A 31 year old woman consults her physicain because she is concerned about developing breast cancer. She is currently in good health and she has never had any breast disease. Her concern arises bacause her sister has just been diagnosed as having breast cancer and her mother died of breast cancer.

  • How can one determine if the cancer in this family is likely to be a dominantly inherited predisposition?
  • What is the woman’s cahnce of developing breast cancer?