Diabetes mellitus type 1 (DM1)
is a condition in which cells in the pancreas (beta cells) stop producing insulin, causing abnormally high blood sugar levels. Lack of insulin results in the inability of the body to use glucose for energy and control the amount of sugar in the blood. DM1 can occur at any age, but usually develops by early adulthood, most often in adolescence. Symptoms of high blood sugar may include frequent urination, excessive thirst, fatigue, blurred vision, tingling or loss of feeling in the hands and feet, and weight loss. The exact cause of DM1 is unknown, but having certain "variants" of specific genes may increase a person's risk to develop the condition. A predisposition to develop DM1 runs in families, but no known inheritance pattern exists. Treatment includes blood sugar control and insulin replacement therapy. Improper control can cause recurrence of high blood sugar, or abnormally low blood sugar (hypoglycemia) during exercise or when eating is delayed. If not treated, the condition can be life-threatening. Over many years, chronic high blood sugar may be associated with a variety of complications that affect many parts of the body. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.