BRCA1 and breast cancer: It is estimated that >250 000 women in the UK are at moderate or high-risk of breast cancer and are eligible for risk-reducing interventions (for example, risk-reducing medication, enhanced screening, or surgery).1,2 Until recently, identifying those at increased risk of developing breast cancer in the absence of a relative with a known pathogenic variant in a breast cancer predisposition gene (for example, BRCA1) relied largely on women opportunistically contacting their GP.