@TNP My mom has for BRCA 1 and 2. It was negative, or so she's always told me even with threats of "If you're keeping it from me for my 'peace of mind', it could literally kill me. So don't." There's something else that's causing it which is likely a genetic factor that's not yet been identified given how many variables can go into developing cancer but how consistent it's been in not only occurring in my family, but within a very narrow age window that is generally considered 'early' and the aggressiveness of my mom's variant. Hers fell into the G3 category, which is the highest the grade goes for breast cancer.
I turned 35 this year and needless to say, I'm getting my boobs squished ASAP now that the insurance is willing to cover it. They fought me on it every year from 30-34, despite family history and doctor recommendation. /eyeroll