The study population was selected from among the eligible population in the Denver Metropolitan are as described in the section above. Approximately 50% of the participants are female. The ethnic distribution in the general population newborn cohort is representative of the general Denver Metro area population: 7% African American, 30% Hispanic, 56% non-Hispanic white, and the remaining of biracial or other ethnicity. The ethnic distribution of the sibling/offspring cohort is representative of T1D in the general U.S. population: 5% African American, 10% Hispanic and 85% non-Hispanic white.