Percent of female BRCA1/2 founder mutation carriers identified among 3 types of family history:
(1) high-risk famlies with extensive cancer family-history by National Comprehensive Cancer Network (NCCN) criteria (45% of families).
(2) families with some cancer are deemed as “NCCN Ashkenazi-Jewish Family” when NCCN are met when Ashkenazi-Jewish ancestry is also taken into account (24% of families).
(3) families with no cancer, deemed ‘low-risk’ if cancer information is known for all 1st and 2nd degree relatives, otherwise deemed ‘ambiguous’ if cancer information is missing or a relative died at an early age (31% of families).
Example carrier-probability thresholds of 0.56% and 0.78% are indicated vertically.