Gene variation increases risk of diabetes

Scientists from the Medical College of Georgia, US, have found a gene variation that intensifies the immune response that causes type 1 diabetes. The discovery, to be published in August's edition of the journal Nature Genetics, may increase the accuracy of neonatal tests that determines the likelihood of a child developing the disease.

Type 1 diabetes has no single cause, but high levels of molecules known as cytokines, have previously been associated with the disease. The new discovery by the American research team explains these high levels: an alteration in a gene known as SUMO-4, which controls production of cytokines.
The researchers discovered the link between diabetes and SUMO-4 by looking at nearly 1000 families, comparing the genes of diabetic parents with their diabetic offspring. The researchers then focused their efforts on those gene variations common to both.

SUMO-4 is the fourth gene found to increase the risk of diabetes, though scientists expect there are around 20. Of the four discovered, a variation in a gene known as HLA is the highest risk factor, with SUMO-4 second. Dr Jin-Xiong She, an author of the report, said, 'This helps us understand how type 1 diabetes works, and we can use this improved understanding to better predict who will get the disease and design new intervention strategies for those that do'.

Type 1 diabetes usually develops in childhood and is caused by the child's immune system attacking and destroying the insulin-producing cells of the pancreas. Sufferers are treated with frequent injections of artificially produced insulin. Without insulin, the patient's cells take up less glucose from the blood, resulting a condition known as hyperglycaemia. Although no cure exists, gene therapy and the use of stem cells look promising.