A common test used to diagnose type 2 diabetes is influenced by 60 genetic variants, according to a study by an international team of scientists. One genetic variant which is found only in African Americans significantly reduces the accuracy of the HbA1c blood test used to diagnose and monitor type 2. As a result, as many as 650,000 African Americans in the U.S. could have undiagnosed type 2 diabetes if tested only with the HbA1c test. Using other diagnostic tests in patients with African ancestry could help improve accuracy. Read more