BRCA1 and breast cancer: This incidence was much lower than that reported in Chinese HBOC, in which 5.74 % of breast cancer and 21.79 % of ovarian cancer patients had BRCA1/2 germline mutations, with an overall pathogenic mutation frequency of 69.9 % and 71.1 % for BRCA1 and BRCA2 exons, respectively [11].