Genetic medicine, which consists mostly of screening tests for certain heritable diseases but may soon include treatment for heritable diseases based on molecular genetics, is made possible by two critical junctures in the textual representation of medical subjects. The first is the transformation of organic human genetic material into computationally sophisticated data, and the second is the subsequent conversion of these vast quantities of genetic data into intellectual property through gene patenting and screening-test marketing. This article examines these representational changes in medical subjects through an intertextual and rhetorical analysis of the documentation surrounding the discovery, patenting, and marketing of the breast cancer susceptibility gene BRCA1 by the biotechnology company Myriad Genetics. It identifies the impact of these changes on the analysis of the risks and benefits associated with screening for heritable diseases.