The aim of the project is to positionally clone susceptibility genes for NIDDM. Patients will be ascertained in Finland from previous health surveys and hospital discharge records. Approximately 400 affected sib pairs will be collected. Families will be chosen who have, at most, one parent with NIDDM no history of IDDM. A clinical examination will be undertaken on family members and blood drawn for DNA isolation. Covariates such as body weight, blood pressure, lipid levels and urinary albumin will also be measured. The unaffected spouse and children of a subset of probands will be invited to undergo a frequently-sampled intravenous glucose tolerance test (FSIGT) to measure parameters of pancreatic function and peripheral insulin resistance (IR). A number of unrelated elderly non-diabetic subjects will also be identified to conduct a population-based association analysis.

The FSIGT analysis will be performed in Los Angeles. The DNA will be shipped to Bethesda where a total genomic scan will be performed using semi-automated fluorescence-based genotyping technology. Data from Bethesda, Los Angeles and Finland will be sent to Ann Arbor where parametric and non-parametric methods will be used to analyse both discrete traits such as NIDDM and intermediate traits like IR.