Considerations for comprehensive assessment of genetic predisposition in familial breast cancer.

About 10-15% of breast cancer cases are family related, classified as familial breast cancer. The disease was first reported in 1866 and determined to be an autosomal dominant genetic disease in 1971. Germline mutations in BRCA1 were discovered and deemed as the first genetic predisposition for the disease in 1994. By now, genetic predispositions for about 40% of familial breast cancer families have been identified. New molecular genetic approaches currently under development should accelerate the process to identify the full spectrum of genetic predispositions for the disease, thereby enabling a better understanding of the genetic basis of the disease and therein providing benefit to high-risk patients.