TUMOSPEC is a national family study designed to measure the relative and absolute risk of cancer for carriers of deleterious mutations to these "new" breast cancer (BC) susceptibility genes. Index cases will be enrolled consecutively from patients attending an appointment at one of the Unicancer centres, with no other inclusion criteria, and offered a BRCA1/2 analysis as part of their care plan. A panel of 24 TUMOSPEC genes, chosen in advance by a steering committee, will be tested as the same time as the BRCA1/2 genes, at one of the usual BRCA1/2 analysis laboratories belonging to the same network and participating in the study. If a mutation is found, the index cases will be asked to invite their first and second degree family members and their cousins to take part in the study, regardless of whether they have cancer. Saliva samples will be then taken and used for a targeted analysis of the familial abnormality. Each participant will also complete an epidemiological questionnaire in order to gather information about his/her medical history and any exposure to various risk factors. All medical and genotype data will be centralised at the Genetic Epidemiology Research Platform (PIGE, INSERM). The cumulative mutation frequency for all genes is estimated at 10%. Penetrance will be analysed using methods designed to minimise selection bias. The expression spectrum of the mutations will also be described. For genes where the number of mutated families is too low, the data may be contributed to international consortia. The main project will be preceded by a two-year feasibility study, using the same inclusion criteria and logistic circuits. It is this pilot study to which the current funding application relates.