BRCA 1 positive woman have____ % increased risk of breast carcinoma

(D) 60 # BRCA1 gene has been cloned & is located on the long arm of chromosome 17 (17q).> The gene frequency in the population is approximately 0.0006. It does, however, occur with greater frequency in certain populations such as Ashkenazi Jews, in whom there is often a common (founder) mutation.> BRCA2 is located on chromosome 13q & there is an association with male breast cancer.> Women who are thought to be gene carriers may be offered breast screening (and ovarian screening in the case of BRCA1, which is known to impart a 50% lifetime risk of ovarian cancer), usually as part of a research programme, or genetic counselling & mutation analysis.> Those who prove to be gene positive' have a 50-80% risk of developing breast cancer, predominantly while pre-menopausal.> Many will opt for prophylactic mastectomy. Although this does not completely eliminate the risk, it does reduce it considerably