Exome sequencing greatly expedites the progressive research of Mendelian diseases.

The advent of whole-exome sequencing (WES) has facilitated the discovery of rare structure and functional genetic variants. Combining exome sequencing with linkage studies is one of the most efficient strategies in searching disease genes for Mendelian diseases. WES has achieved great success in the past three years for Mendelian disease genetics and has identified over 150 new Mendelian disease genes. We illustrate the workflow of exome capture and sequencing to highlight the advantages of WES. We also indicate the progress and limitations of WES that can potentially result in failure to identify disease-causing mutations in part of patients. With an affordable cost, WES is expected to become the most commonly used tool for Mendelian disease gene identification. The variants detected cumulatively from previous WES studies will be widely used in future clinical services.