[Genes of hereditary diseases that predispose to tumors].

Ten genes responsible for the increase of specific tumor incidence in affected families have been localized on the human genetic map. This knowledge not only provides the mean of a precise genetic counselling but also opens a way for further investigating the genetic mechanisms of these disorders. Usually, it is admitted that dominantly inherited familial predisposition to tumors is due to a defective tumor suppressor gene. This hypothesis is almost certain for familial retinoblastoma, highly probable for hereditary nephroblastoma and possible for neurofibromatosis type II. In contrast, the gene for familial polyposis coli shows some characteristics of activated oncogenes.