I second what SpecialK wrote. As for a second opinion, do you mean submitting a new sample for genetic testing or simply having another doc review current test results? I am not sure that insurance would cover a repeat of the test but more importantly having the mutation does not mean you will be guaranteed to develop bc. So as was explained you can have family members who are carriers but have never developed bc. Take care.

"Some individuals who have inherited a germline BRCA1 or BRCA2 mutation never develop cancer because they never get the second mutation necessary to knock out the function of the gene and start the process of tumor formation. This can make the cancer appear to skip generations in a family, when, in reality, the mutation is present. Persons with a mutation, regardless of whether they develop cancer, however, have a 50/50 chance to pass the mutation on to the next generation.

It is also important to remember that the BRCA1 and BRCA2 genes are not located on the sex chromosomes. Therefore, mutations can be inherited from the mother or the father's side of the family." https://stanfordhealthcare.org/medical-conditions/...

I don't think it's likely to be wrong. I think it's just likely that your family has been lucky. Tumor formation is dependent on many things - not just a mutation but exposure to various substances and stressors.

The other possibility is of course a question of paternity. Genetic testing has been unveiling that a lot of people had different fathers than they thought https://www.theguardian.com/lifeandstyle/2018/sep/...

One less expensive way of testing BRCA again is to submit a saliva sample to 23andMe. I was BRCA tested at diagnosis because I am adopted with zero information about family history. My BS was not going to make a recommendation regarding surgery type without that info, so I did the blood test. I was negative and we proceeded with surgery, but years later I sent a sample to 23andMe to try to get more info about my adoption and find blood relatives. As part of their suite of testing they included BRCA and some additional tests, which confirmed my earlier result. I believe you can get this done for about $200, but there is also Color Genomics for about $250 for a panel of genetic tests, including BRCA, which allows a similar type of online ordering without running the testing through insurance or bearing the full cost of re-doing your testing with a lab selected by your own doctor.

I have a similar situation in that going back generations on both sides there is no evidence (or at least no evidence in current memory) of breast/ovarian/prostate cancer and so the BRCA test seemed like overkill until it was returned BRCA1+. I did briefly think that it could be wrong, but the sensitivity of the testing has to be so high that it is unlikely it would be a false positive. My mother has since tested negative and we are awaiting my father's test results, although logically it must have come down that side of the family (unless is a super rare de novo genetic mutation case which I doubt).

The genetic counselor in the US my parents saw warned the same thing about the commercial panels, and pointed this out especially due to the relative rarity of BRCA1 and it would likely not have been picked up on those.

jspringer - I would rejoice that you have this knowledge now, especially as you found out with "only" a DCIS diagnosis. Technically you do have options and could possibly elect for ongoing monitoring rather than multiple surgeries. That being said, I was more than happy to get my ovaries out a few months ago for various reasons and wouldnt necessarily dismiss that surgery out of hand - ovarian cancer is more difficult to catch early, especially if you don't have regular scanning.

Jspringer, you said you saw no breast or ovarian cancer in the family tree. According to cancer.gov, BRCA mutations also confer an increased risk of Fallopian tube, primary peritoneal, prostate, and pancreatic cancer. Are there any of these on either side?

I think I understand your desire to feel certain there is no mistake before choosing risk-reducing surgery. Here is an idea: Instead of re-doing your genetic test, have your parents test for the particular BRCA mutation that was found for you. That would be confirmation of an inherited mutation. Since they have a first-degree relative with the mutation (you), single-gene testing for them is within guidelines and should be covered by their health insurance. It would also clue the parent with the mutation that they could get extra screening for themselves.

aram - agree - I would not rely on 23andMe as the primary source for testing either. For me it was confirmatory. If it returned a negative result for the OP a more extensive look would be necessary. I’m sorry that you had a negative result followed later by a positive one, that had to be an unwelcome surprise.