Lack of a gene can make some people more likely to be obese, a new study claims.
In a novel revelation, scientists have unearthed a curious link between the absence of the SMIM1 gene in blood and a heightened risk of obesity.
SMIM1 is a gene that encodes a small, conserved protein that participates in red blood cell formation. A team of international researchers, led by the University of Exeter, discovered that people with a genetic variant that disables the SMIM1 gene have higher body weight because they expend less energy when at rest.
Previously known for its role in the production of the Vel blood group antigen, this gene has now been implicated in metabolic processes that influence body weight. Individuals lacking this gene in their blood were found to be more susceptible to obesity.
The study also found that such people are vulnerable to fat tissue dysfunction, increased fat levels in blood, increased liver enzymes as well as lower levels of thyroid hormone. The new research published in Med, and funded by the National Institute for Health and Care Research (NIHR) and the British Heart Foundation, hopes to find tailored treatments to these concerns.
Obesity rates have nearly tripled in the past 50 years, and by 2030, more than one billion individuals worldwide are projected to be obese, says Lead author Mattia Frontini, Associate Professor of Cell Biology at the University of Exeter Medical School.
"This is due to an imbalance between energy intake and expenditure, often a complex interplay of lifestyle, environmental and genetic factors. When genetics are the key determinant, new treatments can sometimes be found to benefit those people -- and we're now hoping to run a clinical trial to find out whether widely-available drug for thyroid supplementation may be beneficial in treating obesity in people who lack SMIM1," he said.
The researchers examined the genetic makeup of close to 50,000 members of the UK Biobank cohort - a large biomedical database and research resource that follows people long term, and the NIHR National Bioresource, to arrive at this conclusion.
If the results from the cohorts are extrapolated, it is estimated that the SMIM1 variation may have a major role in obesity issues of around 3, 00,000 people or more worldwide. There is a significant variation in the body weights: Women with the gene mutation weighed an extra 4.6 kilograms, and men with the variant weighed an extra 2.4 kilograms than the normal average.
Co-author Jill Storry, Adjunct Professor at Lund University, Sweden, said, "SMIM1 was only discovered a decade ago, as a long-sought blood group protein on red blood cells, but its other function has remained unknown until now. It's very exciting to find that it has a more general role in human metabolism."
The team hopes their findings highlight the need to investigate the genetic cause of obesity -- not only to select the most appropriate and effective treatment, but also to reduce the social stigma associated with it.