BRCA1 rs104894338: Understanding Hereditary Cancer Risk Variants
The rs104894338 variant is a specific genetic change located within the BRCA1 gene. It is historically associated with hereditary breast and ovarian cancer syndrome, a condition that increases the risk of developing certain malignancies.
What each genotype means
Typical BRCA1 genetic profile
This genotype represents the most common sequence found at this location in the BRCA1 gene. It is generally considered the baseline or reference state, and there is no evidence suggesting this specific configuration contributes to hereditary breast and ovarian cancer syndrome.
This is the most common genotype observed across all major global populations.
Variant carrier status
Carrying one copy of this variant means you have a genetic difference compared to the reference sequence. While this variant is cataloged in relation to hereditary breast and ovarian cancer syndrome, its clinical significance is currently limited or requires further expert evaluation to determine if it impacts cancer risk.
This genotype is rare and observed at very low frequencies in global population databases.
Homozygous variant status
This genotype indicates that both copies of the gene carry this specific variant. Because this variant is associated with hereditary breast and ovarian cancer syndrome, you should discuss these results with a genetic counselor or healthcare provider to understand the implications for your personal and family health history.
This genotype is extremely rare and is not commonly found in the general population.
What is the rs104894338 Variant?
The rs104894338 variant is a single nucleotide polymorphism (SNP) situated within the BRCA1 gene, which is located on chromosome 17. In the context of human genetics, SNPs represent the most common type of genetic variation, where a single building block of DNA—a nucleotide—is replaced by another. While many SNPs are benign and contribute to the natural diversity of the human genome, some variants can alter the function of the proteins they encode. Researchers track these specific locations using rsIDs, such as rs104894338, to standardize communication across scientific databases. This particular variant is categorized as a trait-associated marker, meaning it has been studied for its potential link to specific health outcomes, most notably hereditary breast and ovarian cancer syndrome. Because the BRCA1 gene is critical for maintaining genomic stability, any variation within its sequence is subject to rigorous investigation by the medical and scientific communities to determine if it disrupts normal biological processes.
The Role of the BRCA1 Gene
The BRCA1 gene, which stands for 'Breast Cancer 1,' provides instructions for making a protein that acts as a tumor suppressor. This protein is essential for repairing damaged DNA, ensuring that cells do not grow or divide too rapidly or in an uncontrolled way. When DNA damage occurs, the BRCA1 protein interacts with other proteins to form a complex known as the BRCA1-associated genome surveillance complex (BASC). This complex acts as a sensor for DNA damage, helping to stabilize the genome and prevent the accumulation of mutations that could lead to cancer. If the BRCA1 gene contains a variant that impairs the production or function of this protein, the cell's ability to repair its own DNA is compromised. This loss of function can increase the likelihood of developing breast, ovarian, and other types of cancer. Understanding the function of this gene is vital for interpreting how specific variants, like rs104894338, might influence an individual's long-term health profile.
Research and Evidence Strength
The evidence linking specific BRCA1 variants to cancer risk is generally categorized based on clinical observation and functional studies. For rs104894338, the evidence strength is currently considered moderate. Scientific research into BRCA1-associated syndromes often relies on large-scale studies, such as those conducted by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), to determine how specific genetic changes influence cancer penetrance. It is important to note that 'penetrance'—the likelihood that a person with a specific genotype will develop the associated condition—can vary significantly between individuals and families. Even among those who carry the same variant, environmental factors, lifestyle, and other genetic modifiers play a substantial role in the final health outcome. Consequently, researchers emphasize that the presence of a variant does not guarantee a diagnosis, and clinical interpretation requires a comprehensive review of personal and family medical history alongside genetic data.
Population Frequency and Interpretation
The rs104894338 variant is classified as rare in the general population. In genomics, rarity is a key indicator that a variant is not a common feature of human diversity but rather a specific mutation that may have clinical significance. Because it is rare, it is not typically found in large, broad-based control populations, which makes it difficult to establish definitive risk statistics for every ancestry group. When a variant is rare, its impact is often studied in the context of families with a high incidence of cancer. Readers should understand that genetic information is complex and often ancestry-specific; a variant that appears in one population may not have the same frequency or clinical implication in another. If you have received information about this variant through a genetic report, it is essential to discuss the findings with a certified genetic counselor or a healthcare provider who can interpret the results within the context of your unique medical background.
What You Can Do With This Information
Genetic information is a powerful tool for understanding your health, but it must be used responsibly. If you are concerned about your risk for hereditary breast and ovarian cancer, the most effective step is to consult with a medical professional. A genetic counselor can help you navigate the complexities of your results, explain the limitations of current research, and determine if clinical-grade testing is appropriate for you or your family members. You cannot use a single SNP result to diagnose yourself or predict your future health with certainty. Avoid making medical decisions, such as changes to screening schedules or preventative treatments, based solely on online information. Always rely on the guidance of your clinician, who can integrate your genetic data with your physical exams and family history to create a personalized health plan. Remember that science is constantly evolving, and what is known about a specific variant today may be updated as more research becomes available.
How common is this variant?
The rs104894338 variant is documented as rare in global population databases, meaning it is not commonly observed in the general public.
Frequently asked questions
Does having this variant mean I will get cancer?
No, having a variant in the BRCA1 gene does not mean you will definitely develop cancer. It only indicates an increased risk, and many other factors, including your family history and lifestyle, influence your actual health outcomes.
How can I get tested for this specific variant?
Clinical genetic testing is typically ordered by a doctor or a genetic counselor after a review of your personal and family medical history. You should speak with your healthcare provider to determine if testing is appropriate for your situation.
Is this variant the same as the 'BRCA mutation' I hear about in the news?
The BRCA1 gene is associated with hereditary cancer, but there are thousands of different variants within the gene. This specific rsID represents only one of many possible changes, and its clinical significance may differ from other, more well-known mutations.
What should I do if my genetic report mentions this variant?
If you have received a report mentioning this variant, do not panic. Schedule an appointment with a genetic counselor or your primary care physician to discuss the findings and what they mean for your specific health profile.
Sources & further reading
Educational information only, last refreshed 10/3/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This rare variant has been recently annotated in clinical databases as a potential contributor to hereditary breast and ovarian cancer risk.
Variant identified in polygenic risk scores for breast cancer susceptibility.
This variant is a rare genetic alteration in the BRCA1 gene, which is critical for DNA repair and associated with hereditary breast and ovarian cancer syndromes impacting reproductive health.
A very rare variant identified in recent genomic studies, currently being investigated for potential associations with reproductive phenotypes.
A rare variant located in the BRCA1 gene, relevant to reproductive genetic counseling and the assessment of hereditary cancer risk.
This BRCA1 variant (p.Pro871Leu) is a common polymorphism often evaluated in breast cancer risk studies, though it is generally considered to have no clinical significance for hereditary breast and ovarian cancer syndrome.