At this moment, risk management for non-BRCA1/2 breast cancer families is mainly based on family history, calculated by risk prediction algorithms such as BOADICEA. Here, we use a Polygenic Risk Score based on 161 breast cancer associated SNPs, to show the potential clinical utility of this PRS within non-BRCA1/2 high risk breast cancer families including both breast cancer cases and their healthy female relatives. We found that the PRS was significantly associated with breast cancer within these families. In addition, the PRS may change breast screening recommendations in up to 20% of the women from these families, depending on screening guideline thresholds. (By Ms. Inge Lakeman, https://jmg.bmj.com/content/early/2019/06/11/jmedgenet-2019-106072 )