deCODE to integrate new genetic risk factor for type 2 diabetes into its personal genome scan service

Dec 8 2008

deCODE genetics has announced the discovery by an international consortium of scientists from deCODE and major European and US academic institutions of a single letter variation in the human genome (SNP) that is associated with increased fasting glucose levels and risk of type 2 diabetes (T2D).

deCODE will employ its CLIA-registered genotyping laboratory and existing testing platform to swiftly integrate the finding into its deCODEme(TM) personal genome scan, and to assess the addition of this new variant to the company's deCODE T2(TM) reference laboratory test for assessing individual risk of type 2 diabetes.

The multinational study analyzed a number of SNPs that had been suggestively linked with fasting glucose levels in several major studies involving some 36,000 individuals from Europe and the United States. The analysis identified a version of single SNP within the gene encoding melatonin receptor IB (MTNR1B) that was associated with notable increase in fasting glucose levels. The deCODE team then demonstrated in its Icelandic cohort that this SNP also associated with an increased risk of T2D, a finding that was then replicated in a meta-analysis of data from more than 80,000 cases and controls from Europe and the US. Approximately 10% of the participants in this study carry two copies of the at-risk version of this SNP, putting them at more than 15 percent greater risk of type 2 diabetes than individuals who carry no copies. The paper, entitled "Variants in MTNR1B influence fasting glucose levels," is published today in the online edition of Nature Genetics, and will appear in an upcoming print edition of the journal.

"This finding is another step towards rounding out our understanding of the genetic factors that underpin glucose regulation and risk of type 2 diabetes. This variant does not confer sufficient risk to be of clinical utility on its own. But when measured in addition to our TCF7L2 variant that is the anchor of the deCODE T2(TM) test, it may, like other common variants conferring modest risk, enable the test to capture an even larger proportion of inherited risk. We are currently evaluating its integration into deCODE T2(TM), because understanding genetic risk of T2D enables individuals and their physicians to focus, personalize and improve prevention. In the meantime, we will be enabling our deCODEme subscribers to check their profiles for this new variant, keeping them at the cutting edge of human genetics," said Kari Stefansson, CEO of deCODE.

T2D is a chronic condition that develops when the body either becomes resistant to or doesn't secrete enough insulin. Diabetes affects nearly 200 million people worldwide and, according to the American Diabetes Association, some 21 million in the United States. The vast majority of these have T2D, and as many as one third of Americans with diabetes may not even be aware that they have the disease. More than 50 million Americans have pre-diabetes, a condition characterized by elevated blood glucose levels and which puts these individuals at high risk for developing T2D. T2D can be managed and - most importantly - prevented. If losing weight, eating better and getting adequate exercise aren't enough, there are also medications that can help to manage blood sugar levels and insulin response to reduce the likelihood of developing diabetes.