Genetic background of type 2 diabetes

Abstract

Clinical picture of the type 2 diabetes (T2DM) is influenced by two major, coexisting conditions: impaired insulin secretion and insulin resistance. As a result of efforts of the scientists around the world mutations and polymorphisms in a number of genes were linked with monogenic and polygenic forms of T2DM. Monogenic forms, despite their rarity, were the field where a substantial progress has been achieved in recognising the molecular background of T2DM. The monogenic forms comprise MODY (maturity onset diabetes of the young), mitochondrial diabetes (MIDD — maternally inherited diabetes with deafness) and certain rare forms resulting mainly from severe insulin resistance. Efforts aiming to identify genes responsible for more common, polygenic form of T2DM were not so fruitful. The complex, polygenic form of T2DM occurs as an effect of interaction of many environmental and genetic factors, such as certain common gene polymorphisms. So far, only several sequence differences have been verified to play role in the pathogenesis of polygenic T2DM. These are the polymorphisms in genes of calpain 10, PPARγ, KCNJ11 and insulin. It is expected that in the nearest future more T2DM susceptibility genes will be identified.