Discovering My BRCA1 Mutation on 23andMe
Is 23andMe’s BRCA 1 and BRCA 2 Testing Really Useful?
23andMe, a direct-to-consumer DNA testing service that provides genetic ancestry and health information to customers, has gotten a lot of attention for their FDA approval to test for certain BRCA mutations. A lot of the feedback regarding 23andMe’s BRCA report that I’ve seen online seems to be negative, with many people complaining that this report is useless since it only tests for three of the thousands of possible BRCA 1 and 2 mutations that can increase one’s risk of breast and ovarian cancer. There are many people for whom this test can help, however. As long as you understand exactly what this report shows and which gene mutations 23andMe tests for, this is a very useful test. I’m proof.
I first found out that I had a BRCA 1 mutation through 23andMe. I did my test before the company received FDA approval to show health reports including BRCA mutation results, but I did some research and found that it was still possible to get the information from the raw genetic data provided, via the third-party site Promethease. I did already know which mutation was present in my family, which was one of the three mutations that 23andMe tested for, but I wasn’t ready to get an official test that would become part of my permanent medical record at that point, so I did 23andMe instead.
Of course, it came back positive. I am glad that I was able to find out from this at-home test before getting medical professionals involved, but this option isn’t for everyone.
Limitations of 23andMe’s BRCA 1/2 Screening Report
As I already mentioned, 23andMe only tests for 3 of the thousands of possible BRCA 1 and BRCA 2 mutations (2 on BRCA 1 and 1 on BRCA 2). These three mutations are only found in people with Ashkenazi Jewish heritage (conveniently, 23andMe will also tell you about your ancestry too). If your family does not have Ashkenazi ancestry, this test will not tell you if you have a deleterious BRCA 1/2 mutation. The ONLY BRCA mutations 23andMe tests for are the 185delAG and 5382insC variants in the BRCA1 gene, and the 6174delT variant in the BRCA2 gene. If you already know that members of your family have one of these specific mutations, or that you have Ashkenazi Jewish ancestry, 23andMe’s BRCA report might be useful for you. Otherwise, you will need a different test.
Before showing you your BRCA 1/BRCA 2 genetic report, 23andMe requires you to read a brief explanation of how to use the information contained in the report and agree that you understand the risks and limitations involved in viewing the report. You have the option to agree and view the report or decline and not view the report, as some people would prefer not to know if they have one of these mutations, or to find out in a clinical setting. The limitations outlined by 23andMe regarding their BRCA mutation report are as follows:
- Does not test for all possible variants in the BRCA1 and BRCA2 genes. More than 1,000 variants in these genes are known to increase cancer risk. Only three of those variants are included in this test.
- Does not test for variants in other genes linked to hereditary cancers.
- Does not account for non-genetic factors, like environment and lifestyle, that influence overall cancer risk.
- The interpretation of your genetic result depends on the sex you reported in your account settings.
- The variants included in this test are most commonly found in people of Ashkenazi Jewish descent.
Mutations Tested By 23andMe
23andMe Says I Have a BRCA Mutation. What Now?
If 23andMe shows that you do have a BRCA mutation, you will still need to have a clinical blood test done to document your mutation before your doctor will refer you for early surveillance screenings (or preventative surgeries if you choose to go that route). You still need that official test before making any decisions regarding your BRCA mutation.
Your first step should be to make an appointment with a genetic counselor. You will likely need a referral from your primary care physician to see the genetic counselor, so first make an appointment with your regular doctor. Bring any relevant paperwork and information about your family history of breast cancer and ovarian cancer with you to your appointment. Your doctor will refer you to a genetic counselor at this point.
When you have your appointment with the genetic counselor, bring all of the relevant information with you that you have (family history, a printout of your 23andMe results, and anything else you have that might be relevant). The genetic counselor will discuss the next steps you need to take with you and order the official clinical blood test to verify your BRCA mutation. Since you already know which mutation you have, you will only have to be tested for that specific mutation, which should be much cheaper than a full panel test. Your insurance should cover this test, regardless, as long as you meet the guidelines for testing. (Keep an eye out for the Explanation of Benefits from your insurance company for the test. Mine tried to deny coverage. If they do this, fight it until they agree to cover it.)
Once your results from the official DNA test come back, your genetic counselor will contact you to discuss your results and put in a referral for you to start early screening. Mine sent my results, along with some extra information about the organizations FORCE and Bright Pink.
First Steps for Early Screening
Once you get the official test result back confirming your BRCA diagnosis, your genetic counselor will refer you to a specialist for a consultation to begin early screenings (likely breast MRIs and/or mammograms. Your exact recommendations may depend on factors including age, specific family history, specific mutation, or other health factors.) I am supposed to have alternating screening MRIs and mammograms every 6 months (with the mammograms starting at about age 30).
At my consultation appointment, the doctor did a clinical breast exam. I was scheduled for a mammogram if needed, but the doctor didn’t find anything worrying, so I didn’t need the mammogram just yet. I have to have an annual breast MRI as part of my surveillance plan, which has to be scheduled for between days 7 and 14 of my cycle to get the most accurate images. Luckily, my MRI results haven't shown anything worrying, so far. I will also start yearly mammograms later this year in addition to the annual clinical exam and MRI.
Also, at this appointment, the doctor explained that some women opt for preventative mastectomy surgeries, while others choose surveillance (regular screening). I let her know that I already did some research and already decided to just do surveillance, as I personally am not interested in the preventative surgeries (discuss these options with your own doctor, however). She did also explain that I will likely need to consider having my ovaries removed between the ages of 35 and 40, because there is no reliable way to screen for ovarian cancer, but this isn’t something I need to worry about right now.
At the end of the appointment, the doctor also had me talk to a psychologist that specializes in BRCA 1/2 positive patients and discussed making an appointment to talk to her again the same time I come back in 6 months for the mammogram appointment. Some women who have BRCA mutations find it helpful to talk to a psychologist about their cancer risk, according to my doctors.
Managing Your Risk of Cancer
It is scary finding out that you have a very high risk for developing cancer, but it is important to know so that you can get the needed screenings to find it early if you do develop the disease. Early diagnosis can greatly improve your chances for survival. You may also be able to take steps to reduce your overall risk of developing cancer in the future if you know you are at an increased risk. If you found out you have a genetic predisposition to cancer from an at-home test like 23andMe, it is still very important to discuss your risk with your doctor so that you can be properly monitored and so that they can help you to manage your risk.
This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.
Questions & Answers
© 2019 Jennifer Wilber