Not all cases of weight gain can be attributed to lack of willpower or excessive consumption of high calorie foods. In rare situations, obesity is triggered by genetic factors, which Canadian researchers found are more prevalent than previously estimated.
Their work not only provides more insight into the genetic causes of obesity, but it could also be used to help millions of people all around the world take back control over their weight problem.
According to senior study author David Meyre, associate professor at the McMaster University in Ontario and Canada Research Chair in Genetics of Obesity, a deeper understanding of a particular gene and the way it functions pinpoints to the faulty biological mechanism responsible for the onset of obesity.
79 Genetic Syndromes Linked To Obesity
After looking into seven different databases and reviewing 161 papers cited in medical literature on this topic, researchers at the McMaster University and the University of British Columbia discovered the number of genetic conditions associated with obesity far exceeds prior calculations.
The team led by Meyre found a staggering total of 79 genetic syndromes, as opposed to just under 30 formerly known.
"These syndromes, although individually rare, are much more numerous and diverse than anticipated," said Yuvreet Kaur, first author of the study and BSc at McMaster University.
In 19 of these cases, the syndromes were clarified through genetics, reaching the point where the condition could be detected via a plain lab test.
A group of 11 other syndromes were partly resolved, whereas another 27 syndromes were linked to specific chromosomes. The remainder 22 syndromes are yet to be attributed to any genetic origin or chromosomal location.
The new findings were featured March 27 in the journal Obesity Reviews.
Genetics Could Point To Targeted Therapies
Meyre clarified several of the more frequent syndromes have been treated with hormone therapy, which proved effective in alleviating their symptoms. As he puts it, solving the genetics behind each syndrome would allow researchers to establish the most suitable course of treatment.
One example is leptin, the "satiety hormone," whose genetic origin was discovered in 1990 and has greatly contributed to the subsequent comprehension of adipose cells.
His research primarily targeted monogenic forms of obesity, in which the presence of a genetic mutation automatically triggers the onset of weight gain.
In these extremely rare cases — which occur in just 0.5 percent of obese Canadians, literally one in a million — the syndromes provoke not only obesity, but "many additional clinical features, such as intellectual disability, facial and organ-specific abnormalities," detailed Meyre in a news release.
His hope is that the study will enable medical professionals to identify these syndromes in their patients and provide appropriate treatments.
Canadian statistics report nearly 20 percent of the population is obese, while in the United States obesity rates are even higher, at over 30 percent, with southern regions holding the record of America's fattest cities.