Hereditary predisposition to breast (BC) and ovarian cancer (OC) frequently occurs in at-risk families, involving genes such as BRCA1, BRCA2 and other genes. Inclusion criteria for hereditary BC/OC screening are based on family aggregation of BC, to inform screening for the presence of germline (mainly) BRCA1/BRCA2 mutations and candidature for precision therapy. However, incidence rates of hereditary BC in NZ are unknown. We hypothesize that >5% of hereditary BC/OC families remain undiagnosed. In this project, we will use the BC Register to select 300 patients for analysis of hereditary BC genes, which will allow accurate determination of the incidence of hereditary BC/OC in NZ. Maori women, despite having high BC/OC incidence rates, are frequently under-represented, and often fare poorly in outcomes compared to non-Maori. These observations contribute to inequities that Maori women experience for screening and treatment. This project will ultimately contribute to better outcomes for BC/OC patients in NZ.