<P> Pleiotropy (from Greek πλείων pleion, "more", and τρόπος tropos, "way") occurs when one gene influences two or more seemingly unrelated phenotypic traits . Therefore, a mutation in a pleiotropic gene may have an effect on several traits simultaneously due to the gene coding for a product used by a myriad of cells or different targets that have the same signaling function . </P> <P> Pleiotropy can arise from several distinct but potentially overlapping mechanisms, such as molecular gene pleiotropy, developmental pleiotropy, and selectional pleiotropy . Molecular gene pleiotropy occurs when the gene product interacts with multiple other proteins or catalyzes multiple reactions . Developmental pleiotropy occurs when mutations have multiple effects on the resulting phenotype . Selectional pleiotropy occurs when the resulting phenotype has multiple effects on fitness (perhaps depending on age, gender, etc .). </P>

When one or single gene control more than one character