Copy number variation and susceptibility to complex traits

Copy number variations (CNV) within the genome are extremely abundant. In this closeup, Canales and Walz discuss how CNV are associated with normal variation, genomic disorders, genome evolution, adaptive traits and how the use of a novel screen described by Ermakova et al in this issue that is designed to identify human disease-relevant phenotypes associated with CNV in the mouse can help elucidating susceptibility or predisposition to diseases loci.