How do alterations in BRCA1 and BRCA2 affect a Jewish womans risk of breast cancer?
A womans lifetime risk of developing breast cancer is greatly increased if she inherits an altered BRCA1 or BRCA2 gene. Recent studies suggest that the risk may be as high as 50 to 80% for those carrying mutations. It is important to note that not all carriers of a BRCA1 or BRCA2 mutation will develop breast cancer. Among individuals of Ashkenazi Jewish descent, researchers have found that about 1 in 40 carry an altered BRCA1 or BRCA2 gene, compared to 1 in 345 in the general population. Among people with alterations in the BRCA1 or BRCA2 gene, three particular alterations have been found to be most common in the Ashkenazi Jewish populationtwo in the BRCA1 gene and one in the BRCA2 gene. While breast cancer rates do not appear to be higher in Jewish women as compared to the general population, the proportion of breast cancer that is hereditary is higher in Jewish women of Ashkenazi descent.