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Early Development of Newborn Screening for HCU and Current Challenges. Int J Neonatal Screen 2021; 7:ijns7040067. [PMID: 34842599 PMCID: PMC8628950 DOI: 10.3390/ijns7040067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/16/2021] [Accepted: 10/21/2021] [Indexed: 11/17/2022] Open
Abstract
Classic homocystinuria (HCU) was added to newborn screening (NBS) by Robert Guthrie a few years after the disorder was first described. The justification for NBS was similar to that for PKU, that presymptomatic identification and early dietary treatment would prevent the clinical consequences, which, for HCU, are mental deficiency, ectopia lentis, skeletal abnormalities, and thromboembolism. It was assumed that identifying increased methionine in the screening blood specimen would identify all affected neonates. However, it is now clear that many with HCU are missed by NBS, mainly because the methionine level in the first days of life is normal or below the cutoff level in the NBS program. This includes virtually all of those with B6-responsive HCU. Thus, a more effective method of NBS for HCU should be considered. Included among the possibilities are decreasing the methionine cutoff level, requiring an increase in the Met/Phe ratio if the methionine level is not at or greater than the cutoff level, using methionine as the primary screen with homocysteine as a second-tier test, or replacing methionine with homocysteine as the primary screen. Homocysteine is the primary metabolite that increases in HCU, while the methionine increase is secondary, so homocysteine is usually increased before the increase in methionine, almost always during the first few days of life. Finally, targeted gene screening might be considered. All of these possibilities would impose added expense and labor to NBS, so meeting these challenges would likely require a regional or national effort.
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Toriumi K, Berto S, Koike S, Usui N, Dan T, Suzuki K, Miyashita M, Horiuchi Y, Yoshikawa A, Asakura M, Nagahama K, Lin HC, Sugaya Y, Watanabe T, Kano M, Ogasawara Y, Miyata T, Itokawa M, Konopka G, Arai M. Combined glyoxalase 1 dysfunction and vitamin B6 deficiency in a schizophrenia model system causes mitochondrial dysfunction in the prefrontal cortex. Redox Biol 2021; 45:102057. [PMID: 34198071 PMCID: PMC8253914 DOI: 10.1016/j.redox.2021.102057] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/13/2022] Open
Abstract
Methylglyoxal (MG) is a reactive and cytotoxic α-dicarbonyl byproduct of glycolysis. Our bodies have several bio-defense systems to detoxify MG, including an enzymatic system by glyoxalase (GLO) 1 and GLO2. We identified a subtype of schizophrenia patients with novel mutations in the GLO1 gene that results in reductions of enzymatic activity. Moreover, we found that vitamin B6 (VB6) levels in peripheral blood of the schizophrenia patients with GLO1 dysfunction are significantly lower than that of healthy controls. However, the effects of GLO1 dysfunction and VB6 deficiency on the pathophysiology of schizophrenia remains poorly understood. Here, we generated a novel mouse model for this subgroup of schizophrenia patients by feeding Glo1 knockout mice VB6-deficent diets (KO/VB6(−)) and evaluated the combined effects of GLO1 dysfunction and VB6 deficiency on brain function. KO/VB6(−) mice accumulated homocysteine in plasma and MG in the prefrontal cortex (PFC), hippocampus, and striatum, and displayed behavioral deficits, such as impairments of social interaction and cognitive memory and a sensorimotor deficit in the prepulse inhibition test. Furthermore, we found aberrant gene expression related to mitochondria function in the PFC of the KO/VB6(−) mice by RNA-sequencing and weighted gene co-expression network analysis (WGCNA). Finally, we demonstrated abnormal mitochondrial respiratory function and subsequently enhanced oxidative stress in the PFC of KO/VB6(−) mice in the PFC. These findings suggest that the combination of GLO1 dysfunction and VB6 deficiency may cause the observed behavioral deficits via mitochondrial dysfunction and oxidative stress in the PFC. A combination of Glo1 KO and VB6 deficiency induces MG accumulation in the brain. Glo1 KO/VB6(−) mice exhibit schizophrenia-like behavioral deficits. Gene expression related to mitochondria is impaired in the PFC of the Glo1 KO/VB6(−). Mitochondria in the PFC of the Glo1 KO/VB6(−) mice show respiratory dysfunction. Oxidative stress is enhanced in the PFC of the Glo1 KO/VB6(−).
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Affiliation(s)
- Kazuya Toriumi
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan; Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - Stefano Berto
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA; Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29403, USA
| | - Shin Koike
- Department of Analytical Biochemistry, Meiji Pharmaceutical University, Tokyo 204-8588, Japan
| | - Noriyoshi Usui
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA; Center for Medical Research and Education, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan; Department of Neuroscience and Cell Biology, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan; Global Center for Medical Engineering and Informatics, Osaka University, Osaka, 565-0871, Japan
| | - Takashi Dan
- Division of Molecular Medicine and Therapy, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan
| | - Kazuhiro Suzuki
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan; Department of Psychiatry, Graduate School of Medicine, Shinshu University, Nagano, 390-8621, Japan
| | - Mitsuhiro Miyashita
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan
| | - Yasue Horiuchi
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan
| | - Akane Yoshikawa
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan; Department of Psychiatry and Behavioral Science, Graduate School of Medicine, Juntendo University, Tokyo, 113-8421, Japan
| | - Mai Asakura
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan
| | - Kenichiro Nagahama
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hsiao-Chun Lin
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yuki Sugaya
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takaki Watanabe
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Masanobu Kano
- Department of Neurophysiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yuki Ogasawara
- Department of Analytical Biochemistry, Meiji Pharmaceutical University, Tokyo 204-8588, Japan
| | - Toshio Miyata
- Division of Molecular Medicine and Therapy, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan
| | - Masanari Itokawa
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan
| | - Genevieve Konopka
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA
| | - Makoto Arai
- Schizophrenia Research Project, Department of Psychiatry and Behavioral Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, 156-8506, Japan.
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Rasmussen SA, Pomputius A, Amberger JS, Hamosh A. Viewing Victor McKusick's legacy through the lens of his bibliography. Am J Med Genet A 2021; 185:3212-3223. [PMID: 34159717 DOI: 10.1002/ajmg.a.62394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/13/2021] [Accepted: 05/22/2021] [Indexed: 11/09/2022]
Abstract
Victor McKusick's contributions to the field of medical genetics are legendary and include his contributions as a mentor, as creator of Mendelian Inheritance in Man (now Online Mendelian Inheritance in Man [OMIM®]), and as a leader in the field of medical genetics. McKusick's full bibliography includes 772 publications. Here we review the 453 papers authored by McKusick and indexed in PubMed, from his earliest paper published in the New England Journal of Medicine in 1949 to his last paper published in American Journal of Medical Genetics Part A in 2008. This review of his bibliography chronicles McKusick's evolution from an internist and cardiologist with an interest in genetics to an esteemed leader in the growing field of medical genetics. Review of his bibliography also provides a historical perspective of the development of the discipline of medical genetics. This field came into its own during his lifetime, transitioning from the study of interesting cases and families used to codify basic medical genetics principles to an accredited medical specialty that is expected to transform healthcare. Along the way, he helped to unite the fields of medical and human genetics to focus on mapping the human genome, culminating in completion of the Human Genome Project. This review confirms the critical role played by Victor McKusick as the founding father of medical genetics.
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Affiliation(s)
- Sonja A Rasmussen
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Obstetrics and Gynecology, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Epidemiology, University of Florida, College of Public Health and Health Professions and College of Medicine, Gainesville, Florida, USA
| | - Ariel Pomputius
- Health Science Center Libraries, University of Florida, Gainesville, Florida, USA
| | - Joanna S Amberger
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ada Hamosh
- Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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Flores-Flores M, Moreno-García L, Castro-Martínez F, Nahmad M. Cystathionine β-synthase Deficiency Impairs Vision in the Fruit Fly, Drosophila melanogaster. Curr Eye Res 2020; 46:600-605. [PMID: 32865440 DOI: 10.1080/02713683.2020.1818262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Deficiency in Cystathionine β-synthase (CBS) leads to an abnormal accumulation of homocysteine and results in classical homocystinuria, a multi-systemic disorder that affects connective tissue, muscles, the central nervous system, and the eyes. However, the genetic players and mechanisms underlying vision alterations in patients with homocystinuria are little understood. MATERIALS AND METHODS The fruit fly, Drosophila melanogaster, is a useful system to investigate the genetic basis of several human diseases, but no study to date has used Drosophila as model of homocystinuria. Here, we use Drosophila genetic tools to down-regulate CBS expression and evaluate its behavioral response to light. RESULTS We show that CBS-deficient flies do not display the normal stereotypical behavior of attraction towards a luminous source, known as phototaxis. This behavior cannot be attributed to a motor or olfactory deficiency, but it is most likely related to a lower visual acuity. CBS-deficient flies are overall smaller, but smaller eyes do not explain their lack of phototactic response. CONCLUSIONS The vision phenotype of CBS knock-down flies is consistent with severe myopia in homocystinuria patients. We propose to use Drosophila as a model to investigate ocular manifestations underlying homocystinuria.
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Affiliation(s)
- Marycruz Flores-Flores
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
| | - Leonardo Moreno-García
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
| | - Felipe Castro-Martínez
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
| | - Marcos Nahmad
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, Mexico City, Mexico
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Toya T, Sara JD, Lerman B, Ahmad A, Taher R, Godo S, Corban MT, Lerman LO, Lerman A. Elevated plasma homocysteine levels are associated with impaired peripheral microvascular vasomotor response. IJC HEART & VASCULATURE 2020; 28:100515. [PMID: 32322661 PMCID: PMC7171522 DOI: 10.1016/j.ijcha.2020.100515] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/07/2020] [Accepted: 04/08/2020] [Indexed: 12/23/2022]
Abstract
Homocysteine > 10 μmol/L is associated with peripheral microvascular endothelial dysfunction (PMED). Homocysteine > 10 μmol/L was associated with PMED in older, obese, or hypertensive patients. The association of homocysteine and PMED was prominent in patients with B-vitamins. Homocysteine > 10 μmol/L was associated with higher major cardiovascular events in univariate analysis.
Background Hyperhomocysteinemia (HHcy) has been proposed as an important cardiovascular risk factor (cRF). However, little is known about the association between plasma homocysteine levels and peripheral microvascular endothelial dysfunction (PMED), which is an integrated index of vascular health. Methods This cross-sectional and retrospective cohort study included patients who underwent non-invasive PMED assessment using reactive hyperemia peripheral arterial tonometry (RH-PAT). The association between HHcy and PMED, and its impact on MACE (all-cause mortality and atherosclerotic cardiovascular events) was investigated. Results A total of 257 patients were enrolled (HHcy > 10.0 µmol/L, N = 51; lower levels of homocysteine [LHcy] ≤ 10 µmol/L, N = 206). Patients with HHcy were older, predominantly males, and with more comorbidities than patients with LHcy (p < 0.05 for all). RH-PAT index was lower in patients with HHcy versus LHcy (p = 0.01). A significant association between HHcy and PMED was observed in older (≥60 years), obese (≥30 kg/m2), present/past smokers and hypertensive patients. HHcy was significantly associated with PMED even after adjusting for other cRF and B-vitamins supplementation. HHcy was associated with an increased risk of MACE with a hazard ratio of 3.65 (95% CI 1.41–9.48, p = 0.01) and an adjusted hazard ratio of 2.44 (95% CI 0.91–6.51, p = 0.08) after adjustment for age (≥60 years). Conclusion HHcy was independently associated with PMED after adjusting for cRF and B-vitamins supplementation. Thus, the link between homocysteine and MACE could be mediated by endothelial dysfunction, and will require further clarification with future studies.
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Affiliation(s)
- Takumi Toya
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.,Division of Cardiology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama, Japan
| | - Jaskanwal D Sara
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Ben Lerman
- School of Medicine, St. George's University, St George's, West Indies, Grenada
| | - Ali Ahmad
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Riad Taher
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Shigeo Godo
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Michel T Corban
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Lilach O Lerman
- Division of Nephrology and Hypertension, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
| | - Amir Lerman
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA
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Sellos-Moura M, Glavin F, Lapidus D, Evans K, Lew CR, Irwin DE. Prevalence, characteristics, and costs of diagnosed homocystinuria, elevated homocysteine, and phenylketonuria in the United States: a retrospective claims-based comparison. BMC Health Serv Res 2020; 20:183. [PMID: 32143624 PMCID: PMC7059682 DOI: 10.1186/s12913-020-5054-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/28/2020] [Indexed: 11/10/2022] Open
Abstract
Background Classical homocystinuria (HCU), an inborn error of homocysteine metabolism, has previously been estimated to affect approximately 1 in 100,000–200,000 people in the United States (US). HCU is poorly detected by newborn screening, resulting in underestimates of its prevalence. This study compared characteristics, healthcare use and costs, and projected prevalence between patients with diagnosed HCU, elevated total homocysteine (tHcy), and diagnosed phenylketonuria (PKU). Methods Patients in the MarketScan® Research Databases were identified with strictly-defined HCU (> 2 diagnoses, including 1 ICD-10), broadly-defined HCU (> 1 ICD-10), elevated tHcy (> 20 μmol/L) without an HCU diagnosis, or > 1 ICD-9/ICD-10 PKU diagnosis during 1/1/2010–12/31/2016 (first qualifying claim = index). Demographics and healthcare utilization and costs per patient per month (PPPM) were compared between all cohorts, frequencies of comorbidities and medications were compared between HCU and elevated tHcy patients, and healthcare provider types were assessed among HCU patients. The prevalence of patients meeting each cohort definition was projected to the United States (US) population. Results Patients with strictly-defined (N = 2450) and broadly-defined (N = 6613) HCU, and with elevated tHcy (N = 2017), were significantly older than PKU patients (N = 5120) (57 vs. 56 vs. 53 vs. 18 years; p < 0.05). Vitamin D deficiency, hyperlipidemia, folic acid/B vitamins, and lipid-lowering medications, among others, were more common among diagnosed HCU patients vs. those with elevated tHcy (all p < 0.05). Rates of healthcare utilization were generally higher among HCU and elevated tHcy patients, compared to PKU, though total healthcare costs were similar between groups. Most HCU patients (~ 38%) received their index diagnosis from a primary care physician; very few (~ 1%) had any claim from a geneticist during their enrollment. The age-adjusted national prevalence of HCU was projected at 31,162 (95% CI: 30,411 – 31,913; ~ 1 in 10,000 of the US population) using the broad definition. Conclusions The actual prevalence of HCU may be > 10 times prior estimates, at 1 in 10,000 in the US, and this study suggests that HCU is not being diagnosed until later in life. Improvements to newborn screening, detection in young children, and physician education regarding HCU among patients may be necessary to alleviate the burden of this genetic disease.
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Affiliation(s)
| | - Frank Glavin
- Orphan Technologies, 430 Bedford St, Lexington, MA, 02420, USA
| | - David Lapidus
- LapidusData Inc, 321 NE 4th St, Oklahoma City, OK, 73104, USA
| | - Kristin Evans
- IBM Watson Health, 75 Binney St, Cambridge, MA, 02142, USA
| | - Carolyn R Lew
- IBM Watson Health, 75 Binney St, Cambridge, MA, 02142, USA
| | - Debra E Irwin
- IBM Watson Health, 75 Binney St, Cambridge, MA, 02142, USA
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Safi M, Nejad SK, O'Hara M, Shankar SP. Ectopia Lentis et Pupillae Caused by ADAMTSL4 Pathogenic Variants and an Algorithm for Work-up. J Pediatr Ophthalmol Strabismus 2019; 56:e45-e48. [PMID: 31282960 DOI: 10.3928/01913913-20190509-01] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 03/26/2019] [Indexed: 11/20/2022]
Abstract
Ectopia lentis is displacement of the lens from its original position. It can be inherited or acquired with isolated or systemic findings. The authors describe a 4-year-old girl with isolated ectopia lentis et pupillae caused by pathogenic variants in the ADAMTSL4 gene and discuss the molecular genetic work-up of individuals with ectopia lentis. [J Pediatr Ophthalmol Strabismus. 2019;56:e45-e48.].
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8
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Revising the Psychiatric Phenotype of Homocystinuria. Genet Med 2019; 21:1827-1831. [DOI: 10.1038/s41436-018-0419-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 12/17/2018] [Indexed: 11/09/2022] Open
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Abstract
Systems composed of many components which interact with each other and lead to unpredictable global behaviour, are considered as complex systems. In a biological context, complex systems represent living systems composed of a large number of interacting elements. In order to study these systems, a precise mathematical modelling was typically used in this context. However, this modelling has limitations in the structural understanding and the behavioural study. In this sense, formal computational modelling is an approach that allows to model and to simulate dynamical properties of these particular systems. In this paper, we use Hybrid Functional Petri Net (HFPN), a Petri net extension dedicated to study and verify biopathways, to model and study the Methionine metabolic pathway. Methionine and its derivatives play significant roles in human bodies. We propose a set of simulations for the purpose of studying and analysing the Methionine pathway’s behaviour. Our simulation results have shown that several important abnormalities in this pathway are related to sever diseases such as Alzheimer’s disease, cardiovascular disease, cancers and others.
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Morris AAM, Kožich V, Santra S, Andria G, Ben-Omran TIM, Chakrapani AB, Crushell E, Henderson MJ, Hochuli M, Huemer M, Janssen MCH, Maillot F, Mayne PD, McNulty J, Morrison TM, Ogier H, O'Sullivan S, Pavlíková M, de Almeida IT, Terry A, Yap S, Blom HJ, Chapman KA. Guidelines for the diagnosis and management of cystathionine beta-synthase deficiency. J Inherit Metab Dis 2017; 40:49-74. [PMID: 27778219 PMCID: PMC5203861 DOI: 10.1007/s10545-016-9979-0] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/11/2016] [Accepted: 09/12/2016] [Indexed: 12/17/2022]
Abstract
Cystathionine beta-synthase (CBS) deficiency is a rare inherited disorder in the methionine catabolic pathway, in which the impaired synthesis of cystathionine leads to accumulation of homocysteine. Patients can present to many different specialists and diagnosis is often delayed. Severely affected patients usually present in childhood with ectopia lentis, learning difficulties and skeletal abnormalities. These patients generally require treatment with a low-methionine diet and/or betaine. In contrast, mildly affected patients are likely to present as adults with thromboembolism and to respond to treatment with pyridoxine. In this article, we present recommendations for the diagnosis and management of CBS deficiency, based on a systematic review of the literature. Unfortunately, the quality of the evidence is poor, as it often is for rare diseases. We strongly recommend measuring the plasma total homocysteine concentrations in any patient whose clinical features suggest the diagnosis. Our recommendations may help to standardise testing for pyridoxine responsiveness. Current evidence suggests that patients are unlikely to develop complications if the plasma total homocysteine concentration is maintained below 120 μmol/L. Nevertheless, we recommend keeping the concentration below 100 μmol/L because levels fluctuate and the complications associated with high levels are so serious.
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Affiliation(s)
- Andrew A M Morris
- Institute of Human Development, University of Manchester, Manchester, UK.
- Willink Unit, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals, St Mary's Hospital, Oxford Road, Manchester, M13 9WL, UK.
| | - Viktor Kožich
- Institute of Inherited Metabolic Disorders, Charles University in Prague-First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | - Saikat Santra
- Clinical IMD, Birmingham Children's Hospital, Birmingham, UK
| | - Generoso Andria
- Department of translational medicine, Federico II University, Naples, Italy
| | | | | | - Ellen Crushell
- National Centre for Inherited Metabolic Disorders, Temple Street Children's University Hospital, Dublin, Ireland
| | - Mick J Henderson
- Willink Unit, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals, St Mary's Hospital, Oxford Road, Manchester, M13 9WL, UK
- Biochemical Genetics, St James' University Hospital, Leeds, UK
| | - Michel Hochuli
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zürich, Zurich, Switzerland
| | - Martina Huemer
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, Zurich, Switzerland
- Rare Disease Initiative Zürich, University of Zürich, Zurich, Switzerland
- Dept. of Paediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria
| | - Miriam C H Janssen
- Department of Internal medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Philip D Mayne
- Newborn Bloodspot Screening Laboratory, Temple Street Children's University Hospital, Dublin, Ireland
| | - Jenny McNulty
- National Centre for Inherited Metabolic Disorders, Temple Street Children's University Hospital, Dublin, Ireland
| | | | - Helene Ogier
- Service de Neurologie Pédiatrique et des Maladies Métaboliques, Hôpital Robert Debré, Paris, France
| | | | - Markéta Pavlíková
- Institute of Inherited Metabolic Disorders, Charles University in Prague-First Faculty of Medicine and General University Hospital in Prague, Prague, Czech Republic
| | | | - Allyson Terry
- Institute of Human Development, University of Manchester, Manchester, UK
- Dietetic Department, Alder Hey Hospital, Liverpool, UK
| | - Sufin Yap
- Dept of Inherited Metabolic Diseases, Sheffield Children's Hospital, Sheffield, UK
| | - Henk J Blom
- Laboratory of Clinical Biochemistry and Metabolism, Department of General Pediatrics, Adolescent Medicine and Neonatology, University Medical Centre Freiburg, Freiburg im Breisgau, Germany
| | - Kimberly A Chapman
- Division of Genetic and Metabolism, Children's National Health System, Washington, DC, USA
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12
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Affiliation(s)
- E M Brett
- Hospital for Sick Children, Great Ormond Street, London
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13
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Abstract
Deep vein thrombosis (DVT) leads to venous ulcers in later life. Venous ulcers are the majority of chronic lower extremity wounds. Recent evidence suggests that hyperhomocysteinemia is an independent risk factor for venous thrombosis. Other evidence suggests that dietary supplementation with folic acids and vitamins helps to change hyper-homocysteinemia. This may be the key to wound management in the future.
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Affiliation(s)
- Paul Lee
- Department of Physiology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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Bhatia P, Singh N. Homocysteine excess: delineating the possible mechanism of neurotoxicity and depression. Fundam Clin Pharmacol 2015; 29:522-8. [DOI: 10.1111/fcp.12145] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 07/06/2015] [Accepted: 08/18/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Pankaj Bhatia
- CNS Research Laboratory; Pharmacology Division; Department of Pharmaceutical Sciences and Drug Research; Faculty of Medicine; Punjabi university; Patiala 147002 Punjab India
| | - Nirmal Singh
- Pharmacology Division; Department of Pharmaceutical Sciences and Drug Research; Faculty of Medicine; Punjabi university; Patiala 147002 Punjab India
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Park DH, Chung JK. Modified Capsular Tension Ring Scleral Fixation and Toric Intraocular Lens Implantation in a Patient with Homocystinuria. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2015. [DOI: 10.3341/jkos.2015.56.4.614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Dae Hyun Park
- Department of Ophthalmology, Soonchunhyang University College of Medicine, Cheonan, Korea
| | - Jin Kwon Chung
- Department of Ophthalmology, Soonchunhyang University College of Medicine, Cheonan, Korea
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16
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Atypical presentation of ectopia lentis in Marfan's syndrome. Int Ophthalmol 2013; 34:129-32. [PMID: 23479050 DOI: 10.1007/s10792-013-9750-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 02/22/2013] [Indexed: 10/27/2022]
Abstract
The purpose of this article is to report an unusual bilateral inferior subluxation of the lens in a patient with Marfan's syndrome. A 14-year-old boy presented with gradual painless diminution of vision in both eyes. His family history showed that his maternal uncle also had similar complaints. Systemic examination of the patient revealed no neurological deficits. Cardiovascular system examination was unremarkable. Hands and fingers were long and slender with hyperflexible joints. The ratio of arm spam to height was 1.06. He was myopic with a best-corrected visual acuity of 6/24 with -11 D spherical/- 2 D cylindrical in both eyes. Anterior chambers were deep with the presence of mild iridodonesis in both eyes. Pupillary reactions were sluggish. On pupillary dilatation, the lens was found to be subluxated inferiorly which is unlike the typical superotemporal subluxation of the lens in Marfan's syndrome. The diagnosis of Marfan's syndrome is usually made on clinical examination only, as there is no specific investigation for this condition; however, it may have atypical presentations. Therefore, it is important to recognize and report such atypical cases.
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Joseph J, Joseph L. Hyperhomocysteinemia and cardiovascular disease: new mechanisms beyond atherosclerosis. Metab Syndr Relat Disord 2012; 1:97-104. [PMID: 18370631 DOI: 10.1089/154041903322294425] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The association of hyperhomocysteinemia (Hhe) with cardiovascular disease (CVD) has been explored in detail over the last four decades since initial reports in the 1960s. Although several epidemiological studies have shown an association, convincing mechanistic studies are still lacking. However, recent prospective studies demonstrate a strong association of Hhe with coronary disease. Several pathogenic mechanisms have been studied in Hhe and indicate alterations in the various components of vascular disease, namely endothelial cells, vascular smooth muscle cells, platelets, and the coagulation/fibrinolytic systems. Increased oxidative stress, hypomethylation, and protein homocysteinylation have been proposed as potential molecular mechanisms in Hhe-induced CVD. In addition, recent studies indicate a novel link between Hhe and CVD, that is, direct effects on coronary arteriolar and myocardial remodeling resulting in cardiac dysfunction.
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Affiliation(s)
- Jacob Joseph
- The Departments of Internal Medicine and Pharmaceutical Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
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Affiliation(s)
- Hala Ahmadieh
- Department of Internal Medicine, American University of Beirut, Beirut, Lebanon
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Correction of endothelial dysfunction after selective homocysteine lowering gene therapy reduces arterial thrombogenicity but has no effect on atherogenesis. J Mol Med (Berl) 2011; 89:1051-8. [PMID: 21688073 DOI: 10.1007/s00109-011-0778-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 05/26/2011] [Accepted: 05/30/2011] [Indexed: 12/20/2022]
Abstract
Hyperhomocysteinemia is an independent risk factor for ischemic cardiovascular diseases, but its causal role in atherothrombosis remains controversial. Proatherogenic and/or prothrombotic effects may underlie the potential causal relation between hyperhomocysteinemia and cardiovascular events. Here, the effects of selective lowering of plasma homocysteine, plasma cholesterol, or both on endothelial function and on atherogenesis in male hyperlipidemic and hyperhomocysteinemic C57BL/6 low-density lipoprotein receptor (LDLr)(-/-)/cystathionine-β-synthase (CBS)(+/-)-deficient mice were investigated. Second, we evaluated whether selective homocysteine lowering has anti-thrombotic effects in a model of arterial thrombosis. A hyperhomocysteinemic and atherogenic diet was started at the age of 12 weeks. Three weeks later, gene transfer was performed with E1E3E4-deleted adenoviral vectors for hepatocyte-restricted overexpression of CBS (AdCBS) or of the LDLr (AdLDLr), or with the control vector Adnull. In a fourth group, AdCBS and AdLDLr were co-administered. Selective homocysteine lowering but not selective cholesterol lowering restored endothelial function at 6 weeks after gene transfer. Intimal area in the aortic root and in the brachiocephalic artery at 13 weeks was more than 100-fold (p < 0.001) smaller in AdLDLr and AdCBS/AdLDLr mice than in control mice and AdCBS mice. No differences in intimal area were observed between control mice and AdCBS mice. In a model of carotid artery thrombosis, the average time to first occlusion and to stable occlusion were 1.9-fold (p < 0.01) and 2.1-fold longer (p < 0.01), respectively, in AdCBS-treated mice than in control mice. Taken together, these data show that correction of endothelial dysfunction following selective homocysteine lowering has anti-thrombotic but no anti-atherogenic effects.
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Other A. Congenital cataract, mental retardation and amino-aciduria. Amino-acid excretion determined by high-voltage electrophoresis in patients with mental retardation and congenital cataract. Acta Ophthalmol 2009; 46:404-12. [PMID: 5755731 DOI: 10.1111/j.1755-3768.1968.tb02823.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Ranucci M, Ballotta A, Frigiola A, Boncilli A, Brozzi S, Costa E, Mehta RH. Pre-operative homocysteine levels and morbidity and mortality following cardiac surgery. Eur Heart J 2009; 30:995-1004. [PMID: 19224934 PMCID: PMC2668805 DOI: 10.1093/eurheartj/ehp015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aims Elevated homocysteinaemia is associated not only with an increased risk for cardiovascular disease but also for increased morbidity and mortality in patients with established coronary artery or cerebrovascular disease. Whether elevated homocysteine further increases the morbidity and mortality in patients undergoing cardiac surgery on cardiopulmonary bypass (CPB) (a prothrombotic state itself) remains less known. Methods and results Accordingly, we conducted a prospective observational study with pre-operative measurement of plasma homocysteine levels in 531 consecutive patients undergoing cardiac operations on CPB. The association of pre-operative plasma homocysteine levels with post-operative morbidity and hospital mortality was evaluated. Elevated homocysteine levels (>15 µmol/L) were observed in 209 patients (39.4%), and homocysteinaemia was associated with a higher mortality and perioperative morbidity (major morbidity, low cardiac output, acute renal failure, mesenteric infarction, and thrombo-embolic events). Even after accounting for the differences in baseline clinical features, EuroSCORE, and CPB time, pre-operative homocysteine levels remained independently associated with hospital mortality [odds ratio (OR) 1.06, 95% confidence interval (CI) 1.03–1.11], major morbidity (OR 1.04, 95% CI 1.01–1.07), low cardiac output (OR 1.04, 95% CI 1.02–1.08), mesenteric infarction (OR 1.06, 95% CI 1.01–1.11), and thrombo-embolic events (OR 1.09, 95% CI 1.04–1.13). This association of homocysteine with increased risk of morbidity and mortality was observed particularly in CABG patients. Conclusion Elevated pre-operative homocysteine level is independently associated with increased morbidity and mortality, particularly in patients undergoing CABG. Specific post-operative antithrombotic strategies may be advisable in hyperhomocysteinaemic patients.
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Affiliation(s)
- Marco Ranucci
- Department of Cardiothoracic-Vascular Anesthesia and Intensive Care, IRCCS Policlinico S.Donato, Milan, Italy
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Abstract
Bone tissue quality is determined not only by multiple architectural variables, but also by the mechanical properties of collagen type 1. Homocysteinuria is a genetic disease whose manifestations include severe hyperhomocysteinemia and decreased bone strength. The effects of smaller homocysteine elevations on bone tissue are difficult to demonstrate in clinical studies. Studies in animals and in humans suggest that homocysteine may weaken collagen crosslinks and, if present in large amounts, interfere with bone remodeling. Whether routine homocysteine assays should be performed to detect bone frailty remains unclear. In clinical practice, the focus should be on identifying patients with potential causes of homocysteine elevation (e.g., medications), who should then be given vitamin D and folic acid supplementation if needed. This approach may improve not only bone health, but also vascular and general health.
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Affiliation(s)
- Régis Levasseur
- Service de Rhumatologie et Pôle ostéo-articulaire, CHU d'Angers, Inserm U922, Faculté de Médecine d'Angers, 49933 Angers Cedex, France.
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Heijbel J, Jagell S. Spastic paraplegia, glaucoma and mental retardation--in three siblings. A new genetic syndrome. Hereditas 2009; 94:203-7. [PMID: 7298353 DOI: 10.1111/j.1601-5223.1981.tb01753.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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Abstract
This is an account of almost 60 years' experience in the clinical delineation of genetic disorders, mapping genes on chromosomes, and cataloging human disease-related genes and genetic disorders. The origins of medical genetics as a clinical specialty, of the Human Genome Project, of genomics (including the term), and of HUGO are recounted.
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Affiliation(s)
- Victor A McKusick
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-4922, USA
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Chang PY, Lu SC, Lee CM, Chen YJ, Dugan TA, Huang WH, Chang SF, Liao WSL, Chen CH, Lee YT. Homocysteine inhibits arterial endothelial cell growth through transcriptional downregulation of fibroblast growth factor-2 involving G protein and DNA methylation. Circ Res 2008; 102:933-41. [PMID: 18309099 DOI: 10.1161/circresaha.108.171082] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Homocysteine (Hcy) contributes to atherogenesis and angiostasis by altering the phenotype of arterial endothelial cells (ECs). The present study was aimed at elucidating potential mechanisms by which Hcy can slow EC proliferation and induce EC apoptosis, thereby disrupting endothelial integrity. Given the strong mitogenic and antiapoptotic properties of fibroblast growth factor (FGF)2, we examined whether Hcy can modulate its expression. In cultured human coronary and bovine aortic ECs, Hcy exerted time- and concentration-dependent (0 to 500 micromol/L) reduction of the mRNA and protein levels of FGF2, whereas vascular endothelial growth factor expression was not affected until Hcy reached a proapoptotic 500 micromol/L. By testing a panel of signal transduction inhibitors, we found that the Hcy-induced downregulation of FGF2 was specifically attenuated by pertussis toxin, an inhibitor of Gi protein signaling. Hcy induced cell cycle arrest at the G(1)/S transition and increased TUNEL-positive apoptotic cells in a graded manner. These effects were effectively counteracted by exogenous FGF2. Reporter gene assays showed that Hcy downregulated FGF2 by transcriptional repression of the gene promoter encompassed in a CpG dinucleotide-rich island. This region was heavily methylated at the cytosine residues by Hcy despite decreased methylation potential (S-adenosylmethionine to S-adenosylhomocysteine ratio). Normal levels of FGF2 transcription were restored to ECs simultaneously exposed to Hcy and 5-aza-deoxycytidine. We conclude that homocysteine disrupts the growth and survival of ECs through a G protein-mediated pathway associated with altered promoter DNA methylation and the transcriptional repression of FGF2.
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Affiliation(s)
- Po-Yuan Chang
- Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
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Baines M, Kredan MB, Usher J, Davison A, Higgins G, Taylor W, West C, Fraser WD, Ranganath LR. The association of homocysteine and its determinants MTHFR genotype, folate, vitamin B12 and vitamin B6 with bone mineral density in postmenopausal British women. Bone 2007; 40:730-6. [PMID: 17141597 DOI: 10.1016/j.bone.2006.10.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 09/08/2006] [Accepted: 10/01/2006] [Indexed: 01/30/2023]
Abstract
We studied the association between plasma total homocysteine (tHcy), its determinants folate, vitamin B(12), vitamin B(6) and MTHFR genotype, and bone mineral density (BMD) in 328 postmenopausal British women. When the subjects were assigned to one of 3 groups (control, osteopenic or osteoporotic) according to their BMD at the os calcis, those in the osteoporotic group had, compared with the controls, a significantly lower serum folate concentration, a significantly higher % of current smokers and a significantly higher incidence of recent fracture. In the population as a whole, we found significant associations of BMD with tHcy (r=-0.130, p=0.033, log tHcy) and folate (r=0.132, p=0.025, log folate). The association of folate with BMD was maintained after correction for age, weight and height (r=0.124, p=0.042, log folate), but the association of tHcy with BMD weakened after correction for age, weight, height and creatinine (r=-0.117, p=0.059, log tHcy). Vitamins B(12) and B(6) were not associated with BMD, but were significantly associated with tHcy, vitamin B(12) (r=-0.34, p<0.0001), vitamin B(6) (r=-0.16, p=0.007), as was folate (r=-0.41, p<0.0001). There was an increasing frequency of the MTHFR TT genotype across the 3 BMD groups, but this did not attain significance. Individuals with the TT genotype had significantly higher plasma tHcy but there was no difference between the genotypes (CC, CT, TT) for folate or BMD. Smoking was associated with a highly significant reduction in BMD and lower weight, and a significant reduction in circulating folate and vitamin B(6) concentrations, but no change in tHcy or vitamin B(12) concentrations when compared with non-smokers. We conclude that low serum folate is a significant risk factor for osteoporosis, with plasma tHcy having a lesser effect. Both vitamins B(12) and B(6), by acting through tHcy, may also have an effect on the skeleton, albeit a weaker one than folate. Cigarette smoking is a strong determinant of BMD, and may act through effects on folate and vitamin B(6).
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Affiliation(s)
- M Baines
- Department of Clinical Biochemistry and Metabolic Medicine, Royal Liverpool University Hospital, Liverpool, UK.
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Lawson-Yuen A, Levy HL. The use of betaine in the treatment of elevated homocysteine. Mol Genet Metab 2006; 88:201-7. [PMID: 16545978 DOI: 10.1016/j.ymgme.2006.02.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 02/02/2006] [Accepted: 02/03/2006] [Indexed: 11/22/2022]
Abstract
Elevation of homocysteine is implicated in multiple medical conditions, including classical homocystinuria, a variety of remethylation disorders, and most recently in coronary artery disease. Betaine is a methyl donor agent that is beneficial in lowering homocysteine through the remethylation of methionine. Betaine therapy alone has been shown to prevent vascular events in homocystinuria and may have clinical benefits in other hyperhomocysteinemic disorders when used as adjunctive therapy. Betaine does raise the methionine level and cerebral edema has occurred when plasma methionine exceeds 1000 micromol/L. Thus the plasma methionine as well as homocysteine must be monitored in patients receiving betaine.
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Affiliation(s)
- Amy Lawson-Yuen
- Division of Genetics, Children's Hospital Boston, Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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Snyderman SE. Liver failure and neurologic disease in a patient with homocystinuria. Mol Genet Metab 2006; 87:210-2. [PMID: 16359898 DOI: 10.1016/j.ymgme.2005.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Revised: 10/31/2005] [Accepted: 10/31/2005] [Indexed: 11/22/2022]
Abstract
A homocystinuric patient with the typical clinical and metabolic features of the disorder started treatment at 22 years of age. A diet with controlled methionine intake resulted in good metabolic control for five years, but control could not be attained for the following 1 1/2 years. This was accompanied by the development of paraparesis and increasing liver failure. A liver transplantation was successful in achieving metabolic control without the need for any dietary restrictions.
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Affiliation(s)
- Selma E Snyderman
- Department of Human Genetics, Mount Sinai School of Medicine, One Gustave L. Levy place, Box 1497, New York, NY 10029, USA.
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Warsi AA, Davies B, Morris-Stiff G, Hullin D, Lewis MH. Abdominal aortic aneurysm and its correlation to plasma homocysteine, and vitamins. Eur J Vasc Endovasc Surg 2004; 27:75-9. [PMID: 14652841 DOI: 10.1016/j.ejvs.2003.09.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Hyperhomocysteinemia is a recognised independent risk factor in the genesis of atherosclerotic diseases. However, very little is known about the relationship between homocysteine and abdominal aortic aneurysm (AAA). Vitamins, namely B12 and folic acid have been implicated in the regulation of plasma homocysteine levels. However, there has been no prospective study that has analysed the relationship of AAA and plasma homocysteine in light of serum vitamin levels. AIMS To study the relationship between plasma homocysteine, serum B12 and folic acid levels, and AAA. METHOD Case control study including 38 AAA patients and 36 controls. Fasting homocysteine, B12 and folic acid were determined in serum separated within 1 h of blood collection using a fluorescence polarisation immunoassay technique (FPIA). RESULTS Twenty-six (68%) of the AAA patients had elevated levels of homocysteine compared to 2 (6%) in the case control group. The mean homocysteine level in the AAA group was 19.4 micromol/L (SE +/- 1.1) (95% CI 17.17-21.65) and in the control group was 10.9 micromol/L (SE +/- 1) (95% CI 9.95-11.88) (p<0.001). Mean vitamin B12 levels in the AAA and the controls was 332.11 pg/L (SE +/- 16.44) and 414.33 pg/L (SE +/- 19.72), respectively (p<0.004). Mean folic acid in the AAA was 8.02 (SE +/- 0.71) and the control was 9.8 etagm/L (SE +/- 0.69), (ns). CONCLUSION This study confirms significantly higher levels of plasma homocysteine in AAA patients but lower levels of B12. Use of supplemental vitamins that should lower plasma homocysteine may modify vascular disease progression. Clinical trials in this direction are warranted.
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Affiliation(s)
- A A Warsi
- Royal Glamorgan Hospital, Ynysmaerdy, Llantrisant, Rhondda Cynon Taff, S Wales, UK
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Abstract
Homocystinuria due to cystathionine beta-synthase deficiency is the second most treatable aminoacidopathy. The reported incidence varies from 1 in 344,000 worldwide to 1 in 65,000 in Ireland. Untreated patients with homocystinuria have severe hyperhomocysteinaemia. Amongst its pathological sequelae, which include mental retardation, ectopia lentis and osteoporosis, vascular events remain the major cause of morbidity and mortality in untreated patients. Recognized modalities of treatment include pyridoxine, in combination with folic acid and vitamin B12; methionine-restricted, cystine-supplemented diet; and betaine. The natural history of vascular events is such that half will have an event before age 30 years and there is a predicted one event per 25 years at the time of maximal risk. In 158 patients with 2822 patient-years of treatment, there would be a predicted 112 events if left untreated, but instead only 17 vascular events were recorded during treatment (relative risk 0.09, 95% CI 0.036 to 0.228; p < 0.0001). Appropriate chronic treatment to lower hyperhomocysteinaemia is effective in reducing the potentially life-threatening vascular risk in patients with homocystinuria. These findings may also have relevance to the significance of mild hyperhomocysteinaemia that is commonly found in patients with premature vascular disease.
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Affiliation(s)
- S Yap
- National Center for Inherited Metabolic Disorders, The Children's University Hospital, Temple Street, Dublin 1, Ireland.
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Fuglsang J, Stender M, Zhou J, Møller J, Falk E, Ravn HB. Platelet activity and in vivo arterial thrombus formation in rats with mild hyperhomocysteinaemia. Blood Coagul Fibrinolysis 2002; 13:683-9. [PMID: 12441906 DOI: 10.1097/00001721-200212000-00003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Elevated plasma levels of total homocysteine (hcy) have been associated with an increased occurrence of arterial thrombosis. In the present study, we investigated the influence of hyperhomocysteinaemia on platelet aggregation and arterial thrombus formation in vivo. Fifty-one rats were included in the study, of which 29 received hcy in the drinking water for 4 weeks. Blood samples were withdrawn for measurement of platelet count and mean platelet volume. Platelet aggregation response in platelet-rich plasma following adenosine diphosphate or collagen stimulation were examined. In vivo thrombus formation was investigated by transillumination and videotape recording of the rat femoral artery after a thrombogenic injury was established. Off-line videotape analysis using computer-assisted planimetry permitted quantification of the thrombus area, and area versus time curves were obtained. In the intervention group receiving hcy, total hcy in plasma increased two-fold to 14.3 micromol/l, as compared with 7.3 micromol/l in the control group (P < 0.001). The platelet count and mean platelet volume did not differ between the two groups. In vivo thrombus formation expressed as the area under the curve or maximum thrombus area was not found to be altered in the presence of an increased homocysteine level, neither was adenosine diphosphate-induced platelet aggregation. However, collagen-induced platelet aggregation significantly decreased in the hcy group (P = 0.02). Pro-thrombotic effects of isolated mild hyperhomocysteinaemia are not supported by the present study in rats.
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Affiliation(s)
- J Fuglsang
- Institute of Experimental Clinical Research, Aarhus University Hospital, Skejby Hospital, Denmark.
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Simorre B, Quéré I, Berrut G, Chassé JF, Bellet H, Kamoun P, le Hello C, Saudubray JM, Janbon C. [Vascular complications of homocystinuria: a retrospective multicenter study]. Rev Med Interne 2002; 23:267-72. [PMID: 11928374 DOI: 10.1016/s0248-8663(01)00551-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Arterial or venous thromboses are frequent in patients with homocystinuria. Because severe homocystinuria is rare, prevalence of thrombosis, especially in France, is still unknown. METHODS Review of the clinical outcome of 37 patients with homocystinuria due to cystathionine-cystathionine beta-synthase deficiency (34) and 5,10-methylenetetrahydrofolate reductase (three) lead us to describe vascular complications occurring in 12 (32%) of them. RESULTS Venous thromboembolism is the earlier and the most frequent one and is mainly found in untreated late-diagnosed cases. Under specific treatment of homocystinuria, thromboses are rare and always a complication of surgery associated with high thromboembolic risk. Association with factor V Leiden increased the risk of venous thrombosis.
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Affiliation(s)
- B Simorre
- Service de médecine interne et maladies vasculaires, hôpital Saint-Eloi, 2, avenue Bertin-Sans, 34295 Montpellier, France
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Nallamothu BK, Fendrick AM, Omenn GS. Homocyst(e)ine and coronary heart disease: pharmacoeconomic support for interventions to lower hyperhomocyst(e)inaemia. PHARMACOECONOMICS 2002; 20:429-442. [PMID: 12093299 DOI: 10.2165/00019053-200220070-00001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Homocyst(e)ine, a sulphur-containing amino acid, is an intermediate formed during the metabolism of the essential amino acid methionine. Biological and epidemiological evidence suggest that elevated plasma levels of homocyst(e)ine are a risk factor for atherosclerosis and coronary heart disease (CHD). In the general US population, hyperhomocyst(e)inaemia is common and most often due to mild nutritional deficiencies in the B vitamins (folic acid, vitamin B(12) and vitamin B(6)). While high homocyst(e)ine levels can be effectively lowered using folic acid and other B vitamins, it is unknown whether such vitamin therapy will lead to clinical benefits. Given that strategies for homocyst(e)ine-lowering are safe and inexpensive, however, even small reductions in CHD risk will be highly cost effective. Thus, it may be prudent for patients to ensure an adequate daily intake of dietary folic acid and other B vitamins and for physicians to screen high-risk adults such as those with established CHD as we await definitive results from ongoing clinical trials.
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Affiliation(s)
- Brahmajee K Nallamothu
- Department of Internal Medicine, University of Michigan Medical School, B1F245 University Hospital, Ann Arbor, MI 49109-0022, USA.
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Khajuria A, Houston DS. Pathogenesis of Hyperhomocysteinemia-New Insights. Hematology 2001; 6:217-30. [PMID: 27414841 DOI: 10.1080/10245332.2001.11746575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Mild to moderately elevated levels of homocysteine (Hey) in plasma, denoted as hyperhomocysteinemia, is emerging as a prevalent and strong risk factor for atherosclerotic vascular disease in coronary, cerebral and peripheral vessels, as well as for arterial and venous thromboembolism. Despite its clinical significance, the molecular mechanism of homocysteine's effects is not yet clearly defined. Most of the effects of homocysteine that have been demonstrated in vitro, affecting endothelial function have been attributed to the oxidant reactivity of this molecule, which is shown to affect the vasoregulatory and thrombotic/fibrinolytic function of endothelium. However, the relevance of these observations to the clinical situations is questionable, since excessively high concentrations of homocysteine are used in most of the experiments. We have observed that homocysteine, at physiologically relevant concentrations, specifically induces the expression of tissue factor by monocytes, and a non-specific redox effect is not involved. Tissue factor expression by monocytes is mediated by increased intracellular concentrations of the metabolic intermediate, S-adenosylhomocysteine, which is a potent inhibitor of methyl transferases. These studies suggest that tissue factor expression by circulating monocytes by intracellular perturbations may be a plausible mechanism by which homocysteine may induce thrombosis.
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Affiliation(s)
- A Khajuria
- a Department of Clinical Chemistry, Health Sciences Centre , 820 Sherbrook Street, Winnipeg , Canada MB R3A 1R9
| | - D S Houston
- b Manitoba Institute of Cell Biology , 675 Mc Dermot Avenue, Winnipeg , Canada MB R3E 0V9
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Abstract
Hyperhomocysteinemia has emerged as an important risk factor for cardiovascular disease. However, its place in clinical practice is somewhat unclear, due to the lack of clinical trials documenting the benefit of treatment on reducing cardiovascular events. Vitamin therapy, particularly with folic acid, reduces plasma homocysteine significantly and improves other surrogate markers of cardiovascular risk such as endothelial function. Although a consensus is lacking on the right approach to diagnosis and treatment of this risk factor, we have suggested an algorithm based on data from clinical studies. We are optimistic that such an approach will be helpful for the clinician until clinical trials, with cardiovascular events as endpoints, are completed.
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Affiliation(s)
- M E Keebler
- Section of Endocrinology, Department of Medicine, Tulane University School of Medicine, 1430 Tulane Avenue (SL 53), New Orleans, LA 70112, USA
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Abstract
Both markedly and mildly elevated circulating homocysteine concentrations are associated with increased risk of vascular occlusion. Here we review possible mechanisms that mediate these effects. Inborn errors of homocysteine metabolism result in markedly elevated plasma homocysteine (200-300 micromol/L) and thromboembolic (mainly venous) disease: treatment to lower but not to normalize these concentrations prevents vascular events. Mild homocysteine elevation (>15 micromol/L) occurs in approximately 20-30% of patients with atherosclerotic disease. Usually, this is easily normalized with oral folate and ongoing trials are assessing the effect of folate treatment on outcomes. Although there is evidence of endothelial dysfunction with both markedly and mildly elevated homocysteine concentrations, the elevated homocysteine concentration in atherosclerotic patients is also associated with most standard vascular risk factors, and importantly, with early decline in renal function, which is common in atherosclerosis. Decline in renal function alone causes elevated plasma homocysteine (and cysteine). These observations suggest that mild hyperhomocysteinemia could often be an effect rather than a cause of atherosclerotic disease. Data on the common C677T methylenetetrahydrofolate reductase polymorphism supports this, in that, although homozygosity is a frequent cause of mild hyperhomocysteinemia when plasma folate is below median population concentrations, it appears not to increase cardiovascular risk. Indeed, there is recent evidence suggesting an acute antioxidant effect of folic acid independent of its effect on homocysteine concentrations. This antioxidant mechanism may oppose an oxidant effect of homocysteine and be relevant to treatment of patients with vascular disease, especially those with chronic renal insufficiency. Such patients have moderately elevated plasma homocysteine and greatly increased cardiovascular risk that is largely unexplained.
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Affiliation(s)
- L Brattström
- Department of Medicine, County Hospital, Kalmar, Sweden.
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38
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Abstract
Recent data have shown that an elevated plasma level of the amino acid homocysteine (Hcy) is a common, independent, easily modifiable and possibly causal risk factor for cardiovascular disease (CVD) which may be of equal importance to hypercholesterolemia, hypertension and smoking. This paper reviews the biochemical, clinical, epidemiological and experimental data underlying this conclusion and is critically questioning whether elevated tHcy is a causal factor.
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Affiliation(s)
- O Nygård
- Division for Medical Statistics, Department of Public Health, University of Bergen, Norway, Sweden.
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39
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Fonseca V, Guba SC, Fink LM. Hyperhomocysteinemia and the endocrine system: implications for atherosclerosis and thrombosis. Endocr Rev 1999; 20:738-59. [PMID: 10529901 DOI: 10.1210/edrv.20.5.0381] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- V Fonseca
- Department of Medicine, Tulane University Medical School, New Orleans, Louisiana 70112, USA.
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40
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Abstract
Homocysteine is an amino acid that has been strongly associated with vascular disease. Plasma homocysteine concentrations are known to vary with dietary patterns and to decrease with exogenous estrogen use, but no other behavioral factors have been examined as potential modifiers of this risk factor. Because psychological stress has also been implicated in the development of cardiovascular disease, the purpose of this study was to test the hypothesis that acute psychological stress induces elevations in plasma homocysteine concentrations. A secondary aim was to test potential differences in response between premenopausal and postmenopausal women. Thirty-four healthy women, one-half of whom were naturally postmenopausal with no hormone replacement, participated in this study. The psychological stressors included standard mental arithmetic and speech stressors. Blood samples were taken prior to, during, and after the stressors, and heart rate and blood pressure were also monitored. Results indicated significant elevations in plasma homocysteine during acute psychological stress, with a return to baseline concentrations during recovery. The pattern of findings for blood pressure and heart rate was similar, suggesting that the rise in homocysteine concentrations may have been sympathetically-mediated. No effects of menopausal status or endogenous estrogens were found. The findings provide preliminary evidence that plasma homocysteine may be an important factor in the relationship between psychological stress and risk for heart disease.
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Affiliation(s)
- C M Stoney
- The Ohio State University, Columbus 43210-1222, USA.
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Pacher P, Ungvari Z, Kecskemeti V. Electrophysiological effects of homocysteine in isolated rat right ventricular papillary muscles and left atria. GENERAL PHARMACOLOGY 1999; 32:439-43. [PMID: 10323484 DOI: 10.1016/s0306-3623(98)00213-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There is clinical and epidemiological evidence that elevated plasma homocysteine (Hcy) levels are associated with increased myocardial infarction mortality; however, very little is known about Hcy's direct cardiac effects. Thus, we aimed to characterize the cellular electrophysiologic effects of Hcy, a sulfur-containing amino acid in isolated rat hearts. A conventional microelectrode technique was used in left atria and right ventricular papillary muscles. At concentrations higher than 10(6) M, Hcy significantly decreased the maximum rate of rise of the depolarization phase (Vmax) in both cardiac preparations in a dose-dependent manner. Hcy at 10(-4)-5 x 10(-4) M concentrations increased the action potential duration (APD) at late stages of repolarization (at 75% and 90% of APD) both in atria and in ventricles. There was a slight decrease in action potential amplitude in ventricular papillary muscles and atria at concentrations higher that 10(-5) M. The resting membrane potential and the early repolarization phase (APD25 and APD50) remained unchanged in every preparation studied at all concentrations of Hcy administered. The present data suggest that homocysteine may decrease the Na+ channel activity in in vitro cardiac preparations. reserved.
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Affiliation(s)
- P Pacher
- Department of Pharmacology, Semmelweis University of Medicine, Budapest, Hungary
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42
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43
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Abstract
The sulfur-containing amino acid, homocysteine, is formed from the essential amino acid methionine, and a number of B vitamins are involved in methionine metabolism. Pyridoxine, vitamin B6, is a cofactor for cystathionine beta synthase, which mediates the transformation of homocysteine to cystathionine, the initial step in the transsulfuration pathway and the urinary excretion of sulfur. In a normal diet there is conservation of the carbon skeleton, and about 50% of the homocysteine formed is remethylated to methionine via steps that require folic acid and vitamin B12. A deficiency of any of these three vitamins leads to modest homocyst(e)ine elevation, as does diminished renal function, both of which are common in the elderly. It is also established that homocyst(e)ine elevation of this order is associated with increased cardiovascular risk but is also associated with most established risk factors, although it is thought to be an independent contributor. In the inborn error of metabolism homocystinuria due to cystathionine beta synthase deficiency there is greatly increased circulating homocyst(e)ine and a clear association with precocious vascular disease. In about 50% of these patients there is a vascular event before the age of 30 years. The homocysteine-induced adverse vascular changes appear to result from endothelial and smooth muscle cell effects and increased thrombogenesis. We have documented a highly significant reduction in the occurrence of vascular events during 539 patient years of treatment in 32 patients with cystathionine beta synthase deficiency (mean age 30 years, range 9-66 years) by aggressive homocyst(e)ine lowering with pyridoxine, folic acid, and B12 (p = 0.0001). The 15 pyridoxine nonresponsive patients also received oral betaine. Although a cause and effect relationship is postulated for the increased cardiovascular risk associated with mild homocysteine elevation, a common cause of this elevation is the methylenetetrahydrofolate reductase C677T mutation. Homozygotes occur in about 11% of Caucasian populations. However, the mutation is not associated with increased coronary risk. Since mild homocysteine elevation is easily normalized by B vitamin supplementation, usually with folic acid, it remains for controlled clinical trials of this inexpensive therapy to determine whether normalizing mild homocyst(e)ine elevation reduces cardiovascular risk.
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Affiliation(s)
- D E Wilcken
- Department of Cardiovascular Medicine, University of New South Wales, Prince Henry Hospital, Sydney.
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Stern JM, Saver JL, Boldy RM, DeGregorio F. Homocysteine associated hypercoagulability and disseminated thrombosis--a case report. Angiology 1998; 49:765-9. [PMID: 9756429 DOI: 10.1177/000331979804901009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The authors report the occurrence of vascular occlusion due to hyperhomocysteinemia without significant underlying atherosclerotic disease. This unique observation supports the potential of hyperhomocysteinemia to induce thrombosis and the independence of the thrombosis from hyperhomocysteinemia's associated atherosclerosis. The case demonstrates the clinical relevance of the effects of hyperhomocysteinemia on the coagulation cascade. A 42-year-old woman who lacked signs of classic homocystinuria developed disseminated thrombosis with a 24-hour urine homocysteine concentration of 384 mg, twelve times the upper limit of normal. Thrombosis was present in the aortic arch and its major branches and in the mesenteric arteries and veins. A fatal stroke resulted from the thrombosis. Autopsy revealed minimal atherosclerotic disease and no complicated plaques. This case demonstrates an expanded role of hyperhomocysteinemia in clinically significant vascular occlusion. Serum homocysteine concentration determination may be a factor in the evaluation of a hypercoagulable state. Hyperhomocysteinemia should be considered when evaluating arterial or venous thrombosis in a young person regardless of whether atherosclerosis or other signs of abnormal homocysteine metabolism are present.
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Affiliation(s)
- J M Stern
- Department of Neurology, University of California at Los Angeles School of Medicine, 90095-1769, USA
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Dettmeyer R, Varchmin-Schultheiss K, Madea B. Sudden death of an 18-year-old man with homocystinuria and intracranial inflammatory pseudotumor (IPT). Forensic Sci Int 1998; 94:19-24. [PMID: 9670479 DOI: 10.1016/s0379-0738(98)00054-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
An 18-year-old mentally deficient man with well-known homocystinuria died suddenly within a few minutes. He had a history of severe oligophrenia, bilateral ectopia lentis requiring extraction of both lenses and operatively corrected genu valgum on both sides. In 1993 a hypergammaglobulinemia was noticed and a decortication on the left side after purulent pneumonia became necessary. Four months before death multiple abscesses in the spleen and pancreas lead to splenectomy and resection of the pancreatic tail. Furthermore, an isolated inflammatory pseudotumor (IPT) of the brain was found. Autopsy revealed as cause of death a pulmonary embolism. The pathogenesis of the cause of death and concomitant diseases will be discussed.
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Affiliation(s)
- R Dettmeyer
- Institute of Forensic Medicine, University of Bonn, Germany
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Abstract
A rare case of plasma cell granuloma (PCG) of the brain is reported. An 18-year-old man with a well known homocystinuria and a history of severe oligophrenia, grand-mal-epilepsia, bilateral ectopia lentis requiring extraction of both lens and operatively correlated genu valgum, died suddenly within a few minutes. In 1993 a hypergammaglobulinemia was noticed and a decortication on the left side after purulent pneumonia became necessary. Four months before death, multiple abscesses in the spleen and pancreas led to splenectomy and resection of the pancreatic tail. Autopsy revealed a pulmonary embolism and an isolated intracranial plasma cell granuloma of the left hemisphere.
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Affiliation(s)
- R Dettmeyer
- Department of Forensic Medicine, University of Bonn, Germany
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Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 10-1998. A 46-year-old man with chest pain and coronary ostial stenosis. N Engl J Med 1998; 338:897-903. [PMID: 9518283 DOI: 10.1056/nejm199803263381308] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Abstract
An elevated level of total homocysteine (tHcy) in blood, denoted hyperhomocysteinemia, is emerging as a prevalent and strong risk factor for atherosclerotic vascular disease in the coronary, cerebral, and peripheral vessels, and for arterial and venous thromboembolism. The basis for these conclusions is data from about 80 clinical and epidemiological studies including more than 10,000 patients. Elevated tHcy confers a graded risk with no threshold, is independent of but may enhance the effect of the conventional risk factors, and seems to be a particularly strong predictor of cardiovascular mortality. Hyperhomocysteinemia is attributed to commonly occurring genetic and acquired factors including deficiencies of folate and vitamin B12. Supplementation with B-vitamins, in particular with folic acid, is an efficient, safe, and inexpensive means to reduce an elevated tHcy level. Studies are now in progress to establish whether such therapy will reduce cardiovascular risk.
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Affiliation(s)
- H Refsum
- Department of Pharmacology, University of Bergen, Norway.
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Donner MG, Klein GK, Mathes PB, Schwandt P, Richter WO. Plasma total homocysteine levels in patients with early-onset coronary heart disease and a low cardiovascular risk profile. Metabolism 1998; 47:273-9. [PMID: 9500562 DOI: 10.1016/s0026-0495(98)90256-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mild hyperhomocysteinemia has been associated with an increased risk to develop premature coronary heart disease. Recently, the homocysteine concentration has been positively correlated with several main cardiovascular risk factors. We addressed the issue as to whether patients with coronary heart disease and a low cardiovascular risk profile also have a higher prevalence of hyperhomocysteinemia than matched controls. Ninety-five patients (aged 50.5 +/- 6.6 years) and 34 controls (50.0 +/- 6.7 years) less than 60 years of age were selected from a sample of patients after coronary angiography. Subjects with hypertension, diabetes, and moderate or severe hyperlipidemia were excluded. We determined plasma aminothiols (total homocysteine, cysteine, and glutathione), lipoprotein fractions, fibrinogen, and uric acid, the body mass index (weight in kilograms divided by height in meters squared), and the waist to hip ratio. Furthermore, 37 healthy subjects aged 30.8 +/- 7.5 years underwent aminothiol determinations. Patients and controls were similar with regard to age and primary cardiovascular risk factors. Total homocysteine concentrations in the patient group (9.2 +/- 2.4 micromol/L) were significantly higher than in the healthy subjects (8.0 +/- 2.0 micromol/L). However, they did not differ from the levels in the age-matched controls (9.3 +/- 3.0 micromol/L). Neither total cysteine nor glutathione concentrations were significantly different between patients and controls. Male patients (n = 85) had higher mean very-low-density lipoprotein (VLDL) triglycerides (1.36 +/- 0.90 mmol/L) and lower high-density lipoprotein 3 (HDL3) cholesterol (0.75 +/- 0.21 mmol/L) than male controls (n = 28; 1.01 +/- 0.62 and 0.88 +/- 0.26 mmol/L, respectively). Female patients did not have any significant differences in lipoprotein concentrations versus the controls. Among further cardiovascular risk factors, we found a higher prevalence of central obesity in male patients. In conclusion, there was not a higher incidence of hyperhomocysteinemia among patients with premature coronary heart disease and a low cardiovascular risk profile. The higher prevalence of hyperhomocysteinemia found in other studies may be related to the primary risk factors seen in these populations, and may therefore be an indicator of the global cardiovascular risk.
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Affiliation(s)
- M G Donner
- Medical Department II, University of Munich, Klinikum Grosshadern, Germany
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50
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Nygård O, Nordrehaug JE, Refsum H, Ueland PM, Farstad M, Vollset SE. Plasma homocysteine levels and mortality in patients with coronary artery disease. N Engl J Med 1997; 337:230-6. [PMID: 9227928 DOI: 10.1056/nejm199707243370403] [Citation(s) in RCA: 1164] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Elevated plasma homocysteine levels are a risk factor for coronary heart disease, but the prognostic value of homocysteine levels in patients with established coronary artery disease has not been defined. METHODS We prospectively investigated the relation between plasma total homocysteine levels and mortality among 587 patients with angiographically confirmed coronary artery disease. At the time of angiography in 1991 or 1992, risk factors for coronary disease, including homocysteine levels, were evaluated. The majority of the patients subsequently underwent coronary-artery bypass grafting (318 patients) or percutaneous transluminal coronary angioplasty (120 patients); the remaining 149 were treated medically. RESULTS After a median follow-up of 4.6 years, 64 patients (10.9 percent) had died. We found a strong, graded relation between plasma homocysteine levels and overall mortality. After four years, 3.8 percent of patients with homocysteine levels below 9 micromol per liter had died, as compared with 24.7 percent of those with homocysteine levels of 15 micromol per liter or higher. Homocysteine levels were only weakly related to the extent of coronary artery disease but were strongly related to the history with respect to myocardial infarction, the left ventricular ejection fraction, and the serum creatinine level. The relation of homocysteine levels to mortality remained strong after adjustment for these and other potential confounders. In an analysis in which the patients with homocysteine levels below 9 micromol per liter were used as the reference group, the mortality ratios were 1.9 for patients with homocysteine levels of 9.0 to 14.9 micromol per liter, 2.8 for those with levels of 15.0 to 19.9 micromol per liter, and 4.5 for those with levels of 20.0 micromol per liter or higher (P for trend=0.02). When death due to cardiovascular disease (which occurred in 50 patients) was used as the end point in the analysis, the relation between homocysteine levels and mortality was slightly strengthened. CONCLUSIONS Plasma total homocysteine levels are a strong predictor of mortality in patients with angiographically confirmed coronary artery disease.
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Affiliation(s)
- O Nygård
- Department of Public Health and Primary Health Care, University of Bergen, Haukeland University Hospital, Norway
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