Case study: You and your friend Sally are talking about her family. She has three older sisters and an older brother. Sally jokingly calls herself the "afterthought" because all of her siblings are so much older. In fact, Sally's sister Sarah is 18 years older and is like a second mom to her. Sally is worried about Sarah, who has just been diagnosed with breast cancer. You are surprised that she is not more upset. When you comment on that, Sally tells you it's only because she has become used to dealing with the breast cancer issue. Her grandma Elise died from breast cancer when Sally was very young, and Sally's mom, Elizabeth, is currently in remission. Sally goes on to tell you that she worries about the odds being stacked against her. She thinks there's a good likelihood that she will also develop the disease.
You tell Sally you have heard there's a genetic test that will inform her about her susceptibility. You don't know much about it, but it has something to do with the BRCA1 gene that you heard about on the news. You are eager to help Sally learn as much as possible, so you go to the library to do some research.
According to your research, write a message to Sally, including answers to these questions: What is the normal function of BRCA1 protein? What kind of mutation is present in the gene in the breast cancer condition, and how does that mutation affect the protein's function (specifically in the cell cycle)? If Sally had the genetic test, what would the doctors be looking for? If they found that she had a copy of the mutated BRCA1 gene, what would that mean?