A gene that makes people vulnerable to obesity also produces a protein that may directly modify DNA in a region of the brain known to control food intake. The unexpected finding sheds light on how gene variants can predispose individuals to obesity, say scientists.Earlier this year, analysis of blood samples from nearly 40,000 individuals linked certain variants of a gene called FTO with a 70% increased risk of obesity. Those people who carried two defective copies of the FTO gene were 3 kilograms heavier on average than their counterparts with normal versions of the gene. The biological function of the FTO gene, however, remained a mystery.
