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Homocysteine metabolism

Homocysteine is converted to methionine by receiving a methyl group from 5-methyltetrahydrofolate (active form of folate; betaine). Irreversible removal of homocysteine occurs via the transsulphuration pathway, which combines Hcy with serine to form cystathionine. B6: vitamin B6, B12: vitamin B12, BHMT: betaine homocysteine methyltransferase, CBS: cystathionine beta synthase, CTH: cystathionine gamma ligase, DH: dihydro, DMG: dimethylglycine, HCy: homocysteine, Met: methionine, MS: methionine synthase (MTR gene), MHTFR: methylenetetrahydrofolate reductase, TH: tetrahydro. Adapted from (Larsson et al 2019).

Associated Disorders

  • Cerebral venous thrombosis
  • Deep venous thrombosis
  • Ischemic stroke
  • Myocardial infarction
  • Neural tube defects
  • Peripheral vascular disease
  • Pulmonary embolism