Scientists have discovered rare gene differences that could raise the risk of obesity by as much as six times.
A study by the Medical Research Council (MRC) identified genetic variants in two genes, BSN and APBA1, that have some of the largest impacts on obesity risk discovered to date.
More than a quarter (25.9 per cent) of adults in England are estimated to be obese, according to the latest Government figures. Obesity is a significant risk factor for other serious diseases, including heart disease and type 2 diabetes.
But until now, the genetic reason why some people are more prone to weight gain were not well understood.
The researchers used data from the UK Biobank to perform whole exome sequencing, an advanced type of genetic testing, of body mass index (BMI) in more than 500,000 people.
They found that variants in the gene BSN, also known as Bassoon, can raise the risk of obesity by up to six times.
It was also associated with an increased risk of non-alcoholic fatty liver disease and of type 2 diabetes.
These gene variants were found to affect one in 6,500 adults, suggesting they could affect about 10,000 people in the UK.
Professor Giles Yeo, study author based at the MRC Metabolic Diseases Unit, said: “We have identified two genes with variants that have the most profound impact on obesity risk at a population level we’ve ever seen, but perhaps more importantly, that the variation in Bassoon is linked to adult-onset and not childhood obesity.
“Thus these findings give us a new appreciation of the relationship between genetics, neurodevelopment and obesity.”
Professor John Perry, study author and an MRC investigator at the University of Cambridge, said: “These findings represent another example of the power of large-scale human population genetic studies to enhance our understanding of the biological basis of disease.
“The genetic variants we identify in BSN confer some of the largest effects on obesity, type 2 diabetes and fatty liver disease observed to date and highlight a new biological mechanism regulating appetite control.”
The findings are published in Nature Genetics.
