Missing Chromosome Piece Causes Extra Weight

A very specific class of obese patients may not owe their condition to a life of excesses, but to a missing set of genes that can no longer be found on one of their chromosomes. A research group has, in fact, determined that a piece of the chromosome is missing entirely. This may help scientists get a new perspective on devising cures and possible treatments for obesity, which would rely on using the genes usually located on the missing chromosome sections, ScienceNow reports.

According to preliminary analyses of the missing genes, it may be that one of them is directly involved in managing blood sugar and appetite levels inside the body. Without it, people feel like they need to eat at all times, and consume large amounts of sugar as well. This favors the onset and development of obesity and diabetes, two diseases that unfortunately go hand in hand in the United States today. The group that conducted the new research says that the finding helps explain a large number of obesity cases.

The disease is known to run in families, and thus far investigators from various study groups have been able to identify several genetic variants that they have linked to increased risks of obesity. But these genes only helped explain a small number of cases, critics to that course of investigation said at the time. In the new work, sections of the chromosome known as copy number variants (CNVs) have been found to be responsible for the increased risk. The portions are responsible for the difference in the number of copies of a certain gene that appear between different people.

In charge of the new study has been University of Cambridge endocrinologist Sadaf Farooqi, who has managed to peer into the chromosomes of 300 extremely obese children, in order to see which sections they have more or less of. A deletion from chromosome 16 has been found to exist in nearly all the test subjects, as opposed to normal children, of average weight. “This study shows for the first time that CNVs can cause a metabolic disease like obesity,” Farooqi says. Details of the investigation appear in the latest issue of the scientific journal Nature.