BRCA2 and complete blood cell count: In other study, Yoon et al. showed that non-carriers with high risk of hereditary breast cancer patients have also been found to have a higher risk of CBC, the 10-year cumulative risk for CBC was 9.8% for non-carriers, 23.8% for BRCA1 mutation carriers, and 19.1% for BRCA2. There was no statistically significant difference in CBC risk between BRCA mutation carriers and non-carriers [19].