How do BRCA1 and BRCA2 gene mutations affect a persons risk of cancer?
Not all gene changes, or mutations, are deleterious (harmful). Some mutations may be beneficial, whereas others may have no obvious effect (neutral). Harmful mutations can increase a person’s risk of developing a disease, such as cancer. A woman’s lifetime risk of developing breast and/or ovarian cancer is greatly increased if she inherits a harmful mutation in BRCA1 or BRCA2. Such a woman has an increased risk of developing breast and/or ovarian cancer at an early age (before menopause) and often has multiple, close family members who have been diagnosed with these diseases. Harmful BRCA1 mutations may also increase a woman’s risk of developing cervical, uterine, pancreatic, and colon cancer . Harmful BRCA2 mutations may additionally increase the risk of pancreatic cancer, stomach cancer, gallbladder and bile duct cancer, and melanoma . Men with harmful BRCA1 mutations also have an increased risk of breast cancer and, possibly, of pancreatic cancer, testicular cancer, and ear