The genetic link between type 1 and type 2 diabetes



Based on the longstanding assumption that type 1 and type 2 diabetes were different, researchers worked on either the autoimmune disease (type 1) or the metabolic disorder (type 2). But they are now reconsidering this approach. Since Sylvie Lesage, researcher at Hôpital Maisonneuve-Rosemont and professor in the Department of Microbiology, Infectious Diseases and Immunology at Université de Montréal, helped identify a genetic link between the two types of diabetes, she has heard from numerous investigators seeking to join forces with her and share their data with her team.

Sylvie Lesage identified a root factor of types 1 and 2: beta cell fragility.

In people with diabetes, the body has trouble regulating glucose as a source of energy. The immune systems of patients with type 1 diabetes destroy the pancreatic beta cells that produce insulin—the hormone that enables the organism to use glucose. Type 1 diabetes generally occurs in childhood. With type 2 diabetes, which tends to appear in adults, patients are affected by a metabolic disturbance that stops the insulin from acting on several tissues, including the liver, brain and muscles.

Until very recently, experts thought that there were few genetic links between the two types. But by studying the immune responses of transgenic mice with type 1 diabetes, Sylvie Lesage identified a root factor of types 1 and 2: beta cell fragility. This inherited genetic defect increases the risk of diabetes. She therefore believes that stronger beta cells could help prevent type 1 and type 2 diabetes since the individuals who inherit more robust beta cells are less prone to developing the disease.