pleiotropy /plī·ot″rəpē/ [Gk, pleion, more, trepein, to turn] , the production by a single gene of a complex of unrelated phenotypic effects. The effects may be a manifestation of a particular disorder, such as the cluster of symptoms in Marfan’s syndrome: aortic aneurysm, dislocation of the optic lens, skeletal deformities, and arachnodactyly, any or all of which may be present.
