Coronary artery disease appears to be a consequence of the interaction between an individual's genotype and exposure to environmental factors. Genetic information has the potential to contribute to the identification of families and individuals with a biological predisposition for developing coronary artery disease. Although numerous studies have suggested the possibility of a link between polymorphic genetic variation and coronary heart disease, it has not been possible to use any single genetic locus or combination of loci to establish a person's risk except for the case of familial hypercholesterolemia.