The results of genetic testing for Type 2 diabetes are not significantly better than an assessment based on traditional risk factors for the disease, a new study published today in the New England Journal of Medicine has found. Many risk factors for Type 2 diabetes are well known, including weight, blood pressure and blood sugar levels.

For the study, Dr. James Meigs, an assistant professor at Harvard Medical School and Massachusetts General Hospital, Boston, and his colleagues examined 18 gene mutations associated with type 2 diabetes in 2,377 people participating in the Framingham Offspring Study. These participants were followed for 28 years, during which time 255 developed type 2 diabetes. The researchers compared the patients’ genotype score to their family history and other risk factors, such as obesity, age, blood pressure, cholesterol, fasting glucose and tryglyceride level. They found a difference of only 4% between the old fashioned methods of predicting risk and genetic testing.

In a separate study, published in the New England Journal of Medicine, researchers from Sweden’s Lund University and colleagues looked at 16 gene variants associated with type 2 diabetes in 16,061 Swedish and 2,770 Finnish individuals. The results were similar: genetic screening performed only slightly better than traditional methods of predicting who would get the disease.

Genetic testing identifies changes in chromosomes, genes, or proteins. The human genome is believed to contain around 20,000-25,000 genes. It includes biochemical tests for the possible presence of genetic diseases, or mutant form of the genes associated with an increased risk of developing genetic disorders. When interpreting test results, healthcare professionals consider a person’s medical history, family history, and the type of genetic test that was done.