ABSTRACT
Type 1 diabetes mellitus (DM) is a disease of multifactorial autoimmune causation. Worldwide, there is a marked geographic variation in prevalence. The overall lifetime risk in Caucasian subjects is approximately 0-4%. Type 1 DM is caused by an interaction between environmental factors and an inherited genetic predisposition. In twin studies, a significant genetic contribution is suggested by a concordance value for type 1 DM of 30-50%. The risk to a first-degree relative is approximately 5%. The high discordance rate supports the notion that type 1 DM is multifactorial in etiology. Environmental triggers may account for up to twothirds of the disease susceptibility.
