Breast Cancer Genes: What Your DNA Reveals About Risk

From inherited mutations to predictive models and emotional decisions, breast cancer risk isn’t just about what runs in your family—it’s about how science, support, and personal context come together. Whether you’re considering genetic testing or trying to make sense of a recent result, here’s what your DNA might be telling you—and what to do with that information

What are breast cancer genes?

Your DNA can hold clues about your chances of developing breast cancer—and sometimes those clues are inherited across generations. Genes like BRCA1 and BRCA2 are among the most well-known for their role in hereditary breast cancer, but they’re not the only ones worth paying attention to.

BRCA1 and BRCA2: the heavy hitters

Mutations in the BRCA1 and BRCA2 genes are strongly linked to breast and ovarian cancer. These genes usually help repair damaged DNA, but when mutated, they stop doing their job properly—leading to a much higher risk of cancer. For example, someone with a BRCA1 mutation might face a lifetime breast cancer risk of up to 72%, compared to about 13% for the general population.

These mutations are passed down in families, so if your mother, sister, or grandmother had breast or ovarian cancer—especially at a young age—there’s a chance you could carry one too.

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Other genes that raise risk

BRCA1 and BRCA2 aren’t the whole story. Mutations in other genes—like PALB2, CHEK2, ATM, and TP53—can also raise the odds of developing breast cancer, though typically not as dramatically. These are known as moderate-penetrance genes, meaning they raise risk to a lesser degree than BRCA mutations, but still significantly more than average. Research shows that people with mutations in these moderate-risk genes often benefit from changes in clinical care, even if they don’t meet traditional criteria for genetic testing.

Some of these genes are also tied to broader cancer syndromes, like Li-Fraumeni syndrome (linked to TP53) or Lynch syndrome, which primarily increases colorectal and endometrial cancer risk but may also be associated with breast cancer in some families.

How these genes are inherited

Most hereditary breast cancer mutations are passed down in an autosomal dominant pattern. This means you only need to inherit one copy of the mutated gene—from either parent—for your risk to go up. That also means each of your children has a 50% chance of inheriting the mutation.

Because these patterns often show up in family history, understanding your relatives’ cancer diagnoses can play a big role in assessing your own risk—and deciding whether genetic testing makes sense.

How genetic mutations increase breast cancer risk

Not all genetic mutations carry the same weight. Some dramatically raise your risk of breast cancer, while others cause a smaller bump. Understanding this difference—and what the science calls penetrance—can help you make sense of what a genetic test result really means.

High-penetrance vs. moderate-penetrance genes

When we talk about high-penetrance genes, we’re usually referring to BRCA1 and BRCA2. People with mutations in these genes face a sharply elevated risk of developing breast cancer—often between 45% and 72% over their lifetime. These mutations are rare in the general population, but when present, they can be highly predictive of future cancer.

Moderate-penetrance genes—like CHEK2, ATM, and PALB2—are more common and tend to increase risk by a smaller degree. For instance, a CHEK2 mutation might raise a person’s lifetime breast cancer risk to around 20–30%. That’s still significantly higher than the population average but not as striking as BRCA mutations.

Risk isn’t binary—it’s a spectrum

Carrying a mutation doesn’t mean you will develop cancer; it just means your chances are higher. Other factors—like lifestyle, reproductive history, and even polygenic risk scores (which look at many small gene variants together)—can further influence your personal level of risk.

Researchers now describe breast cancer risk as a continuum, shaped by both rare high-impact mutations and more common low-impact variants. Tools like the BOADICEA model combine this genetic information with clinical data to give a more personalized risk estimate.

Men aren’t immune

Although far less common, men can also carry BRCA1 and BRCA2 mutations—and those mutations raise their risk for male breast cancer, prostate cancer, and pancreatic cancer. If you’re a man with a strong family history of cancer, genetic testing may still be recommended.

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How genetic testing works—and who should consider it

Genetic testing can help uncover whether you carry mutations linked to a higher risk of breast cancer—but deciding to get tested is a personal and often emotional decision. Knowing what to expect, and whether testing makes sense for you, can make the process feel a lot more manageable.

What the process looks like

Testing is usually done through a simple blood or saliva sample, either at a clinic or through a home testing kit. The sample gets sent to a lab, where technicians look for mutations in genes known to be associated with breast cancer—typically BRCA1, BRCA2, and sometimes a broader panel that includes PALB2, CHEK2, ATM, and others.

Results usually take a few days to a few weeks. Once you receive your results, they’re usually categorized as:

• Positive (a known harmful mutation was found)
• Negative (no mutation was found)
• Variant of uncertain significance (VUS), which means a genetic change was found, but researchers aren’t sure if it increases cancer risk yet

Who might benefit from testing

You may want to consider genetic testing if:

• You have a strong family history of breast, ovarian, or prostate cancer—especially if relatives were diagnosed young
• A relative has already tested positive for a mutation
• You’re of Ashkenazi Jewish ancestry, which carries a higher rate of BRCA mutations
• You’ve had breast cancer yourself, especially at a young age or if it was triple-negative

It’s not just about prevention. If you’ve already been diagnosed with breast cancer, test results can shape treatment choices—such as using PARP inhibitors for BRCA-positive tumors.

Don’t skip the counseling

Before and after testing, genetic counseling can help you understand what the results mean—not just medically, but emotionally and socially too. Counselors can explain terms like “penetrance” and “pathogenic variants,” help you prepare for difficult conversations with family members, and guide you through next steps if a mutation is found.

How risk models like BOADICEA and Gail improve predictions

Genetic testing isn’t the only tool used to assess breast cancer risk. Several risk prediction models—like BOADICEA, Gail, and Tyrer-Cuzick—can combine personal history, family history, and genetic information to give a more complete picture. These models are especially helpful for guiding decisions around screening, testing, and preventive care.

What is the BOADICEA model?

BOADICEA (short for Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) is a sophisticated tool that uses:

• Your family history of cancer
• Presence of BRCA1/BRCA2 and other mutations
• Reproductive factors (like age at first period, childbirth history)
• Lifestyle data (e.g., BMI, alcohol use)
• And increasingly, polygenic risk scores

It provides a personalized percentage estimate of your lifetime breast cancer risk—and it’s especially useful for people with complex family histories or those considering genetic testing.

Gail model: simpler but limited

The Gail model uses a smaller set of information—like age, reproductive history, and number of relatives with breast cancer—to estimate a woman’s five-year and lifetime risk of developing breast cancer. It’s widely used in clinical settings but doesn’t account for BRCA mutations or paternal family history, so it’s less accurate for people with a strong inherited risk.

Polygenic risk scores add new layers

More recently, researchers have been developing polygenic risk scores (PRS), which analyze hundreds or even thousands of small genetic variants. These individual variants don’t mean much on their own, but together they can provide a more refined risk estimate.

In the future, polygenic scores may help customize screening schedules or preventive treatments—even in people without BRCA mutations—by identifying subtler inherited risks that traditional models might miss.

What emerging research says about the future of genetic risk

As science digs deeper into the human genome, the way we understand breast cancer risk is changing—fast. Researchers are uncovering new genetic markers, refining predictive models, and even exploring how inherited mutations influence treatment outcomes. It’s not just about BRCA anymore.

Beyond BRCA: new genes and biomarkers

While BRCA1 and BRCA2 are still the most well-known, studies have identified other genes that play meaningful roles in breast cancer development. Mutations in BARD1, RAD51C, RAD51D, and NBN are being investigated as potential contributors to breast cancer susceptibility.

At the same time, biomarkers—measurable indicators of disease, often found in blood or tissue—are being studied for their ability to detect cancer earlier and predict outcomes more accurately. As testing panels expand, these discoveries could help tailor screening and prevention strategies even further.

Tumor evolution and personalized care

Thanks to tumor genomic sequencing, researchers can now trace how cancers evolve over time—how they develop resistance to drugs, how they mutate, and how they spread. Understanding these patterns can influence treatment plans and may eventually guide the use of personalized cancer immunotherapies, especially for those with inherited mutations.

For example, people with BRCA-related cancers may respond well to PARP inhibitors, which target a weakness in how these cancer cells repair DNA. Studies are also examining how immune checkpoint inhibitors could work in patients with certain genetic profiles.

The future is layered and personal

We’re moving toward a world where your breast cancer risk score isn’t based on a single gene, but rather on the full scope of your DNA, family history, environmental exposures, and even your body’s immune response. As technology improves, so will the precision with which doctors can identify risk—and recommend prevention or treatment strategies that actually fit your genetic makeup.

What Medicare covers for genetic testing and counseling

If you’re eligible for Medicare, you may be wondering whether it covers the cost of genetic testing for breast cancer. The short answer: sometimes. Coverage depends on your personal and family history, the type of test being ordered, and whether it’s deemed medically necessary.

When Medicare covers genetic testing

Medicare Part B may cover genetic testing for breast cancer genes, including BRCA1 and BRCA2, if:

• You have a personal history of breast, ovarian, or related cancers
• A doctor determines the test is medically necessary
• You meet specific clinical criteria (e.g., early-onset cancer, triple-negative breast cancer)

In most cases, Medicare won’t cover testing just based on family history alone—you generally need a prior cancer diagnosis.

However, if you’ve already had cancer and meet the criteria, the test may be fully covered, especially if results could guide future treatment.

Genetic counseling may also be covered

Medicare may also cover genetic counseling when it’s connected to a covered genetic test. Counseling is often provided before testing to assess eligibility and after testing to help interpret the results.

That said, not all genetic counselors accept Medicare, so it’s a good idea to check in advance whether your provider is Medicare-approved.

Watch for gaps and out-of-pocket costs

Even if the testing itself is covered, not all labs are in-network, and expanded gene panels (beyond BRCA1/2) may not be reimbursed. Medicare Advantage (Part C) plans can have different coverage rules, so it’s worth double-checking with your insurance carrier before proceeding.

If your test is denied or only partially covered, you may still be able to appeal the decision—and that’s an area where an advocate can make a big difference.

How patient advocates help you move forward

Getting a genetic test is just one step. Figuring out what it means—and what to do next—is where many people get stuck. That’s where patient advocates come in.

You don’t have to sort through this alone

If you’re facing a positive test result or uncertain genetic risk, an advocate can help you:

• Understand the difference between high- and moderate-risk mutations
• Find a Medicare-covered genetic counselor or second opinion
• Prepare for conversations with your oncologist or primary care provider
• Coordinate follow-up screenings, preventive steps, or treatments
• Navigate appeals if coverage was denied

Advocates act as a go-between, helping translate medical language into plain English and making sure nothing falls through the cracks.

Solace provides advocates who specialize in this kind of care

Solace advocates are trained to support patients with genetic mutations like BRCA1, BRCA2, CHEK2, and PALB2—helping them understand their results, coordinate follow-up care, and make informed decisions about their health.

If you’ve had genetic testing or received a breast cancer diagnosis, your advocate can help you sort through next steps: scheduling MRIs, following up with high-risk specialists, or making sense of what increased surveillance or risk-reducing surgery could mean for you. They’ll explain test results in plain language, help prioritize your care, and ensure your doctors stay in sync.

And if something gets in the way—like a delayed referral or a denied insurance authorization—your advocate will step in and resolve it.

Solace is covered by Medicare—most patients pay $0 out of pocket.

Moving from confusion to clarity

Understanding your genetic risk for breast cancer can feel overwhelming—but it doesn’t have to. With the right support, you can turn test results into action. Your advocate can help you reclaim a sense of control, so you’re not left wondering what comes next.

FAQ: Frequently Asked Questions About Breast Cancer Genes

Is breast cancer hereditary?

Yes—breast cancer can be hereditary, particularly when certain gene mutations are passed down through families. Around 5–10% of breast cancer cases are linked to inherited mutations like BRCA1, BRCA2, or CHEK2. If your close relatives had breast or ovarian cancer—especially at a young age—you may benefit from genetic counseling and testing for breast cancer genes.

What are BRCA1 and BRCA2, and how do they relate to breast cancer risk?

When people ask “What is the breast cancer gene?”, they’re usually referring to BRCA1 or BRCA2—genes that, when mutated, significantly raise the risk of developing breast cancer. BRCA1 and BRCA2 are tumor suppressor genes. When they work correctly, they help repair damaged DNA. But if you inherit a pathogenic variant in one of these genes, your body’s ability to fix cell damage is impaired—raising your hereditary breast cancer risk significantly. People with BRCA mutations may also face higher risks for ovarian, pancreatic, and prostate cancer.

What other breast cancer genes should I know about besides BRCA1 and BRCA2?

Beyond BRCA, there are moderate-penetrance breast cancer genes like PALB2, CHEK2, ATM, TP53, and BARD1. These mutations still raise cancer risk but to a lesser extent. Many genetic testing panels now include these genes, and researchers continue to uncover new genetic biomarkers through genome-wide association studies (GWAS).

How does genetic testing for breast cancer work?

Genetic testing for breast cancer typically involves a blood or saliva sample, analyzed for specific mutations. Tests may focus solely on BRCA1/2 or include a multigene panel. Results usually fall into three categories: positive (pathogenic variant detected), negative, or variant of uncertain significance (VUS).

Who qualifies for genetic testing under Medicare?

Medicare may cover genetic testing for breast cancer if you have a personal history of breast, ovarian, or related cancers and meet criteria like early age at diagnosis or a known BRCA1/BRCA2 mutation in the family. Genetic counseling is often included when part of a covered testing process.

What is the BOADICEA model, and how does it predict cancer risk?

The BOADICEA model (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) combines family history, gene mutations (like BRCA1/BRCA2), and risk factors such as reproductive history and polygenic risk scores to give a personalized estimate of breast cancer risk. It’s one of the most comprehensive cancer risk assessment models in clinical use.

What are polygenic risk scores and how are they used in breast cancer prediction?

Polygenic risk scores (PRS) evaluate hundreds or thousands of low-risk genetic variants across your genome. When combined, these variants provide a more detailed picture of your breast cancer susceptibility, especially for those without high-penetrance mutations like BRCA1 or BRCA2. PRS is a growing tool in personalized cancer risk stratification.

What are the emotional and psychosocial effects of genetic testing for breast cancer?

Learning you carry a mutation can lead to anxiety, fear, or guilt—especially regarding family communication and passing the gene to children. Many people also experience uncertainty about preventive measures or feel pressure to undergo surgery or heightened screening. Genetic counseling helps manage the psychosocial effects and guide decision-making.

Can men inherit and be affected by BRCA mutations?

Yes. BRCA1 and BRCA2 mutations in men can lead to elevated risks of male breast cancer, prostate cancer, and pancreatic cancer. Men with a family history of these conditions should consider genetic counseling to evaluate their cancer predisposition genes and determine whether genetic testing is appropriate.

What is the difference between high-penetrance and moderate-penetrance genes?

High-penetrance genes, like BRCA1 and BRCA2, substantially raise your lifetime risk of breast cancer—often above 50%. Moderate-penetrance genes, such as CHEK2 or ATM, raise risk to a lesser degree but still more than the general population. These categories help doctors determine your screening and prevention strategy.

How can a patient advocate help after receiving genetic test results?

A patient advocate can help you interpret complex test results, find Medicare-covered genetic counselors, appeal denied insurance claims, and coordinate follow-up care or preventive strategies. Services like Solace offer access to dedicated advocates who assist with everything from care navigation to appointment scheduling—so you’re never left figuring it out alone.

This article is for informational purposes only and should not be substituted for professional advice. Information is subject to change. Consult your healthcare provider or a qualified professional for guidance on medical issues, financial concerns, or healthcare benefits.

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