Are specific mutations in BRCA1 and BRCA2 more common in certain populations?
Yes. For example, three specific mutations, two in the BRCA1 gene and one in the BRCA2 gene, are the most common mutations found in these genes in the Ashkenazi Jewish population. In one study, 2.3 percent of participants (120 out of 5,318) carried one of these three mutations (9). This frequency is about five times higher than that found in the general population (10). It is not known whether the increased frequency of these mutations is responsible for the increased risk of breast cancer in Jewish populations compared with non-Jewish populations. Other ethnic and geographic populations around the world, such as the Norwegian, Dutch, and Icelandic peoples, also have higher frequencies of specific BRCA1 and BRCA2 mutations. In addition, limited data indicate that the frequencies of specific BRCA1 and BRCA2 mutations may vary among individual racial and ethnic groups in the United States, including African Americans, Hispanics, Asian Americans, and non-Hispanic whites (11–13). This info