TODAY Genetics Study

Inclusion Criteria: * Diabetes by ADA criteria (laboratory determinations of fasting glucose ≥ 126 mg/dL, random glucose ≥ 200 mg/dL, or two-hour oral glucose tolerance test (OGTT) glucose ≥ 200 mg/dL) documented and confirmed in medical record or a laboratory determination of HbA1c ≥ 7%. For asymptomatic patients diagnosed with diabetes with a normal fasting glucose but an elevated two-hour glucose during an OGTT, the HbA1c must be ≥ 6%. * BMI ≥ 85th percentile documented at time of diagnosis or at screening. * Age \< 18 at time of diagnosis. * Signed informed consent and assent forms as appropriate. Exclusion Criteria: * Genetic syndrome or disorder known to affect glucose tolerance other than diabetes. * Patient on medication known to affect glucose tolerance, insulin sensitivity or secretion within 60 days of the time of diagnosis. If diagnosis is confirmed after the patient has been off the medication for 60 days, the patient may be included. Exclusionary medications include but are not limited to 1. inhaled steroids at dose above 1000 mcg daily fluticasone equivalent, 2. oral glucocorticoids, 3. antirejection or chemotherapy agents (e.g., tacrolimus, L-asparaginase), 4. atypical antipsychotics.