Genetic Testing: Ethical Issues

Susceptibility testing is another area that raises possible ethical issues for patients and clinicians. Recall that susceptibility implies that the genetic test does not provide the final answer regarding disease, but rather that additional factors are involved. For example, cardiovascular disease is a major source of morbidity and mortality. Polymorphic variants in the apolipoprotein E gene (APOE) have been found to be associated with variations in blood levels of lipids, lipoproteins, and apolipoproteins, which may in turn influence risk for heart disease. Clinicians and patients may wish to learn which APOE variants they have, to help determine their susceptibility to cardiovascular disease and the likelihood that altering their lifestyle risk factors or using pharmaceutical therapy might help prevent cardiovascular disease.

When deciding to test for APOE gene variants, however, there are additional consequences that must be considered, particularly the fact that the gene may play multiple roles in health and disease (pleiotropy). Studies have shown that one version of APOE, the e4 allele, is associated with an increased risk of Alzheimer's disease. When deciding to undertake genetic testing for the intended immediate medical benefit of understanding cardiovascular disease risk, the individual should therefore also consider the possibility of learning potentially unwanted additional information.