| Advances in sequencing the human genome and ongoing efforts to define the genetic components of disease and drug response have resulted in the increasing use of genetic and genomic testing. Our understanding of how genes impact health has become more sophisticated, as we recognize that changes in a single gene can impact multiple disease and drug metabolism phenotypes, a phenomenon known as pleiotropy. This means for patients undergoing single gene testing, multiplex testing of many genes, or whole genome sequencing, any result related to a pleiotropic gene will provide so-called ancillary information and, therefore, have informational side effects. There are many ethical, clinical, and policy implications of pleiotropy for genetic and genomic testing, including its impact on obtaining informed consent and on patient decision-making.;The goal of this study is to identify factors that influence patient decision-making and perspectives regarding the clinical use of pleiotropic genetic tests. Specifically, this study utilized quantitative survey methodology to assess patient decisions to undergo hypothetical genetic tests that represented both clinical risk assessment and pharmacogenetic testing scenarios. This study examines the roles that ancillary information and patient attitudes and beliefs have in the testing decision. In addition, qualitative interviews were conducted with a sub-sample of patients who completed the survey to explore the decision-making process and to investigate patient perceptions about the many practical and ethical challenges involved in pleiotropic genetic testing.;Results from this study suggest that interest in genetic susceptibility testing and pharmacogenetic testing is not negatively impacted by the possibility of learning of ancillary information, and that interest in testing is associated with patients' perceptions about both the intended and ancillary uses of the test. Results from the qualitative interviews indicate that patients' beliefs about the actionability of genetic information are important in their considerations of whether or not to undergo pharmacogenetic testing in the context of pleiotropy. Additionally, results from the qualitative interviews suggest that patients have a strong desire for clinicians to disclose ancillary disease associations as part of the informed consent process. Findings from this study have implications for the integration of pleiotropic genetic testing into clinical use. |
