A Common Variant in the <i>FTO</i> Gene Is Associated with Body Mass Index and Predisposes to Childhood and Adult Obesity

TLDR

Obesity is a major global health issue linked to numerous diseases, yet the genetic contributors to obesity remain largely unclear. A common FTO variant is strongly associated with higher BMI, with homozygotes weighing about 3 kg more and having 1.67‑fold higher obesity odds, a relationship evident from age 7 and driven by increased fat mass.

Abstract

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.