BRCA2 rs11571836: What Your Genotype Means
The rs11571836 variant, commonly known as K3326X, is a genetic change located in the BRCA2 gene. It is associated with a moderate increase in susceptibility to certain hormone-related cancers, including breast, ovarian, and prostate cancer.
What each genotype means
Typical BRCA2 genetic profile
This genotype represents the common, non-truncated version of the BRCA2 gene at this position. It is not associated with the specific cancer susceptibility risks linked to the K3326X variant.
This is the most common genotype found in the vast majority of the global population.
Increased cancer susceptibility carrier
This genotype, also known as K3326X, results in a truncated BRCA2 protein. Research indicates this variant is associated with a moderate increase in susceptibility to certain cancers, including breast, ovarian, and prostate cancers, though it is distinct from fully pathogenic BRCA2 mutations.
Carried by roughly 1 in 100 people of European ancestry, with lower frequencies observed in East Asian and African populations.
Increased cancer susceptibility homozygous
This genotype indicates that both copies of the BRCA2 gene carry the K3326X truncation. Individuals with this profile may have a similar or slightly elevated risk profile for specific cancers compared to single-copy carriers, though clinical evidence remains focused on the general association with the variant.
This genotype is rare, occurring at a very low frequency in the general population.
Understanding the rs11571836 Variant
The rs11571836 variant is a single nucleotide polymorphism (SNP) located within the BRCA2 gene on chromosome 13. In scientific literature, it is frequently referred to as K3326X or Lys3326Ter. This specific notation indicates that the variant causes a premature stop codon at position 3326 of the BRCA2 protein, leading to a truncation of the protein's C-terminus. Because this change occurs at the very end of the protein, it does not result in the complete loss of function typically seen with more severe, pathogenic BRCA2 mutations. Instead, it is often classified as a polymorphic variant, meaning it is a common variation in the genetic code that may have a milder impact on biological processes compared to classic, high-risk mutations that cause hereditary breast and ovarian cancer syndrome.
The Role of the BRCA2 Gene
The BRCA2 gene provides instructions for making a protein that acts as a tumor suppressor. This protein plays a critical role in repairing damaged DNA, specifically through a process called homologous recombination, which helps maintain the stability of a cell's genetic information. When DNA is damaged, the BRCA2 protein helps coordinate the repair process to ensure that the genetic code is copied accurately during cell division. If the BRCA2 protein is absent or malfunctioning, damaged DNA may not be repaired correctly, which can lead to the accumulation of genetic mutations. Over time, these errors can cause cells to grow and divide uncontrollably, potentially leading to the development of cancer. While the K3326X variant alters the structure of this protein, its impact is distinct from the complete loss of function associated with high-penetrance BRCA2 mutations.
Research and Cancer Associations
Research into rs11571836 has consistently identified a moderate association with an increased risk of several cancers, including breast, ovarian, and prostate cancer. Large-scale studies, such as those utilizing the iCOGS dataset, have analyzed tens of thousands of individuals to estimate the odds ratios for carriers of this variant. While the evidence suggests a link to increased risk, the effect size is generally considered smaller than that of fully pathogenic BRCA2 mutations. Furthermore, some researchers have noted that it is difficult to determine if the observed risk is entirely due to the K3326X variant itself or if it is influenced by linkage disequilibrium with other nearby genetic factors. Because the evidence is considered limited or moderate, it is not typically used in isolation to make definitive clinical predictions about an individual's cancer risk.
What You Can and Cannot Do With This Information
Genetic information regarding variants like rs11571836 is intended for educational purposes and should not be used for self-diagnosis or to make medical decisions. If you have received results indicating you carry this variant, it is important to discuss the findings with a qualified healthcare provider or a genetic counselor. They can help place the result in the context of your personal and family medical history, which are often more significant indicators of cancer risk than a single genetic variant. You cannot use this information to determine a specific cancer diagnosis or to predict your future health outcomes with certainty. Always consult with a medical professional before making changes to your health screenings or lifestyle, as they can provide personalized guidance based on the most current clinical guidelines and your unique health profile.
How common is this variant?
The minor allele frequency for rs11571836 is approximately 0.01 in European populations, with lower frequencies observed in East Asian and African ancestries.
Frequently asked questions
Is rs11571836 the same as a BRCA2 mutation?
While rs11571836 is a variant in the BRCA2 gene, it is distinct from the high-risk, pathogenic mutations that are typically associated with hereditary breast and ovarian cancer syndrome. It is often described as a polymorphic stop codon with a more moderate impact on cancer risk.
Does having the K3326X variant mean I will get cancer?
No, having this variant does not mean you will develop cancer. It is associated with a moderate increase in risk, but many factors, including family history, lifestyle, and other genetic markers, contribute to an individual's overall cancer risk.
Should I get tested for rs11571836?
Genetic testing should be discussed with a healthcare provider or genetic counselor. They can determine if testing is appropriate based on your personal and family medical history rather than testing for individual variants in isolation.
How does K3326X affect the BRCA2 protein?
The K3326X variant causes a premature stop codon at the end of the BRCA2 protein, resulting in a truncated C-terminus. This structural change is thought to potentially affect the protein's function, though it is less severe than mutations that cause a complete loss of protein production.
Sources & further reading
Educational information only, last refreshed 9/27/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Get my report — $29Related variants in BRCA2
This variant is a clinically significant allele in the BRCA2 gene associated with hereditary breast and ovarian cancer syndrome.
This variant (p.Lys3326Ter) is classified as a benign polymorphism and is not considered a primary driver of hereditary breast and ovarian cancer susceptibility.
A pathogenic variant in BRCA2 associated with hereditary breast and ovarian cancer syndrome.
A pathogenic variant in the BRCA2 gene associated with hereditary breast and ovarian cancer.
A rare pathogenic variant in the BRCA2 gene associated with hereditary breast and ovarian cancer syndrome.
Protein-truncating variant (K3326X) in BRCA2 associated with a modest increase in risk for breast and other cancers.