More than a third of individuals in the populations studied carry one copy of the at-risk variant and are at an approximately 45% increased risk of the disease compared to controls; 7% carry two copies and are at a 141% greater risk, the scientists report.
“Importantly, virtually all of this risk can be captured by looking at a single-letter change in DNA – ideal for the development of a genetic test for assessing individual risk and developing more personalized and effective prevention strategies,” said Kari Stefansson, CEO of DeCode and senior author on the study. “This is also an exciting starting point for the discovery of new drugs, and we are actively pursuing the development of both diagnostic and therapeutic products to better prevent and treat type 2 diabetes.”
The variant is located in a gene encoding a protein called transcription factor 7-like 2 (TCF7L2). DeCode isolated the gene by following up on the results of a population-based, genome-wide linkage scan in Iceland that identified a promising region on chromosome 10.
The original finding was made in Iceland and was subsequently confirmed in studies in Denmark and the US. The scientists reported their findings in the journal Nature Genetics.