1. The MTHFR gene C677T polymorphism results in the decrease of MTHFR activity, causing elevated homocysteine levels, cause cytotoxicity, vascular endothelial cell damage, stimulating vascular smooth muscle cell proliferation, destroy the body's blood coagulation and fibrinolytic system, eventually leading to atherosclerosis, increase the risk of cardio-cerebrovascular disease such as coronary heart disease, cerebral infarction.
2. MTHFR C677T gene polymorphism leads to the obstruction of the conversion of homocysteine to S-adenosine methionine, which affects the synthesis of methionine or S-adenosine methionine and the methylation process in lymphocytes. Since DNA methylation affects gene expression, MTHFR C677T gene polymorphism can lead to defective cell growth transmission or carcinogenesis.