February 22, 2009

expert comments on research investigating the FTO gene and obesity, as published in Nature

The research identifies a link between the FTO gene and factors involved with obesity including appetite and metabolic rate, raising the possibility of treatments that work by modulating these relationships.

Prof Stephen O’Rahilly, University of Cambridge Metabolic Research Laboratories, said:

“Genetic variation close to the FTO gene is definitely associated with obesity in humans, but, until now, it was not clear whether this genetic variation was likely to influence obesity by altering the expression or function of the FTO gene itself or some neighbouring gene. This work shows that if mice lack the FTO gene they are very lean because they spontaneously burn off enormous amounts of energy. So it does seem that the FTO gene does have an effect on this aspect of energy balance in a mammalian relative of humans.

“This is a bit puzzling as several recent studies have suggested that the variant in the human FTO gene that increases the risk of obesity has effects on appetite and food intake but does not seem to have any effect on how quickly energy is burned off.

“So, this work provides a crucial piece of evidence supporting the notion that the FTO gene itself is likely to be involved in the effects of common human genetic variants on body fat. This finding will promote research into the development of drugs that modulate FTO activity. We strongly suspect that, in man, FTO might have more complex effects on both food intake and energy expenditure than has been so far suggested and that it is still not clear what the overall effect of inhibiting FTO in humans would be.”