Heterozygous methylene tetrahydrofolate reductase mutation with mild hyperhomocysteinemia associated with deep vein thrombosis

Hyperhomocysteinemia is known to be associated with arterial occlusive vascular disease and venous thrombosis. Here we report a young ethnic Omani patient with recurrent venous thrombosis who was found to be heterozygous for the C677T mutation in the enzyme methyltetrahydrofolate reductase (MTHFR). Moderate hyperhomocysteinemia was also documented in the presence of normal red cell folate and serum B₁₂ levels. No other marker usually associated with hereditary thrombophilia could be demonstrated in the patient, despite extensive investigations on multiple occasions.