"It is now clear that several drugs should be used together to control this disease. Our new study provides scientists developing treatments with a straightforward target for a new drug to treat type 2 diabetes," added Professor Froguel.

The researchers carried out a multistage association study to identify the new gene. First, they looked at genome-wide association data from 1,376 French individuals and identified 16,360 single-nucleotide polymorphisms (SNPs), or genetic variations, associated with type 2 diabetes. The researchers then studied these variations in 4,977 French individuals.

Next, the team selected the 28 most strongly associated SNPs and looked for them in 7,698 Danish individuals. Finally, the researchers identified four SNPs strongly associated with type 2 diabetes. The most significant of these variations was located near the insulin receptor substrate 1, or IRS1, gene.

To test their findings, the team analysed biopsies of skeletal muscle from Danish twins, one of whom had type 2 diabetes. They found that the twin with diabetes had the variation near IRS1 and this variation resulted in insulin resistance in the muscle. They also noted that the variation affected the amount of protein produced by the gene IRS1, suggesting that the SNP controls the IRS1 gene.

Source: Imperial College London