considered a normal part of human genetic variation rather than a rare mutation. When interpreting information about this variant, it is crucial to understand that having a specific genotype does not constitute a medical diagnosis or a prediction of health outcomes. Genetic associations are based on population-level data and cannot predict an individual's specific hormone levels or health trajectory. If you have questions about your hormone levels, reproductive health, or how genetic factors might relate to your personal health history, you should discuss these topics with a qualified healthcare provider or a genetic counselor who can provide context based on your full clinical picture.
How common is this variant?
The rs11225154 variant is a common genetic marker observed across all major global ancestral populations, with varying frequencies of the A and G alleles.
Frequently asked questions
Does this variant mean I will have early menopause?
No. While some studies suggest associations between CYP19A1 variants and the timing of menopause, these are statistical trends observed in large groups. They cannot predict the specific timing of menopause for any individual.
Can I use this information to change my hormone levels?
No. Genetic variants like rs11225154 are fixed at birth. You should never attempt to alter your hormone levels based on genetic data without the direct supervision and guidance of a medical professional.
Is this variant a cause of infertility?
There is no evidence that this specific variant causes infertility. Infertility is a complex condition with many potential causes, and genetic variants in the aromatase gene are only one of many factors researchers study.
Should I get my hormone levels tested because of this genotype?
Decisions about medical testing should be made based on your symptoms and clinical history, not your genotype. If you have concerns about your health, consult your doctor to determine if hormone testing is appropriate for you.
Sources & further reading
Educational information only, last refreshed 10/22/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This variant in the aromatase gene is associated with circulating estrogen levels and influences the timing of natural menopause and cardiovascular risk profiles in postmenopausal women.
Pathogenic variant causing aromatase deficiency characterized by female pseudohermaphroditism, maternal virilization during pregnancy, and absent pubertal development.
Intronic variant in the CYP19A1 gene associated with circulating estradiol and follicle-stimulating hormone (FSH) levels in men.
This variant in the aromatase gene is associated with variations in sex hormone levels and potential risk modulation for hormone-dependent reproductive cancers.
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Polymorphism in the aromatase gene (CYP19A1) associated with circulating estradiol levels and bone mineral density.