Germline BRCA1&2 mutations do not explain a large proportion of the families with hereditary breast cancer. This bilateral research project aims to gain insight in the role of ATM, BRIP1, CHEK2 and PALB2 mutations in Flemish and Québec breast cancer families using the next generation sequencing (NGS) technology. The expertise of both research groups in complementary: the Flemish group will be strongly involved in the development of an effecient genotyping platforms using NGS. A multimodal approach for functional analyses of the variant identified will be developed by the Québec research group.