- Researchers know that genetics plays a role in obesity.
- Scientists from the University of Exeter Medical School have discovered that people lacking a specific blood type due to a genetic variant may be genetically predisposed to obesity or being overweight.
- Researchers believe that people lacking the SMIM1 gene could be treated with an already available drug for thyroid dysfunction.
Although some lifestyle factors play a role in obesity, researchers have realized that
For example, a study presented earlier this year found that children can inherit obesity from their parents. A study published in February 2023 linked
Scientists at the University of Exeter Medical School in England have discovered that people do not have a specific blood type due to a
Researchers believe that these people lack the
The study was recently published in the journal
For this study, researchers used genetic data from around 500,000 people from the UK Biobank and four other cohorts to identify those with a genetic variant that turns off the SMIM1 gene.
“SMIM1 is a gene that codes for a 68-amino acid protein that protrudes from the cell membrane on red blood cells,” explained Mattia Frontini, PhD, associate professor of cell biology at the University of Exeter Medical School and lead author of the study. Medical news today“Very little is known about this gene. The family to which it belongs is a set of genes which have in common the fact that they code for short transmembrane proteins. »
“The initial discovery of the gene and its defective copy 10 years ago was driven by the need to develop a genetic test for a blood type that is difficult to typify using traditional methods, known as
Using both genetic data and blood samples, Frontini and his team found that people with loss of SMIM1 gene function were more likely to be overweight.
“We found that people with two defective copies of the gene (SMIM1) – about 1 in 5,000 – are heavier than those who don’t have it. They have altered blood lipids and consume less energy for the same caloric intake. The excess will (be) stored as fat,” Frontini explained.
The researchers also found that people lacking SMIM1 gene function were more likely to have other obesity-related measures, including high blood fat levels, signs of adipose tissue dysfunction, and increased liver enzymes, as well as lower levels of thyroid hormones.
“What we found is that SMIM1 has an effect on the hypothalamus-pituitary-thyroid axis, which controls the production of many hormones. Lack of SMIM1 causes a mild form of hypothyroidism that results in reduced resting energy expenditure. In other words, these people consume less energy for the same caloric intake (meals), which results in the excess being stored as fat. This is a common phenomenon: almost 2% of the UK population receives thyroid supplementation, which is an effective and inexpensive treatment,” explained Frontini.
“For the first time, we have linked this gene (SMIM1) and its product to the control of metabolism. Further research is now needed to determine whether the gene is part of an entirely new pathway or whether it feeds into one of the many known pathways that control metabolism.
— Mattia Frontini, Ph.D.
After reviewing this study, Hans J. Schmidt, MD, director of the Center for Weight Loss and Metabolic Health and chief of minimally invasive and bariatric surgery at Hackensack University Medical Center in New Jersey, said: MNT There is no doubt that in many cases obesity has a genetic cause.
“Some people gain weight easily and others eat whatever they want and never gain a pound. These are many genes involved in fat metabolism and storage, but in rare cases, a single genetic variant leads to obesity. This study shows that there is evidence suggesting a link between loss of function of the SMIM1 gene and excess weight. SMIM1 encodes a protein involved in the regulation of fat metabolism. In patients without the gene function, reduced energy expenditure leads to weight gain.
— Hans J. Schmidt, MD
“The patients in this study were being studied for genes coding for a specific blood type,” he continued.
“Researchers have also discovered a link with obesity. The best next step would be to engage other researchers, studying other genetic traits, to see if there is an association between other genes and weight – both in the overweight and in those who are underweight. to gain weight. The more we understand the genetic basis of obesity, the better we will be able to treat it,” Schmidt said.
MNT also spoke with Mir Ali, MD, a board-certified bariatric surgeon and medical director of the MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, Calif., about this study, which he said he found interesting .
“We have known for some time that obesity has a significant genetic component and is multifactorial: there is not just one gene that contributes to being overweight. But our genetics and hereditary factors play an important role in obesity,” Ali said.
“If we can identify genetic variants that may be predisposed to obesity, we may be able to intervene at an earlier age and perhaps find drugs and products that block or overcome this genetic variant.”
—Mir Ali, MD
“(And) it’s not just one thing to identify the genetic variant, but what is the best treatment for that type of variant? Look at different modalities and see if there are one or more things that could help these obesity-prone patients,” he added.