Genetic diagnosis. Implications for medical practice.

Genetic diagnostic techniques increasingly permit the detection of predisposition to illness long before the onset of the disease process itself. Medicine is on the verge of becoming a predictive science as well as a diagnostic and therapeutic one. Genetic diagnosis could have profound effects on many aspects of our health care system, including the prestige and effectiveness of preventive medicine, the competitive behavior of health care organizations and insurance companies, access to private health insurance, the ability of primary care physicians to serve as gatekeepers, and other matters. This article examines the range of potential effects of the new genetic diagnostics on the organization and financing of health care. For purposes of illustration the authors examine in detail the possible consequences of genetic tests for predisposition to two diseases: Reye's Syndrome and lung cancer in smokers.