Mutation screening of the RNF8, UBC13 and MMS2 genes in Northern Finnish breast cancer families

BACKGROUND: Currently known susceptibility genes such as BRCA1 and BRCA2 explain less than 25% of familial aggregation of breast cancer, which suggests the involvement of additional susceptibility genes. RNF8, UBC13 and MMS2 are involved in the DNA damage response pathway and play important roles in BRCA1-mediated DNA damage recognition. Based on the evidence that several players in the ubiquitin-mediated BRCA1-dependent DDR seem to contribute to breast cancer predisposition, RNF8, UBC13 and MMS2 were considered plausible candidate genes for susceptibility to breast cancer. METHODS: The entire coding region and splice junctions of RNF8, UBC13 and MMS2 genes were screened for mutations in affected index cases from 123 Northern Finnish breast cancer families by using conformation sensitive gel electrophoresis, high resolution melting (HRM) analysis and direct sequencing. RESULTS: Mutation analysis revealed several changes in RNF8 and UBC13, whereas no aberrations were observed in MMS2. None of the found sequence changes appeared to associate with breast cancer susceptibility. CONCLUSIONS: The present data suggest that mutations in RNF8, UBC13 and MMS2 genes unlikely make any sizeable contribution to breast cancer predisposition in Northern Finland.