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Type 1 Diabetes, Type 2 Diabetes, Other Specific Types Of Diabetes, Genetic Susceptibility To ComplicationsGestational Diabetes Mellitus

Diabetes mellitus is a group of diseases characterized by elevated levels of glucose in the blood. Diabetes is caused by problems producing or responding to the hormone insulin. Insulin is produced in the pancreas by specialized cells called beta cells, in response to the presence of glucose absorbed through the gastrointestinal tract following a meal. Insulin promotes the uptake of glucose into muscle and fat cells, and it promotes the storage of excess glucose in the liver.

Excess blood glucose over time damages organs, particularly the eyes, kidneys, nerves, heart, and blood vessels. It is the leading cause of adult blindness, end-stage kidney disease, and lower limb amputations, and it is a major risk factor for heart attacks and strokes. Diabetes is classified into four major groups: type 1 diabetes (T1DM), type 2 diabetes (T2DM), other specific types, and gestational diabetes (GDM), occurring during pregnancy. Approximately 5 percent to 8 percent of the people of the industrialized world have diabetes, mostly (approximately 90 percent) type 2, which at least 16 million Americans have.

Hormones associated with pregnancy may cause diabetes in susceptible individuals. Although the diabetes goes away after the pregnancy, individuals who have had GDM are at increased risk of developing T2DM. Currently very little is known about the genetic basis of GDM. It is possible that some of the same genes responsible for T2DM are also involved in GDM.

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Medicine EncyclopediaGenetics in Medicine - Part 1