Homocysteine - Wikipedia, the free encyclopedia
Homocysteine [IPA: ˌhəʊməʊˈsɪstiːn] is a non-protein α-amino acid. It is a homologue of the amino acid cysteine, differing by an additional methylene bridge (-CH2-). It is biosynthesized from methionine by the removal of its terminal Cε methyl group. Homocysteine can be recycled into methionine or converted into cysteine with the aid of B-vitamins.
While detection of high levels of homocysteine has been linked to
cardiovascular disease, lowering homocysteine levels may not improve
A high level of homocysteine makes a person more prone to endothelial
injury, which leads to vascular inflammation, which in turn may lead to
atherogenesis, which can result in ischemic injury. Hyperhomocysteinemia is therefore a possible risk factor for coronary artery disease.
Coronary artery disease occurs when an atherosclerosis leads to
occlusion of the lumina of the coronary arteries. These arteries supply
the heart with oxygenated blood.
Hyperhomocysteinemia has been correlated with the occurrence of blood
clots, heart attacks and strokes, though it is unclear whether
hyperhomocysteinemia is an independent risk factor for these conditions.
It can cause miscarriage and/or pre-eclampsia in pregnant women, and
can lead to birth defects.