Obesity genes found to be shared across ethnic groups - study

While lifestyle plays an important role, genetics also makes a significant contribution. A new study by scientists at the University of Pennsylvania has identified 13 genes associated with obesity in people from six different ethnic backgrounds.

The results are published in the journal Nature Communications.

The study involved about 850,000 adults from six continental groups: African, American, East Asian, European, Middle Eastern and South Asian.

Of the 13 genes found, eight had already been mentioned in previous studies, including the well-known MC4R and BSN. However, five genes - YLPM1, RIF1, GIGYF1, SLC5A3 and GRM7 - are linked to obesity for the first time. They may increase the risk of severe obesity by about threefold, the analysis showed.

"Previous work has mainly focused on populations of European descent," says the study's lead author, PhD student Dipro Banerjee. - This creates bias and misses genes that are more common in other populations, but are still clinically important in Europeans as well."

The team analysed data from two biobanks: more than 450,000 participants from the UK Biobank and about 385,000 from the US National Institutes of Health's All of Us programme, which seeks more diverse ethnic representation.

The scientists paid particular attention to rare mutations that disrupt gene function. It is these mutations, they said, that are most likely to cause serious diseases. It turned out that the newly discovered genes are expressed in the brain and adipose tissue and are associated with an increase in the percentage of body fat.

In addition, the study found that many of these genes influence comorbidities including type 2 diabetes, hypertension and heart failure. Using the statistical method of mediator analysis, the team found that some genes increase the risk of these diseases both directly and through increased body mass index (BMI).

For example, the genes BSN, GIGYF1 and SLTM increased the risk of type 2 diabetes both directly and indirectly through obesity. The direct effect was stronger.

In some of the participants, the researchers also analysed plasma proteins. This helped identify obesity-related changes that could become targets for future drugs or biomarkers of therapy efficacy.

"Our work highlights the importance of cross-analyses between populations," said Professor Santhosh Girirajan. - 'Many genes previously linked to obesity show a significant association only in Europeans. But we have found new genes with comparable effects that may be relevant to other groups as well."

The scientists hope that such studies will help develop more accurate and universal approaches to obesity treatment, targeting patients' specific genetic characteristics.