Largest study on genetic risk for type 2 diabetes published

An international study of more than 2.5 million people has identified parts of the genome associated with the risk of developing type 2 diabetes in diverse population groups from across the globe.

The study potentially paves the way for genetically determined predictors of disease complications to allow earlier interventions.

Published in Nature, the study co-led by Professor Andrew Morris from The University of Manchester is a collaboration of more than 350 authors from 130 studies around the world and the largest type 2 diabetes genome-wide association study to date.

The researchers scanned complete sets of DNA (genomes) from 2.5 million people – a sample size almost three times larger than in previous studies – to identify variations in the genetic sequence associated with the development and progression of type 2 diabetes.

More than 400 million people worldwide are living with type 2 diabetes, a condition which occurs when the body is not able to make enough of the hormone insulin, causing the level of sugar in the blood to become too high.

Left untreated, high blood sugar levels can cause serious health problems and complications that affect  the eyes, kidney and nerves. People with type 2 diabetes are also more likely to suffer from heart disease and stroke.

As well as factors such as weight and exercise, the risk of developing type 2 diabetes, which is the most common type of diabetes, is also linked to genetics. Variations of the genetic code can increase the risk of developing type 2 diabetes and its complications, which can be passed down through families.

The research team revealed over 600 places in the genome -  a biological blueprint needed for life to exist - which increase the risk of type 2 diabetes, of which 145 had previously been unidentified.

The DNA of more than 2.5 million people were analysed, including 428,452 people who have type 2 diabetes from six different ancestry groups: African American, East Asian, European, Hispanic, South African and South Asian.

Studying a range of ancestry groups ensures that the findings of the research are relevant to diverse populations across the globe, where type 2 diabetes is a major health concern.

For the first time across multiple ancestry groups, the team were also able to generate genetic risk scores associated with developing harmful type 2 diabetes complications such as coronary artery disease and diabetic kidney disease.

Senior co-corresponding author Professor Andrew Morris, Professor of Statistical Genetics at The University of Manchester and the National Institute for Health and Care Research (NIHR) Manchester Biomedical Research Centre (BRC), said:

“Our work has improved our knowledge of the biological processes that lead to the development of type 2 diabetes and progression to its complications in diverse population groups across the world.

“Better understanding of the genetic causes of the disease has the potential to allow us to predict these complications before they occur and may help put in place early interventions to delay or even prevent these debilitating medical conditions."