Gene clue in obesity research

Your appetite may be influenced by your genetic make-up, according to a new study by a group of UK, US and French researchers. People who inherit an altered version of the GAD2 gene are more likely to give in to hunger and overeat, say the team, who published their findings in the freely available Public Library of Science Biology (PLoS Biology) journal last week. Lead researcher Philippe Froguel, based at Imperial College London, stressed that obesity was a complex problem, which cannot be explained by one factor alone. But he said by identifying one of the genes involved 'it may be possible to develop a screening programme to identify those who may be at risk of becoming obese in later life, and take effective preventative measures.

The scientists analysed DNA samples from 575 obese people, and compared them with those taken from 646 people of normal weight. They also questioned the participants, who all lived in France, on their eating habits. They found that those who inherited a particular version of GAD2 were more likely to be obese. Interestingly, another variant of the gene appeared to confer protection from obesity. The researchers think that variations in the protein made by GAD2 (called GAD65) could affect a person's appetite by altering levels of another brain protein, called GABA (gamma aminobutyric acid). This chemical messenger triggers the desire to eat, so anything that affects its activity could have an effect on appetite and body weight, the researchers say.

Obesity increases the risk of cancer, diabetes, heart attacks and strokes. Froguel says that although genetic factors alone cannot explain the rapid rise in obesity, they may provide clues to 'preventative and therapeutic approaches that will ease the health burden associated with obesity'. But as many as 250 different genes may be linked to obesity, cautions Ian Campbell, chairman of the National Obesity Forum. 'If we can identify genes which have a particular prominent influence on obesity that would be useful, but it wouldn't necessarily make treatment any easier' he told BBC News Online.