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the production by a single gene of multiple phenotypic effects. The term is often used to refer to a single gene defect that is expressed as problems in multiple systems of the body, such as in osteogenesis imperfecta, where the gene causes defects in several different systems that contain collagen.
pleiotropism/plei·ot·ro·pism/ (pli-ot´rah-pizm) pleiotropy.
pleiotropisma state in which one gene affects two or more aspects of the PHENOTYPE that are apparently unrelated. For example, the ‘vestigial wing’ mutation of Drosophila not only controls the size and shape of the wings but also affects several other features, including reduced FECUNDITY.
the production by a single gene of multiple phenotypic effects.