BRCA1 and breast carcinoma: Overall, in this typically Asian cohort where 80% (149 of 187) of the breast cancer patients had no or only a single first- or second-degree relative with breast cancer or ovarian cancer, 15% of women carried deleterious mutations in BRCA1 or BRCA2. This suggests that a family history as reported by an individual who carries a mutation in BRCA1 or BRCA2 may be neither dramatic nor obvious.