Genetics of ischaemic heart disease.

Coronary heart disease, especially when it affects younger individuals, tends to cluster in families. Known risk factors occur in 50-75% of patients with myocardial infarction. Yet commonly occurring risk factors are not strongly inherited, and the familial aggregation of coronary heart diseas may not be attributable to familial resemblance in serum cholesterol and blood pressure levels. Alternatively, such aggregation may be due to unknown familial risk factors. Nevertheless, screening of relatives of individuals with evident risk factors is of importance, and environmental manipulation is likely to be of value in prevention of coronary heart disease.