Gene mutation may lead to obesity

Researchers believe they have discovered a gene mutation that blocks the body’s message to stop eating when full.

Researchers believe they've discovered a gene mutation that blocks the body's satiety signals.

Scientists at Georgetown University Medical Centre found that a mutation in the brain-derived neurotrophic factor (Bdnf) gene in mice disrupted the brain’s response to leptin and insulin, appetite hormones that tell the brain the body is full.

The study, published in Nature Medicine, may explain cases of obesity caused by an out-of-control appetite.

“If there is a problem with the Bdnf gene, neurons can’t talk to each other, and the leptin and insulin signals are ineffective, and appetite is not modified,” said Baoji Xu, the study’s senior investigator.

The mice that had been genetically modified to have the mutation ate 80 per cent more food than mice without the mutation and grew to be severely obese.

Humans also have the Bdnf gene and it has been linked to obesity in previous studies, but researchers say until now it was not evident how the gene controlled weight.

Xu said the discovery could lead to strategies to help the brain control body weight, such as a drug that activates Bdnf expression.

Photo © Lauren Mitsuki