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BRCA1 and BRCA2 genes: Role in hereditary breast and ovarian cancer in Italy
Author(s) -
Santarosa Manuela,
Dolcetti Riccardo,
Magri Maria Donatella,
Crivellari Diana,
Tibiletti Maria Grazia,
Gallo Angelo,
Tumolo Salvatore,
Della Puppa Lara,
Furlan Daniela,
Boiocchi Mauro,
Viel Alessandra
Publication year - 1999
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19990924)83:1<5::aid-ijc2>3.0.co;2-u
Subject(s) - brca2 protein , ovarian cancer , frameshift mutation , breast cancer , biology , genetics , mutation , cancer research , gene , population , missense mutation , cancer , germline mutation , medicine , environmental health
The heritable defects of BRCA1 and BRCA2 genes have been shown to predispose to breast and ovarian cancers. In a previous report, we analyzed 46 Italian families with breast and/or ovarian cancer for BRCA1 mutations. In the present study, those families and 11 others were screened for BRCA2 mutations; the newly enrolled families were also analyzed for the BRCA1 gene. The coding region and splice boundaries of BRCA2 and BRCA1 genes were assessed by the protein‐truncation test and single‐strand conformational polymorphism. A total of 20 different mutations were found in 21 families (37%). A total of 9 families (16%) showed mutations in the BRCA1 gene, including the one new mutation identified in this study (5382insC), and 12 families (21%) presented mutations in the BRCA2 gene. BRCA2 ‐mutated families presented breast and ovarian cancers or breast cancers only, whereas most BRCA1 ‐mutated families presented ovarian cancer alone or in association with breast cancer. All the BRCA2 mutations led to a truncated protein: 6 were frameshift mutations, 4 were non‐sense mutations and 2 involved the intronic invariant region leading to splice variants. Therefore, in the Italian population, the cumulative proportion of BRCA1 and BRCA2 mutations was within the range observed in other studies (37%), with higher involvement of BRCA2 than of BRCA1. Many families in which no mutations were found presented a very high incidence of breast and/or ovarian cancer. Among the 36 BRCA1 and BRCA2 wild‐type families, 24 presented at least 4 cancer cases, indicating the existence of other important predisposing genes. Int. J. Cancer 83:5–9, 1999. © 1999 Wiley‐Liss, Inc.