- Multiple, often seemingly unrelated, physical effects caused by a single altered gene or pair of altered genes
Definition from: GeneReviews
from the University of Washington and the National Center for Biotechnology Information
- The phenomenon of variable phenotypes for a number of distinct and seemingly unrelated phenotypic effects.
Definition from: Office of Rare Diseases
at the National Institutes of Health
- Producing more than one effect; especially : having multiple phenotypic expressions <a pleiotropic gene>.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
See also Understanding Medical Terminology.