Evaluation of the BRCA1 interacting genes RAP80 and CCDC98 in familial breast cancer susceptibility.

RAP80 and CCDC98 have arisen as new candidate breast cancer susceptibility genes, since they encode for two very recently identified BRCA1 interacting proteins. In this study we have performed the first mutational analysis of both genes in 168 multiple-case breast/ovarian cancer families, negative for mutations in BRCA1 or BRCA2. We have not found truncating mutations in any of the genes and only two missense variants, p.Tyr564His in RAP80, and p.Met299Ile in CCDC98 were found that could be suspected to have a pathogenic effect, although further analyses suggested that they were probably non deleterious. Our analysis suggests that RAP80 and CCDC98 do not play an important role as high penetrance breast cancer susceptibility genes.