Methionine synthase reductase 66A→G polymorphism is associated with increased plasma homocysteine concentration when combined with the homozygous methylenetetrahydrofolate reductase 677C→T variant. - Vaughn,JD.; Bailey,LB.; Shelnutt,KP.; Dunwoody,KM.; Maneval,DR.; Davis,SR.; Quinlivan,EP.; Gregor,JF.; Theriaque,DW.; Kauwell,GP. (J Nutr, 2004)