peer reviewedA personal or family history of cancer has now become the primary cause of genetic consultations. In recent years, various genes have been identified that are associated with a more or less marked genetic predisposition to the development of cancers. The syndrome associated with the hereditary risk of breast and ovarian cancer and the Lynch syndrome are the most frequent ones, but there are many other, much less common, situations associated with familial cancer risk. In most cases, there are clear recommendations regarding the indications for genetic testing and the follow-up of patients identified as having a predisposition to cancer. At the CHU of Liège, we currently perform more than 1.400 oncogenetic consultations per year...