In the context of high-risk families the most important genes are BRCA1 on chromosome 17q, which is associated with a high penetrance of both breast and ovarian cancer, and BRCA2 on chromosome 13q, which causes a high risk of breast cancer but a lower risk of ovarian cancer.
Chromosome 13 contains at least two cancer genes, the well-characterized RB1 gene located at 13q14 and the breast cancer-susceptibility gene, BRCA2, recently localized to 13q12.
However, recently another candidate tumour-suppressor gene has been identified on chromosome 13 by linkage analysis, the breast cancer susceptibility gene BRCA2.
These results suggest that BRCA2 is a tumor suppressor gene and may be involved in the tumorigenesis of several cancer types in addition to breast cancer.
The recently discovered BRCA2 gene on chromosome 13q is thought to account for some families with increased risk of breast cancer, including male breast cancer.
The recent cloning of a breast-ovarian cancer susceptibility gene (BRCA1), and determination of the locus of a related gene (BRCA2), offers potential for clinical genetic testing for breast cancer susceptibility.
The development and refinement of risk prediction models provide an epidemiologic basis for counseling women with a family history that does not appear related to a dominant susceptibility gene. contrast, the recent isolation of BRCA1, the localization of BRCA2, and the acknowledgement that additional breast cancer susceptibility genes must exist provide a molecular basis for counseling some high-risk women.
The breast cancer susceptibility gene BRCA1 has been cloned and a second susceptibility gene, BRCA2, chromosomally mapped; will most breast and ovarian cancer turn out to be familial?
Preliminary evidence suggests that BRCA2 confers a high risk of breast cancer but, unlike BRCA1, does not confer a substantially elevated risk of ovarian cancer.
Here we report the identification of a gene in which we have detected six different germline mutations in breast cancer families that are likely to be due to BRCA2.
Recently, linkage analyses of large families with a predisposition to breast cancer have been performed in order to map breast cancer susceptibility genes (TP53, BRCA1, BRCA2).
On the basis of linkage to chromosomes 17q or 13q and/or the presence of ovarian and male breast cancer, HBC families were classified as either "BRCA1-related" (26 families, 90 breast cancer pathology cases) or "Other" (26 families, 85 cases), in which most BRCA2 cases were likely to reside.