Starting from our experience with breast cancer patients, we will tackle the problem of the consequences due to the notion of genetic predisposition of certain pathologies with a legal prognosis. During clinical interviews with women having undergone a mammectomy, genetic risk is discussed. How do they deal with this medical fact? Does the mother who has borne life see herself with cancer as the carrier of death? Is the diagnosis of this disease an obstacle to building up mother-daughter relationships? How can psychotherapy enable us to rethink a fairy of darkness as a good-enough mother? All these questions are expanded on in this article based on a case report.