Scientists Identify New Genetic Variant Related to Obesity

Researchers from the IMDEA Food Institute identified a new gene variant that correlates with the probability of having a high Body Mass Index (BMI), a common indicator of being overweight or suffering from obesity. The team recently published their findings in the journal Genome Biology.

The Connection Between Genetics and Obesity

Excessive adipose tissue accumulation causes obesity and constitutes a health risk. According to the World Health Organization (WHO), obesity is one of the most alarming health problems globally, with a body mass index (BMI) exceeding 30kg/m2 defined as an obese state. An elevated BMI strongly associates with several metabolic abnormalities, including insulin resistance and metabolic syndrome, cardiovascular diseases (CVDs), and cancer. 

Both genetic and environmental factors contribute to the development of overweight and obesity, while lifestyle habits such as excessive caloric intake and insufficient physical activity are the critical drivers. As for the general population, the genetic influence is around 20% according to previous studies that have analyzed the complete genome of tens of thousands of people, which means genetic factors also play an important role in body weight.

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Providing Insights on How Evolution Modifies Body Weight

To search for genetic variants that influence the phenomenon and the associated metabolic alterations, the team collected genetic material and data such as weight, BMI, total and visceral fat, muscle mass, and waist and hip circumferences from 790 healthy volunteers.

The researchers then analyzed the possible associations of these parameters with 48 specific genetic variants selected for their possible functional relevance. Finally, they came up with a significant correlation between one of these variants in the FNIP2 gene and many of those obesity-related parameters.

Next, the team studied the effect of this variant in mice, which were genetically modified to express it. As for the result, mice with this variant have between 10% and 15% less fat than their non-carrier counterparts. However, in humans, the effect of this variant cannot be isolated from that of the many other genetic and environmental variables that influence physique, so it is impossible to estimate precisely the strength of its effect. 

Given that the influence of genetics on obesity does not exceed 20%, the contribution of the variant now identified is necessarily small. Thus, the current interest of scientists would be to understand the molecular basis of what this genetic variant does, including its biochemical pathway in cells. 

Author

Nai Ye Yeat