HYPERHOMOCYSTEINEMIA: GENETIC POLYMORPHISMS AND RISK OF CORONARY ARTERY DISEASE

Abstract

This comprehensive literature review focuses on homocysteine, gene polymorphisms related to homocysteine metabolism and their relationship to coronary artery disease (CAD). Currently, CAD is known as a multifactorial genetic disease, resulting from complex interactions between genetic factors and various environmental influences. In recent years, tremendous knowledge about the hereditary aspect of CAD has been gained, including an understanding of CAD as a multifactorial condition resulting from complex interactions between genetic factors and various environmental influences that trigger, accelerate, or exacerbate the disease process. Among the risk factors for CAD, hyperhomocysteinemia has been recognized for its relation to atherosclerotic alterations in the vessels. In addition, gene polymorphisms in methylene - tetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), methionine synthase (MS), and cystathionine ß - synthase (CßS), which are involved in homocysteine metabolism, have been identified as a result of advances in genetic research related to cardiovascular pathophysiology. In particular, the results of recent salient studies have provided evidence of significant association of these genetic polymorphisms and CAD in Japanese and part of European populations but not in the United States, Australian, and part of European populations. This disparity may explain the variation of prevalence of CAD among different populations. Potential gene - environment interactions may elevate homocysteine levels and increase the risk of CAD. This discussion includes the pathogenesis of hyperhomocysteinemia, definitions of normal and elevated homocysteine levels, the physiological background of homocysteine metabolism, polymorphisms of genes involved in homocysteine metabolism from the perspective of CAD risk, and implications for nursing practice based on emerging information regarding hyperhomocysteinemia as a risk factor for CAD. Findings from these recent studies are important for nurses, clinicians, and researchers to be able to incorporate cardiovascular genetic information in their practice and research and provide more adequate care to reduce the risk for CAD and improve patient outcomes.