The question not asked: the challenge of pleiotropic genetic tests

Kennedy Inst Ethics J. 1998 Jun;8(2):131-44. doi: 10.1353/ken.1998.0013.


Nearly all of the literature on the ethical, legal, or social issues surrounding genetic tests has proceeded on the assumption that any particular test for a gene mutation yields information about only one disease condition. Even though the phenomenon of pleiotropy, where a single gene has multiple, apparently unrelated phenotypic effects, is widely recognized in genetics, it has not had much significance for genetic testing until recently. In this article, I examine a moral dilemma created by one sort of pleiotropic testing, APOE genotyping, which can yield information about the risk of two different conditions -- coronary heart disease and Alzheimer's disease. A physician administering APOE testing for the beneficial purpose of assessing the risk of heart disease may discover medically useless and socially harmful information about the patient's risk of Alzheimer's disease. I explore how much providers should disclose to patients about pleiotropic test results and whether patients are obligated to know as much about their genetic condition as possible.

MeSH terms

  • Dementia*
  • Disclosure*
  • Double Effect Principle
  • Ethics
  • Genetic Counseling
  • Genetic Diseases, Inborn*
  • Genetic Predisposition to Disease
  • Genetic Privacy*
  • Genetic Testing*
  • Heart Diseases*
  • Humans
  • Incidental Findings*
  • Informed Consent
  • Intention
  • Moral Obligations
  • Motivation
  • Patients
  • Pedigree*
  • Physicians
  • Policy Making
  • Prejudice
  • Risk
  • Risk Assessment
  • Social Responsibility
  • Stress, Psychological
  • Time Factors
  • Truth Disclosure*