Diabetes affects millions of people worldwide, and its chronic complications are a leading cause of death in many industrialized countries. In a minority of patients, diabetes is brought about by the auto-immune destruction of insulin-producing pancreatic beeta cells (Type 1 diabetes). In the vast majority of patients, diabetes is brought about by a combination of genetic and environmental factors that affect the organisms ability to respond to insulin (Type 2 diabetes). This impairment is due to a complex abnormality involving insulin action at the periphery and insulin production in the beta cell. Genetic factors play a key role in the development of type 2 diabetes. However, the inheritance of diabetes is non-Mendelian in nature, due to genetic heterogeneity, polygenic pathogenesis and incomplete penetrance. For these reasons, many laboratories have developed