A 25 year old female is referred to the genetic clinic. Her maternal aunt died from breast cancer at the age of 28 and another aunt had ovarian cancer at the age of 34. Her own mother had suffered from breast cancer at a young age. Her maternal uncle had colon cancer at age 42. Which gene is responsible?
BRCA1 and 2 mutations overlap considerable and both lead to increased risk of breast and ovarian cancer. There is also increased risk of fallopian tube, pancreatic and prostate cancers. These are DNA repair genes. However in BRCA1 there is also increased risk of cervical, uterine, and colon cancer whilst in BRCA2 there is increased risk of gastric cancer, gallbladder and bile duct cancer, and melanoma.