An international team of researchers from Europe, the United States, and Canada, while investigating DNA and type 2 diabetes, has found 12 new gene links that offer important clues to how this chronic disease works. They state that their findings, which were published in the journal Nature Genetics, will improve understanding of what lies behind type 2 diabetes and suggest new biological processes that can be explored as possible targets for new medicines. Type 2 diabetes is caused by the body’s inability to adequately use insulin produced in the pancreas to control glucose sugar produced from food. An estimated 180 million people worldwide now have diabetes. The identification of 12 new genes brings the total number of genetic regions known to be linked with type 2 diabetes to 38. These new genes tend to be involved in the working of pancreatic cells that produce insulin and in the control of insulin’s action in the body. Each of the gene variants carried only a very small effect on diabetes risk, and even combined, their capacity to predict future diabetes risk was modest. However, several of the genes seem to be important in controlling the number of pancreatic beta-cells a person has. These cells produce insulin, and this result would help settle a long-standing puzzle about the role of beta-cell numbers in type 2 diabetes. It also points to the importance of developing therapies that are able to preserve or restore depleted numbers of beta-cells. The research team used gene sequencing technology to compare the DNA of more than 8,000 people with type 2 diabetes with almost 40,000 people without the condition at almost 2.5 million places across the genome. The researchers then checked the genetic variations they found in another group of more than 34,000 people with diabetes and approximately 60,000 more people without it. Another interesting finding was that the diabetes susceptibility genes also contain variants that increase the risk of other unrelated diseases, including skin and prostate cancer, heart disease, and high cholesterol, implying that different regulation of these genes can lead to many different diseases.
(Source: Nature Genetics via Reuters online, June 27, 2010; view at link.reuters.com/hab64m)
