Professor Arnold Hill:

If somebody who is diagnosed carries a gene then their siblings have a 50% chance of carrying that gene. We follow up by invitation. When somebody in a family finds out that they carry a gene that caused them to get breast cancer that news will spread throughout the family. Then they will be invited for genetic testing. It is much simpler to test for it once you know the mutation that is in that family. The challenge is for each individual member who turns out to be BRCA1 or BRCA2 positive. It has huge implications for a woman's whole life, for herself and her children. It is a life changing event. She may end up having a bilateral mastectomy with a reconstruction or she may have bilateral oopherectomy, having her ovaries removed. It is an enormous change to your life so we do not take it lightly. Once a mutation is identified, it is very significant for the whole family.