SORCS1: A Novel Human Type 2 Diabetes Susceptibility Gene Suggested by the Mouse

SORCS1: A Novel Human Type 2 Diabetes Susceptibility Gene Suggested by the Mouse Mark O. Goodarzi 1 2 , Donna M. Lehman 3 , Kent D. Taylor 2 , Xiuqing Guo 2 , Jinrui Cui 2 , Manuel J. Quiñones 4 , Susanne M. Clee 5 , Brian S. Yandell 5 , John Blangero 6 , Willa A. Hsueh 4 , Alan D. Attie 5 , Michael P. Stern 3 and Jerome I. Rotter 2 1 Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 2 Departments of Pediatrics and Medicine, Medical Genetics Institute, Steven Spielberg Pediatric Research Center, Cedars-Sinai Medical Center, Los Angeles, California 3 Department of Medicine/Clinical Epidemiology, University of Texas Health Science Center, San Antonio, Texas 4 Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 5 Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 6 Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas Address correspondence and reprint requests to Mark O. Goodarzi, MD, PhD, Cedars-Sinai Medical Center, Division of Endocrinology, Diabetes, and Metabolism, 8700 Beverly Blvd., Becker B-131, Los Angeles, CA 90048. E-mail: mark.goodarzi{at}cshs.org Abstract OBJECTIVE —A small number of susceptibility genes for human type 2 diabetes have been identified by candidate gene analysis or positional cloning. Genes found to influence diabetes or related traits in mice are likely to be susceptibility genes in humans. SorCS1 is the gene identified as responsible for the mouse chromosome 19 T2dm2 quantitative trait locus for fasting insulin levels, acting via impaired insulin secretion and increased islet disruption in obese females. Genes that impair compensatory insulin secretion in response to obesity-induced insulin resistance may be particularly relevant to human diabetes. Thus, we sought to determine whether variation in the human SORCS1 gene was associated with diabetes-related traits. RESEARCH DESIGN AND METHODS —We assessed the contribution of variation in SORCS1 to human insulin–related traits in two distinct Mexican-American cohorts. One cohort (the Mexican-American Coronary Artery Disease [MACAD] cohort) consisted of nondiabetic individuals, allowing assessment of genetic association with subclinical intermediate insulin-related traits; the second cohort (the San Antonio Family Diabete