THINNESS LIES IN OUR GENES, FINDS A NEW STUDY

A study that examined DNA of 95,000 people shows that individuals that stay extremely thin all their lives might have extra copies of genes on chromosome 16. This genitic condition seen in one in 2000 people makes men 23 times more likely to be very skinny. "The genome is full of holes where genes are lost, and in other places. We have extra copies of genes. In many cases, duplications and deletions have no effect, but occasionaly they can lead to disease," says professor philippe froguel from imperial college london, lead author of study. Half of the children found to have this duplication were diagnosed with reduced appetites indicating that unwillingness to eat might be "genetically driven". A quarter of people with the duplication have microcephaly, a condition in which the head and brain are abnormally small, which is associated with neurological defects and shorter life expectancy. The same gene when missing a copy, was found to greatly increase the chance of obesity. "It's also the first example of deletion and a duplication of one part of genome having opposite effects. At the moment we don't know anything about the genes in this region. 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," says professor Froguel.