MAPPING GENES FOR NIDDM - DESIGN OF THE FINLAND UNITED-STATES INVESTIGATION OF NIDDM GENETICS (FUSION) STUDY

OBJECTIVE - To map and identify susceptibility genes for NIDDM and for the intermediate quantitative traits associated with NIDDM. RESEARCH DESIGN AND METHODS - We describe the methodology and sample of the Fin land-United States Investigation of NIDDM Genetics (FUSION) study The whole genome search approach is being applied in studies of several di fferent ethnic groups to locate susceptibility genes for NIDDM, Detail ed description of the study materials and designs of such studies are important, particularly when comparing the findings in these studies a nd when combining different data sets. RESULTS - Using a careful selec tion strategy we have ascertained 495 families with confirmed NIDDM in at least two siblings and no history of IDDM among the first-degree r elatives. These families were chosen from more than 22,000 NIDDM patie nts. representative of patients with NIDDM in the Finnish population. In a subset of families, a spouse and offspring were sampled, and they participated in a frequently sampled intravenous glucose tolerance te st (FSIGT) analyzed with the Minimal Model. An FSIGT was completed suc cessfully for at least two nondiabetic offspring in 156 families with a confirmed nondiabetic spouse and no history of IDDM in first-degree relatives. CONCLUSIONS - Our work demonstrates the feasibility of coll ecting a large number of affected sib-pair families with NIDDM to prot ide data that will enable a whole genome search approach, including li nkage analysis.