Apolipoprotein E polymorphism and coronary heart disease.

Apolipoprotein E is a constituent of various lipoproteins and plays an important role in the transport of cholesterol and other lipids among cells of various tissues. The gene is polymorphic with three alleles (epsilon2, epsilon3, and epsilon4) coding for isoforms E2, E3, and E4 and having different binding affinities for the apo E receptors. While the epsilon2 allele is associated with elevated triglyceride levels, epsilon4 allele is associated with increased cholesterol levels. Though several studies support the role of apo E polymorphism in CHD either directly or indirectly via its influence on lipid and lipoprotein levels, there are some studies, which show no association. With the increasing incidence of CHD among Indians, it becomes imperative to identify genetic markers that may predispose individuals to coronary events. It would be of importance to determine if apo E gene will become a usefuladjunct to assess cardiovascular risk profile when performing genetic studies in families.