Depending on the mechanisms responsible for the state of hyperglycemia, different forms of the pathology can be distinguished: (a) type 1 (or insulin-dependent DM), in which the pancreas does not produce insulin; (b) type 2 (or insulin-independent DM), in which the amount of insulin produced is insufficient to meet the body’s needs or does not act adequately on the tissues (insulin resistance); (c) gestational DM (GDM), in when increased blood glucose levels occur during the period of pregnancy. This evidence concerns the gene INS and diabetes mellitus.