The most common forms of diabetes, type 1 and type 2, are polygenic, meaning the risk of developing these forms of diabetes is related to multiple genes . Environmental factors, such as obesity in the case of type 2 diabetes, also play a part in the development of polygenic forms of diabetes. Polygenic forms of diabetes often run in families. Doctors diagnose polygenic forms of diabetes by testing blood glucose in individuals with risk factors or symptoms of diabetes .
Some rare forms of diabetes result from mutations in a single gene and are called monogenic . Monogenic forms of diabetes may account for about 1 to 5 percent of all cases of diabetes in young people . In some cases of monogenic diabetes, the gene mutation is inherited; but in others, the gene mutation develops spontaneously . Most mutations in monogenic diabetes reduce the body's ability to produce insulin, a protein produced in the pancreas that is essential for the body to use glucose for energy . As a result, monogenic diabetes can easily be mistaken for type 1 diabetes . Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.