BRCA1 and breast cancer: Of the 20 mutation-positive probands, 11 had breast cancer alone (5 BRCA1 and 6 BRCA2), three had ovarian cancer alone (3 BRCA1), three had bilateral breast cancer (2 BRCA1 and 1 BRCA2), two had both breast and ovarian cancer (1 BRCA1 and 1 BRCA2) and one had both bilateral breast and ovarian cancer (BRCA1).