How to see if a gene is the product of copy number variation?

Copy number variation (CNV) is a phenomenon in which sections of the genome are repeated and the number of repeats in the genome varies between individuals.Copy number variation is a type of structural variation: specifically, it is a type of duplication or deletion event that affects a considerable number of base pairs. I have a set of protein coding genes and I would like to verify them to be the product of CNV. My first idea was to overlap their domains, that are well separated by homopeptide regions but before to do this I would like to know whether more suitable indexes exist to infer this characteristic. Can anyone help?