[Genetic and environmental factors in insulin-dependent diabetes]

Insulin-dependent diabetes results from the interaction of genetic, immunological and environmental factors. In view of the association between insulin-dependent diabetes and HLA system, it has been postulated that the diabetogenic gene(s) is (or are) located in the region of the DR locus in that system. The hypothesis of viral factors is supported by epidemiological arguments and experimental models but has only been exceptionally confirmed in man. The fact that anti-islet antibodies are frequently detected at the onset of insulin-dependent diabetes or even before the first symptoms develop suggests that an auto-immune mechanism might be involved in the destruction of beta-cells. Although the mode of inheritance of genes supposed to predispose to insulin-dependent diabetes as well as the mechanisms behind the pancreatic lesion are still poorly understood, determining "markers" of the disease should eventually make it possible to detect subjects at risk of diabetes and to prevent its development.