[Coronary heart disease: epidemiologic-genetic aspects].

Coronary heart disease and the risk factors which predispose to it aggregate in families. How much of this clustering of disease is "explained" by the familial resemblance in predisposing factors? The published reports which bear on this question fall into six distinct study designs: prospective studies, persons at high or low risk or persons with and without a positive family history as points of departure, case-control studies, studies of patients who had a coronary angiogram and studies in different ethnic groups. The findings of the 16 investigations reviewed suggest that there are as yet unidentified factors - genetic, environmental or both - which are responsible for familial clustering of coronary heart disease, apart from the three main risk factors (serum lipids, blood pressure, smoking) and diabetes. Future research must put greater emphasis on studies of families rather than individuals and on closer collaboration between epidemiologists and geneticists, in order to fill these gaps in knowledge. It is likely that the individual predisposition to coronary heart disease is due in part to genetic influences which remain to be discovered in the course of such studies. They would help in identifying susceptible person in the population with greater precision than is now possible. The "high-risk strategy" of coronary heart disease prevention will become more efficient as more specific and sensitive tests of disease prediction are developed. In the meantime, preventive programmes must be put into action on the basis of what is already known, on the level of both the high-risk and the community-wide mass strategy.