This thesis describes the search for new high-risk breast cancer susceptibility genes by linkage analysis. To date 20-25% of familial breast cancer is explained by mutations in the high-risk BRCA1 and BRCA2 breast cancer susceptibility genes. For the remaining families the genetic etiology is unknown. It is still possible that other high-penetrant genes play a role. Although a polygenic model with multiple low-penetrant genes acting additive or multiplicative will probable explain most of the BRCA1/2 negative families. Linkage in an international set of 150 high-risk breast cancer families couldn__t identify high-risk genes. However when limiting the linkage analysis to Dutch families only, we identified 9q21-22 as a putative breast cancer susceptibility locusThe Dutch Cancer SocietyUBL - phd migration 201
