CYP1B1 rs1056838: What Your Genotype Means
The rs1056838 variant is a single nucleotide polymorphism located within the CYP1B1 gene. It is primarily studied for its potential role in influencing how the body metabolizes estrogen and other steroid hormones.
What each genotype means
Typical CYP1B1 activity
This genotype represents the most common form of the CYP1B1 gene in many populations. Research into this variant focuses on its role in the 4-hydroxylation of estrogens, though individual health outcomes are influenced by many factors beyond this single genetic marker. Please discuss any concerns regarding hormone metabolism or health risks with your healthcare provider.
This is a common genotype, though exact frequencies vary significantly by ancestry.
Varied CYP1B1 activity
Carrying one copy of each allele may result in intermediate enzyme activity levels compared to those with two copies of the same allele. While some studies investigate links between CYP1B1 variants and estrogen metabolite ratios, the clinical significance of this specific genotype remains limited and inconsistent across different research studies. Always consult with a clinician or pharmacist regarding any questions about your health or medication metabolism.
This heterozygous genotype is frequently observed in European and Hispanic populations, where the minor allele frequency is approximately 0.20 to 0.30.
Potential altered enzyme activity
This genotype is associated with functional differences in the 4-hydroxylation of estrogens in some research models. Because the evidence linking this specific variant to clinical health outcomes is limited and often conflicting, it is not used to predict individual disease risk. Please discuss any questions about your genetic profile or hormone-related health with your doctor.
This genotype is less common than the CC or CG genotypes in many populations, occurring in a smaller subset of individuals.
Understanding the rs1056838 Variant
The rs1056838 variant is a specific change in the DNA sequence of the CYP1B1 gene, which stands for cytochrome P450 family 1 subfamily B member 1. Located on chromosome 2, this gene provides instructions for making an enzyme that plays a critical role in the body's chemical processes. In genetics, a single nucleotide polymorphism (SNP) like rs1056838 represents a variation at a single position in the DNA building blocks. While many such variations have no observable effect on health, researchers track them to see if they correlate with differences in how individuals process hormones or respond to environmental factors. Because this variant is located in a gene responsible for metabolic pathways, it has been a subject of interest in studies examining hormone-related traits and metabolic efficiency.
The Role of the CYP1B1 Gene
The CYP1B1 gene encodes an enzyme that is part of the cytochrome P450 family, a group of proteins essential for the metabolism of various substances, including drugs and endogenous compounds like steroid hormones. Specifically, the CYP1B1 enzyme is known for its role in the 4-hydroxylation of estrogens. This process converts estrogens into catechol estrogens, which are then further processed by the body. Because this enzyme is expressed in tissues that are sensitive to hormones—such as the breast, uterus, and ovaries—it is a focal point for research into how genetic variations might influence hormone levels. By regulating the breakdown of these hormones, the CYP1B1 enzyme helps maintain the delicate balance of signaling molecules that influence cell growth and tissue function throughout the body.
Research and Evidence Strength
Current scientific evidence regarding rs1056838 is considered limited. While some studies have explored the broader CYP1B1 gene in the context of hormone metabolism and potential links to various health conditions, the specific functional impact of the rs1056838 variant remains a subject of ongoing investigation. Research in this field often looks at how different genotypes might correlate with variations in estrogen metabolite ratios. However, it is important to note that many of these associations are observed in specific, smaller study populations and have not always been consistently replicated across larger, more diverse groups. Consequently, the evidence is not currently strong enough to draw definitive conclusions about the variant's clinical significance. Researchers continue to study these pathways to better understand the complex interplay between genetics, hormone metabolism, and long-term health outcomes.
Population Frequency
The frequency of the rs1056838 variant varies across different ancestral groups. According to available genetic databases, the minor allele frequency (MAF) is typically observed in the range of 0.20 to 0.30 among European and Hispanic populations. This means that a significant portion of these populations carries at least one copy of the variant allele. Because frequency can differ substantially based on geographic and ancestral background, researchers often account for these differences when conducting large-scale genetic studies. Understanding these frequency patterns is essential for scientists to determine whether a specific genetic variant is common enough to be considered a standard variation within a population or if it is rare and potentially linked to specific, less common traits.
Interpreting Your Genetic Information
If you have received information about your rs1056838 genotype, it is important to view it within the context of current scientific understanding. Genetic variants are only one piece of a much larger puzzle that includes lifestyle, environment, and other genetic factors. Because the evidence for this specific variant is limited, it should not be used to make assumptions about your health or to guide medical decisions. If you are concerned about hormone levels, metabolic health, or how your body processes medications, the most appropriate step is to consult with a qualified healthcare provider or a clinical geneticist. They can help you interpret your results in the context of your overall health history and provide guidance based on established clinical standards rather than preliminary research findings.
How common is this variant?
The rs1056838 variant has a minor allele frequency of approximately 0.20 to 0.30 in European and Hispanic populations.
Frequently asked questions
Is rs1056838 a diagnostic marker for disease?
No, rs1056838 is not a diagnostic marker. Current research into this variant is exploratory, and it is not used in clinical settings to diagnose any medical condition.
Does this variant affect how I should take medication?
There is no established clinical guidance linking rs1056838 to specific medication dosing. If you have questions about your medication, please discuss them with your clinician or pharmacist.
Why is the evidence for this variant considered limited?
Evidence is considered limited because studies have shown mixed results, and many findings have not been consistently replicated in large, diverse populations. More research is needed to confirm the functional impact of this variant.
Can I change my health outcomes based on this genotype?
Genetic variants are only one factor in your overall health. You should focus on established health practices, such as a balanced diet and regular check-ups, and consult a doctor for personalized health advice.
Sources & further reading
Educational information only, last refreshed 9/23/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This variant (p.Asn453Ser, formerly Val432Leu) in the CYP1B1 gene is associated with altered enzyme activity and has been investigated for susceptibility to various cancers, including breast and prostate cancer.
This variant (p.Gly61Glu) is a well-documented pathogenic mutation associated with primary congenital glaucoma (PCG) and is also studied for its role in oxidative stress and drug response pathways.
A missense variant in CYP1B1 (p.Ala119Ser) associated with primary congenital glaucoma and juvenile open-angle glaucoma risk.
A well-characterized loss-of-function missense variant causing primary congenital glaucoma through abnormal trabecular meshwork development.
Missense variant in CYP1B1 associated with primary congenital glaucoma.
A classic founder missense mutation in CYP1B1 responsible for early-onset recessive infantile and juvenile glaucoma.