Epigenetics and epigenetic mechanisms in disease with emphasis on autoimmune diseases.

Epigenetics deals with molecular heritable patterns relating to chromatin, which exists in two alterable and inter-convertible states. The two conformations of chromatin i.e., compact and relaxed are due to epigenetic regulation. The alterations in chromatin normalize gene expression patterns. Thus, the epigenetic marks on chromatin are the deciding factors for either gene silencing or activation. The epigenetics introduced a new term viz., epiallele which deviates from the classical Mendelian allele. The remodeling of chromatin during embryonic phase, post-translational aberrations of chromatin proteins causing cellular dysfunction and possible epigenetic therapies are discussed in the present article. The role of epigenetic mechanisms in triggering / progression of several autoimmune diseases is being emphasized off late. The study of such complex epigenetic processes becomes very important in understanding the etiopathology of the disease as well as in designing target therapies.