- Ole Ammerpoht: Institute of Human Genetics, University Medical Center Schleswig-Holstein, Kiel, Germany. oammerpohl@medgen.uni-kiel.de
By adding adaptable information about the activity of genes, epigenetics enables the activation of specific genes depending on the prevalent environmental conditions and individual requirements of a cell. Although epigenetic information is heritable, it is not stored in the sequence of the DNA but mainly in the modification pattern of the chromatin, i.e., the methylation of cytosine residues in the DNA or covalent modifications of the histones. By controlling gene activity and therefore the availability of the final gene product in the cell, epigenetic alterations can have similar effects as classical genetic mutations. Indeed, the recent past epigenetic modifications have become a focus for the clinic for diagnostics, prognostics, as well as therapeutic purposes. This review briefly summarizes the major aspects of epigenetics and presents a comprehensive overview about the fundamental principles of DNA methylation analysis.