How is diabetes inherited

Diabetes Germany

Type 1 diabetes

In diabetes mellitus, four major groups are distinguished: type 1, type 2 diabetes, gestational diabetes (gestational diabetes) and other forms of diabetes. Type 1 diabetes (around 3-5% of all diabetes cases) develops due to the destruction of the insulin-producing beta cells.
The result is a “real” insulin deficiency right from the start, which now has to be constantly supplied from the outside in order to ensure survival. This is where the earlier term “insulin-dependent diabetes” comes from.

The combination of hereditary predisposition, external factors (e.g. certain viral infections) and a malfunction of the immune system are held responsible for the development of type 1 diabetes. In the course of the disease, the body's own immune cells (T lymphocytes) turn against the insulin-producing cells in the pancreas (beta cells) and destroy them. The consequence of the progressive destruction of the beta cells is an insulin deficiency. Without insulin, the energy supplier glucose can no longer be absorbed and used by most body cells: the sugar level in the blood rises.

Type 1 diabetes usually occurs in children, adolescents and early adulthood. This is why this form of diabetes was often referred to as adolescent or juvenile diabetes in the past. Type 1 diabetes can also develop in toddlers or later in adulthood.


It is believed that a certain genetic predisposition increases the susceptibility to type 1 diabetes. Type 1 diabetes is inherited from one parent to a child with a 3-5% chance. If both parents have type 1 diabetes, the risk increases to 10-25%. In the case of an identical twin of a type 1 diabetic who is not initially ill, the risk of the other twin also developing type 1 diabetes is 30-50%.

Malfunction of the immune system

Type 1 diabetes is one Autoimmune Disease: In addition to the hereditary predisposition, from today's scientific point of view, other external influencing factors (environmental factors) must follow in order for the disease to occur. Virus infections, possibly also nutritional factors, are held responsible as triggers. With a corresponding predisposition, these influences lead to a misdirected defense reaction (immune reaction), in which not only “foreign intruders” but also the body's own cells are attacked and destroyed - in this case the insulin-producing beta cells. In this context, one speaks of an autoimmune disease. For example, a viral infection can trigger an autoimmune disease in which immune cells and antibodies (defense substances) are formed that react against the body's own tissue. The most important antibodies in type 1 diabetes are cytoplasmic islet cell antibodies (ICA), insulin autoantibodies (IAA), antibodies against the enzyme glutamate decarboxylase (GADA) and antibodies against tyrosine kinase IA-2 (IA-2A). These antibodies can be detected in the blood of those affected months to years before the onset of diabetes.

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