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Single Gene Mutation Responsible for Uncontrolled Obesity


A new study by researchers at Georgetown University Medical Center has determined that a single gene mutation is responsible for a type of uncontrolled obesity.

The study which is published on the website of Nature Medicine identifies how the single gene mutation involved, fails to pass along appetite suppressing signals from the body to the appropriate location within the brain. The mutation causes a malfunction in which brain neurons are unable to properly pass along chemical signals from leptin and insulin. This results in a voracious and uncontrolled appetite.

Under normal circumstances, the release of these hormones takes place following an intake of food in order to prevent over-eating and signal that the person is “full”. Without these brain signals reaching the correct location in the hypothalamus, there is no indication of satiety.

Researchers in the study used mice to examine the link between the gene mutation and obesity. The gene in question is responsible for producing a growth factor which in turn, controls communication (signals) between neurons. The mice also suffered from learning and memory problems as well as obesity due to the mutated gene.

Large scale studies have already shown that genetic variations are linked to obesity in humans, but until this study the actual process involved was unknown.

Leptin and insulin regulate the production of the growth factor which stimulates the chemical messages across neurons. Without the brain-derived neurotrophic factor (BDNF) the messages are not properly received, and the person’s appetite goes unchecked. The result is uncontrolled over-eating and obesity.

Thanks to this discovery, the researchers are hoping to explore new treatments for obesity. One possibility involves medication that would be able to stimulate BDNF within the hypothalamus. This would “repair” the neural pathways and enable the brain process by which the leptin and insulin signals are able to effectively modify the appetite.

Source: Medical News Today

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