Mutations on the genes BRCA1 and BRCA2, that predispose women to breast and ovarian cancer were localised in 1990 (Hall et al. 1990, Narod et al. 1991). With the improvement of the test procedures questions concerning the pros and cons of genetic diagnostic are growing in importance, especially because there are only few scientific studies on the social and psychological consequences of this development. In this article the demands to be made on genetic counselling, the present practice of tests employed in Germany and some "typical" problems of the decision and the consequences of the tests are described.
