Introductory Chapter: General Aspects Regarding Homocysteine

Abstract

The first description of homocysteine (Hcy), a non-proteinogenic amino acid, was introduced within a case study in 1932. The first patient was an 8-year-old child with a mental retardation disorder who died of a myocardial infarction. Meanwhile, research continued; in 1969, Dr. Kilmer McCully was the first to describe the vascular pathology in patients with homocystinuria associated with hemodynamic changes, progressive arterial stenosis, and proliferation of smooth muscle cells. He also noted that homocysteine may have a causal role in any metabolic abnormality. This idea is the basis of his theory that a moderately elevated level of homocysteine is an important risk factor for cardiovascular disease. His theory was sustained only in 1976 through a clinical trial demonstrating an increase in coronary artery disease in people with hyperhomocysteinemia. Since then, a particular interest has been given to studying this relationship.