MTHFR and coronary artery disorder: Further subgroup analyses per ethnic subgroups revealed that the MTHFR 677 TT and CT genotypes were associated with CAD risk in Caucasian, East Asian, South Asian, Middle-Eastern, and African groups, with RRs ranging from 1.11 to 2.56 for TT, and 1.18 to 1.36 for CT.