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Isasi E, Wajner M, Duarte JA, Olivera-Bravo S. Cerebral White Matter Alterations Associated With Oligodendrocyte Vulnerability in Organic Acidurias: Insights in Glutaric Aciduria Type I. Neurotox Res 2024; 42:33. [PMID: 38963434 DOI: 10.1007/s12640-024-00710-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 04/27/2024] [Accepted: 06/14/2024] [Indexed: 07/05/2024]
Abstract
The white matter is an important constituent of the central nervous system, containing axons, oligodendrocytes, and its progenitor cells, astrocytes, and microglial cells. Oligodendrocytes are central for myelin synthesis, the insulating envelope that protects axons and allows normal neural conduction. Both, oligodendrocytes and myelin, are highly vulnerable to toxic factors in many neurodevelopmental and neurodegenerative disorders associated with disturbances of myelination. Here we review the main alterations in oligodendrocytes and myelin observed in some organic acidurias/acidemias, which correspond to inherited neurometabolic disorders biochemically characterized by accumulation of potentially neurotoxic organic acids and their derivatives. The yet incompletely understood mechanisms underlying the high vulnerability of OLs and/or myelin in glutaric acidemia type I, the most prototypical cerebral organic aciduria, are particularly discussed.
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Affiliation(s)
- Eugenia Isasi
- Laboratorio de Neurobiología Celular y Molecular, Unidad Académica de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
- Departamento de Neurobiología y Neuropatología, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Montevideo, Uruguay
| | - Moacir Wajner
- Department of Biochemistry, Instituto de Ciencias Básicas da Saude, Universidade Federal de Río Grande do Sul, Porto Alegre, Brazil
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Juliana Avila Duarte
- Departamento de Medicina Interna, Serviço de Radiología, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Silvia Olivera-Bravo
- Departamento de Neurobiología y Neuropatología, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Montevideo, Uruguay.
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Gold JI, Stefanatos AK, Fraser JL, Vanderver A, Cuddapah S. Enasidenib-induced hepatitis in an individual with Type II D2-hydroxyglutaric aciduria. JIMD Rep 2024; 65:156-162. [PMID: 38736636 PMCID: PMC11078709 DOI: 10.1002/jmd2.12421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/22/2024] [Accepted: 03/26/2024] [Indexed: 05/14/2024] Open
Abstract
Type II D-2-Hydroxyglutaric aciduria (T2D2HGA) is caused by a gain-of-function pathogenic variant in Isocitrate Dehydrogenase 2 (IDH2). Patients with T2D2HGA commonly present with developmental delay, seizures, cardiomyopathy, and arrhythmias. The recently approved IDH2-inhibitor Enasidenib targets the p.Arg140Gln pathogenic IDH2 variant and decreases production of D2HGA. We present a 7-year-old female with T2D2HGA due to the p.Arg140Gln variant. She was diagnosed at 3-years-old after presenting with global developmental delay, leukoencephalopathy, communicating hydrocephalus, seizures, and dilated cardiomyopathy. At age 3 years 11 months, 50 mg Enasidenib daily was initiated. Primary outcomes included seizure frequency, hospital admissions, development, and cardiac structure. Laboratories were monitored biweekly for common Enasidenib side effects. Our patient tolerated Enasidenib well. Urine 2-HGA decreased significantly from 244 mg/g creatinine to undetectable within 2 weeks of treatment. Inpatient admissions decreased from 8 during the 2 years preceding treatment to 1 during treatment. She has been seizure-free since Enasidenib initiation. Echocardiography showed improvement in dilated cardiomyopathy with normal left ventricular systolic function. Developmental assessment demonstrated improvements in gross motor, fine motor, language, and socialization domains. Treatment was complicated by mild elevations in alanine transaminase (118 IU/L, range 0-28) and creatine kinase (334 U/L, range 45-198) that resolved by decreasing Enasidenib dosing frequency to three times weekly. Enasidenib is a viable treatment for Type II D2HGA with benefits including developmental gains, fewer acute medical interventions, and cardiomyopathy improvement. While drug-induced hepatitis is a novel adverse effect of Enasidenib, it can be ameliorated by decreasing dose frequency.
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Affiliation(s)
- Jessica I. Gold
- Division of Medical Genetics, Department of PediatricsNorthwell HealthNew YorkNew YorkUSA
| | - Arianna K. Stefanatos
- Department of Child and Adolescent Psychiatry and Behavioral SciencesChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | - Jamie L. Fraser
- Prenatal Pediatrics InstituteChildren's National HospitalWashingtonDCUSA
- The George Washington University School of Medicine and Health SciencesWashingtonDCUSA
- Division of Fetal and Translational MedicineChildren's National HospitalWashingtonDCUSA
| | - Adeline Vanderver
- Division of Neurology, Department of PediatricsChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
- Department of NeurologyPerelman School of Medicine, University of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Sanmati Cuddapah
- Section of Biochemical Genetics, Division of Genetics, Department of PediatricsChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
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Zmuda AJ, Kang X, Wissbroecker KB, Freund Saxhaug K, Costa KC, Hegeman AD, Niehaus TD. A universal metabolite repair enzyme removes a strong inhibitor of the TCA cycle. Nat Commun 2024; 15:846. [PMID: 38287013 PMCID: PMC10825186 DOI: 10.1038/s41467-024-45134-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
A prevalent side-reaction of succinate dehydrogenase oxidizes malate to enol-oxaloacetate (OAA), a metabolically inactive form of OAA that is a strong inhibitor of succinate dehydrogenase. We purified from cow heart mitochondria an enzyme (OAT1) with OAA tautomerase (OAT) activity that converts enol-OAA to the physiological keto-OAA form, and determined that it belongs to the highly conserved and previously uncharacterized Fumarylacetoacetate_hydrolase_domain-containing protein family. From all three domains of life, heterologously expressed proteins were shown to have strong OAT activity, and ablating the OAT1 homolog caused significant growth defects. In Escherichia coli, expression of succinate dehydrogenase was necessary for OAT1-associated growth defects to occur, and ablating OAT1 caused a significant increase in acetate and other metabolites associated with anaerobic respiration. OAT1 increased the succinate dehydrogenase reaction rate by 35% in in vitro assays with physiological concentrations of both succinate and malate. Our results suggest that OAT1 is a universal metabolite repair enzyme that is required to maximize aerobic respiration efficiency by preventing succinate dehydrogenase inhibition.
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Affiliation(s)
- Anthony J Zmuda
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA
| | - Xiaojun Kang
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA
| | - Katie B Wissbroecker
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA
| | - Katrina Freund Saxhaug
- Department of Horticultural Science, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA
| | - Kyle C Costa
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA
| | - Adrian D Hegeman
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA
- Department of Horticultural Science, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA
| | - Thomas D Niehaus
- Department of Plant and Microbial Biology, University of Minnesota, Twin Cities, Saint Paul, MN, 55108, USA.
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4
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Cansever MŞ, Öztekin N, Kıykım E, Zübarioğlu T, Aktuğlu Zeybek AÇ. Separation and quantification of the urinary enantiomers of 2-hydroxyglutaric acid by capillary electrophoresis with capacitively coupled contactless conductivity detection: Application to the diagnosis of D- and L-2-hydroxyglutaric aciduria. J Sep Sci 2023; 46:e2300145. [PMID: 37269210 DOI: 10.1002/jssc.202300145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/02/2023] [Accepted: 05/22/2023] [Indexed: 06/04/2023]
Abstract
2-hydroxyglutaric aciduria is an inherited neurometabolic disorder with two major types: D-2-hydroxyglutaric aciduria and L-2-hydroxyglutaric aciduria. An easy and fast capillary electrophoresis system combined with a capacitively coupled contactless conductivity detection method was developed for the enantioseparation and determination of D- and L-2-hydroxyglutaric acid in urine. D- and L-2-hydroxyglutaric acids were separated using vancomycin as the chiral selector. The optimal separation conditions for enantiomers were achieved by the use of a buffer containing 50 mM 4-(N-morpholino) butane sulfonic acid solution (pH 6.5), an electroosmotic flow modifier (0.001% [w/v] polybrene), and 30 mM vancomycin as chiral selector. The analysis time was 6 min under optimal conditions. The optimized and validated method was successfully implemented for quantifying D- and L-2-hydroxyglutaric aciduria in patients' urine, without any pretreatment step. The linearity of the method was determined to be in the range of 2-100 mg/L for D- and L-2-hydroxyglutaric acid in urine. The precision (relative standard deviation%) was obtained at about 7%. For D- and L-2-hydroxyglutaric acids, the limits of detection were 0.567 and 0.497 mg/L, respectively.
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Affiliation(s)
- M Şerif Cansever
- Department of Medical Services and Techniques, Vocational School of Health Services, Istanbul University-Cerrahpaşa, Istanbul, Turkey
| | - Nevin Öztekin
- Department of Chemistry, Istanbul Technical University, Istanbul, Turkey
| | - Ertuğrul Kıykım
- Department of Pediatric Nutrition and Metabolism, Cerrahpaşa Medical School, Istanbul University-Cerrahpaşa, İstanbul, Turkey
| | - Tanyel Zübarioğlu
- Department of Pediatric Nutrition and Metabolism, Cerrahpaşa Medical School, Istanbul University-Cerrahpaşa, İstanbul, Turkey
| | - Ayşe Çiğdem Aktuğlu Zeybek
- Department of Pediatric Nutrition and Metabolism, Cerrahpaşa Medical School, Istanbul University-Cerrahpaşa, İstanbul, Turkey
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Ribeiro RT, Roginski AC, Marschner RA, Wajner SM, Castilho RF, Amaral AU, Wajner M. Disruption of mitochondrial bioenergetics, calcium retention capacity and cell viability caused by D-2-hydroxyglutaric acid in the heart. Biochimie 2023; 207:153-164. [PMID: 36372308 DOI: 10.1016/j.biochi.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 11/03/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
Accumulation of D-2-hydroxyglutaric acid (D-2-HG) is the biochemical hallmark of D-2-hydroxyglutaric aciduria type I and, particularly, of D-2-hydroxyglutaric aciduria type II (D2HGA2). D2HGA2 is a metabolic inherited disease caused by gain-of-function mutations in the gene isocitrate dehydrogenase 2. It is clinically characterized by neurological abnormalities and a severe cardiomyopathy whose pathogenesis is still poorly established. The present work investigated the potential cardiotoxicity D-2-HG, by studying its in vitro effects on a large spectrum of bioenergetics parameters in heart of young rats and in cultivated H9c2 cardiac myoblasts. D-2-HG impaired cellular respiration in purified mitochondrial preparations and crude homogenates from heart of young rats, as well as in digitonin-permeabilized H9c2 cells. ATP production and the activities of cytochrome c oxidase (complex IV), alpha-ketoglutarate dehydrogenase, citrate synthase and creatine kinase were also inhibited by D-2-HG, whereas the activities of complexes I, II and II-III of the respiratory chain, glutamate, succinate and malate dehydrogenases were not altered. We also found that this organic acid compromised mitochondrial Ca2+ retention capacity in heart mitochondrial preparations and H9c2 myoblasts. Finally, D-2-HG reduced the viability of H9c2 cardiac myoblasts, as determined by the MTT test and by propidium iodide incorporation. Noteworthy, L-2-hydroxyglutaric acid did not change some of these measurements (complex IV and creatine kinase activities) in heart preparations, indicating a selective inhibitory effect of the enantiomer D. In conclusion, it is presumed that D-2-HG-disrupts mitochondrial bioenergetics and Ca2+ retention capacity, which may be involved in the cardiomyopathy commonly observed in D2HGA2.
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Affiliation(s)
- Rafael Teixeira Ribeiro
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Ana Cristina Roginski
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Rafael Aguiar Marschner
- Departamento de Medicina Interna, Faculdade de Medicina, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Simone Magagnin Wajner
- Departamento de Medicina Interna, Faculdade de Medicina, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Roger Frigério Castilho
- Departamento de Patologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Alexandre Umpierrez Amaral
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Departamento de Ciências Biológicas, Universidade Regional Integrada Do Alto Uruguai e Das Missões, Erechim, RS, Brazil
| | - Moacir Wajner
- Programa de Pós-Graduação Em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
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6
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Wu B, Li Z, Kang Z, Ma C, Song H, Lu F, Zhu Z. An Enzymatic Biosensor for the Detection of D-2-Hydroxyglutaric Acid in Serum and Urine. BIOSENSORS 2022; 12:bios12020066. [PMID: 35200327 PMCID: PMC8869338 DOI: 10.3390/bios12020066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/19/2022] [Accepted: 01/22/2022] [Indexed: 05/28/2023]
Abstract
D-2-hydroxyglutaric acid (D2HG) is overproduced as a result of the D-2-hydroxyglutaric aciduria and relevant cancers, caused by gene mutation. Accurate analysis of D2HG could help rapid diagnosis of these diseases and allow for timely treatment. In this work, a D-2-hydroxyglutarate dehydrogenase from Ralstonia solanacearum (RsD2HGDH) is cloned and recombinantly expressed. This enzyme features the direct electron transfer to chemical electron mediators (such as methylene blue (MB)) in the absence of additional coenzymes. Therefore, NAD+, a natural electron acceptor for the commercial D2HGDH and usually known for being unstable and difficult for immobilization can be avoided in the preparation of biosensors. The RsD2HGDH and MB are co-immobilized on a two-dimensional material, Ti3C2 MXene, followed by drop-coating on the gold screen-printed electrode (AuSPE) to construct a compact and portable biosensor. The D2HG in samples can be catalyzed by RsD2HGDH, where the current change is measured by chronoamperometry at -0.23 V. The biosensor shows a D2HG detection range of 0.5 to 120 µM (R2 = 0.9974) with a sensitivity of 22.26 μA mM-1 cm-2 and a detection limit of 0.1 µM (S/N = 3). The biosensor retains 72.52% performance of its incipient state after 30 days of storage. The samples of D2HG-containing fetal bovine serum and artificial urine were analyzed with the recovery of 99.56% to 106.83% and 97.30% to 102.47% further indicating the great application potential of our portable D2HG biosensor.
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Affiliation(s)
- Bo Wu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, No.9, 13th Avenue, Tianjin Economic and Technological Development Area, Tianjin 300457, China; (B.W.); (F.L.)
- Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, No.9, 13th Avenue, Tianjin Economic and Technological Development Area, Tianjin 300457, China
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin 300308, China; (Z.L.); (Z.K.); (C.M.); (H.S.)
| | - Zehua Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin 300308, China; (Z.L.); (Z.K.); (C.M.); (H.S.)
- University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Zepeng Kang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin 300308, China; (Z.L.); (Z.K.); (C.M.); (H.S.)
| | - Chunling Ma
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin 300308, China; (Z.L.); (Z.K.); (C.M.); (H.S.)
| | - Haiyan Song
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin 300308, China; (Z.L.); (Z.K.); (C.M.); (H.S.)
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, No.9, 13th Avenue, Tianjin Economic and Technological Development Area, Tianjin 300457, China; (B.W.); (F.L.)
- Tianjin Key Laboratory of Industrial Microbiology, The College of Biotechnology, Tianjin University of Science and Technology, No.9, 13th Avenue, Tianjin Economic and Technological Development Area, Tianjin 300457, China
| | - Zhiguang Zhu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin 300308, China; (Z.L.); (Z.K.); (C.M.); (H.S.)
- University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
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7
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Neuronal Death, Glial Reactivity, Microglia Activation, Oxidative Stress and Bioenergetics Impairment Caused by Intracerebroventricular Administration of D-2-hydroxyglutaric Acid to Neonatal Rats. Neuroscience 2021; 471:115-132. [PMID: 34333063 DOI: 10.1016/j.neuroscience.2021.07.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 02/07/2023]
Abstract
D-2-hydroxyglutaric acid (D-2-HG) accumulates and is the biochemical hallmark of D-2-hydroxyglutaric acidurias (D-2-HGA) types I and II, which comprehend two inherited neurometabolic diseases with severe cerebral abnormalities. Since the pathogenesis of these diseases is poorly established, we tested whether D-2-HG could be neurotoxic to neonatal rats. D-2-HG intracerebroventricular administration caused marked vacuolation in cerebral cortex and striatum. In addition, glial fibrillary acidic protein (GFAP), S-100 calcium binding protein B (S100B) and ionized calcium-binding adapter molecule 1 (Iba-1) staining was increased in both brain structures, suggesting glial reactivity and microglial activation. D-2-HG also provoked a reduction of NeuN-positive cells in cerebral cortex, signaling neuronal death. Considering that disturbances in redox homeostasis and energy metabolism may be involved in neuronal damage and glial reactivity, we assessed whether D-2-HG could induce oxidative stress and bioenergetics impairment. D-2-HG treatment significantly augmented reactive oxygen and nitrogen species generation, provoked lipid peroxidation and protein oxidative damage, diminished glutathione concentrations and augmented superoxide dismutase and catalase activities in cerebral cortex. Increased reactive oxygen species generation, lipoperoxidation and protein oxidation were also found in striatum. Furthermore, the antagonist of NMDA glutamate receptor MK-801 and the antioxidant melatonin were able to prevent most of D-2-HG-induced pro-oxidant effects, implying the participation of these receptors in D-2-HG-elicited oxidative damage. Our results also demonstrated that D-2-HG markedly reduced the respiratory chain complex IV and creatine kinase activities. It is presumed that these deleterious pathomechanisms caused by D-2-HGA may be involved in the brain abnormalities characteristic of early-infantile onset D-2-HGA.
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Accogli A, Geraldo AF, Piccolo G, Riva A, Scala M, Balagura G, Salpietro V, Madia F, Maghnie M, Zara F, Striano P, Tortora D, Severino M, Capra V. Diagnostic Approach to Macrocephaly in Children. Front Pediatr 2021; 9:794069. [PMID: 35096710 PMCID: PMC8795981 DOI: 10.3389/fped.2021.794069] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 12/02/2021] [Indexed: 01/19/2023] Open
Abstract
Macrocephaly affects up to 5% of the pediatric population and is defined as an abnormally large head with an occipitofrontal circumference (OFC) >2 standard deviations (SD) above the mean for a given age and sex. Taking into account that about 2-3% of the healthy population has an OFC between 2 and 3 SD, macrocephaly is considered as "clinically relevant" when OFC is above 3 SD. This implies the urgent need for a diagnostic workflow to use in the clinical setting to dissect the several causes of increased OFC, from the benign form of familial macrocephaly and the Benign enlargement of subarachnoid spaces (BESS) to many pathological conditions, including genetic disorders. Moreover, macrocephaly should be differentiated by megalencephaly (MEG), which refers exclusively to brain overgrowth, exceeding twice the SD (3SD-"clinically relevant" megalencephaly). While macrocephaly can be isolated and benign or may be the first indication of an underlying congenital, genetic, or acquired disorder, megalencephaly is most likely due to a genetic cause. Apart from the head size evaluation, a detailed family and personal history, neuroimaging, and a careful clinical evaluation are crucial to reach the correct diagnosis. In this review, we seek to underline the clinical aspects of macrocephaly and megalencephaly, emphasizing the main differential diagnosis with a major focus on common genetic disorders. We thus provide a clinico-radiological algorithm to guide pediatricians in the assessment of children with macrocephaly.
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Affiliation(s)
- Andrea Accogli
- Division of Medical Genetics, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada
| | - Ana Filipa Geraldo
- Diagnostic Neuroradiology Unit, Imaging Department, Centro Hospitalar Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal
| | - Gianluca Piccolo
- Pediatric Neurology and Neuromuscular Diseases Unit, IRCCS Giannina Gaslini Institute, Genoa, Italy
| | - Antonella Riva
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Marcello Scala
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Ganna Balagura
- Pediatric Neurology and Neuromuscular Diseases Unit, IRCCS Giannina Gaslini Institute, Genoa, Italy
| | - Vincenzo Salpietro
- Pediatric Neurology and Neuromuscular Diseases Unit, IRCCS Giannina Gaslini Institute, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Francesca Madia
- Pediatric Clinic and Endocrinology, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Mohamad Maghnie
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy.,Pediatric Clinic and Endocrinology, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy.,Medical Genetics Unit, IRCCS Giannina Gaslini Institute, Genoa, Italy
| | - Pasquale Striano
- Pediatric Neurology and Neuromuscular Diseases Unit, IRCCS Giannina Gaslini Institute, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Domenico Tortora
- Neuroradiology Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | | | - Valeria Capra
- Medical Genetics Unit, IRCCS Giannina Gaslini Institute, Genoa, Italy
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9
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Park KC, Krywawych S, Richard E, Desviat LR, Swietach P. Cardiac Complications of Propionic and Other Inherited Organic Acidemias. Front Cardiovasc Med 2020; 7:617451. [PMID: 33415129 PMCID: PMC7782273 DOI: 10.3389/fcvm.2020.617451] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/24/2020] [Indexed: 12/12/2022] Open
Abstract
Clinical observations and experimental studies have determined that systemic acid-base disturbances can profoundly affect the heart. A wealth of information is available on the effects of altered pH on cardiac function but, by comparison, much less is known about the actions of the organic anions that accumulate alongside H+ ions in acidosis. In the blood and other body fluids, these organic chemical species can collectively reach concentrations of several millimolar in severe metabolic acidoses, as in the case of inherited organic acidemias, and exert powerful biological actions on the heart that are not intuitive to predict. Indeed, cardiac pathologies, such as cardiomyopathy and arrhythmia, are frequently reported in organic acidemia patients, but the underlying pathophysiological mechanisms are not well established. Research efforts in the area of organic anion physiology have increased dramatically in recent years, particularly for propionate, which accumulates in propionic acidemia, one of the commonest organic acidemias characterized by a high incidence of cardiac disease. This Review provides a comprehensive historical overview of all known organic acidemias that feature cardiac complications and a state-of-the-art overview of the cardiac sequelae observed in propionic acidemia. The article identifies the most promising candidates for molecular mechanisms that become aberrantly engaged by propionate anions (and its metabolites), and discusses how these may result in cardiac derangements in propionic acidemia. Key clinical and experimental findings are considered in the context of potential therapies in the near future.
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Affiliation(s)
- Kyung Chan Park
- Department of Anatomy, Physiology and Genetics, Burdon Sanderson Cardiac Science Centre, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
| | - Steve Krywawych
- Department of Chemical Pathology, Great Ormond Street Hospital, London, United Kingdom
| | - Eva Richard
- Centro de Biología Molecular Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Cientificas (UAM-CSIC), Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), IdiPaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Lourdes R Desviat
- Centro de Biología Molecular Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Cientificas (UAM-CSIC), Centro de Investigacion Biomedica en Red de Enfermedades Raras (CIBERER), IdiPaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Pawel Swietach
- Department of Anatomy, Physiology and Genetics, Burdon Sanderson Cardiac Science Centre, British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, United Kingdom
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10
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Wajner M, Vargas CR, Amaral AU. Disruption of mitochondrial functions and oxidative stress contribute to neurologic dysfunction in organic acidurias. Arch Biochem Biophys 2020; 696:108646. [PMID: 33098870 DOI: 10.1016/j.abb.2020.108646] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/18/2020] [Accepted: 10/20/2020] [Indexed: 02/08/2023]
Abstract
Organic acidurias (OADs) are inherited disorders of amino acid metabolism biochemically characterized by accumulation of short-chain carboxylic acids in tissues and biological fluids of the affected patients and clinically by predominant neurological manifestations. Some of these disorders are amenable to treatment, which significantly decreases mortality and morbidity, but it is still ineffective to prevent long-term neurologic and systemic complications. Although pathogenesis of OADs is still poorly established, recent human and animal data, such as lactic acidosis, mitochondrial morphological alterations, decreased activities of respiratory chain complexes and altered parameters of oxidative stress, found in tissues from patients and from genetic mice models with these diseases indicate that disruption of critical mitochondrial functions and oxidative stress play an important role in their pathophysiology. Furthermore, organic acids that accumulate in the most prevalent OADs were shown to compromise bioenergetics, by decreasing ATP synthesis, mitochondrial membrane potential, reducing equivalent content and calcium retention capacity, besides inducing mitochondrial swelling, reactive oxygen and nitrogen species generation and apoptosis. It is therefore presumed that secondary mitochondrial dysfunction and oxidative stress caused by major metabolites accumulating in OADs contribute to tissue damage in these pathologies.
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Affiliation(s)
- Moacir Wajner
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
| | - Carmen Regla Vargas
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Alexandre Umpierrez Amaral
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Departamento de Ciências Biológicas, Universidade Regional Integrada do Alto Uruguai e das Missões, Erechim, RS, Brazil
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11
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Niehaus TD, Hillmann KB. Enzyme promiscuity, metabolite damage, and metabolite damage control systems of the tricarboxylic acid cycle. FEBS J 2020; 287:1343-1358. [DOI: 10.1111/febs.15284] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/26/2020] [Accepted: 03/05/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Thomas D. Niehaus
- Department of Plant and Microbial Biology University of Minnesota Twin Cities Saint Paul MN USA
| | - Katie B. Hillmann
- Department of Plant and Microbial Biology University of Minnesota Twin Cities Saint Paul MN USA
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12
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Phillips E, Sasarman F, Sinasac D, Al-Hertani W. D-2-hydroxyglutaric aciduria in a patient with speech delay due to a novel homozygous deletion in the D2HGDH gene. Mol Genet Metab Rep 2019; 20:100482. [PMID: 31431883 PMCID: PMC6580329 DOI: 10.1016/j.ymgmr.2019.100482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 06/08/2019] [Accepted: 06/08/2019] [Indexed: 12/01/2022] Open
Abstract
D-2-hydroxyglutaric aciduria is a rare neurometabolic condition with a variable clinical spectrum. Here we report on a patient with speech delay, ascertained for an elevated urine 2-hydroxyglutaric acid levels, and found to have a novel pathogenic homozygous deletion in D2HGDH (NG_012012.1(NM_152783.4):c.(292 + 1_293–1)_(*847_?)del). This case expands on the reported phenotype, with speech delay being the prominent clinical finding and despite identifying a large deletion in the D2HGDH gene, the patient presents with the mild phenotype.
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13
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Wild-Type IDH Enzymes as Actionable Targets for Cancer Therapy. Cancers (Basel) 2019; 11:cancers11040563. [PMID: 31010244 PMCID: PMC6520797 DOI: 10.3390/cancers11040563] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/12/2019] [Accepted: 04/16/2019] [Indexed: 12/11/2022] Open
Abstract
Isocitrate dehydrogenases (IDHs) are enzymes that catalyze the oxidative decarboxylation of isocitrate, producing α-ketoglutarate (αKG) and CO2. The discovery of IDH1 and IDH2 mutations in several malignancies has brought to the approval of drugs targeting IDH1/2 mutants in cancers. Here, we summarized findings addressing the impact of IDH mutants in rare pathologies and focused on the relevance of non-mutated IDH enzymes in tumors. Several pieces of evidence suggest that the enzymatic inhibition of IDHs may have therapeutic potentials also in wild-type IDH cancers. Moreover, IDHs inhibition could enhance the efficacy of canonical cancer therapies, such as chemotherapy, target therapy, and radiotherapy. However, further studies are required to elucidate whether IDH proteins are diagnostic/prognostic markers, instrumental for tumor initiation and maintenance, and could be exploited as targets for anticancer therapy. The development of wild-type IDH inhibitors is expected to improve our understanding of a potential non-oncogenic addition to IDH1/2 activities and to fully address their applicability in combination with other therapies.
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14
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Pop A, Struys EA, Jansen EEW, Fernandez MR, Kanhai WA, van Dooren SJM, Ozturk S, van Oostendorp J, Lennertz P, Kranendijk M, van der Knaap MS, Gibson KM, van Schaftingen E, Salomons GS. D-2-hydroxyglutaric aciduria Type I: Functional analysis of D2HGDH missense variants. Hum Mutat 2019; 40:975-982. [PMID: 30908763 PMCID: PMC6619364 DOI: 10.1002/humu.23751] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 03/12/2019] [Accepted: 03/20/2019] [Indexed: 11/25/2022]
Abstract
D‐2‐hydroxyglutaric aciduria Type I (D‐2‐HGA Type I), a neurometabolic disorder with a broad clinical spectrum, is caused by recessive variants in the D2HGDH gene encoding D‐2‐hydroxyglutarate dehydrogenase (D‐2‐HGDH). We and others detected 42 potentially pathogenic variants in D2HGDH of which 31 were missense. We developed functional studies to investigate the effect of missense variants on D‐2‐HGDH catalytic activity. Site‐directed mutagenesis was used to introduce 31 missense variants in the pCMV5‐D2HGDH expression vector. The wild type and missense variants were overexpressed in HEK293 cells. D‐2‐HGDH enzyme activity was evaluated based on the conversion of [2H4]D‐2‐HG to [2H4]2‐ketoglutarate, which was subsequently converted into [2H4]L‐glutamate and the latter quantified by LC‐MS/MS. Eighteen variants resulted in almost complete ablation of D‐2‐HGDH activity and thus, should be considered pathogenic. The remaining 13 variants manifested residual activities ranging between 17% and 94% of control enzymatic activity. Our functional assay evaluating the effect of novel D2HGDH variants will be beneficial for the classification of missense variants and determination of pathogenicity.
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Affiliation(s)
- Ana Pop
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Eduard A Struys
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Erwin E W Jansen
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Matilde R Fernandez
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Warsha A Kanhai
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Silvy J M van Dooren
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Senay Ozturk
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Justin van Oostendorp
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Pascal Lennertz
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Martijn Kranendijk
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
| | - Marjo S van der Knaap
- Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam and Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - K Michael Gibson
- Department of Pharmacotherapy, College of Pharmacy and Pharmaceutical Sciences, Washington State University, Spokane, Washington
| | - Emile van Schaftingen
- Walloon Excellence in Life Sciences and Biotechnology, Brussels, Belgium.,Laboratory of Biochemistry, de Duve Institute, University of Louvain, Brussels, Belgium
| | - Gajja S Salomons
- Metabolic Unit, Department of Clinical Chemistry, Amsterdam University Medical Centers, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands.,Department of Genetic Metabolic Diseases, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands
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15
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16
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Reddy N, Calloni SF, Vernon HJ, Boltshauser E, Huisman TAGM, Soares BP. Neuroimaging Findings of Organic Acidemias and Aminoacidopathies. Radiographics 2018; 38:912-931. [PMID: 29757724 DOI: 10.1148/rg.2018170042] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although individual cases of inherited metabolic disorders are rare, overall they account for a substantial number of disorders affecting the central nervous system. Organic acidemias and aminoacidopathies include a variety of inborn errors of metabolism that are caused by defects in the intermediary metabolic pathways of carbohydrates, amino acids, and fatty acid oxidation. These defects can lead to the abnormal accumulation of organic acids and amino acids in multiple organs, including the brain. Early diagnosis is mandatory to initiate therapy and prevent permanent long-term neurologic impairments or death. Neuroimaging findings can be nonspecific, and metabolism- and genetics-based laboratory investigations are needed to confirm the diagnosis. However, neuroimaging has a key role in guiding the diagnostic workup. The findings at conventional and advanced magnetic resonance imaging may suggest the correct diagnosis, help narrow the differential diagnosis, and consequently facilitate early initiation of targeted metabolism- and genetics-based laboratory investigations and treatment. Neuroimaging may be especially helpful for distinguishing organic acidemias and aminoacidopathies from other more common diseases with similar manifestations, such as hypoxic-ischemic injury and neonatal sepsis. Therefore, it is important that radiologists, neuroradiologists, pediatric neuroradiologists, and clinicians are familiar with the neuroimaging findings of organic acidemias and aminoacidopathies. ©RSNA, 2018.
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Affiliation(s)
- Nihaal Reddy
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Sonia F Calloni
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Hilary J Vernon
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Eugen Boltshauser
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Thierry A G M Huisman
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
| | - Bruno P Soares
- From the Division of Pediatric Radiology and Pediatric Neuroradiology, Russell H. Morgan Department of Radiology and Radiological Science (N.R., S.F.C., T.A.G.M.H., B.P.S.), and McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics (H.J.V.), The Johns Hopkins University School of Medicine, Charlotte R. Bloomberg Children's Center Bldg, Sheikh Zayed Tower, Room 4174, 1800 Orleans St, Baltimore, MD 21287-0842; Università degli Studi di Milano, Postgraduation School in Radiodiagnostics, Milan, Italy (S.F.C.); Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, Md (H.J.V.); and Department of Pediatric Neurology, University Children's Hospital of Zurich, Zurich, Switzerland (E.B.)
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17
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Thirumal Kumar D, Jerushah Emerald L, George Priya Doss C, Sneha P, Siva R, Charles Emmanuel Jebaraj W, Zayed H. Computational approach to unravel the impact of missense mutations of proteins (D2HGDH and IDH2) causing D-2-hydroxyglutaric aciduria 2. Metab Brain Dis 2018; 33:1699-1710. [PMID: 29987523 DOI: 10.1007/s11011-018-0278-3] [Citation(s) in RCA: 24] [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] [Received: 03/14/2018] [Accepted: 06/20/2018] [Indexed: 01/28/2023]
Abstract
The 2-hydroxyglutaric aciduria (2-HGA) is a rare neurometabolic disorder that leads to the development of brain damage. It is classified into three categories: D-2-HGA, L-2-HGA, and combined D,L-2-HGA. The D-2-HGA includes two subtypes: type I and type II caused by the mutations in D2HGDH and IDH2 proteins, respectively. In this study, we studied six mutations, four in the D2HGDH (I147S, D375Y, N439D, and V444A) and two in the IDH2 proteins (R140G, R140Q). We performed in silico analysis to investigate the pathogenicity and stability changes of the mutant proteins using pathogenicity (PANTHER, PhD-SNP, SIFT, SNAP, and META-SNP) and stability (i-Mutant, MUpro, and iStable) predictors. All the mutations of both D2HGDH and IDH2 proteins were predicted as disease causing except V444A, which was predicted as neutral by SIFT. All the mutants were also predicted to be destabilizing the protein except the mutants D375Y and N439D. DSSP plugin of the PyMOL and Molecular Dynamics Simulations (MDS) were used to study the structural changes in the mutant proteins. In the case of D2HGDH protein, the mutations I147S and V444A that are positioned in the beta sheet region exhibited higher Root Mean Square Deviation (RMSD), decrease in compactness and number of intramolecular hydrogen bonds compared to the mutations N439D and D375Y that are positioned in the turn and loop region, respectively. While the mutants R140Q and R140QG that are positioned in the alpha helix region of the protein. MDS results revealed the mutation R140Q to be more destabilizing (higher RMSD values, decrease in compactness and number of intramolecular hydrogen bonds) compared to the mutation R140G of the IDH2 protein. This study is expected to serve as a platform for drug development against 2-HGA and pave the way for more accurate variant assessment and classification for patients with genetic diseases.
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Affiliation(s)
- D Thirumal Kumar
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India
| | - L Jerushah Emerald
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India
| | - C George Priya Doss
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
| | - P Sneha
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India
| | - R Siva
- Department of Integrative Biology, School of Bio Sciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India
| | - W Charles Emmanuel Jebaraj
- Faculty of Biomedical Sciences, Technology and Research, Sri Ramachandra Medical College and Research Institute, Chennai, Tamil Nadu, 600116, India
| | - Hatem Zayed
- Department of Biomedical Sciences, College of Health and Sciences, Qatar University, Doha, Qatar.
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18
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Rodrigues DGB, de Moura Coelho D, Sitta Â, Jacques CED, Hauschild T, Manfredini V, Bakkali A, Struys EA, Jakobs C, Wajner M, Vargas CR. Experimental evidence of oxidative stress in patients with l-2-hydroxyglutaric aciduria and that l-carnitine attenuates in vitro DNA damage caused by d-2-hydroxyglutaric and l-2-hydroxyglutaric acids. Toxicol In Vitro 2017; 42:47-53. [DOI: 10.1016/j.tiv.2017.04.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/05/2017] [Accepted: 04/06/2017] [Indexed: 11/29/2022]
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19
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In-vivo brain H1-MR-Spectroscopy identification and quantification of 2-hydroxyglutarate in L-2-Hydroxyglutaric aciduria. Brain Res 2016; 1648:506-511. [DOI: 10.1016/j.brainres.2016.08.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 08/10/2016] [Accepted: 08/11/2016] [Indexed: 12/24/2022]
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20
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Abstract
Up to 14% of patients with congenital metabolic disease may show structural brain abnormalities from perturbation of cell proliferation, migration, and/or organization. Most inborn errors of metabolism have a postnatal onset. Abnormalities from genetic disease processes have a prenatal onset. Energy impairment, substrate insufficiency, cell membrane receptor and cell signaling abnormalities, and toxic byproduct accumulation are associations between genetic disorders and structural brain anomalies. Collective imaging patterns of brain abnormalities can provide clues to the underlying etiology. We review selected metabolic diseases associated with brain malformations and highlight characteristic clinical and imaging manifestations that help narrow the differential diagnosis.
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Affiliation(s)
- Matthew T Whitehead
- Department of Radiology, Children's National Medical Center, 111 Michigan Avenue Northwest, Washington, DC 20010, USA.
| | - Stanley T Fricke
- Department of Radiology, Children's National Medical Center, 111 Michigan Avenue Northwest, Washington, DC 20010, USA
| | - Andrea L Gropman
- Department of Neurology, Children's National Medical Center, 111 Michigan Avenue Northwest, Washington, DC 20010, USA
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21
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da Rosa M, Seminotti B, Amaral A, Parmeggiani B, de Oliveira F, Leipnitz G, Wajner M. Disruption of redox homeostasis and histopathological alterations caused by in vivo intrastriatal administration of D-2-hydroxyglutaric acid to young rats. Neuroscience 2014; 277:281-93. [DOI: 10.1016/j.neuroscience.2014.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/26/2014] [Accepted: 07/08/2014] [Indexed: 10/25/2022]
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22
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Liubinas SV, D'Abaco GM, Moffat BM, Gonzales M, Feleppa F, Nowell CJ, Gorelik A, Drummond KJ, O'Brien TJ, Kaye AH, Morokoff AP. IDH1 mutation is associated with seizures and protoplasmic subtype in patients with low-grade gliomas. Epilepsia 2014; 55:1438-43. [DOI: 10.1111/epi.12662] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Simon V. Liubinas
- Department of Neurosurgery; The Royal Melbourne Hospital; Parkville Victoria Australia
- The Department of Surgery (RMH); The University of Melbourne; Parkville Victoria Australia
| | - Giovanna M. D'Abaco
- The Department of Surgery (RMH); The University of Melbourne; Parkville Victoria Australia
| | - Bradford M. Moffat
- The Department of Radiology (RMH/WH); The University of Melbourne; Parkville Victoria Australia
| | - Michael Gonzales
- Department of Pathology; The Royal Melbourne Hospital; Parkville Victoria Australia
| | - Frank Feleppa
- Department of Pathology; The Royal Melbourne Hospital; Parkville Victoria Australia
| | - Cameron J. Nowell
- Ludwig Institute for Cancer Research; Melbourne Parkville Victoria Australia
| | - Alexandra Gorelik
- The Melbourne Epicentre; The Royal Melbourne Hospital; Parkville Victoria Australia
| | - Katharine J. Drummond
- Department of Neurosurgery; The Royal Melbourne Hospital; Parkville Victoria Australia
- The Department of Surgery (RMH); The University of Melbourne; Parkville Victoria Australia
| | - Terence J. O'Brien
- The Department of Medicine (RMH); The University of Melbourne; Parkville Victoria Australia
- Department of Neurology; The Royal Melbourne Hospital; Parkville Victoria Australia
| | - Andrew H. Kaye
- Department of Neurosurgery; The Royal Melbourne Hospital; Parkville Victoria Australia
- The Department of Surgery (RMH); The University of Melbourne; Parkville Victoria Australia
| | - Andrew P. Morokoff
- Department of Neurosurgery; The Royal Melbourne Hospital; Parkville Victoria Australia
- The Department of Surgery (RMH); The University of Melbourne; Parkville Victoria Australia
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23
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Yang E, Prabhu SP. Imaging manifestations of the leukodystrophies, inherited disorders of white matter. Radiol Clin North Am 2014; 52:279-319. [PMID: 24582341 DOI: 10.1016/j.rcl.2013.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The leukodystrophies are a diverse set of inherited white matter disorders and are uncommonly encountered by radiologists in everyday practice. As a result, it is challenging to recognize these disorders and to provide a useful differential for the referring physician. In this article, leukodystrophies are reviewed from the perspective of 4 imaging patterns: global myelination delay, periventricular/deep white matter predominant, subcortical white matter predominant, and mixed white/gray matter involvement patterns. Special emphasis is placed on pattern recognition and unusual combinations of findings that may suggest a specific diagnosis.
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Affiliation(s)
- Edward Yang
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
| | - Sanjay P Prabhu
- Department of Radiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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24
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Akbay EA, Moslehi J, Christensen CL, Saha S, Tchaicha JH, Ramkissoon SH, Stewart KM, Carretero J, Kikuchi E, Zhang H, Cohoon TJ, Murray S, Liu W, Uno K, Fisch S, Jones K, Gurumurthy S, Gliser C, Choe S, Keenan M, Son J, Stanley I, Losman JA, Padera R, Bronson RT, Asara JM, Abdel-Wahab O, Amrein PC, Fathi AT, Danial NN, Kimmelman AC, Kung AL, Ligon KL, Yen KE, Kaelin WG, Bardeesy N, Wong KK. D-2-hydroxyglutarate produced by mutant IDH2 causes cardiomyopathy and neurodegeneration in mice. Genes Dev 2014; 28:479-90. [PMID: 24589777 PMCID: PMC3950345 DOI: 10.1101/gad.231233.113] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) have been discovered in several cancers, and these mutant enzymes exhibit neomorphic activity resulting in production of D2-hydroxyglutaric acid (D-2HG). Akbay et al. find that adult transgenic mice with conditionally activated IDH2R140Q and IDH2R172K alleles exhibit dilated cardiomyopathy and muscular dystrophy. These phenotypes were even more pronounced in embryos. Cardiac hypertrophy was also observed in nude mice implanted with IDH2R140Q-expressing xenografts. Silencing of IDH2R140Q in mice with an inducible transgene restored heart function by lowering 2HG levels. Mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) have been discovered in several cancer types and cause the neurometabolic syndrome D2-hydroxyglutaric aciduria (D2HGA). The mutant enzymes exhibit neomorphic activity resulting in production of D2-hydroxyglutaric acid (D-2HG). To study the pathophysiological consequences of the accumulation of D-2HG, we generated transgenic mice with conditionally activated IDH2R140Q and IDH2R172K alleles. Global induction of mutant IDH2 expression in adults resulted in dilated cardiomyopathy, white matter abnormalities throughout the central nervous system (CNS), and muscular dystrophy. Embryonic activation of mutant IDH2 resulted in more pronounced phenotypes, including runting, hydrocephalus, and shortened life span, recapitulating the abnormalities observed in D2HGA patients. The diseased hearts exhibited mitochondrial damage and glycogen accumulation with a concordant up-regulation of genes involved in glycogen biosynthesis. Notably, mild cardiac hypertrophy was also observed in nude mice implanted with IDH2R140Q-expressing xenografts, suggesting that 2HG may potentially act in a paracrine fashion. Finally, we show that silencing of IDH2R140Q in mice with an inducible transgene restores heart function by lowering 2HG levels. Together, these findings indicate that inhibitors of mutant IDH2 may be beneficial in the treatment of D2HGA and suggest that 2HG produced by IDH mutant tumors has the potential to provoke a paraneoplastic condition.
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Affiliation(s)
- Esra A Akbay
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
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25
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Nota B, Hamilton EM, Sie D, Ozturk S, van Dooren SJM, Ojeda MRF, Jakobs C, Christensen E, Kirk EP, Sykut-Cegielska J, Lund AM, van der Knaap MS, Salomons GS. Novel cases of D-2-hydroxyglutaric aciduria with IDH1 or IDH2 mosaic mutations identified by amplicon deep sequencing. J Med Genet 2013; 50:754-9. [PMID: 24049096 DOI: 10.1136/jmedgenet-2013-101961] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Mosaic IDH1 mutations are described as the cause of metaphyseal chondromatosis with increased urinary excretion of D-2-hydroxyglutarate (MC-HGA), and mutations in IDH2 as the cause of D-2-hydroxyglutaric aciduria (D-2HGA) type II. Mosaicism for IDH2 mutations has not previously been reported as a cause of D-2HGA. Here we describe three cases: one MC-HGA case with IDH1 mosaic mutations, and two D-2HGA type II cases. In one D-2HGA case we identified mosaicism for an IDH2 mutation as the genetic cause of this disorder; the other D-2HGA case was caused by a heterozygous IDH2 mutation, while the unaffected mother was a mosaic carrier. METHODS We performed amplicon deep sequencing using the 454 GS Junior platform, next to Sanger sequencing, to identify and confirm mosaicism of IDH1 or IDH2 mutations in MC-HGA or D-2HGA, respectively. RESULTS AND CONCLUSIONS We identified different mutant allele percentages in DNA samples derived from different tissues (blood vs fibroblasts). Furthermore, we found that mutant allele percentages of IDH1 decreased after more passages had occurred in fibroblast cell cultures. We describe a method for the detection and validation of mosaic mutations in IDH1 and IDH2, making quantification with laborious cloning techniques obsolete.
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Affiliation(s)
- Benjamin Nota
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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26
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Choo HJ, Cho TJ, Song J, Tiller GE, Lee SH, Park G, Lee IS, Lachman R, Superti-Furga A, Kim OH. Metaphyseal chondromatosis combined with D-2-hydroxyglutaric aciduria in four patients. Skeletal Radiol 2012; 41:1479-87. [PMID: 22639207 DOI: 10.1007/s00256-012-1442-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 05/02/2012] [Accepted: 05/03/2012] [Indexed: 02/02/2023]
Abstract
We report four patients who presented with a severe form of metaphyseal chondromatosis in association with D-2-hydroxyglutaric aciduria (D-2-HGA). All patients showed splaying columns of irregular ossification defects with bulbous metaphyses of the long tubular bones, as well as remarkable involvement of the short tubular and flat bones. The vertebral bodies revealed platyspondyly with irregular, stippled endplates. D-2-HGA has been described as a neurometabolic disorder manifesting a broad range of impairment in mental and motor development. Although hydroxyglutaric acid was excreted in high amounts in the urine of all four patients described herein, no significant neurologic abnormalities were evident. This unusual combination of characteristic skeletal and metabolic abnormalities has rarely been reported. Thus, our report will facilitate the recognition of this distinctive entity, and we suggest that a urine organic acid screening be obtained in patients who present with generalized enchondromatosis.
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Affiliation(s)
- Hye Jung Choo
- Department of Radiology, Inje University Pusan Paik Hospital, Pusan, Korea
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27
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Kranendijk M, Struys EA, Salomons GS, Van der Knaap MS, Jakobs C. Progress in understanding 2-hydroxyglutaric acidurias. J Inherit Metab Dis 2012; 35:571-87. [PMID: 22391998 PMCID: PMC3388262 DOI: 10.1007/s10545-012-9462-5] [Citation(s) in RCA: 200] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 01/25/2012] [Accepted: 01/30/2012] [Indexed: 12/16/2022]
Abstract
The organic acidurias D: -2-hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and combined D,L-2-hydroxyglutaric aciduria (D,L-2-HGA) cause neurological impairment at young age. Accumulation of D-2-hydroxyglutarate (D-2-HG) and/or L-2-hydroxyglutarate (L-2-HG) in body fluids are the biochemical hallmarks of these disorders. The current review describes the knowledge gathered on 2-hydroxyglutaric acidurias (2-HGA), since the description of the first patients in 1980. We report on the clinical, genetic, enzymatic and metabolic characterization of D-2-HGA type I, D-2-HGA type II, L-2-HGA and D,L-2-HGA, whereas for D-2-HGA type I and type II novel clinical information is presented which was derived from questionnaires.
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Affiliation(s)
- Martijn Kranendijk
- Metabolic Unit - Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Eduard A. Struys
- Metabolic Unit - Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Gajja S. Salomons
- Metabolic Unit - Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | | | - Cornelis Jakobs
- Metabolic Unit - Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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Abstract
Recently, the isocitrate dehydrogenase (IDH) enzymes have become a focal point for research aimed at understanding the biology of glioma and identifying novel targets for therapy. Following the publication of a landmark genetic sequencing study in 2008, which identified IDH1 as a frequently mutated gene in glioblastoma, much work has been carried out to further characterize the frequency, associations and clinical implications of IDH1/2 mutations. Mutations in IDH genes are thought to occur early in tumorigenesis and define a subgroup of glioma that are characterized by specific metabolic changes and improved prognosis. At present, assays identifying tumors with IDH1 mutations are clinically useful as prognostic markers. While the mechanisms linking IDH1/2 mutations to tumor development are still under investigation, the cellular milieu created by these mutations offers potential targets for the development of novel therapeutics.
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Affiliation(s)
- Brian M Alexander
- Dana-Farber/Brigham and Women's Cancer Center, Department of Radiation Oncology, Boston, MA, USA
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Van Hove JLK, Lohr NJ. Metabolic and monogenic causes of seizures in neonates and young infants. Mol Genet Metab 2011; 104:214-30. [PMID: 21839663 DOI: 10.1016/j.ymgme.2011.04.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Revised: 04/20/2011] [Accepted: 04/20/2011] [Indexed: 11/22/2022]
Abstract
Seizures in neonates or young infants present a frequent diagnostic challenge. After exclusion of acquired causes, disturbances of the internal homeostasis and brain malformations, the physician must evaluate for inborn errors of metabolism and for other non-malformative genetic disorders as the cause of seizures. The metabolic causes can be categorized into disorders of neurotransmitter metabolism, disorders of energy production, and synthetic or catabolic disorders associated with brain malformation, dysfunction and degeneration. Other genetic conditions involve channelopathies, and disorders resulting in abnormal growth, differentiation and formation of neuronal populations. These conditions are important given their potential for treatment and the risk for recurrence in the family. In this paper, we will succinctly review the metabolic and genetic non-malformative causes of seizures in neonates and infants less than 6 months of age. We will then provide differential diagnostic clues and a practical paradigm for their evaluation.
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Affiliation(s)
- Johan L K Van Hove
- Department of Pediatrics, University of Colorado, Clinical Genetics, Aurora, CO 80045, USA.
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A lymphoblast model for IDH2 gain-of-function activity in d-2-hydroxyglutaric aciduria type II: novel avenues for biochemical and therapeutic studies. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1380-4. [PMID: 21889589 DOI: 10.1016/j.bbadis.2011.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 08/16/2011] [Accepted: 08/17/2011] [Indexed: 11/20/2022]
Abstract
The recent discovery of heterozygous isocitrate dehydrogenase 2 (IDH2) mutations of residue Arg(140) to Gln(140) or Gly(140) (IDH2(wt/R140Q), IDH2(wt/R140G)) in d-2-hydroxyglutaric aciduria (D-2-HGA) has defined the primary genetic lesion in 50% of D-2-HGA patients, denoted type II. Overexpression studies with IDH1(R132H) and IDH2(R172K) mutations demonstrated that the enzymes acquired a new function, converting 2-ketoglutarate (2-KG) to d-2-hydroxyglutarate (D-2-HG), in lieu of the normal IDH reaction which reversibly converts isocitrate to 2-KG. To confirm the IDH2(wt/R140Q) gain-of-function in D-2-HGA type II, and to evaluate potential therapeutic strategies, we developed a specific and sensitive IDH2(wt/R140Q) enzyme assay in lymphoblasts. This assay determines gain-of-function activity which converts 2-KG to D-2-HG in homogenates of D-2-HGA type II lymphoblasts, and uses stable-isotope-labeled 2-keto[3,3,4,4-(2)H(4)]glutarate. The specificity and sensitivity of the assay are enhanced with chiral separation and detection of stable-isotope-labeled D-2-HG by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Eleven potential inhibitors of IDH2(wt/R140Q) enzyme activity were evaluated with this procedure. The mean reaction rate in D-2-HGA type II lymphoblasts was 8-fold higher than that of controls and D-2-HGA type I cells (14.4nmolh(-1)mgprotein(-1) vs. 1.9), with a corresponding 140-fold increase in intracellular D-2-HG level. Optimal inhibition of IDH2(wt/R140Q) activity was obtained with oxaloacetate, which competitively inhibited IDH2(wt/R140Q) activity. Lymphoblast IDH2(wt/R140Q) showed long-term cell culture stability without loss of the heterozygous IDH2(wt/R140Q) mutation, underscoring the utility of the lymphoblast model for future biochemical and therapeutic studies.
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Kranendijk M, Struys EA, Gibson KM, Wickenhagen WV, Abdenur JE, Buechner J, Christensen E, de Kremer RD, Errami A, Gissen P, Gradowska W, Hobson E, Islam L, Korman SH, Kurczynski T, Maranda B, Meli C, Rizzo C, Sansaricq C, Trefz FK, Webster R, Jakobs C, Salomons GS. Evidence for genetic heterogeneity in D-2-hydroxyglutaric aciduria. Hum Mutat 2010; 31:279-83. [PMID: 20020533 DOI: 10.1002/humu.21186] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We performed molecular, enzyme, and metabolic studies in 50 patients with D-2-hydroxyglutaric aciduria (D-2-HGA) who accumulated D-2-hydroxyglutarate (D-2-HG) in physiological fluids. Presumed pathogenic mutations were detected in 24 of 50 patients in the D-2-hydroxyglutarate dehydrogenase (D2HGDH) gene, which encodes D-2-hydroxyglutarate dehydrogenase (D-2-HGDH). Enzyme assay of D-2-HGDH confirmed that all patients with mutations had impaired enzyme activity, whereas patients with D-2-HGA whose enzyme activity was normal did not have mutations. Significantly lower D-2-HG concentrations in body fluids were observed in mutation-positive D-2-HGA patients than in mutation-negative patients. These results imply that multiple genetic loci may be associated with hyperexcretion of D-2-HG. Accordingly, we suggest a new classification: D-2-HGA Type I associates with D-2-HGDH deficiency, whereas idiopathic D-2-HGA manifests with normal D-2-HGDH activity and higher D-2-HG levels in body fluids compared with Type I patients. It remains possible that several classifications for idiopathic D-2-HGA patients with diverse genetic loci will be revealed in future studies.
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Affiliation(s)
- Martijn Kranendijk
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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32
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Affiliation(s)
- Jan Smeitink
- Department of Pediatrics, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands
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33
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Haliloglu G, Temucin CM, Oguz KK, Celiker A, Coskun T, Sass JO, Fischer J, Topcu M. Peripheral neuropathy in a patient with D-2-hydroxyglutaric aciduria. J Inherit Metab Dis 2009; 32 Suppl 1:S21-5. [PMID: 19169842 DOI: 10.1007/s10545-009-0933-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2008] [Revised: 12/03/2008] [Accepted: 12/09/2008] [Indexed: 11/30/2022]
Abstract
D-2-hydroxyglutaric aciduria (D-2-HGA; OMIM 600721) is a rare autosomal recessive neurometabolic disorder with a wide clinical spectrum. The severe phenotype is homogeneous and is characterized by early infantile-onset epileptic encephalopathy with hypotonia, delayed cerebral visual development, cardiomyopathy and facial dysmorphic features. The mild phenotype has a more variable clinical expression with hypotonia and developmental delay. We present peripheral neuropathy as an additional clinical and electrophysiological feature in a 16-year-old boy with a homozygous missense mutation in exon 3 of the D-2-hydroxyglutarate dehydrogenase gene (D2HGDH) at position c.458T>C. This mutation results in replacement of a methionine residue, which was highly conserved during evolution, by threonine (p.Met153Thr).
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MESH Headings
- Adolescent
- Alcohol Oxidoreductases/genetics
- Brain/pathology
- Brain Diseases, Metabolic, Inborn/complications
- Brain Diseases, Metabolic, Inborn/enzymology
- Brain Diseases, Metabolic, Inborn/genetics
- Brain Diseases, Metabolic, Inborn/pathology
- Electrophysiological Phenomena
- Genes, Recessive
- Homozygote
- Humans
- Magnetic Resonance Imaging
- Male
- Mutation, Missense
- Neural Conduction/genetics
- Peripheral Nervous System Diseases/etiology
- Peripheral Nervous System Diseases/genetics
- Peripheral Nervous System Diseases/physiopathology
- Phenotype
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Affiliation(s)
- G Haliloglu
- Department of Pediatric Neurology, Hacettepe University Children's Hospital, 06100, Ankara, Turkey
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34
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Steenweg ME, Salomons GS, Yapici Z, Uziel G, Scalais E, Zafeiriou DI, Ruiz-Falco ML, Mejaski-Bosnjak V, Augoustides-Savvopoulou P, Wajner M, Walter J, Verhoeven-Duif NM, Struys EA, Jakobs C, van der Knaap MS. L-2-Hydroxyglutaric aciduria: pattern of MR imaging abnormalities in 56 patients. Radiology 2009; 251:856-65. [PMID: 19474378 DOI: 10.1148/radiol.2513080647] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To describe the pattern of magnetic resonance (MR) imaging abnormalities in l-2-hydroxyglutaric aciduria (L2HGA) and to evaluate the correlation between imaging abnormalities and disease duration. MATERIALS AND METHODS MR images in 56 patients (30 male, 26 female; mean age +/- standard deviation, 11.9 years +/- 8.5) with genetically confirmed L2HGA were retrospectively reviewed, with institutional review board approval and waiver of informed consent. At least one complete series of transverse T2-weighted images was available for all patients. The images were evaluated by using a previously established scoring list. The correlation between MR imaging abnormalities and disease duration was assessed (Mann-Whitney or Kruskal-Wallis test). RESULTS The cerebral white matter (WM) abnormalities preferentially affected the frontal and subcortical regions. The abnormal subcortical WM often had a mildly swollen appearance (37 patients). Initially, the WM abnormalities were at least partially multifocal (32 patients). In patients with longer disease duration, the WM abnormalities became more confluent and spread centripetally, but the periventricular rim remained relatively spared (41 patients). The mean disease duration in patients with WM atrophy (14.8 years) was significantly longer (P = .001) than that in patients without atrophy (6.7 years). Bilateral involvement of the globus pallidus (55 patients), caudate nucleus (56 patients), and putamen (56 patients) was seen at all stages. The cerebellar WM was never affected. The dentate nucleus was involved bilaterally in 55 of 56 patients. CONCLUSION L2HGA has a distinct highly characteristic pattern of MR imaging abnormalities: a combination of predominantly subcortical cerebral WM abnormalities and abnormalities of the dentate nucleus, globus pallidus, putamen, and caudate nucleus. With increasing disease duration, WM abnormalities and basal ganglia signal intensity abnormalities become more diffuse and cerebral WM atrophy ensues.
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Affiliation(s)
- Marjan E Steenweg
- Dept of Child Neurology, VU Univ Medical Ctr, De Boelelaan 1117, 1081 HV Amsterdam, the Netherlands
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35
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Wickenhagen WV, Salomons GS, Gibson KM, Jakobs C, Struys EA. Measurement of D: -2-hydroxyglutarate dehydrogenase activity in cell homogenates derived from D: -2-hydroxyglutaric aciduria patients. J Inherit Metab Dis 2009; 32:264-8. [PMID: 19283509 DOI: 10.1007/s10545-009-1104-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 01/19/2009] [Accepted: 01/29/2009] [Indexed: 10/21/2022]
Abstract
D: -2-Hydroxyglutaric aciduria (D: -2-HGA) is a neurometabolic disorder characterized by elevated levels of D: -2-hydroxyglutarate (D: -2-HG) in physiological fluids. Recent findings revealed that mutations in the D2HGDH gene, encoding D: -2-hydroxyglutarate dehydrogenase, cause D: -2-HGA. So far, a functionalenzyme assay to determine D: -2-hydroxyglutarate dehydrogenase activity, converting D: -2-HG into 2-ketoglutarate (2-KG), has been unavailable. We have now developed a unique enzyme assay for the determination of D: -2-hydroxyglutarate dehydrogenase activity in cells derived from D: -2-HGA patients and controls. The enzyme assay was performed using enantiomerically pure stable-isotope-labelled D: -2-hydroxy[3,3,4,4-(2)H(4)]glutarate. This substrate is convertedby D: -2-hydroxyglutarate dehydrogenase into 2-[3,3,4,4-(2)H(4)]ketoglutarate, which is subsequently converted into L: -[3,3,4,4-(2)H(4)]glutamate by L: -glutamate dehydrogenase, present in saturating amounts in cell homogenates. Enzyme activities were quantified using LC-MS/MS. The mean activities in control fibroblast and lymphoblast homogenates were 298 +/- 207 and 1670 +/- 940 pmol/h per mg protein, respectively. In fibroblast and lymphoblast cell lines derived from patients with pathogenic mutations in the D2HGDH gene, considerably decreased enzyme activities (e.g. <41 pmol/h per mg protein) were found compared with controls. This enzyme assay will have additional utility in further differentiating patients with D: -2-HGA and L: -2-HGA and in assessing the residual activities linked to pathogenic mutations in the D2HGDH gene.
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Affiliation(s)
- W V Wickenhagen
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands
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Hendriksz CJ. Inborn errors of metabolism for the diagnostic radiologist. Pediatr Radiol 2009; 39:211-20. [PMID: 19082997 DOI: 10.1007/s00247-008-1072-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 09/28/2008] [Accepted: 10/06/2008] [Indexed: 11/24/2022]
Abstract
Inherited metabolic disorders are becoming more important with the increasing availability of diagnostic methods and therapies for these conditions. The radiologist has become an important link in making the diagnosis or collaborating with the specialist centre to diagnose these disorders and monitor effects of therapy. The modes of presentation, disease-specific groups, classic radiological features and investigations are explored in this article to try and give the general radiologist some crucial background knowledge. The following presentations are covered: acute intoxication, hypoglycaemia, developmental delay and storage features. Specific groups of disorders covered are the abnormalities of intermediary metabolism, disorders of fatty acid oxidation and ketogenesis, mitochondrial disorders, lysosomal storage disorders, and, briefly, other groups such as peroxisomal disorders, disorders of glycosylation, and creatine synthesis disorders. New advances and the demands for monitoring are also briefly explored.
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Affiliation(s)
- Chris J Hendriksz
- Department of Clinical Inherited Metabolic Disorders, Birmingham Children's Hospital NHS Foundation Trust, Steelhouse Lane, Birmingham, B4 6NH, UK.
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37
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Williams CA, Dagli A, Battaglia A. Genetic disorders associated with macrocephaly. Am J Med Genet A 2008; 146A:2023-37. [PMID: 18629877 DOI: 10.1002/ajmg.a.32434] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Macrocephaly is associated with many genetic disorders and is a frequent cause of referral to the clinical geneticist. In this review we classify the commonly encountered macrocephaly disorders into useful categories and summarize recent genetic advances. Conditions where macrocephaly is a predominant aspect of the clinical presentation are discussed and a diagnostic approach to the common macrocephaly disorders is provided. Some emphasis is placed on familial macrocephaly (sometimes referred to as benign external hydrocephalus) and on the macrocephaly associated with autism spectrum disorders. The more recent conditions associated with the leukodystrophies and the organic acidurias are reviewed, but the well known conditions involving storage disorders and bone dysplasias are mentioned but not discussed. The genetic macrocephaly conditions cover a broad spectrum of gene disorders and their related proteins have diverse biological functions. As of yet it is not clear what precise biological pathways lead to generalized brain overgrowth.
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Affiliation(s)
- Charles A Williams
- Raymond C. Philips Research and Education Unit, Division of Genetics, Department of Pediatrics, University of Florida, Gainesville, Florida 32610, USA.
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38
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Achouri Y, Noël G, Van Schaftingen E. 2-Keto-4-methylthiobutyrate, an intermediate in the methionine salvage pathway, is a good substrate for CtBP1. Biochem Biophys Res Commun 2006; 352:903-6. [PMID: 17157814 DOI: 10.1016/j.bbrc.2006.11.111] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Accepted: 11/20/2006] [Indexed: 10/23/2022]
Abstract
In the present work, we have studied the kinetic properties of the catalytic domain of CtBP1, a co-repressor belonging to the d-2-hydroxyacid dehydrogenase family and known to reduce pyruvate in the presence of NADH. CtBP1 acted on a variety of alpha-keto acids, for which it displayed biphasic curves with inhibition at elevated concentrations, as observed with other dehydrogenases of the same family. Based on catalytic efficiencies, the best substrate was 2-keto-4-methylthiobutyrate, an intermediate of the methionine salvage pathway. It was about 20-fold better than 2-ketoisocaproate and glyoxylate, and 80-fold better than pyruvate. From these data we conclude that 2-keto-4-methylthiobutyrate may be an important regulator of CtBP activity, possibly linking gene repression to the activity of the methionine salvage and spermine synthesis pathways.
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Affiliation(s)
- Younes Achouri
- Université catholique de Louvain, Christian de Duve Institute of Cellular Pathology, Avenue Hippocrate 75, B-1200 Brussels, Belgium.
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39
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Juul K, Andersen J, Basile Cvitanich V, Meldgaard Lund A. Case 2: Suspected non-accidental injury. Acta Paediatr 2006; 95:1322-3; discussion 1325-6. [PMID: 16982514 DOI: 10.1080/08035250600580552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Klaus Juul
- Department of Paediatrics, Hillerød Hospital, Hillerød, Denmark.
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Struys EA. D-2-Hydroxyglutaric aciduria: unravelling the biochemical pathway and the genetic defect. J Inherit Metab Dis 2006; 29:21-9. [PMID: 16601864 DOI: 10.1007/s10545-006-0317-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Accepted: 01/23/2006] [Indexed: 11/27/2022]
Abstract
D-2-Hydroxyglutaric aciduria (D-2-HGA) is a neurometabolic inherited disorder first described in 1980. In the following years, it became clear that the clinical phenotype of the disease varies widely from severe neonatal to asymptomatic. However, the sparse biochemical knowledge made D-2-HGA a poorly understood disease. Much progress has been made in the last five years in various studies, revealing two human enzymes that play a role in the metabolism of D-2-hydroxyglutarate (D-2-HG): hydroxyacid-oxoacid transhydrogenase (HOT) and D-2-HG dehydrogenase. HOT is expected to be responsible for the formation of D-2-HG, while D-2-HG dehydrogenase converts D-2-HG into 2-ketoglutarate. We demonstrated pathogenic mutations in the D2HGD gene in patients with D-2-HGA, helping to unravel the primary defect causing D-2-HGA. However, in approximately 50% of the patients with D-2-HGA examined, no pathogenic mutations have yet been found.
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Affiliation(s)
- Eduard A Struys
- VU University Medical Centre, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
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Struys EA, Korman SH, Salomons GS, Darmin PS, Achouri Y, van Schaftingen E, Verhoeven NM, Jakobs C. Mutations in phenotypically mild D-2-hydroxyglutaric aciduria. Ann Neurol 2005; 58:626-30. [PMID: 16037974 DOI: 10.1002/ana.20559] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
D-2-hydroxyglutaric aciduria is a neurometabolic disorder with mild and severe phenotypes. Recently, we reported pathogenic mutations in the D-2-hydroxyglutarate dehydrogenase gene as the cause of the severe phenotype of D-2-hydroxyglutaric aciduria in two patients. Here, we report two novel pathogenic mutations in this gene in one patient with a mild presentation and two asymptomatic siblings with D-2-hydroxyglutaric aciduria from two unrelated consanguineous Palestinian families: a splice error (IVS4-2A-->G) and a missense mutation (c.1315A-->G;p.Asn439Asp). Overexpression of this mutant protein showed marked reduction of the enzyme activity.
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Affiliation(s)
- Eduard A Struys
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
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42
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Struys EA, Verhoeven NM, Ten Brink HJ, Wickenhagen WV, Gibson KM, Jakobs C. Kinetic characterization of human hydroxyacid-oxoacid transhydrogenase: relevance to D-2-hydroxyglutaric and gamma-hydroxybutyric acidurias. J Inherit Metab Dis 2005; 28:921-30. [PMID: 16435184 DOI: 10.1007/s10545-005-0114-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Accepted: 07/19/2005] [Indexed: 10/25/2022]
Abstract
We investigated the presence of hydroxyacid-oxoacid transhydrogenase (HOT), which catalyses the cofactor-independent conversion of gamma-hydroxybutyrate (GHB) to succinic semialdehyde coupled to reduction of 2-ketoglutarate (2-KG) to D-2-hydroxyglutarate (D-2-HG), in human liver extracts employing [2H6]GHB and 2-KG as substrates. We measured incorporation of 2H in D-[2H]2-HG using GC-MS analyses, providing evidence for HOT activity in humans. Kinetic characterization of HOT was undertaken in forward and reverse directions. We employed [2H6]GHB and [2H4]2-KG as cosubstrates in order to develop a HOT activity assay in cultured human fibroblasts derived from patients with D-2-hydroxyglutaric aciduria. HOT activity was quantified in this system by the measurement of D-[2H5]2-HG production. Fibroblasts derived from patients with D-2-hydroxyglutaric aciduria showed normal HOT activities. Our results provide the first demonstration and preliminary kinetic characterization of HOT activity in human tissues.
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Affiliation(s)
- E A Struys
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
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43
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Read MH, Bonamy C, Laloum D, Belloy F, Constans JM, Guillois B, Kottler ML, Verhoeven NM, Jakobs C. Clinical, biochemical, magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H MRS) findings in a fourth case of combined D- and L-2 hydroxyglutaric aciduria. J Inherit Metab Dis 2005; 28:1149-50. [PMID: 16435212 DOI: 10.1007/s10545-005-4565-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We report the fourth case of combined D-and L-2-hydroxyglutaric aciduria presenting with neonatal encephalopathy and subependymal cysts.
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Affiliation(s)
- M-H Read
- Departement Genetique et Reproduction, Centre hospitalier universitaire, Caen, France.
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44
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Achouri Y, NOëL G, Vertommen D, Rider M, Veiga-Da-Cunha M, van Schaftingen E. Identification of a dehydrogenase acting on D-2-hydroxyglutarate. Biochem J 2004; 381:35-42. [PMID: 15070399 PMCID: PMC1133759 DOI: 10.1042/bj20031933] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 03/16/2004] [Accepted: 04/07/2004] [Indexed: 11/17/2022]
Abstract
Extracts of frozen rat liver were found to catalyse the formation of 3H2O from DL-2-hydroxy[2-3H]glutarate. Three peaks of enzyme activities were observed on separation by chromatography on DEAE-Sepharose. The first and second peaks corresponded to an enzyme acting on L-2-hydroxyglutarate and the third peak corresponded to an enzyme acting on D-2-hydroxyglutarate, as indicated by competitive inhibition of the detritiation of the racemic radioactive compound by the unlabelled L- and D-isomers respectively. The enzyme acting on the D-form was further characterized. It was independent of NAD or NADP and it converted D-2-hydroxyglutarate into a-ketoglutarate, transferring electrons to artificial electron acceptors. It also oxidized D-lactate, D-malate and meso-tartrate and was stimulated by Zn2+, Co2+ and Mn2+, but not by Mg2+ or Ca2+. Subcellular fractionation indicated that it was present in the mitochondrial fraction. The enzyme was further purified by chromatography on Blue Trisacryl and phenyl-Sepharose, up to a stage where only a few bands were still visible by SDS/PAGE. Among the four candidate polypeptides that were identified by MS, one corresponded to a predicted mitochondrial protein homologous with FAD-dependent D-lactate dehydrogenase. The corresponding human protein was expressed in HEK-293 cells and it was shown to catalyse the detritiation of DL-2-hydroxy[2-3H]glutarate with similar properties as the purified rat enzyme.
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Affiliation(s)
- Younes Achouri
- *Laboratory of Physiological Chemistry, Université catholique de Louvain and Christian de Duve Institute of Cellular Pathology (ICP), Avenue Hippocrate 75, B-1200 Brussels, Belgium
| | - Gaëtane NOëL
- *Laboratory of Physiological Chemistry, Université catholique de Louvain and Christian de Duve Institute of Cellular Pathology (ICP), Avenue Hippocrate 75, B-1200 Brussels, Belgium
| | - Didier Vertommen
- †Hormone and Metabolic Research Unit, Université catholique de Louvain and Christian de Duve Institute of Cellular Pathology (ICP), Avenue Hippocrate 75, B-1200 Brussels, Belgium
| | - Mark H. Rider
- †Hormone and Metabolic Research Unit, Université catholique de Louvain and Christian de Duve Institute of Cellular Pathology (ICP), Avenue Hippocrate 75, B-1200 Brussels, Belgium
| | - Maria Veiga-Da-Cunha
- *Laboratory of Physiological Chemistry, Université catholique de Louvain and Christian de Duve Institute of Cellular Pathology (ICP), Avenue Hippocrate 75, B-1200 Brussels, Belgium
| | - Emile van Schaftingen
- *Laboratory of Physiological Chemistry, Université catholique de Louvain and Christian de Duve Institute of Cellular Pathology (ICP), Avenue Hippocrate 75, B-1200 Brussels, Belgium
- To whom correspondence should be addressed (e-mail )
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45
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Junqueira D, Brusque AM, Porciúncula LO, Rotta LN, Frizzo MES, Wyse ATS, Wannmacher CMD, Souza DO, Wajner M. In vitro effects of D-2-hydroxyglutaric acid on glutamate binding, uptake and release in cerebral cortex of rats. J Neurol Sci 2004; 217:189-94. [PMID: 14706223 DOI: 10.1016/j.jns.2003.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Neurological dysfunction is common in patients with D-2-hydroxyglutaric aciduria (DHGA). However, the mechanisms underlying the neuropathology of this disorder are far from understood. In the present study, we investigated the in vitro effects of D-2-hydroxyglutaric acid (DGA) at various concentrations (0.1-1.0 mM) on various parameters of the glutamatergic system, namely the basal and potassium-induced release of L-[3H]glutamate by synaptosomal preparations, Na(+)-dependent L-[3H]glutamate uptake by synaptosomal preparations and Na(+)-independent L-[3H]glutamate uptake by synaptic vesicles, as well as of Na(+)-independent and dependent L-[3H]glutamate binding to synaptic plasma membranes from cerebral cortex of male adult Wistar rats. We observed that DGA significantly increased synaptosomal L-[3H]glutamate uptake, without altering the other parameters. Although these findings do not support a direct excitotoxic action for DGA since the metabolite did not affect important parameters of the main neurotransmission system, they do not exclude a direct action of DGA on NMDA or other glutamate receptors. More comprehensive studies are therefore necessary to evaluate the exact role of DGA on neurotransmission.
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Affiliation(s)
- Débora Junqueira
- Departamento de Bioqui;mica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, RS, Porto Alegre, Brazil
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46
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Struys EA, Verhoeven NM, Brunengraber H, Jakobs C. Investigations by mass isotopomer analysis of the formation of D-2-hydroxyglutarate by cultured lymphoblasts from two patients with D-2-hydroxyglutaric aciduria. FEBS Lett 2004; 557:115-20. [PMID: 14741351 DOI: 10.1016/s0014-5793(03)01459-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
D-2-Hydroxyglutaric aciduria is an inborn error of metabolism first described in 1980. To date, more than 40 patients have been diagnosed with this disease. To identify the metabolic precursor of D-2-hydroxyglutarate (D-2-HG), cultured human lymphoblasts from two patients with D-2-HG aciduria were grown in culture medium supplemented with [U-(13)C(6)]glucose or [(2)H(5)]glutamate. Mass isotopomer distribution measurements of D-2-HG, 2-ketoglutarate (2-KG) and citrate were performed by gas chromatography-mass spectrometry. The mass isotopomer distributions in D-2-HG, 2-KG and citrate, following [U-(13)C(6)]glucose and [(2)H(5)]glutamate incubations, revealed that 2-KG interconverts rapidly to D-2-HG and that D-2-HG is formed within the mitochondria.
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Affiliation(s)
- Eduard A Struys
- Department of Clinical Chemistry, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
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da Silva CG, Bueno ARF, Schuck PF, Leipnitz G, Ribeiro CAJ, Wannmacher CMD, Wyse ATS, Wajner M. D-2-hydroxyglutaric acid inhibits creatine kinase activity from cardiac and skeletal muscle of young rats. Eur J Clin Invest 2003; 33:840-7. [PMID: 14511354 DOI: 10.1046/j.1365-2362.2003.01237.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Tissue accumulation of high amounts of D-2-hydroxyglutaric acid (DGA) is the biochemical hallmark of the inherited neurometabolic disorder D-2-hydroxyglutaric aciduria (DHGA). Patients affected by this disease usually present hypotonia, muscular weakness, hypertrophy and cardiomyopathy, besides severe neurological findings. However, the underlying mechanisms of muscle injury in this disorder are virtually unknown. MATERIALS AND METHODS In the present study we have evaluated the in vitro role of DGA, at concentrations ranging from 0.25 to 5.0 mM, on total, cytosolic and mitochondrial creatine kinase activities from skeletal and cardiac muscle of 30-day-old Wistar rats. We also tested the effects of various antioxidants on the effects elicited by DGA. RESULTS We first verified that total creatine kinase (CK) activity from homogenates was significantly inhibited by DGA (22-24% inhibition) in skeletal and cardiac muscle, and that this activity was approximately threefold higher in skeletal muscle than in cardiac muscle. We also observed that CK activities from mitochondrial (Mi-CK) and cytosolic (Cy-CK) preparations from skeletal muscle and cardiac muscle were also inhibited (12-35% inhibition) by DGA at concentrations as low as 0.25 mm, with the effect being more pronounced in cardiac muscle preparations. Finally, we verified that the DGA-inhibitory effect was fully prevented by preincubation of the homogenates with reduced glutathione and cysteine, suggesting that this effect is possibly mediated by modification of essential thiol groups of the enzyme. Furthermore, alpha-tocopherol, melatonin and the inhibitor of nitric oxide synthase L-NAME were unable to prevent this effect, indicating that the most common reactive oxygen and nitrogen species were not involved in the inhibition of CK provoked by DGA. CONCLUSION Considering the importance of creatine kinase activity for cellular energy homeostasis, our results suggest that inhibition of this enzyme by increased levels of DGA might be an important mechanism involved in the myopathy and cardiomyopathy of patients affected by DHGA.
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Affiliation(s)
- C G da Silva
- Department of Biochemistry, Institute of Basic Sciences and Health, UFRGS, Porto Alegre, RS, Brazil
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48
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da Silva CG, Bueno ARF, Rosa RB, Dutra Filho CS, Wannmacher CMD, Wyse ATS, Wajner M. Inhibition of mitochondrial creatine kinase activity by D-2-hydroxyglutaric acid in cerebellum of young rats. Neurochem Res 2003; 28:1329-37. [PMID: 12938854 DOI: 10.1023/a:1024936129908] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
D-2-Hydroxyglutaric aciduria (DHGA) is a neurometabolic disorder biochemically characterized by tissue accumulation and excretion of high amounts of D-2-hydroxyglutaric acid (DGA). Although the affected patients have predominantly severe neurological findings, the underlying mechanisms of brain injury are virtually unknown. In previous studies we have demonstrated that DGA, at concentrations as low as 0.25 mM, significantly decreased creatine kinase activity and other parameters of energy metabolism in cerebral cortex of young rats. In the present study, we investigated the effect of DGA (0.25-5 mM) on total creatine kinase (tCK) activity, as well as on CK activity in cytosolic (Cy-CK) and mitochondrial (Mi-CK) preparations from cerebellum of 30-day-old Wistar rats in order to test whether the inhibitory effect of DGA on CK was tissue specific. We verified that tCK (22% inhibition) and Mi-CK (40% inhibition) activities were moderately inhibited by DGA at concentrations of 2.5 mM and higher, in contrast to Cy-CK, which was not affected by the acid. Kinetic studies revealed that the inhibitory effect of DGA was noncompetitive in relation to phosphocreatine. We also observed that this inhibition was fully prevented by preincubation of the homogenates with reduced glutathione, suggesting that the inhibition of CK activity by DGA is possibly mediated by modification of essential thiol groups of the enzyme. Our present results therefore demonstrate a relatively weak inhibitory effect of DGA on cerebellum Mi-CK activity, as compared to that provoked in cerebral cortex, and may possibly be related to the neuropathology of DHGA, characterized by cerebral cortex abnormalities.
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Affiliation(s)
- Cleide G da Silva
- Department of Biochemistry, Institute of Basic Sciences and Health, UFRGS, Porto Alegre, RS, Brazil
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Clarke NF, Andrews I, Carpenter K, Jakobs C, van der Knaap MS, Kirk EP. D-2-hydroxyglutaric aciduria: a case with an intermediate phenotype and prenatal diagnosis of two affected fetuses. Am J Med Genet A 2003; 120A:523-7. [PMID: 12884432 DOI: 10.1002/ajmg.a.20120] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
D-2-hydroxyglutaric aciduria (D2HGA) is a rare autosomal recessive disorder with variable clinical expression. The biochemical defect is unknown at present. Previously reported cases have either followed a severe clinical course characterized by neonatal epileptic encephalopathy, cortical blindness, and profound developmental delay, or a mild course characterized by mild developmental delay, manageable epilepsy, and mild hypotonia. To date there has been a clear distinction between these two groups. We report the second case of a child with D2HGA who has followed an intermediate course. She presented in infancy with hypotonia, manageable epilepsy and developed moderate to severe developmental delay, and cortical visual impairment. The proposita had a coarse facial appearance, flat face, broad nasal bridge, up-turned nose, and simple, anteverted ears. These facial anomalies have been noted in other children with D2HGA and this case strengthens the proposed association between this facial phenotype and D2HGA. We also report the third and fourth instances of prenatal diagnosis for D2HGA. At each prenatal diagnosis, an affected fetus was diagnosed on the basis of markedly increased levels of D-2-hydroxyglutaric acid in amniotic fluid.
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Affiliation(s)
- Nigel F Clarke
- Department of Medical Genetics, Sydney Children's Hospital, Sydney, Australia
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50
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Struys EA, Verhoeven NM, Roos B, Jakobs C. Disease-related metabolites in culture medium of fibroblasts from patients with D-2-hydroxyglutaric aciduria, L-2-hydroxyglutaric aciduria, and combined D/L-2-hydroxyglutaric aciduria. Clin Chem 2003; 49:1133-8. [PMID: 12816910 DOI: 10.1373/49.7.1133] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND D-2-Hydroxyglutaric aciduria (D-2-HGA), L-2-hydroxyglutaric aciduria (L-2-HGA), and the combined D/L-2-hydroxyglutaric aciduria (D/L-2-HGA) are poorly understood organic acidurias. To investigate the usefulness of cultured human skin fibroblasts for both diagnostic and research purposes, we measured disease-related metabolites in the cell culture medium. METHODS We measured D-2-hydroxyglutarate (D-2-HG), L-2-hydroxyglutarate (L-2-HG), succinate, 2-ketoglutarate, and citrate in fibroblast cell medium by stable-isotope-dilution gas chromatography-mass spectrometry and glutamine, glutamic acid, and lysine with an amino acid analyzer. We used six cell lines from patients with D-2-HGA, two from patients with L-2-HGA, three from patients with D/L-2-HGA, and seven control cell lines. Culture medium was analyzed after a 96-h incubation period. RESULTS Culture media from cell lines from D-2-HGA patients contained D-2-HG at concentrations 5- to 30-fold higher than media from controls, whereas the concentration of L-2-HG in media was not increased. Media from L-2-HGA cell lines showed a fivefold increase in L-2-HG compared with controls. Media containing fibroblasts from D/L-2-HGA patients contained moderately increased amounts of both D-2-HG and L-2-HG. For all cell lines, succinate concentrations in the blank medium were higher than after 96 h of incubation with the exception of two of three D/L-2-HGA cell lines. Media of D-2-HGA cell lines had 2-ketoglutarate concentrations that were 40% of that for controls. Glutamic acid concentrations in media of these cell lines were 60% lower than in controls. CONCLUSIONS Cell culture media from fibroblasts from patients with D-2-HGA, L-2-HGA, or D/L-2-HGA contain increased amounts the corresponding 2-HGs, demonstrating the suitability of fibroblasts for both diagnosis of and research concerning 2-HGAs.
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Affiliation(s)
- Eduard A Struys
- Department of Clinical Chemistry, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
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