chromosome structure variation copy number variation http://purl.obolibrary.org/obo/VariO_0187 http://semanticscience.org/resource/SIO_001328 http://www.ebi.ac.uk/efo/EFO_0004798 https://en.wikipedia.org/wiki/Copy_number_variation https://www.wikidata.org/wiki/Q1501491 CNV DNA copy number variation Increase or decrease of the number of copies of a chromosomal region. Sizes of copy number variations range from about 1 kilobase to several megabases. copy number variations copy-number variation