by Katherine Kozlowski (Medical Writer)
The methylenetetrahydrofolate reductase (MTHFR) mutation is a polymorphism mapped on the first chromosome. Mutations on the MTHFR gene disrupt the conversion of homocysteine to methionine in the presence of Vitamin B12 and folic acid; Therefore, serum (blood) levels of Vitamin B12 and folic acid are inversely related to serum homocysteine levels.
What does all this mean? When vitamin B12 and folic acid levels are low, serum hoocysteine levels are high.
Hperhomocysteinemia, or high serum homocysteine levels, is a risk factor for vascular disease, both arterial and venous thrombosis.
The proposed meechanisms by which hyperhomocysteinemia produces a prothrombotic effect incudes impaired endothelial cell anticoagulant function, increasing procoagulat factors in the clotting cascade and inhibiting cofactors required for anticoagulant function.
Overall, hyperhomocysteinemia is estimated to increase the risk for developing deep vein throimbosis 2.5 to 3 fold.