MAPPING GENES FOR NON-INSULIN DEPENDENT DIABETES MELLITUS:  DESIGN OF THE
FINLAND-UNITED STATES INVESTIGATION OF NIDDM GENETICS (FUSION) STUDY.
Valle, T., Tuomilehto, J., Bergman, R.N., Ghosh, S., Hauser, E.R.,
Eriksson, J., Nylund, S.J., Kohtamaki, K., Tuomilehto-Wolf, E., Toivanen,
L., Vidgren, G., Ehnholm, C., Blaschak, J., Langefeld, C.D., Watanabe,
R.M., Magnuson, V., Ally, D.S., Hagopian, W.A., Ross, E., Buchanan, T.A.,
Collins, F., Boehnke, M.

Several ongoing studies in different ethnic groups are using the whole genome
search approach to locate susceptibility genes for non-insulin-dependent
diabetes mellitus (NIDDM).  Detailed description of the study materials and
designs of such studies are important, particularly when comparing the findings
in these studies and when combining different data sets.  In this paper we
describe the methodology and the study material of the Finland-United States
Invedstigation of NIDDM Genetics (FUSION) Study.  Our aim is to map and
identify susceptibility genes for NIDDM and for the intermediate quantitative
traits associated with NIDDM.  Using a careful selection strategy, we have
ascertained 495 families with at least two affected siblings with confirmed
NIDDM and no history of IDDM among the first-degree relatives.  These families
were chosen from more than 22,000 NIDDM patients, representative of patients
with NIDDM in the Finnish population.  In a subset of families, a spouse and
offspring were sampled and participated in a frequently-sampled intravenous
glucose tolerance test (FSIGT) analyzed with the Minimal Model.  An FSIGT
was completed successfully for at least two non-diabetic offspring in 156
families with a confirmed non-diabetic spouse and no history of IDDM in
first-degree relatives.  Our work demonstrates the feasibility of collecting
a large number of affected sib-pair families with NIDDM to provide data
which will enable a whole genome search approach including linkage analysis.