*Cases*: T2D cases were selected from FUSION ASP families, each reporting at least one T2D sibling, and from Finrisk 2002, a Finnish population-based risk factor survey. T2D was defined by WHO 1999 criteria of fasting plasma glucose >= 7.0 mmol/l or 2-h plasma glucose >= 11.1 mmol/l, by report of diabetes medication use, or based on medical record review. FUSION cases with known or probable type 1 diabetes among their first degree relatives were excluded.

*Controls*: NGT controls for GWAS were selected from FUSION, including subjects from Vantaa, Finland, who were NGT at ages 65 and 70 years, and spouses of FUSION subjects, and from Finrisk 2002. Additional NGT controls for sequencing were selected from D2D 2004, Finrisk 1987, Health 2000, and the Savitaipale Diabetes Study. NGT was defined by WHO 1999 criteria of fasting glucose < 6.1 mmol/l and 2-h glucose < 7.8 mmol/l. Controls were frequency-matched to the cases as described in the sub-study descriptions.