Exome and genome sequencing: a revolution for the discovery and diagnosis of monogenic disorders.

Massively parallel DNA sequencing has revolutionized analyses of human genetic variation. From having been out of reach for individual research groups and even more so for clinical diagnostic laboratories until recently, it is now possible to analyse complete human genomes within reasonable time frames and at a reasonable cost using technologies that are becoming increasingly available. This represents a huge advance in our ability to provide correct diagnoses for patients with rare inherited disorders and their families. This paradigm shift is especially dramatic within the area of monogenic disorders. Not only can rapid and safe diagnostics of virtually all known single-gene defects now be established, but novel causes of disease in previously unsolved cases can also be identified, illuminating novel pathways important for normal physiology. This greatly increases the capability not only to improve management of rare disorders, but also to improve understanding of pathogenetic mechanisms relevant for common, complex diseases.