A simple explanation of the BRCA2 gene mutation

Everyone carries two important genes called BRCA1 and BRCA2. These genes are part of our body’s natural repair system. They help fix damage in our DNA and keep cells functioning normally. Not only are they not bad genes, they are actually critical tools our cells use to prevent mistakes from turning into cancer.

We all inherit one copy of each of these genes from each of our parents: one from Mom and one from Dad. If one of those genes has a normal (healthy) version, it does the repair work as it should. But if one copy has a harmful mutation, the body doesn’t have the full set of tools it needs to fix DNA damage, and that increases the risk that damaged cells can grow unchecked and become cancer.

In families where a parent carries a BRCA1 or BRCA2 mutation, each child has a 50% chance of inheriting that same mutation, because inheritance of each gene copy is random.

In my case, we know the BRCA2 mutation didn’t come from my mom’s side. She and I took the gene testing at the same time and her results came back normal. The fact that the gene mutation came from my dad's side (assuming the test wasn't faulty. Let's be honest, everyone prays their test result is wrong), actually explains why there’s little family history of cancers in the last two generations. My dad is one of three brothers, and while men certainly can develop cancers linked to BRCA mutations, those risks sometimes “hide” in male lines because many of the cancer types associated with these mutations are more common in women or appear as men age.

Cancer Risks with BRCA Mutations

When I saw the risk stats, it was devasting. How could I possibly have something that carries so much risk. And am I willing to play the odds? Risk estimates are estimates, so you often see ranges rather than one single number.

For women with a brca2 gene mutation, their lifetime risk is:

Developing breast cancer at some point in their lifetime is 55% to 69% (this number makes my heart hurt), compared to the average risk without a mutation between 12% to 13% 

Ovarian cancer (lifetime risk, includes fallopian tube and primary peritoneal) is 13% to 29% compared to the average risk without a mutation between 1% to 2%.

Other cancers with increased risk in BRCA2:

• Pancreatic cancer: 5% to 10% lifetime

• Melanoma: 3% to 5% lifetime

For men

BRCA mutations affect men too, just with a different risk pattern. Male breast cancer is 2% to 7%, compared to a 0.1% without a mutation.

Prostate cancer (by age 80) is 19% to 61%, compared to 10.6% by age 80.

Other cancers:

• Pancreatic cancer: 5% to 10% lifetime

• Melanoma: 3% to 5% lifetime

  
  

What This Means for Me

I do not “have BRCA1 or BRCA2” in the sense of having something unusual. Everyone has those genes. What I have is a confirmed BRCA2 mutation, meaning one copy of my BRCA2 gene does not function normally. That increases my risk and while I understand that having this mutation does not guarantee a future cancer diagnosis, it felt like a cancer diagnosis.

I try to remind myself that nothing really changed, even though it feels like everything changed. I now have the information, resources, and access to the right support to make decisions about screening and prevention.

And knowing this likely came through my dad’s side helps my story make more sense, not as a random lightning strike, but as something that may have been quietly present for generations, waiting until someone looked closely enough to find it.

I'm sad that I was the one to find it. But I'm also hopeful that this means I won't ever have to hear the words "you have cancer." That I have the information and power to make decisions that are right for me and my family.