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How do genes influence the risk of type 1 diabetes?

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immune system disorder False-color scanning electron micrograph of a T cell infected with HIV (human immunodeficiency virus), the agent that causes AIDS (acquired immunodeficiency syndrome).

Type 1 diabetes is primarily an autoimmune disorder, and while it has a strong genetic link, genes do not act alone in causing the disease.12

Genetic influence is most notably associated with variations in the human leukocyte antigen (HLA) complex. Located on chromosome 6, these genes encode proteins that help the immune system present antigens to immune cells. In individuals with certain genetic variations, this process may become dysregulated, leading the immune system to mistakenly initiate the production of autoantibodies that attack the body’s own cells—specifically the islets of Langerhans in the pancreas.13

Despite this genetic susceptibility, the actual destruction of pancreatic tissue is thought to be driven by immune cells sensitized to islet components. Environmental factors, such as viral infections, foreign proteins, or toxins, are believed to act as potential triggers for this autoimmune process. Consequently, having a genetic predisposition does not guarantee the development of the disease; for example, only about 2 to 5 percent of children with an affected parent will develop type 1 diabetes.12