Researchers find gene linked to obesity in children, adults

BDNF will produce fewer proteins that control the appetite, thus playing a strong role in obesity risk for adults and children. According to a press release from the National Institute of Health, a variation of a gene for brain-derived neurotropic factor, known as BDNF, has been found to lead to lower levels of the protein by the same name, which controls appetite. Obesity makes problems like cardiovascular disease, stroke, and type 2 diabetes even worse, placing strain on the country's health care systems.

The way the process can work, according to this study, is by operating a genetic change on the BDNF gene and thus affecting its protein levels. The authors propose that boosting BDNF protein levels may offer a therapeutic strategy for people with the genetic variation, which tends to occur more frequently in African Americans and Hispanics, than in non-Hispanic Caucasians. Their study, published in Nature Medicine's website, suggested there might be a way to stimulate expression of that gene to treat obesity caused by uncontrolled eating.

This BDNF protein is important since it is responsible for providing a feeling of contentment which hopefully comes after a meal. Researchers were able to analyze brain tissue samples and identify an area of the gene where one single change altered BDNF levels in the hypothalamus, a part of the brain that controls eating and body weight.

The study examined BDNF genes in four groups containing over 31,000 people.

"The BDNF gene has previously been linked to obesity, and scientists have been working for several years to understand how changes in this particular gene may predispose people to obesity", explains Dr. Jack Yanovski, who is an investigator at the Eunice Kennedy Shriver National Institute of Child Health and Human Development. It was led by Joan C. Han, researcher at the University of Tennessee Health Science Center.

The genetic change identified by researchers does not constitute a rare mutation. People who had two copies of gene "T" were compared with the ones with one or two rare gene "C", eventually. The fact that the existence of this single gene in a few people, more commonly found in Hispanic and black people than white people as the study found, and the fact that it represents a specific cause of obesity in a few, can help doctors find more effective and personalized treatments for many patients. Every person has two copies, or alleles, of each gene, inheriting one copy from each parent. Alleles can vary at any location across the gene. "If these findings are supported by additional studies, boosting BDNF levels may prove beneficial", said Han. The CC genetic combination has been linked with higher body fat and BMI than Connecticut and TT combinations.

In African Americans and Latinos, the team found that Connecticut and CC combinations were associated with a higher risk of obesity and weight gain in both adults and children.