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Homocystinuria, arteriosclerosis, methylmalonic aciduria, and methyltransferase deficiency: a key case revisited
1Laboratory Service, Veterans Affairs Medical Center, Providence, RI 02908-4799.
Insights
Reexamining a case of Cb1 C disease revealed how excess homocysteine thiolactone causes vascular lesions and gastric mucosal changes, advancing the homocysteine theory of arteriosclerosis.
Area of Science:
- Biochemistry
- Pathology
- Genetics
Background:
- The study reexamines a unique case of Cb1 C disease, characterized by homocystinuria, cystathioninuria, methylmalonic aciduria, and hypomethioninemia.
- This case is crucial for understanding the development of the homocysteine theory of arteriosclerosis.
Observation:
- Vascular lesions included proliferative fibrous intimal plaques and focal artery wall necrosis.
- Gastric mucosa exhibited atrophic, metaplastic, and dysplastic changes.
Findings:
- Excess homocysteine thiolactone was linked to low-density lipoprotein (LDL) aggregation and endothelial cell respiration impairment, causing vascular damage.
- Homocysteine thiolactone's impact on keratin, sulfomucin, and nucleoprotein synthesis contributed to gastric mucosal alterations.
Implications:
- Investigating inborn errors of metabolism provides insights into disease pathophysiology.
- This research illuminates normal metabolic pathways and critical cellular functions.
- Understanding these mechanisms can inform future therapeutic strategies for metabolic and vascular diseases.
Abstract:
The original case of Cb1 C disease with homocystinuria, cystathioninuria, methylmalonic aciduria, and hypomethioninemia was reexamined because of its importance in the discovery of the homocysteine theory of arteriosclerosis. The vascular lesions in the case consist of proliferative fibrous intimal plaques and focal necrosis of the artery wall, which are attributed to effects of excess homocysteine thiolactone on aggregation of low-density lipoproteins (LDL) and on respiration of endothelial cells. Atrophic, metaplastic, and dysplastic changes within the gastric mucosa are attributed to effects of excess homocysteine thiolactone on synthesis of keratin, sulfomucins, and nucleoproteins within affected cells. The case illustrates how investigation of an inborn error of metabolism illuminates pathophysiological disease processes, normal metabolic pathways, and important aspects of cellular function.