mosaicism /mōzā″isiz′əm/ [L, Musa, goddess of the arts] , (in genetics) a condition in which an individual or an organism that develops from a single zygote has two or more cell populations that differ in genetic constitution. Most commonly seen in humans is a variation in the number of chromosomes in the cells, which may involve either a particular autosome, such as in Down syndrome, or the sex chromosomes, such as in Turner’s syndrome and Klinefelter’s syndrome. See also mosaic, sex chromosome mosaic.
