Peninsula Medical School, Exeter, and the University of Oxford scientists report that they have identified the most unequivocal genetic connection yet to obesity. People with two copies of a particular gene variant showed a 70% higher risk of being obese than those with no copies.
The researchers first identified a genetic link to obesity through a genome-wide study of 2,000 people with type 2 diabetes and 3,000 controls. They found a strong association between an increase in BMI and a variation, or allele, of the gene FTO. The team then tested a further 37,000 samples for this gene from Bristol, Dundee, and Exeter as well as a number of other regions in the U.K. and Finland.
The results showed that people carrying one copy of the FTO allele have a 30% increased risk of being obese compared to a person with no copies. Additionally, a person carrying two copies has a 70% increased risk of being obese. This population were, on average, 3 kg, or 6.6 pounds, heavier than a similar person with no copies. Amongst white Europeans, approximately one in six people carry both copies of the allele, according to the investigators.
The study is published online in Science. It was part of the Wellcome Trust Case Control Consortium, which seeks to identify the genetic variations that may predispose people to or protect them from major diseases.