Methionine synthase and neural tube defects.

It has been indicated lately that higher plasma homocysteine is one of the risk factors in neural tube defects(NTDs) and vascular disease. Methionine synthase is a key enzyme in homocysteine metabolism. The defects of methionine synthase activity could result in hyperhomocysteinemia and methionine auxotrophy. The gene mutations of methionine synthase with the epidemiological studies of NTDs are reviewed in this paper. It is considered that the gene mutations of methionine synthase can not make a relation to NTDs and hyperhomocysteine, but methionine synthase reductase may be a clue for the study on NTDs in the future.