Women carrying a fault in BRCA1/BRCA2 genes are at increased risk of breast and ovarian cancer. Identification of BRCA-carriers through genetic testing offers opportunities of early diagnosis, targeted treatment and cancer prevention. Our study evaluated the current rate at which BRCA-carriers have been detected and the time it would take to detect all identifiable BRCA-carriers in the general and Ashkenazi Jewish (AJ) populations of London. We estimate that 97% general and 89% Jewish BRCA-carriers have not been identified. If we continue testing at the current rate, we will never identify all detectable carriers in the general population, although those detectable in the AJ population (50% BRCA-carriers do not fulfil testing criteria) will be detected by 2044.. Hence both alternative strategies and enhancement of ongoing approaches are required. (By Dr. Ranjit Manchanda, http://jmg.bmj.com/content/early/2018/04/05/jmedgenet-2017-105195)