variegated position effect

variegated position effect

[′ver·ē·ə‚gād·əd pə¦zish·ən i‚fekt]
(genetics)
A phenomenon observed in some cases when a chromosome aberration causes a wild-type gene from euchromatin to be relocated adjacent to heterochromatin; the phenotypic expression of the wild-type allele will be unstable, producing patches of phenotypically mutant tissue that differ from the surrounding wild-type tissue.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.