MEASUREMENT OF CIRCULATING MUTATION BURDEN

Cancer-free women with a hereditary predisposition to breast and/or ovarian cancer

Inclusion Criteria: * Female participant * Participant undergoing oncogenetic follow-up at the Centre François Baclesse * Participant belonging to a pair of related biological siblings * Within the sibling pair, one participant is a carrier of a hereditary predisposition linked to a BRCA1/2 mutation (case), and the other participant is not a carrier (control). * Participant between 30 and 50 years of age * Participant affiliated to a social security scheme * Participant having given her consent to participate by signing an informed consent form prior to any specific study-related procedure. Exclusion Criteria: * Male gender * Current cancer or a history of cancer * Current smoker or someone who quit smoking less than 10 years ago with a cumulative exposure of \> 10 packs/year) * Presence of another hereditary predisposition to cancer * History of risk-reduction surgery (adnexectomy, fimbriectomy, mastectomy) * Chronic immunomodulatory treatment * Patients who are incarcerated, under legal guardianship, subject to a legal protective measure, or unable to give informed consent * Patients unable to participate in the study for geographic, social, or psychopathological reasons