The genomic basis of medicine

Abstract The first phase of the studies on genetic variation in humans has been focused on single nucleotide polymorphisms and common variation. The large number of single nucleotide polymorphisms identified has enabled successful genome-wide association studies for disease susceptibility risk of complex traits (e.g. diabetes and cancer), but for the most part has had limited practical applications in clinical medicine. This chapter examines the recent technological developments which have enabled a higher-resolution analysis of the human genome and its extensive submicroscopic structural variation, including copy-number variants. Copy-number variants involving dosage-sensitive genes result in several diseases and contribute to human diversity and evolution. An emerging group of genetic diseases have been described that result from DNA rearrangements (e.g. copy-number variants and other structural variations including copy-number neutral inversions and translocations), rather than from single nucleotide changes.