Effects of polymorphisms of methionine synthase and methionine synthase reductase on total plasma homocysteine in the NHLBI Family Heart Study. - Jacques,P.F.; Bostom,A.G.; Selhub,J.; Rich,S.; Ellison,R.C.; Eckfeldt,J.H.; Gravel,R.A.; Rozen,R. (Atherosclerosis, 2003)