A Large Set of Finnish Affected Sibling Pair Families With Type 2 Diabetes Suggests Susceptibility Loci on Chromosomes 6, 11, and 14 Kaisa Silander 1 , Laura J. Scott 2 , Timo T. Valle 3 , Karen L. Mohlke 1 , Heather M. Stringham 2 , Kerry R. Wiles 1 , William L. Duren 2 , Kimberly F. Doheny 4 , Elizabeth W. Pugh 4 , Peter Chines 1 , Narisu Narisu 1 , Peggy P. White 2 , Tasha E. Fingerlin 2 , Anne U. Jackson 2 , Chun Li 2 , Soumitra Ghosh 1 , Victoria L. Magnuson 1 , Kimberly Colby 1 , Michael R. Erdos 1 , Jason E. Hill 1 , Pablo Hollstein 1 , Kathleen M. Humphreys 1 , Roshni A. Kasad 1 , Jessica Lambert 1 , Konstantinos N. Lazaridis 1 , George Lin 1 , Anabelle Morales-Mena 1 , Kristin Patzkowski 1 , Carrie Pfahl 1 , Rachel Porter 1 , David Rha 1 , Leonid Segal 1 , Yong D. Suh 1 , Jason Tovar 1 , Arun Unni 1 , Christian Welch 1 , Julie A. Douglas 2 , Michael P. Epstein 2 , Elizabeth R. Hauser 2 , William Hagopian 5 , Thomas A. Buchanan 6 , Richard M. Watanabe 2 7 , Richard N. Bergman 8 , Jaakko Tuomilehto 3 9 , Francis S. Collins 1 and Michael Boehnke 2 1 Genome Technology Branch, National Human Genome Research Institute, Bethesda, Maryland 2 Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan 3 Diabetes and Genetic Epidemiology Unit, Department of Epidemiology and Health Promotion, and Department of Biochemistry, National Public Health Institute, Helsinki, Finland 4 Center for Inherited Disease Research, Institute of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland 5 Pacific Northwest Research Institute, Seattle, Washington 6 Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 7 Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 8 Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California 9 Department of Public Health, University of Helsinki, Helsinki, Finland Address correspondence and reprint requests to Michael Boehnke, PhD, Department of Biostatistics, School of Public Health, University of Michigan, 1420 Washington Heights, Ann Arbor, Michigan 48109-2029. E-mail: boehnke{at}umich.edu Abstract The aim of the Finland-United States Investigation of NIDDM Genetics (FUSION) study is to identify genes that predispose to type 2 diabetes or are responsible for variability in diabetes-related traits via a positional cloning and positional candidate gene approach. In a previously published genome-wide scan of 478 Finnish affected sibling pair (ASP) families (FUSION 1), the strongest linkage results were on chromosomes 20 and 11. We now report a second genome-wide scan using an independent set of 242 Finnish ASP families (FUSION 2), a detailed analysis of the combined set of 737 FUSION 1 + 2 families (495 updated FUSION 1 families), and fine mapping of the regions of chromosomes 11 and 20. The strongest FUSION 2 linkage results were on chromosomes 6 (maximum logarithm of odds score MLS = 2.30 at 95 cM) and 14 (MLS = 1.80 at 57 cM). For the combined FUSION 1 + 2 families, three results were particularly notable: chromosome 11 (MLS = 2.98 at 82 cM), chromosome 14 (MLS = 2.74 at 58 cM), and chromosome 6 (MLS = 2.66 at 96 cM). We obtained smaller FUSION 1 + 2 MLSs on chromosomes X (MLS = 1.27 at 152 cM) and 20p (MLS = 1.21 at 20 cM). Among the 10 regions that showed nominally significant evidence for linkage in FUSION 1, four (on chromosomes 6, 11, 14, and X) also showed evidence for linkage in FUSION 2 and stronger evidence for linkage in the combined FUSION 1 + 2 sample. ASP, affected sibling pair CEPH, Centre d’Etude du Polymorphisme Humain CIDR, Center for Inherited Disease Research FUSION, Finland-United States Investigation of NIDDM Genetics IBD, identity by descent LOD, logarithm of odds MLS, maximum LOD score QTL, quantitative trait locus WHO, World Health Organization Footnotes Accepted December 4, 2003. Received July 21, 2003. DIABETES