Epigenetics of diabetes Type 2 Since Type 2 diabetes is characterized by chronic hyperglycaemia as a result of impaired pancreatic beta cell function and insulin resistance in peripheral tissues, it was thought that the gene might be downregulated in type 2 diabetes patients through DNA methylation. The defects in pancreatic beta cell function and insulin resistance in peripheral tissues were thought to be the result of impaired ATP production from reduced oxidative phosphorylation. It was found that the mRNA expression of PPARGC1A was markedly reduced in pancreatic islets from type 2 diabetic donors compared with that of non-diabetic donors. Using bisulfite testing, it was also
Diabetes mellitus type 2 had been found that contribute to the risk of type 2 diabetes. All of these genes together still only account for 10% of the total heritable component of the disease. The TCF7L2 allele, for example, increases the risk of developing diabetes by 1.5 times and is the greatest risk of the common genetic variants. Most of the genes linked to diabetes are involved in beta cell functions. There are a number of rare cases of diabetes that arise due to an abnormality in a single gene (known as monogenic forms of diabetes or "other specific types of diabetes"). These include