Mapping of non-BRCA1/2 breast cancer genes

While the BRCA1 and BRCA2 genes are believed to account for a large proportion of families with a high incidence of site-specific early onset breast cancer, data from the Breast Cancer Linkage Consortium show that these genes may account for only 40% of families with four or five site-specific cases. This finding motivated our search for additional high-risk breast cancer genes. Families have been contributed by different institutions in the United States and Europe. The power of the combined data set for detecting linkage has been estimated. The recent tentative finding of a linkage between markers on chromosome 8p and breast cancer prompted the IARC to carry out genotypes within that region, on a set of 17 families in which the results of mutation screening and rod score calculation for BRCA1 and BRCA2 were negative. Other candidate regions on chromosomes 2, 6, 10, 16, and 11 were also investigated.