Genetic clue to being too fat or thin discovered

Scientists have discovered that underweight people possess extra copies of certain genes. The lack of the same genes has previously been linked to obesity.

Last year the same team found that people with the gene deletions were 43 times more likely to be clinically obese.

Chief scientist Professor Philippe Froguel, from the School of Public Health at Imperial College London, said: “It’s the first example of a deletion and a duplication of one part of the genome (genetic code) having opposite effects.

“If we can work out why gene duplication in this region causes thinness, it might throw up new potential treatments for obesity and appetite disorders.

“We now plan to sequence these genes and find out what they do, so we can get an idea of which ones are involved in regulating appetite.”

Genes are stretches of DNA that provide the coded instructions for making proteins. They generally come in pairs and are housed in the chromosomes inherited from each parent.

However sometimes parts of either chromosome in a pair can be deleted or duplicated, producing too many copies of a certain gene or too few.