# CNV overlap percentage

The _Variant page_ > [_Related Cases_](related_cases_section) section offers a [Dynamic CNV overlap percentage filter](http://help.emedgene.com/en/articles/5640118-related-cases-section#h_c2280a50b3) as well as an [Overlap](http://help.emedgene.com/en/articles/5640118-related-cases-section#h_052c00d560) column for CNVs in the data table. This percentage is computed by dividing the length of a common region between CNVs by the size of the CNV under study.

Examples of CNV overlap percentage calculation (see legend below):

![](https://1131024994-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FGCW0DnLlE7QjoZPNmKIi%2Fuploads%2Fgit-blob-73aef2c831052bd97d6282cbb519e655b4c8f18f%2Fcnv_overlap_percentage_1_cnv%2Boverlap%2Bscheme.png?alt=media)

* Orange represents the current CNV;
* Violet blue represents a previously reported CNV;
* Darker shade indicates the region of overlap between the current and previously reported CNV.
