One of your good friends has a family history of breast cancer. She has her BRCA1 and BRCA2 alleles tested, and no detrimental m
utations are found. She tells you she is so relieved to know that she will not develop breast cancer. Is she correct that she will not develop breast cancer?
She is incorrect in saying that she will not get breast cancer with 100% certainty. Although, since her BRCA1 and BRCA2 alleles were found to have no mutations signalling breast cancer, this means that there might be a very small chance that she could still develop breast cancer.
Even though it is highly unlikely that she will develop breast cancer, there is still a very small chance that it can occur.
