New Gene Hot Spots for Type 2 Diabetes
Multiple Genes Play Role in Susceptibility to Type 2 Diabetes
March 31, 2008 -- Researchers are six steps closer to finding a genetic fingerprint to identify people particularly susceptible to type 2 diabetes.
To climb the six steps, an international consortium of researchers crunched data from three studies of some 2.2 million single DNA changes across the entire genomes of more than 10,000 people, with replication testing in separate samples of up to 54,000 people.
In the end, Wellcome Trust researcher Eleftheria Zeggini, PhD, and colleagues found six new genetic variations that each increase a person's risk of type 2 diabetes. With the six additions, there are now 16 genetic variations independently linked to type 2 diabetes risk.
None of the 16 gene variations causes diabetes. In fact, each contributes only slightly to diabetes. But the more of these variations researchers find, the closer they are to finding a genetic fingerprint for diabetes risk.
"By combining information from the large number of genes now implicated in diabetes risk, it may be possible to use genetic tools to identify people at unusually high or low risk of diabetes," study researcher David Altshuyler, MD, PhD, of Massachusetts General Hospital, MIT, and Harvard say in a news release. "However, until we know how to use this information to prompt beneficial changes in people's treatment or lifestyle, widespread genetic testing would be premature."
Interestingly, the genetic variant that carried the highest diabetes risk has also been found to predispose men to prostate cancer.
It's hard to know what to make of that association -- other than the fact that this gene is also linked to low blood sugar in fetuses and newborns.
The other five new genes linked to type 2 diabetes risk also offer clues to the cause of diabetes. These genes encode proteins that play roles in:
- Disruption of the normal life cycle of cells
- Pancreatic cancer
- Cell death
- Pancreatic function
- The development of pancreatic stem cells
"Each of these genes, therefore, provides new clues to the processes that go wrong when diabetes develops, and each provides an opportunity for the generation of new approaches for treating or preventing this condition," study researcher Mark McCarthy, MD, of the University of Oxford, England, says in the news release.
Researchers from the U.S. National Human Genome Research Institute participated in the study. The study appears in the March 30 advance online issue of Nature Genetics.