Faculty Opinions recommendation of Detection of clinically relevant copy-number variants by exome sequencing in a large cohort of genetic disorders.

Copy-number variation is a common source of genomic variation and an important genetic cause of disease. Microarraybased analysis of copy-number variants (CNVs) has become a firsttier diagnostic test for patients with neurodevelopmental disorders, with a diagnostic yield of 10-20%. However, for most other genetic disorders, the role of CNVs is less clear and most diagnostic genetic studies are generally limited to the study of single-nucleotide variants (SNVs) and other small variants. With the introduction of exome and genome sequencing, it is now possible to detect both SNVs and CNVs using an exome-or genome-wide approach with a single test.