Resolving the variable genome and epigenome in human disease.

The individual human genome and epigenome are being defined at unprecedented resolution by current advances in sequencing technologies with important implications for human disease. This review uses examples relevant to clinical practice to illustrate the functional consequences of genetic and epigenetic variation. The insights gained from genome-wide association studies are described together with current efforts to understand the role of rare variants in common disease, set in the context of recent successes in Mendelian traits through the application of whole exome sequencing. The application of functional genomics to interrogate the genome and epigenome, build up an integrated picture of the regulatory genomic landscape and inform disease association studies is discussed, together with the role of expression quantitative trait mapping and analysis of allele-specific gene expression.