The prevalence of germline DNA damage repair gene (gDDR) mutations in men with metastatic prostate cancer is now understood to be around 10% or greater with important implications for patients and their families. BRCA2 is the most frequently altered gene and prospective data has demonstrated a cumulative risk of prostate cancer for BRCA2 carriers of 60%, higher in the presence of a family history. For men with prostate cancer, a BRCA2 pathogenic variant is an independent prognostic factor for poorer outcomes. Identifying gDDR mutations has important treatment implications. However, guidelines for genetic testing are difficult to establish. The importance, barriers and limitations of identifying gDDR mutations with regard to prostate cancer risk, prognosis, treatment and the broader family context will be discussed.