Researchers Find A Gene Variant Potentially Linked With Obesity

Obesity is one of the biggest problems facing our nation, and researchers have struggled for years to determine its causes.

Jack A. Yanovski, one of the study authors, said that this study explains how a single genetic change in BDNF influences obesity and may affect BDNF protein levels.

At high levels, the BDNF protein creates the sensation of fullness, letting a person know when they are done eating.

By working on samples of brain tissue the scientists involved in the study managed to affect BDNF levels in the brain, specifically in the hypothalamus, which is a part of the brain that controls eating and influences body weight.

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.

A rare version of the BDNF gene could predispose people to gaining weight, by producing lower levels of BDNF protein – a regulator of appetite – in the brain.

During their experiments, researchers referred to the common allele as “T”, and the less common allele – that which produces less BDNF protein – as “C”.

Health conditions such as strokes, diabetes and several heart diseases -all serious issues on the U.S.- are related to obesity, especially in children. The human body relies on these genes to regulate functions and to avoid the disbalance that occurs when excessive energy is stored and the weight increases. 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.

The genetic change identified by researchers does not constitute a rare mutation. Every individual has alleles or two copies of each gene, one copy inherited from each parent.

They studied the gene in four groups of people -more than 31,000 men and women- from several clinical research studies.

Joan C. Han, an investigator from the NICHD and the University of Tennessee’s Health Center and the lead of the research team that carried out the study, has been studying the BDNF protein for a while. Alleles can vary at any location across the gene.

After completing the combination, the researchers discovered that both Hispanic and black children with Connecticut or CC combination genes had higher body BMI AND fat percentages. The CC genetic combination has been found to be linked with higher BMI and body fat than TT or Connecticut combinations.

According to Dr. Han, the findings may lead to future studies that reveals more about the C allele, which could potential result in the development of a drug that can treat obesity. “If these findings are supported by additional studies, boosting BDNF levels may prove beneficial”.