The incidence of insulin-dependent diabetes mellitus (100M) varies dramatically across racial groups and countries, with annual age-adjusted rates of approximately 40/100,000 per year in Finland, but only 0.51100,000 per year in China. Although reasons for these marked geographic differences are unknown, it is likely that genetic variations across populations play a m or role. To determine the contribution of genetic factors to the global patterns of 100M incidence, international comparative studies are now being undertaken as part of the WHO Multinational Project for Childhood Oiabetes,...