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Demaret T, Bédard K, Soucy JF, Watkins D, Allard P, Levtova A, O'Brien A, Brunel-Guitton C, Rosenblatt DS, Mitchell GA. The MMACHC variant c.158T>C: Mild clinical and biochemical phenotypes and marked hydroxocobalamin response in cblC patients. Mol Genet Metab 2024; 142:108345. [PMID: 38387306 DOI: 10.1016/j.ymgme.2024.108345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024]
Abstract
Mutations in MMACHC cause cobalamin C disease (cblC, OMIM 277400), the commonest inborn error of vitamin B12 metabolism. In cblC, deficient activation of cobalamin results in methylcobalamin and adenosylcobalamin deficiency, elevating methylmalonic acid (MMA) and total plasma homocysteine (tHcy). We retrospectively reviewed the medical files of seven cblC patients: three compound heterozygotes for the MMACHC (NM_015506.3) missense variant c.158T>C p.(Leu53Pro) in trans with the common pathogenic mutation c.271dupA (p.(Arg91Lysfs*14), "compounds"), and four c.271dupA homozygotes ("homozygotes"). Compounds receiving hydroxocobalamin intramuscular injection monotherapy had age-appropriate psychomotor performance and normal ophthalmological examinations. In contrast, c.271dupA homozygotes showed marked psychomotor retardation, retinopathy and feeding problems despite penta-therapy (hydroxocobalamin, betaine, folinic acid, l-carnitine and acetylsalicylic acid). Pretreatment levels of plasma and urine MMA and tHcy were higher in c.271dupA homozygotes than in compounds. Under treatment, levels of the compounds approached or entered the reference range but not those of c.271dupA homozygotes (tHcy: compounds 9.8-32.9 μM, homozygotes 41.6-106.8 (normal (N) < 14); plasma MMA: compounds 0.14-0.81 μM, homozygotes, 10.4-61 (N < 0.4); urine MMA: compounds 1.75-48 mmol/mol creatinine, homozygotes 143-493 (N < 10)). Patient skin fibroblasts all had low cobalamin uptake, but this was milder in compound cells. Also, the distribution pattern of cobalamin species was qualitatively different between cells from compounds and from homozygotes. Compared to the classic cblC phenotype presented by c.271dupA homozygous patients, c.[158T>C];[271dupA] compounds had mild clinical and biochemical phenotypes and responded strikingly to hydroxocobalamin monotherapy.
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Affiliation(s)
- Tanguy Demaret
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Centre de Génétique Humaine, Institut de Pathologie et Génétique, Gosselies, Belgium
| | - Karine Bédard
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Laboratoire de Diagnostic Moléculaire, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada; Département de Pathologie et Biologie Cellulaire, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Jean-François Soucy
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada; Department of Medical Genetics, McGill University Health Centre, Montreal, Quebec, Canada
| | - Pierre Allard
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Department of Biochemistry, CHU Sainte-Justine, Montréal, Québec, Canada
| | - Alina Levtova
- Service de Médecine Génique, Département de Médecine, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Alan O'Brien
- Service de Médecine Génique, Département de Médecine, Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada
| | - Catherine Brunel-Guitton
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada; Division of Biochemical Genetics, Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, British Columbia, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada; Department of Medical Genetics, McGill University Health Centre, Montreal, Quebec, Canada
| | - Grant A Mitchell
- Medical Genetics Division, Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine, Université de Montréal, Montréal, Québec, Canada.
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2
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Waisbren SE. Review of neuropsychological outcomes in isolated methylmalonic acidemia: recommendations for assessing impact of treatments. Metab Brain Dis 2022; 37:1317-1335. [PMID: 35348993 DOI: 10.1007/s11011-022-00954-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 03/09/2022] [Indexed: 11/29/2022]
Abstract
Methylmalonic acidemia (MMA) due to methylmalonyl-CoA mutase deficiency (OMIM #251,000) is an autosomal recessive disorder of organic acid metabolism associated with life-threatening acute metabolic decompensations and significant neuropsychological deficits. "Isolated" MMA refers to the presence of excess methylmalonic acid without homocysteine elevation. Belonging to this class of disorders are those that involve complete deficiency (mut0) and partial deficiency (mut-) of the methylmalonyl-CoA mutase enzyme and other disorders causing excess methylmalonic acid excretion. These other disorders include enzymatic subtypes related to cobalamin A defect (cblA) (OMIM #25,110), cobalamin B defect (cblB) (OMIM #251,110) and related conditions. Neuropsychological attributes associated with isolated MMA have become more relevant as survival rates increased following improved diagnostic and treatment strategies. Children with this disorder still are at risk for developmental delay, cognitive difficulties and progressive declines in functioning. Mean IQ for all types apart from cblA defect enzymatic subtype is rarely above 85 and much lower for mut0 enzymatic subtype. Identifying psychological domains responsive to improvements in biochemical status is important. This review suggests that processing speed, working memory, language, attention, and quality of life may be sensitive to fluctuations in metabolite levels while IQ and motor skills may be less amenable to change. Due to slower developmental trajectories, Growth Scale Values, Projected Retained Ability Scores and other indices of change need to be incorporated into clinical trial study protocols. Neuropsychologists are uniquely qualified to provide a differentiated picture of cognitive, behavioral and emotional consequences of MMA and analyze benefits or shortcomings of novel treatments.
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Affiliation(s)
- Susan E Waisbren
- Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
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3
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Wang C, Zhang Y, Shu J, Gu C, Yu Y, Liu W. Association Between Methylmalonic Acid and Cognition: A Systematic Review and Meta-Analysis. Front Pediatr 2022; 10:901956. [PMID: 35844735 PMCID: PMC9276928 DOI: 10.3389/fped.2022.901956] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/09/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Methylmalonic acid (MMA) is an intermediate metabolite of human body. The content of MMA in the blood of healthy people is very low, and its concentration will increase in some diseases and elderly people. Recent studies have shown that MMA has a variety of biological functions. The correlation between MMA and cognition, one of the important functions of the nervous system, is still uncertain. OBJECTIVE Meta-analyses were performed to assess whether elevated MMA was associated with the risk of cognitive decline. MATERIALS AND METHODS Cross-sectional studies, randomized controlled studies, and case-control studies on the relationship between MMA and cognition were obtained by searching PubMed, Web of Science, EMBASE, ProQuest, WANFANG MED ONLINE, China National Knowledge Infrastructure (CNKI) and Chongqing VIP until May 2022. Two researchers independently selected studies according to inclusion and exclusion criteria, evaluated study quality and extracted data. Meta-analyses were performed using Review Manager 5.4 software. The sensitivity analysis of meta-analysis was performed by One by one exclusion method. RESULTS A total of 11 studies were included, including six cross-sectional studies, two randomized controlled studies, and three case-control studies, with a sample of 16,533 subjects. Meta-analysis showed that there was no significant difference in cognitive level between high-level MMA subjects and low-level MMA subjects in the general population [SMD = -2.19, 95% CI (-4.76 ∼ 0.38), Z = 1.67, P = 0.09]. In the population supplemented with VitB12, the increase of MMA level caused by VitB12 supplementation was not related to the change of cognition [SMD = 0.32, 95% CI (-0.19 ∼ 0.84) z = 1.22, P = 0.22]. There was also no significant difference in MMA levels between patients with dementia and the control group [WMD = 20.89, 95% CI (-5.13 ∼ 46.92), z = 1.57, P = 0.12]. CONCLUSION In the general population, whether VitB12 is supplemented or not, there is no correlation between the increase of MMA level and the decrease of cognitive level. In dementia diseases, the level of MMA did not change significantly. High levels of MMA may not be a risk factor for cognitive impairment. The exact relationship between MMA and cognition needs further research. SYSTEMATIC REVIEW REGISTRATION [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021266310], identifier [CRD42021266310].
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Affiliation(s)
- Chao Wang
- Tianjin Pediatric Research Institute, Tianjin Children's Hospital, Children's Hospital of Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China
| | - Ying Zhang
- Tianjin Pediatric Research Institute, Tianjin Children's Hospital, Children's Hospital of Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China
| | - Jianbo Shu
- Tianjin Pediatric Research Institute, Tianjin Children's Hospital, Children's Hospital of Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China
| | - Chunyu Gu
- Tianjin Pediatric Research Institute, Tianjin Children's Hospital, Children's Hospital of Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China
| | - Yuping Yu
- Tianjin Pediatric Research Institute, Tianjin Children's Hospital, Children's Hospital of Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin, China
| | - Wei Liu
- Tianjin Children's Hospital, Children's Hospital of Tianjin University, Tianjin, China
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4
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Luciani A, Denley MCS, Govers LP, Sorrentino V, Froese DS. Mitochondrial disease, mitophagy, and cellular distress in methylmalonic acidemia. Cell Mol Life Sci 2021; 78:6851-6867. [PMID: 34524466 PMCID: PMC8558192 DOI: 10.1007/s00018-021-03934-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/18/2021] [Accepted: 08/30/2021] [Indexed: 01/09/2023]
Abstract
Mitochondria—the intracellular powerhouse in which nutrients are converted into energy in the form of ATP or heat—are highly dynamic, double-membraned organelles that harness a plethora of cellular functions that sustain energy metabolism and homeostasis. Exciting new discoveries now indicate that the maintenance of this ever changing and functionally pleiotropic organelle is particularly relevant in terminally differentiated cells that are highly dependent on aerobic metabolism. Given the central role in maintaining metabolic and physiological homeostasis, dysregulation of the mitochondrial network might therefore confer a potentially devastating vulnerability to high-energy requiring cell types, contributing to a broad variety of hereditary and acquired diseases. In this Review, we highlight the biological functions of mitochondria-localized enzymes from the perspective of understanding—and potentially reversing—the pathophysiology of inherited disorders affecting the homeostasis of the mitochondrial network and cellular metabolism. Using methylmalonic acidemia as a paradigm of complex mitochondrial dysfunction, we discuss how mitochondrial directed-signaling circuitries govern the homeostasis and physiology of specialized cell types and how these may be disturbed in disease. This Review also provides a critical analysis of affected tissues, potential molecular mechanisms, and novel cellular and animal models of methylmalonic acidemia which are being used to develop new therapeutic options for this disease. These insights might ultimately lead to new therapeutics, not only for methylmalonic acidemia, but also for other currently intractable mitochondrial diseases, potentially transforming our ability to regulate homeostasis and health.
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Affiliation(s)
- Alessandro Luciani
- Mechanisms of Inherited Kidney Diseases Group, Institute of Physiology, University of Zurich, 8032, Zurich, Switzerland.
| | - Matthew C S Denley
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, University of Zurich, 8032, Zurich, Switzerland
| | - Larissa P Govers
- Mechanisms of Inherited Kidney Diseases Group, Institute of Physiology, University of Zurich, 8032, Zurich, Switzerland
| | - Vincenzo Sorrentino
- Department of Musculo-Skeletal Health, Nestlé Institute of Health Sciences, Nestlé Research, 1015, Lausanne, Switzerland.
| | - D Sean Froese
- Division of Metabolism and Children's Research Center, University Children's Hospital Zurich, University of Zurich, 8032, Zurich, Switzerland.
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5
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Levtova A, Waters PJ, Buhas D, Lévesque S, Auray-Blais C, Clarke JTR, Laframboise R, Maranda B, Mitchell GA, Brunel-Guitton C, Braverman NE. Combined malonic and methylmalonic aciduria due to ACSF3 mutations: Benign clinical course in an unselected cohort. J Inherit Metab Dis 2019; 42:107-116. [PMID: 30740739 DOI: 10.1002/jimd.12032] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND The clinical significance of combined malonic and methylmalonic aciduria due to ACSF3 deficiency (CMAMMA) is controversial. In most publications, affected patients were identified during the investigation of various complaints. METHODS Using a cross-sectional multicenter retrospective natural history study, we describe the course of all known CMAMMA individuals in the province of Quebec. RESULTS We identified 25 CMAMMA patients (6 months to 30 years old) with a favorable outcome regardless of treatment. All but one came to clinical attention through the Provincial Neonatal Urine Screening Program (screening on day 21 of life). Median methylmalonic acid (MMA) levels ranged from 107 to 857 mmol/mol creatinine in urine (<10) and from 8 to 42 μmol/L in plasma (<0.4); median urine malonic acid (MA) levels ranged from 9 to 280 mmol/mol creatinine (<5). MMA was consistently higher than MA. These findings are comparable to those previously reported in CMAMMA. Causal ACSF3 mutations were identified in all patients for whom genotyping was performed (76% of cases). The most common ACSF3 mutations in our cohort were c.1075G > A (p.E359K) and c.1672C > T (p.R558W), representing 38.2 and 20.6% of alleles in genotyped families, respectively; we also report several novel mutations. CONCLUSION Because our province still performs urine newborn screening, our patient cohort is the only one free of selection bias. Therefore, the favorable clinical course observed suggests that CMAMMA is probably a benign condition, although we cannot exclude the possibility that a small minority of patients may present symptoms attributable to CMAMMA, perhaps as a result of interactions with other genetic or environmental factors.
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Affiliation(s)
- Alina Levtova
- Division of Medical Genetics, Department of Medicine, Centre Hospitalier de l'Université de Montréal (CHUM) and Université de Montréal, Tour Viger, 900 rue St-Denis, R07-462, Montreal, Quebec H2X 0A9, Canada
- Division of Medical Genetics, Department of Pediatrics, CHU Sainte-Justine and Université de Montréal, 3175 Côte-Sainte-Catherine, Montreal, Quebec H3T 1C5, Canada
| | - Paula J Waters
- Division of Medical Genetics, Department of Pediatrics, Université de Sherbrooke, CHUS, 3001 12th Avenue North, Sherbrooke, Quebec J1H 5N4, Canada
| | - Daniela Buhas
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Departments of Medical Genetics and Pediatrics, Montreal Children's Hospital, Montreal, Quebec, Canada
| | - Sébastien Lévesque
- Division of Medical Genetics, Department of Pediatrics, Université de Sherbrooke, CHUS, 3001 12th Avenue North, Sherbrooke, Quebec J1H 5N4, Canada
| | - Christiane Auray-Blais
- Division of Medical Genetics, Department of Pediatrics, Université de Sherbrooke, CHUS, 3001 12th Avenue North, Sherbrooke, Quebec J1H 5N4, Canada
| | - Joe T R Clarke
- Division of Medical Genetics, Department of Pediatrics, Université de Sherbrooke, CHUS, 3001 12th Avenue North, Sherbrooke, Quebec J1H 5N4, Canada
| | - Rachel Laframboise
- Department of Pediatrics, Laval University Hospital Centre, Quebec, Quebec, Canada
| | - Bruno Maranda
- Division of Medical Genetics, Department of Pediatrics, Université de Sherbrooke, CHUS, 3001 12th Avenue North, Sherbrooke, Quebec J1H 5N4, Canada
- Department of Pediatrics, Laval University Hospital Centre, Quebec, Quebec, Canada
| | - Grant A Mitchell
- Division of Medical Genetics, Department of Pediatrics, CHU Sainte-Justine and Université de Montréal, 3175 Côte-Sainte-Catherine, Montreal, Quebec H3T 1C5, Canada
| | - Catherine Brunel-Guitton
- Division of Medical Genetics, Department of Pediatrics, CHU Sainte-Justine and Université de Montréal, 3175 Côte-Sainte-Catherine, Montreal, Quebec H3T 1C5, Canada
| | - Nancy E Braverman
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Departments of Medical Genetics and Pediatrics, Montreal Children's Hospital, Montreal, Quebec, Canada
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6
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Abstract
Defects in the human gene encoding methylmalonyl-CoA mutase enzyme (MCM) give rise to a rare autosomal recessive inherited disorder of propionate metabolism termed mut methylmalonic acidemia (MMA). Patients with mut MMA have been divided into two subgroups: mut0 with complete loss of MCM activity and mut- with residual activity in the presence of adenosylcobalamin (AdoCbl). The disease typically presents in the first weeks or months of life and is clinically characterized by recurrent vomiting, metabolic acidosis, hyperammonemia, lethargy, poor feeding, failure to thrive and neurological deficit. To better elucidate the spectrum of mutations causing mut MMA in Saudi patients, we screened a cohort of 60 Saudi patients affected by either forms of the disease for mutations in the MUT gene. A total of 13 different mutations, including seven previously reported missense changes and six novel mutations, were detected in a homozygous state except for two compound heterozygous cases. The six novel mutations identified herein consist of three nonsense, two missense and one frameshift, distributed throughout the whole protein. This study describes for the first time the clinical and mutational spectrum of mut MMA in Saudi Arabian patients.
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7
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Ruppert T, Schumann A, Gröne HJ, Okun JG, Kölker S, Morath MA, Sauer SW. Molecular and biochemical alterations in tubular epithelial cells of patients with isolated methylmalonic aciduria. Hum Mol Genet 2015; 24:7049-59. [PMID: 26420839 DOI: 10.1093/hmg/ddv405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/22/2015] [Indexed: 12/23/2022] Open
Abstract
Methylmalonic acidurias (MMAurias) are a group of inherited disorders in the catabolism of branched-chain amino acids, odd-chain fatty acids and cholesterol caused by complete or partial deficiency of methylmalonyl-CoA mutase (mut(0) and mut(-) subtype respectively) and by defects in the metabolism of its cofactor 5'-deoxyadenosylcobalamin (cblA, cblB or cblD variant 2 type). A long-term complication found in patients with mut(0) and cblB variant is chronic tubulointerstitial nephritis. The underlying pathomechanism has remained unknown. We established an in vitro model of tubular epithelial cells from patient urine (hTEC; 9 controls, 5 mut(0), 1 cblB). In all human tubular epithelial cell (hTEC) lines we found specific tubular markers (AQP1, UMOD, AQP2). Patient cells showed disturbance of energy metabolism in glycolysis, mitochondrial respiratory chain and Krebs cycle in concert with increased reactive oxygen species (ROS) formation. Electron micrographs indicated increased autophagosome production and endoplasmic reticulum stress, which was supported by positive acridine orange staining and elevated levels of LC3 II, P62 and pIRE1. Screening mTOR signaling revealed a release of inhibition of autophagy. Patient hTEC produced and secreted elevated amounts of the pro-inflammatory cytokine IL8, which was highly correlated with the acridine orange staining. Summarizing, hTEC of MMAuria patients are characterized by disturbed energy metabolism and ROS production that lead to increased autophagy and IL8 secretion.
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Affiliation(s)
- T Ruppert
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Children's Hospital Heidelberg, D-69120 Heidelberg, Germany
| | - A Schumann
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Children's Hospital Heidelberg, D-69120 Heidelberg, Germany, Division of Metabolism and Children's Research Center, University Children's Hospital, Zurich, Switzerland, Institute of Physiology, Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland and
| | - H J Gröne
- Department of Cellular and Molecular Pathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - J G Okun
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Children's Hospital Heidelberg, D-69120 Heidelberg, Germany
| | - S Kölker
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Children's Hospital Heidelberg, D-69120 Heidelberg, Germany
| | - M A Morath
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Children's Hospital Heidelberg, D-69120 Heidelberg, Germany
| | - S W Sauer
- Department of General Pediatrics, Division of Neuropediatrics and Metabolic Medicine, University Children's Hospital Heidelberg, D-69120 Heidelberg, Germany,
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8
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Han L, Wu S, Ye J, Qiu W, Zhang H, Gao X, Wang Y, Gong Z, Jin J, Gu X. Biochemical, molecular and outcome analysis of eight chinese asymptomatic individuals with methyl malonic acidemia detected through newborn screening. Am J Med Genet A 2015; 167A:2300-5. [PMID: 25982642 DOI: 10.1002/ajmg.a.37147] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/19/2015] [Indexed: 12/18/2022]
Abstract
Methyl malonic academia (MMA) is characterized by abnormal accumulation of methyl malonic acid in body fluids. Patients usually have a variety of clinical symptoms including recurrent vomiting, metabolic acidosis, developmental delay, seizure, or death. However, a few cases where the patients have no symptom are also reported. Here, we conducted clinical, biochemical, and molecular analysis of eight Chinese patients identified through newborn screening between 2003 and 2013. All the patients had significantly higher blood propionylcarnitine (C3) concentrations, ratio of propionylcarnitine/acetylcarnitine (C3/C2); and their urine methyl malonic acid and methylcitric acid (MCA) excretions were remarkably higher than normal at diagnosis and during follow-ups. In addition, five different known mutations were identified in seven of the eight patients in either MUT or MMACHC. All these mutations were expected to produce defective proteins that would result in decreased or even total loss of methyl malonyl-CoA mutase activity. However, normal outcomes were found in all patients in physical growth, intellectual performance and cerebral MRI analysis at diagnosis (range, 14-53 days) and during follow-ups (range, 1.8-10 years). Our study is the first report of Chinese MMA patients with increased secretion of methyl malonic acid and molecular defects in MUT or MMACHC yet remain asymptomatic.
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Affiliation(s)
- Lianshu Han
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Shengnan Wu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Pediatric Endocrinology and Genetic Metabolism, Zhengzhou Children's Hospital, Henan, China
| | - Jun Ye
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wenjuan Qiu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Huiwen Zhang
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiaolan Gao
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yu Wang
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhuwen Gong
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jing Jin
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xuefan Gu
- Department of Pediatric Endocrinology and Genetic Metabolism, Xinhua Hospital, Shanghai Institute for Pediatric Research, Shanghai Jiaotong University School of Medicine, Shanghai, China
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9
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Ktena YP, Paul SM, Hauser NS, Sloan JL, Gropman A, Manoli I, Venditti CP. Delineating the spectrum of impairments, disabilities, and rehabilitation needs in methylmalonic acidemia (MMA). Am J Med Genet A 2015; 167A:2075-84. [PMID: 25959030 DOI: 10.1002/ajmg.a.37127] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 04/02/2015] [Indexed: 11/08/2022]
Abstract
Methylmalonic acidemia patients have complex rehabilitation needs that can be targeted to optimize societal independence and quality of life. Thirty-seven individuals with isolated MMA (28 mut, 5 cblA, 4 cblB), aged 2-33 years, were enrolled in a natural history study, and underwent age-appropriate clinical assessments to characterize impairments and disabilities. Neurological examination and brain imaging studies were used to document movement disorders and the presence of basal ganglia injury. A range of impairments and disabilities were identified by a team of physical medicine experts. Movement disorders, such as chorea and tremor, were common (n = 31, 83%), even among patients without evidence of basal ganglia injury. Joint hypermobility (n = 24, 69%) and pes planus (n = 22, 60%) were frequent and, in many cases, under-recognized. 23 (62%) patients required gastrostomy feedings. 18/31 patients >4 years old (58%) had difficulties with bathing and dressing. 16 of 23 school-aged patients received various forms of educational support. Five of the 10 adult patients were employed or in college; three lived independently. Unmet needs were identified in access to rehabilitation services, such as physical therapy (unavailable to 14/31), and orthotics (unavailable to 15/22). We conclude that patients with MMA are challenged by a number of functional limitations in essential activities of mobility, self-care, and learning, in great part caused by movement disorders and ligamentous laxity. Early assessment, referral, and implementation of age-appropriate rehabilitation services should significantly improve independence and quality of life.
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Affiliation(s)
- Yiouli P Ktena
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Scott M Paul
- Rehabilitation Medicine Department, Clinical Center, National Institutes of Health, Bethesda, Maryland
| | - Natalie S Hauser
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Jennifer L Sloan
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Andrea Gropman
- Center for Neuroscience Research (CNR), Children's National Medical Center, Washington, District of Columbia
| | - Irini Manoli
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Charles P Venditti
- Organic Acid Research Section, Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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10
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Wong ESY, McIntyre C, Peters HL, Ranieri E, Anson DS, Fletcher JM. Correction of methylmalonic aciduria in vivo using a codon-optimized lentiviral vector. Hum Gene Ther 2014; 25:529-38. [PMID: 24568291 DOI: 10.1089/hum.2013.111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Methylmalonic aciduria is a rare disorder of organic acid metabolism with limited therapeutic options, resulting in high morbidity and mortality. Positive results from combined liver/kidney transplantation suggest, however, that metabolic sink therapy may be efficacious. Gene therapy offers a more accessible approach for the treatment of methylmalonic aciduria than organ transplantation. Accordingly, we have evaluated a lentiviral vector-mediated gene transfer approach in an in vivo mouse model of methylmalonic aciduria. A mouse model of methylmalonic aciduria (Mut(-/-)MUT(h2)) was injected intravenously at 8 weeks of age with a lentiviral vector that expressed a codon-optimized human methylmalonyl coenzyme A mutase transgene, HIV-1SDmEF1αmurSigHutMCM. Untreated Mut(-/-)MUT(h2) and normal mice were used as controls. HIV-1SDmEF1αmurSigHutMCM-treated mice achieved near-normal weight for age, and Western blot analysis demonstrated significant methylmalonyl coenzyme A enzyme expression in their livers. Normalization of liver methylmalonyl coenzyme A enzyme activity in the treated group was associated with a reduction in plasma and urine methylmalonic acid levels, and a reduction in the hepatic methylmalonic acid concentration. Administration of the HIV-1SDmEF1αmurSigHutMCM vector provided significant, although incomplete, biochemical correction of methylmalonic aciduria in a mouse model, suggesting that gene therapy is a potential treatment for this disorder.
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Affiliation(s)
- Edward S Y Wong
- 1 Genetics and Molecular Pathology, Women's and Children's Hospital , North Adelaide, SA 5006, Australia
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11
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Underhill HR, Hahn SH, Hale SL, Merritt JL. Asymptomatic methylmalonic acidemia in a homozygous MUT mutation (p.P86L). Pediatr Int 2013; 55:e156-8. [PMID: 24330302 DOI: 10.1111/ped.12195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 06/05/2013] [Accepted: 07/09/2013] [Indexed: 11/28/2022]
Abstract
Deficiency in methylmalonyl-coenzyme A mutase (MCM) is associated with accumulation of methylmalonic acid (MMA) and clinical outcomes that include early death and neurological impairment. Reported here are two unrelated patients with a homozygous p.P86L mutation in the MUT gene, which encodes MCM, diagnosed following newborn screening. This is the first description of a homozygous mutation in the N-terminal extended segment of the MCM apoenzyme. Both in vitro and in vivo testing did not find a response to supplemental hydroxocobalamin. After discontinuation of hydroxocobalamin in one patient, serum MMA level remained elevated but stable, while urine MMA increased. Both patients have remained asymptomatic with normal development. The observed homozygous p.P86L mutation in the N-terminal extended segment may yield reduced MCM activity and is refractory to hydroxocobalamin supplementation, while not inducing a metabolically unstable phenotype. These genotype-phenotype associations further enhance the understanding of methylmalonic acidemia, which will continue to improve patient care.
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Affiliation(s)
- Hunter R Underhill
- Department of Neurological Surgery, University of Washington, Seattle, Washington, USA; Department of Medicine (Division of Medical Genetics), University of Washington, Seattle, Washington, USA
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12
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Schuck PF, Januário SB, Simon KR, Scaini G, Mafioleti RL, Malgarin F, Pettenuzzo LF, Streck EL, Ferreira GC. Acute renal failure potentiates brain energy dysfunction elicited by methylmalonic acid. Int J Dev Neurosci 2013; 31:245-9. [DOI: 10.1016/j.ijdevneu.2013.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/18/2013] [Accepted: 02/07/2013] [Indexed: 10/27/2022] Open
Affiliation(s)
- Patrícia F. Schuck
- Laboratório de Erros Inatos do MetabolismoUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
| | - Silvana B. Januário
- Laboratório de Erros Inatos do MetabolismoUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
| | - Kellen R. Simon
- Laboratório de Erros Inatos do MetabolismoUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
| | - Giselli Scaini
- Laboratório de BioenergéticaUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
| | - Renato L. Mafioleti
- Laboratório de Erros Inatos do MetabolismoUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
| | - Fernanda Malgarin
- Laboratório de Erros Inatos do MetabolismoUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
| | - Leticia F. Pettenuzzo
- Departamento de BioquímicaInstituto de Ciências Básicas da SaúdeUniversidade Federal do Rio Grande do SulPorto AlegreRSBrazil
| | - Emilio L. Streck
- Laboratório de BioenergéticaUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
| | - Gustavo C. Ferreira
- Laboratório de Erros Inatos do MetabolismoUnidade Acadêmica de Ciências da SaúdeUniversidade do Extremo Sul CatarinenseCriciúmaSCBrazil
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Morath MA, Hörster F, Sauer SW. Renal dysfunction in methylmalonic acidurias: review for the pediatric nephrologist. Pediatr Nephrol 2013; 28:227-35. [PMID: 22814947 DOI: 10.1007/s00467-012-2245-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/25/2012] [Accepted: 05/25/2012] [Indexed: 12/20/2022]
Abstract
Methylmalonic acidurias are a heterogeneous group of inborn errors of branched-chain amino acid metabolism. Depending on the underlying etiology, acute or chronic renal disease constitutes major (long-term) complications. In recent decades, overall survival has improved due to optimized treatment strategies based on the use of standardized emergency protocols and dialysis techniques. The majority of these patients, especially those having mut°, cblB, and cblA deficiency, are at increased risk of developing chronic kidney disease secondary to tubulointerstitial nephritis to require hemo- or peritoneal dialysis. Kidney and/or liver transplantation, as organ replacement, or even gene therapy on a limited scale, are controversially discussed treatment options in methylmalonic acidurias. The pathophysiological basis of renal disease has not been clarified in detail until now, but a severe mitochondrial dysfunction and an impairment of tubular dicarboxylic acid transport due to accumulated toxic metabolic compounds has been recently proposed. Another severe renal complication of methylmalonic acidurias is the occurrence of cblC-associated infantile atypical hemolytic syndrome, which can result in acute kidney injury. Close collaboration between (pediatric) nephrologists and metabolic specialists is required for the long-term management of these patients.
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Affiliation(s)
- Marina A Morath
- Department of General Pediatrics, Division of Inborn Metabolic Diseases, University Children's Hospital Heidelberg, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany.
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O’Shea CJ, Sloan JL, Wiggs EA, Pao M, Gropman A, Baker EH, Manoli I, Venditti CP, Snow J. Neurocognitive phenotype of isolated methylmalonic acidemia. Pediatrics 2012; 129:e1541-51. [PMID: 22614770 PMCID: PMC3362903 DOI: 10.1542/peds.2011-1715] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Methylmalonic acidemia (MMA) is a metabolic disorder with a poorly defined long-term neurocognitive phenotype. We studied the neuropsychological outcomes of patients and examined clinical covariates that influenced cognition. METHODS A diverse cohort with mut, cblA, or cblB subtypes of isolated MMA (N = 43), ages 2 to 32 years, were evaluated at a single center over a 6-year period. The influence of clinical, laboratory, and metabolic parameters on neuropsychological testing results was determined. RESULTS Early-onset mut patients (n = 21) manifested the most severe neurocognitive impairments, with a mean ± SD full-scale IQ (FSIQ) of 71.1 ± 14.75. Late-onset mut patients (n = 6) had a mean FSIQ of 88.5 ± 27.62. cblA (n = 7), cblB (n = 6), and mut patients diagnosed prenatally or by newborn screening (n = 3) obtained mean FSIQs in the average range (100.7 ± 10.95, 96.6 ± 10.92, and 106.7 ± 6.66, respectively). Hyperammonemia at diagnosis and the presence of a seizure disorder were associated with a lower FSIQ (P = .001 and P = .041, respectively), but other clinical variables, including basal ganglia injury and mutation status, did not. FSIQ remained stable over longitudinal testing (n = 10). Decreased scores on processing speed, compared with all other intellectual domains, emerged as a specific neurocognitive manifestation. CONCLUSIONS The neurocognitive outcomes seen in isolated MMA are highly variable. An earlier age of disease onset, the presence of hyperammonemia at diagnosis, and a history of seizures were associated with more severe impairment. In all patient subtypes, selective deficits in processing speed were present.
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Affiliation(s)
- Colin J. O’Shea
- Office of the Clinical Director, National Institute of Mental Health
| | - Jennifer L. Sloan
- Genetics and Molecular Biology Branch, National Human Genome Research Institute
| | - Edythe A. Wiggs
- Office of the Clinical Director, National Institute of Neurological Disorders and Stroke, and
| | - Maryland Pao
- Office of the Clinical Director, National Institute of Mental Health
| | - Andrea Gropman
- Genetics and Molecular Biology Branch, National Human Genome Research Institute,,Division of Neurology, Children’s National Medical Center, Washington, District of Columbia
| | - Eva H. Baker
- Radiology and Imaging Sciences, National Institutes of Health, Bethesda, Maryland; and
| | - Irini Manoli
- Genetics and Molecular Biology Branch, National Human Genome Research Institute
| | - Charles P. Venditti
- Genetics and Molecular Biology Branch, National Human Genome Research Institute
| | - Joseph Snow
- Office of the Clinical Director, National Institute of Mental Health
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15
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Exome sequencing identifies ACSF3 as a cause of combined malonic and methylmalonic aciduria. Nat Genet 2011; 43:883-6. [PMID: 21841779 PMCID: PMC3163731 DOI: 10.1038/ng.908] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 07/15/2011] [Indexed: 11/08/2022]
Abstract
We used exome sequencing to identify the genetic basis of combined malonic and methylmalonic aciduria (CMAMMA). We sequenced the exome of an individual with CMAMMA and followed up with sequencing of eight additional affected individuals (cases). This included one individual who was identified and diagnosed by searching an exome database. We identify mutations in ACSF3, encoding a putative methylmalonyl-CoA and malonyl-CoA synthetase as a cause of CMAMMA. We also examined a canine model of CMAMMA, which showed pathogenic mutations in a predicted ACSF3 ortholog. ACSF3 mutant alleles occur with a minor allele frequency of 0.0058 in ∼1,000 control individuals, predicting a CMAMMA population incidence of ∼1:30,000. ACSF3 deficiency is the first human disorder identified as caused by mutations in a gene encoding a member of the acyl-CoA synthetase family, a diverse group of evolutionarily conserved proteins, and may emerge as one of the more common human metabolic disorders.
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Watkins D, Rosenblatt DS. Inborn errors of cobalamin absorption and metabolism. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2011; 157C:33-44. [PMID: 21312325 DOI: 10.1002/ajmg.c.30288] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Derivatives of cobalamin (vitamin B(12)) are required for activity of two enzymes in humans. Adenosylcobalamin is required for activity of mitochondrial methylmalonylCoA mutase and methylcobalamin is required for activity of cytoplasmic methionine synthase. Deficiency in cobalamin, or inability to absorb cobalamin normally, can result in accumulation of methylmalonic acid and homocysteine in blood and urine. Methylmalonic acidemia can result in metabolic acidosis which in severe cases may be fatal. Hyperhomocysteinemia along with hypomethioninemia can result in hematologic (megaloblastic anemia, neutropenia, thrombocytopenia) and neurologic (subacute combined degeneration of the cord, dementia, psychosis) defects. Inborn errors affecting cobalamin absorption (inherited intrinsic factor deficiency, Imerslund–Gra¨ sbeck syndrome) and transport (transcobalamin deficiency) have been described. A series of inborn errors of intracellular cobalamin metabolism, designated cblA-cblG, have been differentiated by complementation analysis. These can give rise to isolated methylmalonic acidemia (cblA, cblB, cblD variant 2), isolated hyperhomocysteinemia (cblD variant 1, cblE, cblG) or combined methylmalonic acidemia and hyperhomocysteinemia (cblC, classic cblD, cblF). All these disorders are inherited as autosomal recessive traits. The genes underlying each of these disorders have been identified. Two other disorders, haptocorrin deficiency and transcobalamin receptor deficiency, have been described, but it is not clear that they have any consistent clinical phenotype.
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Affiliation(s)
- David Watkins
- Department of Human Genetics, McGill University, Canada.
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17
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Shigematsu Y, Hata I, Tajima G. Useful second-tier tests in expanded newborn screening of isovaleric acidemia and methylmalonic aciduria. J Inherit Metab Dis 2010; 33:S283-8. [PMID: 20440648 DOI: 10.1007/s10545-010-9111-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 03/19/2010] [Accepted: 04/12/2010] [Indexed: 10/19/2022]
Abstract
Common use of pivalate-generating antibiotics in newborns in Japan and low cutoff value of C5-acylcarnitine (C5) to detect mild forms of isovaleric acidemia (IVA) led to 1,065 positive results from IVA screening among 146,000 newborns tested by tandem mass spectrometry over the last 3 years. Using our method to determine isovalerylglycine (IVG) levels in dried blood spots (DBS) as a second-tier test with IVG cutoff value of 0.5 nmol/ml in DBS, one patient with severe IVA was identified, and no recall of the second DBS was needed. Retrospective analysis revealed that most patients with moderate to severe forms of IVA have decreased free-carnitine levels shortly after birth and higher levels of IVG than those of C5, which suggests that this method is useful in evaluating the severity of IVA. Another second-tier test, to measure methylmalonic acid (MMA) levels in DBS by gas chromatography/mass spectrometry (GC/MS), has been developed to overcome difficulties in screening methylmalonic aciduria (MMAU) and propionic acidemia. Methanol extract from DBS was dried and derivatized using N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide. GC/MS was performed using splitless injection, electron-impact ionization, and selected ion monitoring for data recording. MMAU patients had much higher DBS concentrations of MMA (24.2-321.9 nmol/ml) than control newborns (0.34 ± 0.11 nmol/ml). MMA measurement in DBS was thought to provide useful information about the severity of MMAU, as MMAU patients with high levels of MMA had decreased levels of free carnitine and mildly increased levels of propionylcarnitine.
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Affiliation(s)
- Yosuke Shigematsu
- Department of Health Science, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui, Japan.
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18
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Tu WJ, Dai F, Wang XY, Ho JJ. Liquid chromatography-tandem mass spectrometry for analysis of acylcarnitines in dried blood specimens collected at autopsy from neonatal intensive care unit. ACTA ACUST UNITED AC 2010; 25:109-14. [PMID: 20598234 DOI: 10.1016/s1001-9294(10)60032-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To investigate the feasibility of analyzing acylcarnitine in dry filter-paper blood spots by liquid chromatography-tandem mass spectrometry (LC-MS/MS) which could be applied to detect inborn errors of metabolism in neonates. METHODS We obtained filter-paper blood from 26 dead infants from a neonatal intensive care unit (NICU) between October 1, 2008 and September 30, 2009. Acylcarnitine and amino acid profiles were obtained with LC-MS/MS. Four infants underwent routine autopsy. The postmortem blood specimens were compared with newborn blood specimens, and with specimens obtained from older infants with metabolic disorders. RESULTS Of all the 26 patients, 5 (19.2%) were diagnosed as having different kinds of diseases: 3 with methylmalonic acidemia (the concentration of C3, and the ratio of C3/C16, C3/C2 increased), 1 with maple syrup urine disease (the concentration of leucine and isoleucine increased), and 1 with isovaleric acidemia (the concentration of C5 increased). CONCLUSIONS Postmortem metabolic test can explain infant deaths and provide estimates of deaths attributable to inborn errors of metabolism in NICU. LC-MS/MS is suitable for analysis of postmortem specimens and can be considered for routine application in NICU autopsy.
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Affiliation(s)
- Wen-jun Tu
- Center for Clinical Laboratory Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 102206, China
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Abstract
PURPOSE OF REVIEW To review studies on hereditary disorders of high-density lipoprotein (HDL) metabolism and studies on HDL genetics in mice, which have both provided valuable insight into the pathways of this intriguing lipoprotein and moreover revealed targets to raise HDLc to reduce atherosclerosis. RECENT FINDINGS To date, as many as 11 genes are considered key players in the synthesis, maturation, conversion and/or catabolism of HDL. Five of these genes have been identified in humans, APOA1, LCAT, ABCA1, LIPC, and CETP, whereas the other six genes have been identified in mice, SCARB1, ABCG1, ATPB5, PLTP, LIPG and APOM. Genetic association studies are as yet the best line of evidence of the roles of the 'murine genes' in human HDL pathways. In addition to recent genetic association studies, a third section describes exciting news on six newly proposed HDL genes VNN1, GALNT2, MMAB/MVK, CTalpha, BMP-1 and SIRT1. SUMMARY This review provides a summary of the current literature on the genetics of HDL. New information from this research area may assist us in obtaining a better understanding of HDL biology and identifying novel pharmacological targets.
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Affiliation(s)
- Adriaan G Holleboom
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
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20
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Bjørke-Monsen AL, Torsvik I, Saetran H, Markestad T, Ueland PM. Common metabolic profile in infants indicating impaired cobalamin status responds to cobalamin supplementation. Pediatrics 2008; 122:83-91. [PMID: 18595990 DOI: 10.1542/peds.2007-2716] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE A metabolic profile consistent with impaired cobalamin status is prevalent in breastfed infants. We investigated whether this profile reflects immature organ systems or impaired cobalamin status. METHODS In a single-center, randomized, placebo-controlled trial, we studied 107 six-week-old infants. The infants were randomly assigned to receive either an intramuscular injection of 400 mug of cobalamin or no intervention. Concentrations of cobalamin and folate in serum and total homocysteine, methylmalonic acid, and cystathionine in plasma were determined at enrollment and at the age of 4 months. RESULTS There were no significant differences between the intervention group (n = 54) and the control group (n = 53) in the concentrations of any vitamin marker at baseline (6 weeks). At 4 months, the supplement-treated infants had a 75% higher median serum cobalamin level and remarkable reductions in median plasma total homocysteine (from 7.46 to 4.57 micromol/L) and methylmalonic acid (from 0.58 to 0.20 micromol/L) levels, whereas levels of both metabolites were essentially unchanged during the follow-up period in the control group. CONCLUSIONS Cobalamin supplementation changed all markers of impaired cobalamin status (low cobalamin, high total homocysteine, and high methylmalonic acid levels) toward a profile observed in cobalamin-replete older children and adults. Therefore, the high total homocysteine and methylmalonic acid levels reported for a large fraction of infants reflect not immature metabolism but rather insufficient cobalamin levels to fully sustain cobalamin-dependent reactions fully.
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21
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Van Gosen L. Organic acidemias: a methylmalonic and propionic focus. J Pediatr Nurs 2008; 23:225-33. [PMID: 18492552 DOI: 10.1016/j.pedn.2008.02.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2007] [Revised: 02/02/2008] [Accepted: 02/06/2008] [Indexed: 11/29/2022]
Abstract
The management of children with organic acidemias (OAs) is limited in nursing literature. This article focuses on the two more common OAs, methylmalonic and propionic acidemias. Literature search was done on PUBMED, CINAHL, OVID, UptoDate, and GeneReview. The benefit of early diagnosis and treatment has been well documented, but many unresolved aspects of care management remain. Patient care is a complex necessitation and a lifelong follow-up for complications. Caring for patients with OA requires that nurses increase their familiarity with metabolic genetics and develop a better understanding of proper medical and nursing management while research continues to determine the most beneficial treatment and long-term care management methods.
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Affiliation(s)
- Lori Van Gosen
- Johns Hopkins School of Nursing, Johns Hopkins Children Center, Pediatric Clinical Research Unit, Baltimore, MD 21154, USA.
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Lindner M, Ho S, Kölker S, Abdoh G, Hoffmann GF, Burgard P. Newborn screening for methylmalonic acidurias--optimization by statistical parameter combination. J Inherit Metab Dis 2008; 31:379-85. [PMID: 18563635 DOI: 10.1007/s10545-008-0892-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Revised: 04/29/2008] [Accepted: 04/30/2008] [Indexed: 11/27/2022]
Abstract
With the introduction of tandem mass spectrometry, newborn screening for disorders of propionate metabolism became widely available. However, there is controversy whether population screening for these disorders should be performed. The most widely used primary metabolite C(3) itself has a poor specificity or lacks 100% sensitivity for milder forms and/or defects of cobalamin metabolism. Strategies to improve specificity have included the calculation of metabolite ratios (e.g. C(3)/C(2)) or second-tier strategies with analysis of methylmalonic acid or 2-methylcitric acid from the primary screening specimen. We report the results of a new statistical approach to identify parameter combinations that allow for 100% sensitivity as well as increased specificity. The promising results of this alternative approach will have to be substantiated on larger data sets.
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Affiliation(s)
- M Lindner
- Sektion für angeborene Stoffwechselkrankheiten, Zentrum für Kinder- und Jugendmedizin, INF 153, D-69120, Heidelberg, Germany.
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Mitchell GA, Gauthier N, Lesimple A, Wang SP, Mamer O, Qureshi I. Hereditary and acquired diseases of acyl-coenzyme A metabolism. Mol Genet Metab 2008; 94:4-15. [PMID: 18337138 DOI: 10.1016/j.ymgme.2007.12.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 12/20/2007] [Accepted: 12/20/2007] [Indexed: 01/23/2023]
Abstract
Coenzyme A (CoA) sequestration, toxicity or redistribution (CASTOR) is predicted to occur in many hereditary and acquired conditions in which the degradation of organic acyl esters of CoA is impaired. The resulting accumulation of CoA esters and reduction of acetyl-CoA and free CoA (CoASH) will then trigger a cascade of reactions leading to clinical disease. Most conditions detected by expanded neonatal screening are CASTOR diseases. We review acyl-CoA metabolism, including CoASH synthesis, transesterification of acyl-CoAs to glycine, glutamate or l-carnitine and hydrolysis of CoA esters. Because acyl-CoAs do not cross biological membranes, their main toxicity is intracellular, primarily within mitochondria. Treatment measures directed towards removal of circulating metabolites do not address this central problem of intracellular acyl-CoA accumulation. Treatments usually involve the restriction of dietary precursors and administration of agents like l-carnitine and glycine, which can accept the transfer of acyl groups from acyl-CoA, liberating CoASH. Many hereditary CASTOR patients are chronically ill, with persistent symptoms and continuously abnormal metabolites in blood and urine despite good compliance with treatment. Conversely, asymptomatic patients are also common in hereditary CASTOR conditions. Future challenges include the understanding of pathophysiologic mechanisms in CASTOR diseases, the discovery of reliable predictors of outcome in individual patients and the establishment of therapeutic trials with sufficient numbers of patients to permit solid therapeutic conclusions.
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Affiliation(s)
- Grant A Mitchell
- Division of Medical Genetics, CHU Sainte-Justine, 3175 Côte Sainte-Catherine Road, Montréal, Que., Canada H1R 2A6.
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Mc Guire PJ, Lim-Melia E, Diaz GA, Raymond K, Larkin A, Wasserstein MP, Sansaricq C. Combined liver-kidney transplant for the management of methylmalonic aciduria: a case report and review of the literature. Mol Genet Metab 2008; 93:22-9. [PMID: 17964841 PMCID: PMC2786260 DOI: 10.1016/j.ymgme.2007.08.119] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/08/2007] [Accepted: 08/08/2007] [Indexed: 11/27/2022]
Abstract
Over 27 cases of liver transplant, kidney transplant and combined liver-kidney transplant have been reported for the treatment of methylmalonic aciduria. We describe a case of a 5-year-old boy who underwent combined liver-kidney transplant (CLKT) for phenotypic mut0 disease. His history was notable for more than 30 hospitalizations for severe acidosis, metabolic strokes, liver disease, pancreatic disease, chronic renal insufficiency with interstitial nephritis, and decreased quality of life. Post-CLKT, there was a marked reduction in serum (80%) and urine MMA levels (90%) as well as a cessation of metabolic decompensations. Neurologic deterioration continued post-CKLT manifested as a cerebellar stroke. The clinical details and therapeutic implications of solid organ transplant for methylmalonic aciduria are discussed.
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Affiliation(s)
- Peter J Mc Guire
- Department of Pediatrics, Mt. Sinai Medical Center, One Gustave L. Levy Place, New York, NY 10021, USA.
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25
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Methylmalonic acid values in healthy Dutch children. Eur J Nutr 2007; 47:26-31. [DOI: 10.1007/s00394-007-0692-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 11/30/2007] [Indexed: 10/22/2022]
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Yang Y, Sun F, Song J, Hasegawa Y, Yamaguchi S, Zhang Y, Jiang Y, Qin J, Wu X. Clinical and biochemical studies on Chinese patients with methylmalonic aciduria. J Child Neurol 2006; 21:1020-4. [PMID: 17156691 DOI: 10.1177/7010.2006.00231] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Methylmalonic aciduria is a common organic aciduria disease. Recently, gas chromatography-mass spectrometry has been used to diagnose methylmalonic aciduria in China. Often, however, the diagnosis of methylmalonic aciduria is delayed because of a lack of technical expertise and the limited experience of general clinicians in China. In this study, the natural history, clinical features, and outcome of 77 Chinese patients with methylmalonic aciduria were investigated. Of the 77 patients, 31 (40.3%) had isolated methylmalonic aciduria and 46 (59.7%) had methylmalonic aciduria combined with homocystinemia. Thus, we observed a higher rate of the combined disease than studies conducted in other countries, suggesting that it might be more common in China. Total plasma homocysteine measurement might enable differential diagnoses of methylmalonic aciduria to be distinguished. The clinical spectrum of these 77 patients with methylmalonic aciduria ranged from neonatal death and severe symptoms to benign asymptomatic organic aciduria. Neonatal and infantile onset, which was a characteristic of the majority of cases, was associated with a greater severity relative to later-onset cases. Among the 17 cases who had onset after 3 years of age, only 1 patient had isolated methylmalonic aciduria and 16 had combined methylmalonic aciduria and homocystinemia. Nine of the patients with combined methylmalonic aciduria and homocystinemia completely recovered and exhibited normal intelligence, whereas seven improved, with a mild handicap.
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Affiliation(s)
- Yanling Yang
- Department of Pediatrics, Peking University First Hospital, Xicheng District, Beijing, China.
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Chandler R, Venditti CP. Genetic and genomic systems to study methylmalonic acidemia. Mol Genet Metab 2005; 86:34-43. [PMID: 16182581 PMCID: PMC2657357 DOI: 10.1016/j.ymgme.2005.07.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 07/22/2005] [Accepted: 07/26/2005] [Indexed: 11/17/2022]
Abstract
Methylmalonic acidemia (MMAemia) is the biochemical hallmark of a group of genetic metabolic disorders that share a common defect in the ability to convert methylmalonyl-CoA into succinyl-CoA. This disorder is due to either a mutant methylmalonyl-CoA mutase apoenzyme or impaired synthesis of adenosylcobalamin, the cofactor for this enzyme. In this article, we will provide an overview of the pathways disrupted in these disorders, discuss the known metabolic blocks with a particular focus on molecular genetics, and review the use of selected model organisms to study features of methylmalonic acidemia.
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Affiliation(s)
| | - C. P. Venditti
- Corresponding author. Fax: +1 301 402 2170. Email address: (C. Venditti)
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Hori D, Hasegawa Y, Kimura M, Yang Y, Verma IC, Yamaguchi S. Clinical onset and prognosis of Asian children with organic acidemias, as detected by analysis of urinary organic acids using GC/MS, instead of mass screening. Brain Dev 2005; 27:39-45. [PMID: 15626540 DOI: 10.1016/j.braindev.2004.04.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Revised: 04/13/2004] [Accepted: 04/13/2004] [Indexed: 11/16/2022]
Abstract
Organic acidemias (OAs) have been detected worldwide in symptomatic patients using gas chromatography mass spectrometry. We diagnosed 188 Asian cases of OAs by analysis of urinary organic acids and investigated their clinical onset and outcome. Methylmalonic acidemia (MMA) was most common (74 cases), followed by propionic acidemia (23 cases), ornitine transcarbamylase deficiency (22 cases), and multiple carboxylase deficiency (15 cases). For these 188 patients, onset was most frequent in the neonatal period or early infancy. Approximately 30% of the patients had a family history of similar symptoms or diseases. Although the outcome of OA patients varied, patients with early onset generally had poor outcomes despite early detection. Of the 45 MMA patients whose clinical data were available, 25 were clinically vitamin B12-responsive, while the remaining 20 were non-responsive. A favorable outcome was obtained in 7 of the 25 B12-responsive patients, and in only 3 of the 20 B12-nonresponsive patients. It was suggested that even in B12-responsive MMA cases, earlier detection and B12 therapy were needed to improve the prognosis. We concluded that detection of such patients at the presymptomatic stages using newborn mass screening is essential for prognosis improvement with OAs.
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Affiliation(s)
- Daisuke Hori
- Department of Pediatrics, Faculty of Medicine, Shimane University, 89-1 En-ya-cho, Izumo, Shimane 693-8501, Japan.
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Refsum H, Grindflek AW, Ueland PM, Fredriksen A, Meyer K, Ulvik A, Guttormsen AB, Iversen OE, Schneede J, Kase BF. Screening for Serum Total Homocysteine in Newborn Children. Clin Chem 2004; 50:1769-84. [PMID: 15319318 DOI: 10.1373/clinchem.2004.036194] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Newborn screening for total homocysteine (tHcy) in blood may identify babies with vitamin B12 (B12) deficiency or homocystinuria, but data on the causes of increased tHcy in screening samples are sparse.
Methods: Serum concentrations of tHcy, cystathionine, methionine, folate, and B12 and the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism were determined in 4992 capillary blood samples collected as part of the routine screening program in newborn children. Methylmalonic acid (MMA), gender (SRY genotyping), and the frequency of six cystathionine β-synthase (CBS) mutations were determined in 20–27% of the samples, including all samples with tHcy >15 μmol/L (n = 127), B12 <100 pmol/L (n = 159), or methionine >40 μmol/L (n = 154).
Results: The median (5th–95th percentile) tHcy concentration was 6.8 (4.2–12.8) μmol/L. B12 status, as determined by serum concentrations of B12, tHcy, and MMA, was moderately better in boys than in girls. tHcy concentrations between 10 and 20 μmol/L were often associated with low B12, whereas tHcy >20 μmol/L (n = 43) was nearly always explained by increased methionine. tHcy did not differ according to folate concentrations or MTHFR 677C>T genotypes. None of the babies had definite CBS deficiencies, but heterozygosity led to low cystathionine, increased methionine, but normal tHcy concentrations.
Conclusion: Increased tHcy is a common but not specific finding in newborns. The metabolite and vitamin profiles will point to the cause of hyperhomocysteinemia. Screening for tHcy and related factors should be further evaluated in regions with high prevalence of homocystinuria and in babies at high risk of B12 deficiency.
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Affiliation(s)
- Helga Refsum
- Department of Pharmacology, University of Oxford, UK.
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Monsen ALB, Refsum H, Markestad T, Ueland PM. Cobalamin status and its biochemical markers methylmalonic acid and homocysteine in different age groups from 4 days to 19 years. Clin Chem 2003; 49:2067-75. [PMID: 14633879 DOI: 10.1373/clinchem.2003.019869] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Recent data indicate that cobalamin and folate status, including the metabolic markers methylmalonic acid (MMA) and total homocysteine (tHcy), undergo marked changes during childhood, particularly during the first year. METHODS Serum cobalamin, serum and whole-blood folate, and plasma MMA and tHcy were determined in a cross-sectional study of 700 children, ages 4 days to 19 years. RESULTS During the first 6 months, serum cobalamin was lower than and plasma MMA, tHcy, and serum folate were higher than the concentrations detected in the other age groups. In infants 6 weeks to 6 months of age, median MMA and tHcy concentrations were >0.78 and >75 micro mol/L, respectively. In older children (>6 months), serum cobalamin peaked at 3-7 years and then decreased, median plasma MMA remained low (<0.26 micro mol/L), median plasma tHcy was low (<6 micro mol/L) and increased from the age of 7 years on, and serum folate gradually decreased. Plasma MMA was inversely associated with cobalamin (r = -0.4) in both age groups, but across the whole range of cobalamin concentrations, MMA was markedly higher in infants (< or =6 months) than in older children. Plasma tHcy showed a strong negative correlation to cobalamin (r = -0.52) but not to serum folate in infants < or =6 months. In older children, tHcy showed the expected association with both cobalamin (r = -0.48) and folate (r = -0.51). CONCLUSIONS In infants 6 weeks to 6 months, concentrations of the metabolic markers MMA and tHcy were higher than in the other age groups and strongly correlated to cobalamin, whereas in older children, both makers showed correlations to cobalamin and folate concentrations documented in adults. Whether this metabolic profile in infants is explained by impaired cobalamin status, which in turn may have long-term effects on psychomotor development, remains to be addressed in intervention studies.
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Bjørke Monsen AL, Ueland PM. Homocysteine and methylmalonic acid in diagnosis and risk assessment from infancy to adolescence. Am J Clin Nutr 2003; 78:7-21. [PMID: 12816766 DOI: 10.1093/ajcn/78.1.7] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The concentration of total homocysteine (tHcy) in serum and plasma is elevated in both folate and cobalamin deficiencies, whereas methylmalonic acid (MMA) in serum, plasma, or urine is a specific marker of cobalamin function. The combined measurement of both metabolites is useful for the diagnosis and follow-up of these deficiency states. In addition, tHcy is elevated under various pathologic states (eg, renal failure), and hyperhomocysteinemia is associated with an increased risk of cardiovascular disease, cognitive dysfunction, and adverse pregnancy outcomes. The diagnostic utility of tHcy and MMA concentrations as markers of folate and cobalamin deficiencies in healthy and diseased children has been documented. This article briefly summarizes the biochemical background of tHcy and MMA and the associations of tHcy and MMA with various disease states and focuses on novel data obtained in infants, children, and adolescents, with emphasis on cobalamin status in infants. The utility of tHcy and MMA as indicators of cobalamin and folate deficiencies in adults can be extended to infants and older children. Furthermore, as in adults, tHcy is related to unhealthy lifestyle factors and is a risk factor for vascular disease. High MMA concentrations in newborns, occasionally denoted as benign methylmalonic aciduria, may reflect impaired cobalamin function.
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Auray-Blais C, Giguère R, Lemieux B. Newborn urine screening programme in the province of Quebec: an update of 30 years' experience. J Inherit Metab Dis 2003; 26:393-402. [PMID: 12971427 DOI: 10.1023/a:1025115405074] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The introduction of our voluntary mass screening programme in 1971, in the province of Quebec, has permitted us to detect different inborn errors of metabolism in the newborn population using a thin-layer chromatographic (TLC) technique with sequential use of different sprays on the same plate. Abnormalities in amino acids and organic acids are detected in urine filter paper specimens of 21-day-old babies. Initial parental compliance is 90% and climbs to 99.25% for repeat sample requests. Screening is centralized in one laboratory, while diagnosis, counselling, management and follow-up are done in four regional centres. Over 25 inherited Mendelian disorders can be identified. There have been certain modifications in our programme throughout the years in order to increase efficiency, screen for a larger number of disorders, improve the quality of the collection of the urine filter paper samples, increase parental compliance and better manage the data bank. However, one goal has remained a priority: early prevention of genetic diseases. We present an overall view of our screening programme with an add-on technique to detect different organic acidurias, our recent statistics and the modifications implemented over the years.
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Affiliation(s)
- C Auray-Blais
- Mass Urinary Screening Program, Genetic Service, Centre hospitalier universitaire de Sherbrooke, hôpital Fleurimont, 3 001, 12e avenue Nord, Sherbrooke, Quebec, Canada, J1H 5N4.
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Schoen EJ, Baker JC, Colby CJ, To TT. Cost-benefit analysis of universal tandem mass spectrometry for newborn screening. Pediatrics 2002; 110:781-6. [PMID: 12359795 DOI: 10.1542/peds.110.4.781] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE To estimate potential costs and benefits of routinely using tandem mass spectrometry (MS/MS) to screen newborns for inborn errors of metabolism. METHOD Analysis of costs and benefits resulting from use of MS/MS in screening of 32 000 newborn infants using data from the Kaiser Permanente Medical Care Program of Northern California plus other published data. SETTING A large health maintenance organization. RESULTS In the base scenario, the cost per quality-adjusted life year saved by MS/MS screening was $5827; in the least favorable scenario, this cost was $11 419, and in the most favorable scenario, $736. CONCLUSION Costs per quality-adjusted life year saved by MS/MS screening for inborn errors of metabolism compare favorably with other mass screening programs, including those for breast and prostate cancer.
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Affiliation(s)
- Edgar J Schoen
- Department of Genetics, Kaiser Permanente Medical Center, Oakland, California 94611-5693, USA.
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Shinka T, Inoue Y, Yoshino M, Kakinuma H, Takahashi H, Kuhara T. Two cases of benign methylmalonic aciduria detected during a pilot study of neonatal urine screening. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 776:65-70. [PMID: 12127326 DOI: 10.1016/s1570-0232(02)00127-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two cases of benign methylmalonic aciduria (MMAuria) were found among 9780 neonatal screenings using the previously described screening method consisting of urease digestion, ethanol deproteinization and gas chromatography-mass spectrometry. Combining this screening method with the stable isotope dilution technique showed very specific and sensitive measurements of methylmalonic acid in urine. The concentrations of urinary methylmalonic acid were measured at several ages. The levels of urinary methylmalonic acid in two patients varied from 0.27 to 3.04 mol/mol creatinine (control<0.01 mol/mol creatinine). Methylcitrate and homocystine were not increased in the patient's urine or blood. Blood propionylcarnitine was also at normal levels. The urinary methylmalonate excretions were decreased to the levels of about 50% of the start point after vitamin B12 treatment in one patient, but the other patient showed no change. No clinical abnormalities were observed during these periods.
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Affiliation(s)
- Toshihiro Shinka
- Division of Human Genetics, Medical Research Institute, Kanazawa Medical, University, 1-1 Daigaku, Uchinada, Ishikawa 920-0293, Japan.
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Abstract
Screening of newborn infants for genetic disease began over 35 years ago as a public health measure to prevent mental retardation in phenylketonuria (PKU). It was so successful that tests for several other genetic disorders were added. We review the current status of this screening, including discussions of the genetic disorders often covered and the results of newborn screening for them. We emphasize recent advances. These include expansion of coverage for genetic disorders with the new methodology of tandem mass spectrometry (MS-MS) and the introduction of molecular (DNA) testing to increase the specificity of testing for several disorders, thereby reducing false-positive rates. These and other advances have also produced issues of criteria for screening, missed cases, and appropriate use of stored newborn specimens.
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Affiliation(s)
- H L Levy
- Genetic Service, Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.
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Bjørke Monsen AL, Ueland PM, Vollset SE, Guttormsen AB, Markestad T, Solheim E, Refsum H. Determinants of cobalamin status in newborns. Pediatrics 2001; 108:624-30. [PMID: 11533328 DOI: 10.1542/peds.108.3.624] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Cobalamin deficiency accompanied by bone marrow dysfunction and impaired central nervous system development has been reported in infants who were born to mothers with low cobalamin intake. We investigated the relation between cobalamin status in newborns and in their healthy mothers who consumed an omnivorous diet. METHODS Serum cobalamin and the functional markers plasma methylmalonic acid (MMA) and total homocysteine (tHcy) were determined in 173 newborns and their mothers. Forty-five children and mothers were reinvestigated after 6 weeks. RESULTS At birth, median (interquartile range) serum cobalamin levels were 245 (175-323) pmol/L in the mothers and 314 (238-468) pmol/L in the newborns. In the neonates, serum cobalamin, but not folate, was inversely associated with MMA and tHcy. Among maternal factors, low serum cobalamin was the strongest predictor of impaired cobalamin function (defined as low cobalamin, high tHcy, or high MMA levels) in the newborns. After 6 weeks, the maternal cobalamin levels had increased (to 421 [271-502] pmol/L), whereas the newborn levels had declined (to 230 [158-287] pmol/L). In the same interval, the infants had a marked increase in plasma MMA (from 0.29 [0.24-0.38] to 0.81 [0.37-1.68] micromol/L). At 6 weeks, parity was a strong predictor of cobalamin status in the infant. CONCLUSION The cobalamin status in the neonatal period is strongly associated with maternal cobalamin status and parity. A reduction in serum cobalamin and an increase in metabolite levels are consistent with impaired cobalamin function in a significant portion of the infants who were born to healthy, nonvegetarian mothers.
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Affiliation(s)
- A L Bjørke Monsen
- LOCUS for Homocysteine and Related Vitamins, University of Bergen, Bergen, Norway.
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Affiliation(s)
- S A Rasmussen
- Division of Birth Defects, Child Development, and Disability and Health, National Center for Environmental Health, Atlanta, Georgia, USA
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Abstract
Recombinant DNA technology has altered completely the face of genetics and its clinical practice. cDNAs for enzymes involved in inborn errors were among the first cloned, but the impact of this advance on our subspecialty has been more limited. This discussion addresses the uses and "abuses" of recombinant DNA technology in the field, and areas of greater or lesser usefulness in current practice, and the future, are discussed.
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Affiliation(s)
- S Cederbaum
- Department of Psychiatry, Mental Retardation Research Center, UCLA, Los Angeles, California 90024-1759, USA.
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Pollitt RJ. Tandem mass spectrometry screening: proving effectiveness. ACTA PAEDIATRICA (OSLO, NORWAY : 1992). SUPPLEMENT 1999; 88:40-4. [PMID: 10626576 DOI: 10.1111/j.1651-2227.1999.tb01155.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite the considerable literature now emerging on screening by tandem mass spectrometry there are many points of uncertainty about test performance and much work to do in formalizing and validating follow-up protocols. The relative sensitivities of tandem mass spectrometry and previously-used diagnostic methods may differ for some diseases but not others, with the possibility of some metabolites being over-sensitive and diagnosing mild variants or non-disease. Cut-offs should be set using clinical rather than analytical criteria and at this early stage it is important that presumptive positive cases diagnosed through acylcarnitine profiling are compared as thoroughly as possible with symptomatic cases diagnosed using other techniques. Caution should be used in accepting mutation analysis as the ultimate diagnostic criterion. Consideration of incidence and careful examination of family history will all contribute to evidence of the equivalence or otherwise of screen-detected and symptomatic disease. Finally, there should be registration and long-term surveillance of all cases detected.
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Affiliation(s)
- R J Pollitt
- Neonatal Screening Laboratory, Sheffield Children's Hospital, UK.
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