Association Analysis of 6,736 U.K. Subjects Provides Replication and Confirms TCF7L2 as a Type 2 Diabetes Susceptibility Gene With a Substantial Effect on Individual Risk

• Published in: Diabetes (New York, N.Y.) Vol. 55; no. 9; pp. 2640 - 2644
• Main Authors: Groves, Christopher J., Zeggini, Eleftheria, Minton, Jayne, Frayling, Timothy M., Weedon, Michael N., Rayner, Nigel W., Hitman, Graham A., Walker, Mark, Wiltshire, Steven, Hattersley, Andrew T., McCarthy, Mark I.
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01.09.2006
• Subjects: Adult; Aged; Analysis; Biological and medical sciences; Chromosomes; Diabetes; Diabetes Mellitus, Type 2 - genetics; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Gene Frequency; Genetic aspects; Genetic Predisposition to Disease; Genetic susceptibility; Genetics, Population; Genomes; Genotype; Genotype & phenotype; Humans; Linkage Disequilibrium; Male; Medical sciences; Middle Aged; Polymorphism, Single Nucleotide; Risk Factors; TCF Transcription Factors - genetics; Transcription Factor 7-Like 2 Protein; Transcription factors; Type 2 diabetes; United Kingdom; United Kingdom; United Kingdom > UK; Endocrinopathy; Type 2 diabetes; Human; Sensitivity; Association; Gene; Risk factor; Metabolic diseases; Replication
• ISSN: 0012-1797; 1939-327X
• DOI: 10.2337/db06-0355

Association Analysis of 6,736 U.K. Subjects Provides Replication and Confirms TCF7L2 as a Type 2 Diabetes Susceptibility Gene With a Substantial Effect on Individual Risk Christopher J. Groves 1 , Eleftheria Zeggini 1 2 , Jayne Minton 3 , Timothy M. Frayling 3 , Michael N. Weedon 3 , Nigel W. Rayner 1 2 , Graham A. Hitman 4 , Mark Walker 5 , Steven Wiltshire 2 , Andrew T. Hattersley 3 and Mark I. McCarthy 1 2 1 Diabetes Research Laboratories, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, U.K 2 Wellcome Trust Centre for Human Genetics, Headington, Oxford, U.K 3 Department of Diabetes Research and Vascular Medicine, Peninsula Medical School, Exeter, U.K 4 Department of Diabetes and Metabolic Medicine, Barts and the London, Queen Mary School of Medicine and Dentistry, University of London, London, U.K 5 Department of Medicine, School of Medicine, Newcastle University, Newcastle upon Tyne, U.K Address correspondence and reprint requests to Prof. Mark McCarthy, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Old Road, Headington, Oxford OX3 7LJ, U.K. E-mail: mark.mccarthy{at}drl.ox.ac.uk Abstract Recent data suggest that common variation in the transcription factor 7-like 2 ( TCF7L2 ) gene is associated with type 2 diabetes. Evaluation of such associations in independent samples provides necessary replication and a robust assessment of effect size. Using four TCF7L2 single nucleotide polymorphisms (SNPs; including the two most associated in the previous study), we conducted a case-control study in 2,158 type 2 diabetic subjects and 2,574 control subjects and a family-based association analysis in 388 parent-offspring trios all from the U.K. All SNPs showed powerful associations with diabetes in the case-control analysis, with strongest effects at rs7903146 (allele-wise relative risk 1.36 [95% CI 1.24–1.48], P = 1.3 × 10 −11 ). Data were consistent with a multiplicative model. The family-based analyses provided independent evidence for association at all loci (e.g., rs4506565, 62% transmission, P = 7 × 10 −5 ) with no parent-of-origin effects. The frequency of diabetes-associated TCF7L2 genotypes was greater in cases ascertained for positive family history and early onset (rs4606565, P = 0.02); the population-attributable risk, estimated from the least-selected cases, is ∼16%. The overall evidence for association for these variants ( P = 4.4 × 10 −14 combining case-control and family-based analyses for rs4506565) exceeds genome-wide significance criteria and clearly establishes TCF7L2 as a type 2 diabetes susceptibility gene of substantial importance. SNP, single nucleotide polymorphism Footnotes C.J.G. and E.Z. contributed equally to this work. Additional information for this article can be found in an online appendix at http://diabetes.diabetesjournals.org . The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Accepted May 30, 2006. Received March 17, 2006. DIABETES