A Common Variant in the FTO Gene Is Associated with Body Mass Index and Predisposes to Childhood and Adult ObesityTimothy M. Frayling, Nicholas J. Timpson, Michael N. Weedon, Eleftheria Zeggini, Rachel M. Freathy, Cecilia M. Lindgren, John R. B. Perry, Katherine S. Elliott, Hana Lango, Nigel W. Rayner, Beverley Shields, Lorna W. Harries, Jeffrey C. Barrett, Sian Ellard, Christopher J. Groves, Bridget Knight, Ann-Marie Patch, Andrew R. Ness, Shah Ebrahim, Debbie A. Lawlor, Susan M. Ring, Yoav Ben-Shlomo, Marjo-Riitta Jarvelin, Ulla Sovio, Amanda J. Bennett, David Melzer, Luigi Ferrucci, Ruth J. F. Loos, IneÌs Barroso, Nicholas J. Wareham, Fredrik Karpe, Katharine R. Owen, Lon R. Cardon, Mark Walker, Graham A. Hitman, Colin N. A. Palmer, Alex S. F. Doney, Andrew D. Morris, George Davey Smith, Andrew T. Hattersley, Mark I. McCarthy
Obesity is a serious international health problem that increases the risk of several common diseases. The genetic factors predisposing to obesity are poorly understood. A genome-wide search for type 2 diabetesâsusceptibility genes identified a common variant in the FTO (fat mass and obesity associated) gene that predisposes to diabetes through an effect on body mass index (BMI). An additive association of the variant with BMI was replicated in 13 cohorts with 38,759 participants. The 16% of adults who are homozygous for the risk allele weighed about 3 kilograms more and had 1.67-fold increased odds of obesity when compared with those not inheriting a risk allele. This association was observed from age 7 years upward and reflects a specific increase in fat mass.