A newly discovered genetic alteration may explain why some people with diabetes are more prone than others to severe, life-threatening complications of the eye and kidney.

Dr. Kang Zhang from the University of Utah in Salt Lake City, and colleagues examined more than 600 diabetic patients for single letter changes or polymorphisms (also called SNPs) in their DNA. They found a genetic change associated with diabetics having an increased frequency of severe eye disease called retinopathy and end-stage renal disease (ESRD), the most severe form of kidney disease.

Follow up studies involving nearly 1,500 patients confirmed that diabetics with the newly identified genetic alteration had a heightened risk for severe eye and kidney disease, despite their best efforts to control their blood sugar levels.

In the journal Proceedings of the National Academy of Sciences, the scientists note that these two complications of diabetes are caused by excessive growth of blood vessels. The specific SNP they identified occurred near the erythropoietin (EPO) gene, which encodes a protein that stimulates blood vessel growth and red blood cell production and is illicitly used for sports doping.

“Our findings,” Zhang and associates conclude, “support a key role for erythropoietin in genetic susceptibility to proliferative diabetic retinopathy and ESRD and identify a potentially pathogenetic mechanism for advanced diabetic eye and kidney complications.”

SOURCE: Proceedings of the National Academy of Science, May 13, 2008.