In the past several decades there has been an explosion in our understanding of genetics. The new genetics is an integral part of contemporary biomedicine and promises great advances in alleviating disease, prolonging human life and leading us unto the medicine of the future. The aim of this paper is to explore the ways in which people make sense of the uncertainties that are associated with the new genetics, which by definition involve family and kinship relations. We explore the degree to which medical genetics places the patient in a double bind between the qualitative certainty and quantitative uncertainty of genetic inheritance that reinforce notions both of fear, and control of a person's future health. Second, we propose that the new genetics has medicalized family and kinship creating profound ethical and practical dilemmas for both the individual and for medicine as a whole.