Common BRCA1 and BRCA2 mutations in breast cancer families: a meta-analysis from systematic review.

A number of molecular epidemiological studies have been conducted the screening for BRCA1 and BRCA2 mutations in breast cancer patients with a positive family history of breast and/or ovarian cancer and reported many common mutations in BRCA1 and BRCA2 associated in breast cancer in different population and different ethnicity. However, it's still lack of a systematic analysis on these mutations. To comprehensively evaluate the frequency and distribution of common BRCA1 and BRCA2 mutations which associated with breast cancer risk, we address this issue through system review and meta-analysis on 29 relevant published studies by conducting a literature search on PubMed and CNKI. 20 common founder germline mutations were identified from all 29 studies and 4 of BRCA1 (5382insC, 185delAG, 3819del5 and 4153delA) and 2 of BRCA2 (4075delGT, 5802del4) mutations were repeatedly reported twice or more in different articles, respectively. For the BRCA1, after conducting meta-analysis, we found that the overall frequency of 5382insC was 0.09 (95% CI 0.06-0.12), the frequency of 185delAG was 0.07 (95% CI 0.01-0.13), the frequency of 3819del5 was 0.02 (95% CI 0.01-0.04) and the frequency of 4153delA was 0.06 (95% CI 0.03-0.09). For the BRCA2, the overall frequency of 4075delGT was 0.02 (95% CI 0.00-0.03) and the frequency of 5802del4 was 0.07 (95% CI 0.04-0.11). This article provides a set of common mutations for BRCA1 and BRCA2 mutation carriers and the results may help to explore frequencies of BRCA1 and BRCA2 mutations in a given population and will be of significance both for diagnostic testing and for epidemiological studies.