Scientists have discovered a new cause of why people who lack a specific blood group are genetically predisposed to be overweight or obese. 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. SMIM1 was only identified 10 years ago, whilst searching for the gene encoding a specific blood group, known as Vel.
One in 5,000 people lack both copies of the gene, making them Vel-negative. The findings from the new research suggest that this group is also more likely to be overweight, a conclusion which could one day lead to new treatments. The team now hopes to test whether a cheaply and widely available drug for thyroid dysfunction may be effective in treating obesity in people who lack both copies of SMIM1.
The study also found that people without both copies of the gene have other measures linked to obesity including high levels of fat in the blood, signs of fat tissue dysfunction, increased liver enzymes as well as lower levels of thyroid hormones. The new research is published in Med and was funded by the National Institute for Health and Care Research and the British Heart Foundation. The collaboration included partners at the University of Cambridge, the Sanger Institute, the Copenhagen University in Denmark, and the Lund University in Sweden.
Lead author Mattia Frontini, Associate Professor of Cell Biology at the U.