Breast cancer is the most common cancer and one of the leading causes of the cancer-related death in women. About 10-20% cases of breast cancer are caused by the hereditary germline mutations in functionally important genes, among which BRCA1 and BRCA2 are the most significant ones. BRCA1 and BRCA2 play important roles in maintaining genome stability. Mutations in these two genes disrupt their function, cause genetic instability, and increase the risk of developing breast cancer and several other types of cancer. Studies have identified large number of mutations in BRCA1 and BRCA2, several BRCA mutation reference databases have been developed and used globally for clinical diagnosis, treatment, and prevention of BRCA mutation caused cancer.
Recent studies indicate that mutations in BRCA1 and BRCA2 can be ethnic-specific among diverse human populations. The current BRCA mutation data are derived largely from Caucasians of European and North American population. As a limited non-Caucasian ethnic-specific mutations are included in these databases, relying upon these data as the only reference is not sufficient to reach comprehensive identification of the BRCA mutation carriers with non-Caucasian genetic background. Thus, an imperative need is to develop ethnic-specific BRCA mutation databases for non-Caucasian populations.
With its size over four billion across over 50 different countries and regions in drastic different natural environment, Asian population is the most populous and diversified in the world. We performed a comprehensive data mining to collect BRCA variation data in three Asian populations of 18,604 Indian, 19,263 Korean, and 37,432 Japanese cancer and non-cancer individuals. Using bioinformatics approach, we standardized and annotated the data, and performed a systematic comparison between the datasets, including variant composition, variation spectrum, variant types, clinical classes, founder mutation and high-frequent variant distribution. The database is the largest, open-access Asian BRCA database covering nearly all BRCA variation information reported in those three Asian populations. The data revealed the highly ethnic-specific nature of BRCA variation within the Asia population.