I think that mainly what I've seen as a family physician is the fear of discrimination, with patients not being tested for genetic abnormalities because they're fearful that they won't be insurable or they won't be eligible for employment in a certain field. That fear is very real, and they act on that fear.
I can give you some examples. We have patients in our practice who are twins. One was diagnosed with breast cancer at the age of 43, and the other twin at the age of 44. There likely could be a genetic cause, but neither of them is willing to be tested because of the fear of uninsurability and the implications for their children as well. Their decision not to be tested has actually caused quite a rift in the family; there are various opinions because it affects so many different people.
If these women were tested because of the nature of the gene they have and if they were positive for the nature of the cancer they have, they would be offered treatments—surgical treatments, perhaps removal of their ovaries, or mastectomies and other treatments—that would not be available to them if they were not—