The history of the study of hyperhomocysteinemia goes back half a century. It is interesting that the increased level of homocysteine as a factor of vascular damage was first noticed in pediatric practice. In 1969, Kilmer S. MeCully, a professor in the Department of Pathology at Harvard University, studying a rare genetic disorder manifested by homocysteinuria (increased levels of homocysteine in the urine), suggested a link between elevated serum homocysteine levels and arterial disease. Without treatment, these children usually die at an early age from myocardial infarction or cerebral strokes. During autopsy, it was found that their vessels were the same damaged and thickened as in elderly patients with cardiovascular diseases. Clinically, this disease is characterized by a marfan-like phenotype, connective tissue lesions (high growth, arachnodactyly, lens subluxation, chest deformities, heart defects), neuropsychiatric disorders, arterial thrombosis. The pathology is based on a defect in one of the metabolic enzymes of sulfur-containing methionine, mainly in the amino acid cystothionine-E-synthetase (classical tomocysteinuria). Subsequently, it was shown that moderate and mild homocysteinemia affects the vessels of various localization, leading to pathological changes in them.
