Methods: A biallelic polymorphism of the methylenetretrahydrofolate reductase (MTHFR) gene, reported to influence the plasma level of homocysteine (Hcy), was investigated for a possible role in influencing the risk of ischaemic cerebrovascular disease (ICVD) and occlusive atherosclerosis in 126 patients with ischaemic stroke and 70 patients with internal carotid artery (ICA) stenosis.
Results: Only minor differences were observed between different groups of patients and control subjects. Although 47% of ICA stenosis patients had increased plasma Hcy, the MTHFR genotype did not correlate with levels of either Hcy, folic acid or vitamin B12. In addition, the MTHFR genotype did not affect Hcy levels, even in the presence of low blood folate.
Conclusion: We conclude that this common MTHFR gene polymorphism does not exert a significant influence on the risk of developing ICVD or ICA stenosis, and does not cause the increased level of Hcy observed in ICA stenosis.