Table 3 Frequencies of BRCA1 and BRCA2 mutations in relation to the classification of patients and families
Classification | Number of patients/families | No. of mutations in BRCA1 (%) | No. of mutations in BRCA2 (%) | No. of BRCA1 + BRCA2 mutations (%) |
|---|---|---|---|---|
Cases without a family history of breast and ovarian cancer | Â | Â | Â | Â |
   Breast cancer before 36 | 31 | 3 (9.7) | 1 (3.2) | 4 (12.9) |
   Bilateral breast cancer before 51 | 3 | 1 (33.3) | - | 1 (33.3) |
   Breast and ovarian cancer | 7 | 1 (14.3) | - | 1 (14.3) |
   Medullary breast carcinoma | 14 | 3 (21.4) | - | 3 (21.4) |
Breast cancer families (HBC) | Â | Â | Â | Â |
   2 breast cancer cases | 25 | 5 (20.0) | 2 (8.0) | 7 (28.0) |
   ≥3 breast cancer cases | 35 | 6 (17.1) | 1 (2.9) | 7 (20.0) |
   Total | 60 | 11 (18.3) | 3 (5.0) | 14 (23.3) |
Breast and ovarian cancer families (HBOC) | Â | Â | Â | Â |
   1 breast cancer and 1 ovarian cancer | 5 | 1 (20.0) | 2 (40.0) | 3 (60.0) |
   ≥3 breast and ovarian cancer cases | 27 | 14 (51.9) | 2 (7.4) | 16 (59.3) |
   Total | 32 | 15 (46.9) | 4 (12.5) | 19 (59.4) |
Ovarian cancer families (HOC) | Â | Â | Â | Â |
   ≥2 ovarian cancer cases | 4 | 1 (25.0) | 1 (25.0) | 2 (50.0) |