Hi, I'm Dr. Fergus Couch, a cancer genetics researcher at Mayo Clinic. Happy to participate today. #abcdrbchat

RT Judy Boughey: T1 - Approximatley 1 in 8 women will develop breast cancer in their lifetime, across the general population. #abcdrbchat

T2 15-20% of women have a family history of breast cancer #abcdrbchat

T2 About 5% of women have mutations in high and moderate risk predisposition genes #abcdrbchat

T3 the risk associated with mutations in genes on the 25 gene panels are not well known #abcdrbchat

A1: CHEK2 mutations are seen in as many breast cancer patients as BRCA mutations. The risk is a 2.5 to 3-fold increase over the general population. Women with CHEK2 mutations can benefit from MRI screening for breast cancer. #AskBCRF

A2: There are several other genes. PALB2 is high risk like the BRCA genes, CHEK2, ATM, and RAD51D are moderate risk, TP53, PTEN, and CDH1 are all high risk but are associated with syndromes with multiple cancers. All of these genes are on gene testing panels. 1/2 #AskBCRF

A2: CHEK2 and ATM mutations are as common as BRCA1/2. The others are rare, and are seen in 1 in 500 to 1 in 1000 women with breast cancer. 2/2 #AskBCRF

A3: About 5% of HER2 positive breast cancers are caused by mutations in predisposition genes. CHEK2, ATM and BRCA2 are the most common in this type of breast cancer. #AskBCRF

A4: About 15% of triple negative breast cancer is caused by mutations in predisposition genes. BRCA1 and BRCA2 alone account for about 10%. CHEK2 and ATM do not seem to be involved. Instead BARD1, RAD51D, and PALB2 have become important. #AskBCRF

A5: BRCA2 does cause ovarian cancer. However, we generally do not see an earlier age of diagnosis for ovarian cancer with mutations in this gene. The average age is still over 60. 1/2 #AskBCRF

A5: Many physicians recommend prophylactic surgery in the age 35-40 range to remove the ovaries in order to reduce risk of ovarian and breast cancer. 2/2 #AskBCRF

A6: The new common variants will help to personalize risk for each individual by putting women into higher and lower risk categories compared to the whole population. Some testing companies already offer the PRS score along with their gene panels. #AskBCRF

A7: Finding enough women from the same family with the same mutation is challenging and limits our ability to track how individual mutations influence cancer risk. #AskBCRF

A8: We are constantly finding new genetic risk variants. The current research focuses on understanding how much they influence risk and how frequent they are in the population. #AskBCRF