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Showing posts from April, 2015


Introduction: Homocysteine is a sulphur containing amino acid that is produced during the conversion of methionine to cysteine. Hyperhomocysteinemia results when there is an abnormality in the homocysteine metabolism. It is an independent risk factor for stroke, MI, peripheral arterial disease and venous thrombotic disease. Even mild to moderate hyperhomocysteinemia is a significant risk factor for vascular disease. Pathophysiology: The amino acid homocysteine is normally metabolized via the transsulfuration pathway by the enzyme cystathionine-β-synthase (CBS), which requires vitamin B6 as co-factor and via the remethylation pathway by the enzymes methylenetetrahydrofolate reductase (MTHFR), which is folate dependent and methionine synthase, which requires vitamin B12 as co-factor. 1 - Methylenetetrahydrofolate reductase 2 - Methionine synthase Hyperhomocysteinemia can be either: 1) Inherited or 2) Acquired. Inherited Inherited severe hyperhomocyste