A common variant in the FTO gene is associated with body mass index and predisposes to childhood and adult obesity.
Frayling TM., Timpson NJ., Weedon MN., Zeggini E., Freathy RM., Lindgren CM., Perry JR., Elliott KS., Lango H., Rayner NW., Shields B., Harries LW., Barrett JC., Ellard S., Groves CJ., Knight B., Patch AM., Ness AR., Ebrahim S., Lawlor DA., Ring SM., Ben-Shlomo Y., Jarvelin MR., Sovio U., Bennett AJ., Melzer D., Ferrucci L., Loos RJ., Barroso I., Wareham NJ., Karpe F., Owen KR., Cardon LR., Walker M., Hitman GA., Palmer CN., Doney AS., Morris AD., Smith GD., Hattersley AT., McCarthy MI.
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 diabetes-susceptibility 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.