The BRCA Genes: What are they, and why are they seemingly in control of my life?
“BRCA” stands for Breast Cancer–creative, I know. There are two BRCA genes: breast cancer susceptibility gene 1 (BRCA1) and breast cancer susceptibility gene 2 (BRCA2). They are tumor suppressor genes, which are essentially in charge of regulating cell division. Mutations in either of these genes are linked to higher chances of developing breast cancer and ovarian cancer.
I inherited a BRCA2 mutation from my mother. The specific mutation, 6056delC, is a frameshift mutation with a missing cytosine that creates a stop codon, preventing the rest of the gene from being written correctly. (Didn’t you love learning all about DNA in high school?) Therefore my tumor suppressor gene doesn’t work; there is nothing preventing cells from dividing rapidly.
People with a BRCA mutation have a much higher chance of being diagnosed with breast cancer and ovarian cancer. According to Myriad Genetics & Laboratories, BRCA carriers have:
- a 33-50% chance of being diagnosed with breast cancer by age 50, compared with the 2% chance of the mutation-free population.
- a 56-87% chance of being diagnosed with breast cancer by age 70, compared with the 7% chance of the mutation-free population.
- a 27-44% chance of being diagnosed with ovarian cancer by age 70, compared with the <2% chance of the mutation-free population.
- For male carriers, there is a 6% chance of being diagnosed with breast cancer by age 70, compared with the .05% chance of the mutation-free population.
How do you know if you have a BRCA mutation?
Since the BRCA genes are hereditary, a family history of breast cancer or ovarian cancer should be the first sign of a possible BRCA mutation. If these type of cancers appear sporadically in your family (say your grandmother on your father’s side had breast cancer and your aunt on your mother’s side has ovarian cancer) the likelihood of there being a BRCA gene at work is probably not very high. However, if your family history is strong or certain individuals (like my mom, for example) have had repeated instances of cancer, it might be a sign of a BRCA mutation.
If you are concerned, talk to a genetic counselor. A genetic counselor will do risk assessment based on your family medical history. A blood test determines if an individual has a BRCA mutation. In my case, the lab knew what kind of mutation they were looking for (based on my mom’s results) so they only did a single site analysis.
Once my test results came back, my genetic counselor was able to talk to me about my options. She’s been a great resource for me.
Who is usually a BRCA carrier?
Anyone can be a BRCA carrier. Some people have BRCA mutations and don’t even know it because cancer has (thankfully) not affected them. Men are just as likely as women to have a BRCA mutation, and even though breast cancer is far less likely to strike them, they can still pass that mutation onto their children.
Certain populations are more likely to have BRCA mutations. Ashkenazi Jews, for example, have a higher occurrence of BRCA mutations compared to that of the general population. One study found that in a group of 5,318 participating Ashkenazi Jews, 120 carried one of three particular BRCA mutations. (I always found this to be interesting: I am an Ashkenazi Jew, but my BRCA mutation is from my non-Jewish side!)
Rachel, thanks for posting this explanation. I have been advised to talk to a genetic counselor. I have sons, not daughters; but my sisters have daughters. I’m waiting right now on a reply from the insurance company to see if they’ll allow the testing. I did my own research on it, but your more concise explanation made it much more understandable.
I was not brca positive but I did the test to figure out my treament plan for my breast cancer. My insurance company originally did not authorize my test, but I did file an appeal and wrote a letter and asked my surgeon to write a letter and the paid the !00% on my appeal $3300.00 . Dont take No as a answer from them. I will happily share the format of my appeal letter if you need.
I stumbled onto this blog accidentally – Rachel you are an inspiration.
typo – should say – they paid 100% after my appeal.
Way to be persistent, Michelle! A great lesson for others who are considering genetic testing. Thanks for sharing.
I hope you are recovering well after all you have been through this year! I too am a brca carrier (I’m 21) and I will be having a nipple sparing mastectomy this fall (tissue expanders and incisions underneath my breasts). I was curious from your experience if the cosmetic results are up to your satisfaction. It is certainly traumatic in some ways to have this kind of procedure. Are your results, though not complete yet, up to your expectations? Do you forsee yourself being pleased with the final product ? I have been chronically googling before and afters of the nipple sparing procedure and they seem almost too good to be true-breasts seem to look so ‘normal’ after everything is all said and done. My surgeons before and afters look similar to these pictures too- do you think these images are unrealistic depictions of post op ‘finished’ breasts? Thanks again for your courage and openess, your site is an amazing resource for women!!
Hi Amanda, that’s a great question. If you get a chance, send me an email (firstname.lastname@example.org) and I’d love to talk to you about it in detail.
This is an awesome breakdown of stats. If only there were enough data to have something like this for Cowden’s Syndrome patients. URG!
Hi Rachel, You can never know for sure but we could be long lost cousins. I ttested positive for the BRCA2 (6056delC) deleterious mutation which I inherited from my mom. She fought Hodgkin’s lymphoma that she battled from age 17 up until her mid-30s & was finally declared “cured”. Sadly, she died of Ovarian cancer at age 59 after a long 6 year battle.
As for me, I fought breast cancer at age 46. I was lucky that it was found very early following a routine mammogram. I had a lumpectomy and 7 weeks of radiation therapy. This is when we ran the BRAC Analysis test and found out it was positive.
My mom created this awesome”book of descendents’’ detailing family history. As it turned out, we were able to determine that the BRCA2 mutation originated in Labiischen, Poland, Germany around 1892 & was passed on through the ages. The first reported death was my great-great grandmother who died in 1925 at age 55 after suffering from cancer for more then a year. It’s interesting that she had 9 children.
I always known I had a high-risk family so following my genetic counseling, I opted to have a Prophylactic Oophorectomy to reduce my risk of ovarian cancer by 96% & to further reduce my risk of breast cancer by 50%. I’m ER+ so I take the chemopreventive drug, Tomoxifen. My Oncology doctor says it’s saving my life!”