the change in the expression of a gene accompanying a change in the position of the gene with respect to neighboring genes; the change in position may result from crossing over or from a chromosomal aberration
Used to describe a situation in which the phenotypic influence of a gene is altered by changes in the position of the gene within the genome.
Position effect is the effect on the expression of a gene when its location in a chromosome is changed, often by translocation. This has been well described in Drosophila with respect to eye color and is known as position effect variagation (PEV).