Obesity-related genes revealed in multi-ancestry study

The discovery of new associations between genes and obesity has highlighted the importance of including individuals of non-European ancestry in genetic studies.

Obesity affects millions of people worldwide, and is linked to major health problems such as type 2 diabetes, heart disease and high blood pressure. New research published in Nature Communications identified 13 obesity-related genes. Five of these have not been associated with obesity before, and were discovered because the study included the genomes of people from diverse ancestries and ethnicities.

'Obesity is a complex trait that is influenced by many genetic and lifestyle factors,' explained corresponding author Professor Santhosh Girirajan. 'Studies in a single population can lead us to miss important genes that are shared across populations but may not rise to statistical significance in any one of them, even if they are clinically important in that population.'

Studies like this use biobank data, where genome sequences are stored alongside medical records and data on metrics including body mass index (BMI). The researchers looked for links between high BMI and specific genetic variants. They focused on variants that disrupt gene function, since they are likely to have a significant effect on BMI if the gene is associated with obesity.

Importantly, the study used genetic data from two biobanks: UK Biobank and the US-based All Of Us. Both include participants of African, American, East Asian, European, Middle Eastern and South Asian ancestry. The authors highlighted that the inclusion of non-European populations was essential to identifying the new gene associations.

However, the study also highlights differences between populations: 'Some of the previously discovered obesity genes appear to only have significant association to obesity in Europeans, which could limit their potential as therapeutic targets for a global population,' said Professor Girirajan.

This study highlights the importance of diverse databases, but the authors say more progress is needed: 'New databases that include more representation of individuals with ancestries from around the world are helping to alleviate this bias, but we still need more data from non-European populations,' said Professor Girirajan.