Researchers have discovered that mutations in a single gene has been linked to cases of severe obesity, offering new gene therapy possibilities to fight against the global epidemic.
Obesity – having abnormal or excessive fat accumulation that may impair health (WHO) – is a major public health concern. In 2016, 650 million adults and 381 million children were obese. Over the past decades, the issue has grown in scale, as Worldwide obesity has nearly tripled since 1975. Even more worrying, the prevalence of obesity among children and adolescents aged 5-19 has risen dramatically from just 4% in 1975 to just over 18% in 2016. This condition is preventable.
The main drivers of the obesity epidemic are largely non-genetic, such as the combination of ready access to an unlimited supply of calorie-rich food and “increasingly sedentary lifestyles.” However, not everyone exposed to these environmental conditions becomes obese. Therefore, obesity is not only triggered by gluttony. This has prompted scientists to look into genetic factors that might increase chances of becoming obese.
A recent study, published in Nature Genetics on January 8th linked obesity to a genetic mutation. The team of researchers from the Imperial College London, focused on the genetic profiles of a community of children living in a specific region in Pakistan. This region was chosen because its population displays a high level of consanguinity (inter-family relationships). As a result, parents who are closely related are more likely to be carrying the same mutation.
What’s more, previous studies in obese Pakistani children found that nearly 30 percent of cases have some genetic link which is passed down from generation to generation. This new study used genome sequencing and found mutations in one specific gene related to obesity: adenylate cyclase 3 (ADCY3). When mutations occur in ADCY3, the protein it codes for forms abnormally and as a result, a variety of biological functions don’t function properly -including appetite control.
After identifying the mutations in the Pakistani patients, the researchers entered their results into a program called GeneMatcher, that connected them two other groups of scientists in the Netherlands and Denmark. Both had led similar studies, and found a link between ADCY3 mutations and obesity. Professor Froguel, head of the British team, noted these findings may lead to new obesity treatments. Knowing precisely which genetic mutations lead to obesity will enable researchers to come up with drugs that target these mutations specifically, he explained.
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