Definition of copy number variant

copy number variant (KAH-pee NUM-ber VAYR-ee-unt): A variation in the number of copies of a particular sequence of DNA present in the genome of an individual. Copy number variants include insertions, deletions, and duplications of segments of DNA. They account for a significant number of the genetic variations between individuals. Copy number variants may also be associated with specific traits or disorders. Also called CNV.