By: Jonathan M. Kocarnik, PhD, MPH; Stephanie M. Fullerton, DPhil
JAMA. Published online January 30, 2014. doi:10.1001/jama.2014.369
Multiple recent guidelines and recommendations, in both the clinical and research realms, call for reporting of genetic information (including incidental information) that is clinically useful to patients and research participants and suggest it is appropriate to withhold information that is inaccurate, not actionable, or could potentially lead to harm. Although based on sound ethical principles, including beneficence and respect for persons, these guidelines have largely ignored an important biological phenomenon long-recognized in genetics: pleiotropy, the concept of a single gene or genetic variant affecting multiple phenotypes. Variants in some genes have related pleiotropic effects (eg, BRCA1 and BRCA2 mutations increasing susceptibility for multiple cancer types), and variants in other genes affect multiple phenotypes that are less similar (eg, mutations in PAH leading to phenylketonuria, eczema, light pigmentation, and mental retardation). Insofar as current recommendations do not account for pleiotropy, such guidelines are incomplete—and in some cases, contradictory. This could pose important practical problems for clinicians and investigators who may be trying to decide which, if any, genetic results to return to patients or to study participants.