MTHFR and coronary artery disorder: In addition, those with the C677T mutations are believed to be at an increased risk for CAD, as well as cancers such as acute lymphoblastic leukemia and colon cancer. It is believed that roughly 10% of the population of North America is T-homozygous for the MTHFR polymorphism with Mediterranean individuals and Hispanics having the greatest frequency, Caucasians having the second highest and those of African origin and African Americans having the lowest prevalence [10].