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Viggiano D, Bruchfeld A, Carriazo S, de Donato A, Endlich N, Ferreira AC, Figurek A, Fouque D, Franssen CFM, Giannakou K, Goumenos D, Hoorn EJ, Nitsch D, Arduan AO, Pešić V, Rastenyté D, Soler MJ, Rroji M, Trepiccione F, Unwin RJ, Wagner CA, Wiecek A, Zacchia M, Zoccali C, Capasso G. Brain dysfunction in tubular and tubulointerstitial kidney diseases. Nephrol Dial Transplant 2021; 37:ii46-ii55. [PMID: 34792176 PMCID: PMC8713153 DOI: 10.1093/ndt/gfab276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Indexed: 11/14/2022] Open
Abstract
Kidney function has two important elements: glomerular filtration and tubular function (secretion and reabsorption). A persistent decrease in glomerular filtration rate (GFR), with or without proteinuria, is diagnostic of chronic kidney disease (CKD). While glomerular injury or disease is a major cause of CKD and usually associated with proteinuria, predominant tubular injury, with or without tubulointerstitial disease, is typically non-proteinuric. CKD has been linked with cognitive impairment, but it is unclear how much this depends on a reduced GFR, altered tubular function or the presence of proteinuria. Since CKD is often accompanied by tubular and interstitial dysfunction, we explore here for the first time the potential role of the tubular and tubulointerstitial compartments in cognitive dysfunction. To help address this issue, we have selected a group of primary tubular diseases with preserved GFR, in which to review the evidence for any association with brain dysfunction. Cognition, mood, neurosensory, and motor disturbances are not well characterized in tubular diseases, possibly because they are subclinical and less prominent than other clinical manifestations. The available literature suggests that brain dysfunction in tubular and tubulointerstitial diseases is usually mild and is more often seen in disorders of water handling. Brain dysfunction may occur when severe electrolyte and water disorders in young children persist over a long period of time before the diagnosis is made. We have chosen as examples to highlight this topic, Bartter and Gitelman syndromes and nephrogenic diabetes insipidus. We discuss current published findings, some unanswered questions, and propose topics for future research.
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Affiliation(s)
- Davide Viggiano
- Department of Translational Medical Sciences, Univ. Campania "L.Vanvitelli", Naples, Italy. BIOGEM, Institute of Molecular Biology and Genetics, Ariano Irpino. Italy
| | - Annette Bruchfeld
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden. Department of Renal Medicine, Karolinska University Hospital and CLINTEC Karolinska Institutet, Stockholm, Sweden
| | - Sol Carriazo
- Department of Nephrology and Hypertension, IIS-Fundacion Jimenez Diaz-UAM, Madrid, Spain
| | - Antonio de Donato
- Department of Translational Medical Sciences, Univ. Campania "L.Vanvitelli", Naples, Italy. BIOGEM, Institute of Molecular Biology and Genetics, Ariano Irpino. Italy
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Germany
| | - Ana Carina Ferreira
- Nephrology Department, Centro Hospitalar E Universitário de Lisboa Central, Lisbon, Portugal; Universidade Nova de Lisboa
- Faculdade de Ciências Médicas, Lisbon, Portugal
| | - Andreja Figurek
- Institute of Anatomy, University of Zurich, Zurich, Switzerland
| | - Denis Fouque
- Department of Nephrology, Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Pierre-Benite, France; University of Lyon, France
| | - Casper F M Franssen
- Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Konstantinos Giannakou
- Department of Health Sciences, School of Sciences, European University Cyprus, Nicosia, Cyprus
| | - Dimitrios Goumenos
- Department of Nephrology and Renal Transplantation, Patras University Hospital, Patras, Greece
| | - Ewout J Hoorn
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Dorothea Nitsch
- Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alberto Ortiz Arduan
- Department of Nephrology and Hypertension, IIS-Fundacion Jimenez Diaz-UAM, Madrid, Spain
| | - Vesna Pešić
- Department of Physiology, Faculty of Pharmacy, University of Belgrade, Belgrade, Serbia
| | - Daiva Rastenyté
- Medical Academy, Department of Neurology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Maria José Soler
- Nephrology Department, Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Merita Rroji
- Department of Nephrology, University Hospital Center "Mother Tereza", Tirana, Albania
| | - Francesco Trepiccione
- Department of Translational Medical Sciences, Univ. Campania "L.Vanvitelli", Naples, Italy. BIOGEM, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Robert J Unwin
- Department of Renal Medicine, Division of Medicine, University College London, UK
| | - Carsten A Wagner
- Institute of Physiology, University of Zürich, Zurich, Switzerland
| | - Andrzej Wiecek
- Department of Nephrology, Transplantation and Internal Medicine, Medical University of Silesia, Katowice, Poland
| | - Miriam Zacchia
- Department of Translational Medical Sciences, Univ. Campania "L.Vanvitelli", Naples, Italy. BIOGEM, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
| | - Carmine Zoccali
- Renal Research Institute, New York, USA and Associazione Ipertensione, Nefrologia, Trapianto Renale (IPNET), Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, Univ. Campania "L.Vanvitelli", Naples, Italy. BIOGEM, Institute of Molecular Biology and Genetics, Ariano Irpino, Italy
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Cappuccio G, Ceccatelli Berti C, Baruffini E, Sullivan J, Shashi V, Jewett T, Stamper T, Maitz S, Canonico F, Revah-Politi A, Kupchik GS, Anyane-Yeboa K, Aggarwal V, Benneche A, Bratland E, Berland S, D'Arco F, Alves CA, Vanderver A, Longo D, Bertini E, Torella A, Nigro V, D'Amico A, van der Knaap MS, Goffrini P, Brunetti-Pierri N. Bi-allelic KARS1 pathogenic variants affecting functions of cytosolic and mitochondrial isoforms are associated with a progressive and multisystem disease. Hum Mutat 2021; 42:745-761. [PMID: 33942428 PMCID: PMC8251883 DOI: 10.1002/humu.24210] [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] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/10/2021] [Accepted: 04/07/2021] [Indexed: 12/12/2022]
Abstract
KARS1 encodes a lysyl‐transfer RNA synthetase (LysRS) that links lysine to its cognate transfer RNA. Two different KARS1 isoforms exert functional effects in cytosol and mitochondria. Bi‐allelic pathogenic variants in KARS1 have been associated to sensorineural hearing and visual loss, neuropathy, seizures, and leukodystrophy. We report the clinical, biochemical, and neuroradiological features of nine individuals with KARS1‐related disorder carrying 12 different variants with nine of them being novel. The consequences of these variants on the cytosol and/or mitochondrial LysRS were functionally validated in yeast mutants. Most cases presented with severe neurological features including congenital and progressive microcephaly, seizures, developmental delay/intellectual disability, and cerebral atrophy. Oculo‐motor dysfunction and immuno‐hematological problems were present in six and three cases, respectively. A yeast growth defect of variable severity was detected for most variants on both cytosolic and mitochondrial isoforms. The detrimental effects of two variants on yeast growth were partially rescued by lysine supplementation. Congenital progressive microcephaly, oculo‐motor dysfunction, and immuno‐hematological problems are emerging phenotypes in KARS1‐related disorder. The data in yeast emphasize the role of both mitochondrial and cytosolic isoforms in the pathogenesis of KARS1‐related disorder and supports the therapeutic potential of lysine supplementation at least in a subset of patients.
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Affiliation(s)
- Gerarda Cappuccio
- Department of Translational Medicine, Federico II University, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy
| | - Camilla Ceccatelli Berti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Enrico Baruffini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Jennifer Sullivan
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Vandana Shashi
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Tamison Jewett
- Department of Pediatrics, Section on Medical Genetics, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Tara Stamper
- Department of Pediatrics, Section on Medical Genetics, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Silvia Maitz
- Clinical Pediatric Genetics Unit, Pediatrics Clinics, MBBM Foundation, Hospital San Gerardo, Monza, Italy
| | - Francesco Canonico
- Department of Neuroradiology, San Gerardo Hospital, ASST di Monza, Università degli Studi di Milano Bicocca, Monza, Italy
| | - Anya Revah-Politi
- Department of Pathology and Cell Biology, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, New York, USA
| | - Gabriel S Kupchik
- Division of Medical Genetics, Maimonides Children's Hospital of Brooklyn at Maimonides Medical Center, Downstate Medical Center, State University of New York, New York, New York, USA
| | - Kwame Anyane-Yeboa
- Department of Pediatrics, Institute for Genomic Medicine Columbia University Medical Center, New York, New York, USA
| | - Vimla Aggarwal
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, New York, USA
| | - Andreas Benneche
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Eirik Bratland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Siren Berland
- Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway
| | - Felice D'Arco
- Department of Paediatric Neuroradiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Cesar A Alves
- Division of Neuroradiology, Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia and Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniela Longo
- Department of Diagnostic Imaging, Pediatric Hospital Bambino Gesù, Rome, Italy
| | - Enrico Bertini
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Annalaura Torella
- Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy.,Department of Precision Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy.,Department of Precision Medicine, University of Campania Luigi Vanvitelli, Naples, Italy
| | | | - Alessandra D'Amico
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy
| | - Marjo S van der Knaap
- Department of Child Neurology, Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers and Amsterdam Neuroscience, Amsterdam, The Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Paola Goffrini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Nicola Brunetti-Pierri
- Department of Translational Medicine, Federico II University, Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Naples, Italy
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Itoh M, Dai H, Horike SI, Gonzalez J, Kitami Y, Meguro-Horike M, Kuki I, Shimakawa S, Yoshinaga H, Ota Y, Okazaki T, Maegaki Y, Nabatame S, Okazaki S, Kawawaki H, Ueno N, Goto YI, Kato Y. Biallelic KARS pathogenic variants cause an early-onset progressive leukodystrophy. Brain 2020; 142:560-573. [PMID: 30715177 DOI: 10.1093/brain/awz001] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 11/09/2018] [Accepted: 11/27/2018] [Indexed: 12/13/2022] Open
Abstract
The leukodystrophies cause severe neurodevelopmental defects from birth and follow an incurable and progressive course that often leads to premature death. It has recently been reported that abnormalities in aminoacyl t-RNA synthetase (ARS) genes are linked to various unique leukodystrophies and leukoencephalopathies. Aminoacyl t-RNA synthetase proteins are fundamentally known as the first enzymes of translation, catalysing the conjugation of amino acids to cognate tRNAs for protein synthesis. It is known that certain aminoacyl t-RNA synthetase have multiple non-canonical roles in both transcription and translation, and their disruption results in varied and complicated phenotypes. We clinically and genetically studied seven patients (six male and one female; aged 2 to 12 years) from five unrelated families who all showed the same phenotypes of severe developmental delay or arrest (7/7), hypotonia (6/7), deafness (7/7) and inability to speak (6/7). The subjects further developed intractable epilepsy (7/7) and nystagmus (6/6) with increasing age. They demonstrated characteristic laboratory data, including increased lactate and/or pyruvate levels (7/7), and imaging findings (7/7), including calcification and abnormal signals in the white matter and pathological involvement (2/2) of the corticospinal tracts. Through whole-exome sequencing, we discovered genetic abnormalities in lysyl-tRNA synthetase (KARS). All patients harboured the variant [c.1786C>T, p.Leu596Phe] KARS isoform 1 ([c.1702C>T, p.Leu568Phe] of KARS isoform 2) either in the homozygous state or compound heterozygous state with the following KARS variants, [c.879+1G>A; c.1786C>T, p.Glu252_Glu293del; p.Leu596Phe] ([c.795+1G>A; c.1702C>T, p.Glu224_Glu255del; p.Leu568Phe]) and [c.650G>A; c.1786C>T, p.Gly217Asp; p.Leu596Phe] ([c.566G>A; c.1702C>T, p.Gly189Asp; p.Leu568Phe]). Moreover, similarly disrupted lysyl-tRNA synthetase (LysRS) proteins showed reduced enzymatic activities and abnormal CNSs in Xenopus embryos. Additionally, LysRS acts as a non-canonical inducer of the immune response and has transcriptional activity. We speculated that the complex functions of the abnormal LysRS proteins led to the severe phenotypes in our patients. These KARS pathological variants are novel, including the variant [c.1786C>T; p.Leu596Phe] (c.1702C>T; p.Leu568Phe) shared by all patients in the homozygous or compound-heterozygous state. This common position may play an important role in the development of severe progressive leukodystrophy. Further research is warranted to further elucidate this relationship and to investigate how specific mutated LysRS proteins function to understand the broad spectrum of KARS-related diseases.
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Affiliation(s)
- Masayuki Itoh
- Department of Mental Retardation and Birth Defect Research, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Hongmei Dai
- Department of Mental Retardation and Birth Defect Research, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Shin-Ichi Horike
- Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - John Gonzalez
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Yoshikazu Kitami
- Department of Mental Retardation and Birth Defect Research, National Center of Neurology and Psychiatry, Kodaira, Japan
| | | | - Ichiro Kuki
- Department of Pediatric Neurology, Osaka City General Hospital, Osaka, Japan
| | | | - Harumi Yoshinaga
- Department of Child Neurology, Okayama University, Okayama, Japan
| | - Yoko Ota
- Department of Pathology and Experimental Medicine, Okayama University, Okayama, Japan
| | - Tetsuya Okazaki
- Department of Child Neurology, University of Tottori, Yonago, Japan
| | | | - Shin Nabatame
- Department of Pediatrics, Osaka University, Osaka, Japan
| | - Shin Okazaki
- Department of Pediatric Neurology, Osaka City General Hospital, Osaka, Japan
| | - Hisashi Kawawaki
- Department of Pediatric Neurology, Osaka City General Hospital, Osaka, Japan
| | - Naoto Ueno
- Department of Developmental Biology, National Institute for Basic Biology, Natural Institutes of Natural Sciences, Okazaki, Japan.,Department of Basic Biology, School of Life Science, the Graduate University of Advanced Studies (SOKENDAI), Hayama, Japan
| | - Yu-Ichi Goto
- Department of Mental Retardation and Birth Defect Research, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Yoichi Kato
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA.,Department of Cell Biology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Ardissone A, Tonduti D, Legati A, Lamantea E, Barone R, Dorboz I, Boespflug-Tanguy O, Nebbia G, Maggioni M, Garavaglia B, Moroni I, Farina L, Pichiecchio A, Orcesi S, Chiapparini L, Ghezzi D. KARS-related diseases: progressive leukoencephalopathy with brainstem and spinal cord calcifications as new phenotype and a review of literature. Orphanet J Rare Dis 2018; 13:45. [PMID: 29615062 PMCID: PMC5883414 DOI: 10.1186/s13023-018-0788-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 03/19/2018] [Indexed: 12/22/2022] Open
Abstract
Background KARS encodes lysyl- transfer ribonucleic acid (tRNA) synthetase, which catalyzes the aminoacylation of tRNA-Lys in the cytoplasm and mitochondria. Eleven families/sporadic patients and 16 different mutations in KARS have been reported to date. The associated clinical phenotype is heterogeneous ranging from early onset encephalopathy to isolated peripheral neuropathy or nonsyndromic hearing impairment. Recently additional presentations including leukoencephalopathy as predominant cerebral involvement or cardiomyopathy, isolated or associated with muscular and cerebral involvement, have been reported. A progressive Leukoencephalopathy with brainstem and spinal cord calcifications was previously described in a singleton patient and in two siblings, without the identification of the genetic cause. We reported here about a new severe phenotype associated with biallelic KARS mutations and sharing some common points with the other already reported phenotypes, but with a distinct clinical and neuroimaging picture. Review of KARS mutant patients published to date will be also discussed. Results Herein, we report the clinical, biochemical and molecular findings of 2 unreported Italian patients affected by developmental delay, acquired microcephaly, spastic tetraparesis, epilepsy, sensory-neural hypoacusia, visual impairment, microcytic hypochromic anaemia and signs of hepatic dysfunction. MRI pattern in our patients was characterized by progressive diffuse leukoencephalopathy and calcifications extending in cerebral, brainstem and cerebellar white matter, with spinal cord involvement. Genetic analysis performed on these 2 patients and in one subject previously described with similar MRI pattern revealed the presence of biallelic mutations in KARS in all 3 subjects. Conclusions With our report we define the molecular basis of the previously described Leukoencephalopathy with Brainstem and Spinal cord Calcification widening the spectrum of KARS related disorders, particularly in childhood onset disease suggestive for mitochondrial impairment. The review of previous cases does not suggest a strict and univocal genotype/phenotype correlation for this highly heterogeneous entity. Moreover, our cases confirm the usefulness of search for common brain and spine MR imaging pattern and of broad genetic screening, in syndromes clinically resembling mitochondrial disorders in spite of normal biochemical assay. Electronic supplementary material The online version of this article (10.1186/s13023-018-0788-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anna Ardissone
- Child Neurology, Foundation IRCCS Neurological Institute "C. Besta", Via Celoria 11, 20133, Milan, Italy. .,Department of Molecular and Translational Medicine DIMET, University of Milan-Bicocca, Milan, Italy.
| | - Davide Tonduti
- Child Neurology, Foundation IRCCS Neurological Institute "C. Besta", Via Celoria 11, 20133, Milan, Italy
| | - Andrea Legati
- Molecular Neurogenetics, Foundation IRCCS Neurological Institute "C. Besta", Milan, Italy
| | - Eleonora Lamantea
- Molecular Neurogenetics, Foundation IRCCS Neurological Institute "C. Besta", Milan, Italy
| | - Rita Barone
- Child Neurology and Psychiatry Unit, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Imen Dorboz
- INSERM UMR 1141, DHU PROTECT, Paris Diderot University, Sorbonne Paris Cité, France, Paris 06, Paris, France
| | - Odile Boespflug-Tanguy
- INSERM UMR 1141, DHU PROTECT, Paris Diderot University, Sorbonne Paris Cité, France, Paris 06, Paris, France.,AP-HP, Department of Neuropediatrics and Metabolic Diseases, National Reference Center for Leukodystrophies, Robert Debré Hospital, Paris, France
| | - Gabriella Nebbia
- Service of Paediatric Hepatology, Department of Paediatrics, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Marco Maggioni
- Pathology, Fondazione IRCCS Ca' Granda Ospedale Policlinico Milano, Milan, Italy
| | - Barbara Garavaglia
- Molecular Neurogenetics, Foundation IRCCS Neurological Institute "C. Besta", Milan, Italy
| | - Isabella Moroni
- Child Neurology, Foundation IRCCS Neurological Institute "C. Besta", Via Celoria 11, 20133, Milan, Italy
| | - Laura Farina
- Neuroradiology, Foundation IRCCS Neurological Institute "C. Besta", Milan, Italy
| | - Anna Pichiecchio
- Neuroradiology Department, IRCCS C. Mondino National Neurological Institute, Pavia, Italy
| | - Simona Orcesi
- Child Neurology and Psychiatry Unit, C. Mondino National Neurological Institute, Pavia, Italy
| | - Luisa Chiapparini
- Neuroradiology, Foundation IRCCS Neurological Institute "C. Besta", Milan, Italy
| | - Daniele Ghezzi
- Molecular Neurogenetics, Foundation IRCCS Neurological Institute "C. Besta", Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
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Orcesi S, Tonduti D, La Piana R. Calcifying leukoencephalopathies: new overlapping phenotypes. Am J Med Genet A 2012; 158A:964-5. [PMID: 22419650 DOI: 10.1002/ajmg.a.35242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 12/16/2011] [Indexed: 11/06/2022]
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Orcesi S, La Piana R, Uggetti C, Tonduti D, Pichiecchio A, Pasin M, Viselner G, Comi GP, Del Bo R, Ronchi D, Bastianello S, Balottin U. Spinal cord calcification in an early-onset progressive leukoencephalopathy. J Child Neurol 2011; 26:876-80. [PMID: 21427441 DOI: 10.1177/0883073810390038] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Spinal cord calcifications are an unusual finding in pediatric neurology. We here describe a young child who presented severe psychomotor delay, tetraplegia, deafness, and anemia. Neuroradiological investigations revealed severe leukodystrophy and unusual calcifications in the cerebral white matter and all along the medullary pathways. Common infectious and metabolic diseases were ruled out. A mild reduction in the activity of several respiratory chain complexes was documented on muscle biopsy. Of interest, we found an intronic variant in DARS2, a gene involved in mitochondrial DNA translation, responsible for the syndrome of leukoencephalopathy with brainstem and spinal cord involvement and high brain lactate. In our opinion, our case, and probably 2 previously reported Japanese siblings with a picture very similar to that of our patient, could represent a new, progressive leukoencephalomyelopathy.
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Affiliation(s)
- Simona Orcesi
- Child Neurology and Psychiatry Unit, IRCCS C. Mondino National Institute of Neurology Foundation, Pavia, Italy.
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Meshitsuka S, Aremu DA. (13)C heteronuclear NMR studies of the interaction of cultured neurons and astrocytes and aluminum blockade of the preferential release of citrate from astrocytes. J Biol Inorg Chem 2007; 13:241-7. [PMID: 18008094 DOI: 10.1007/s00775-007-0317-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Accepted: 10/22/2007] [Indexed: 10/22/2022]
Abstract
Citrate has been identified as a major tricarboxylic acid (TCA) cycle constituent preferentially released by astrocytes. We undertook the present study to examine further the nature of metabolic compartmentation in central nervous system tissues using (13)C-labeled glucose and to provide new information on the influence of aluminum on the metabolic interaction between neurons and astrocytes. Metabolites released into the culture medium from astrocytes and neuron-astrocyte coculture, as well as the perchloric acid extracts of the cells were analyzed using 2D (1)H and (13)C NMR spectroscopy. Astrocytes released citrate into the culture medium and the released citrate was consumed by neurons in coculture. Citrate release by astrocytes was blocked in the presence of aluminum, with progressive accumulation of citrate within the cells. We propose citrate supply is a more efficient energy source than lactate for neurons to produce ATP, especially in the hypoglycemic state on account of it being a direct component of the TCA cycle. Astrocytes may be the cellular compartment for aluminum accumulation as a citrate complex in the brain.
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Abstract
The primary or hereditary form of distal renal tubular acidosis (dRTA), although rare, has received increased attention recently because of dramatic advances in the understanding of its genetic basis. The final regulation of renal acid excretion is effected by various acid/base transporters localized in specialized cells in the cortical collecting and outer medullary collecting tubules. Inherited defects in two of the key acid/base transporters involved in distal acidification, as well as mutations in the cytosolic carbonic anhydrase gene, can cause dRTA. The syndrome is inherited in both autosomal dominant and recessive patterns; patients with recessive dRTA present with either acute illness or growth failure at a young age, sometimes accompanied by deafness, whereas dominant dRTA is usually a milder disease and involves no hearing loss. The AE1 gene encodes two Cl-/HCO3- exchangers that are expressed in the erythrocyte and in the acid-secreting intercalated cells of the kidney. AE1 contributes to urinary acidification by providing the major exit route for HCO3- across the basolateral membrane. Several mutations in the AE1 gene cosegregate with dominant dRTA. The modest degree of hypofunction exhibited in vitro by these mutations, however, does not explain the abnormal distal acidification phenotype. Other AE1 mutations have been linked to a recessive syndrome of dRTA and hemolytic anemia in which hypofunction can be discerned by in vitro studies. Several mutations in the carbonic anyhdrase II gene are associated with the autosomal recessive syndrome of osteopetrosis, renal tubular acidosis, and cerebral calcification. Some of these individuals present with deafness of the conductive type. By contrast, more recent studies have shown that mutations in ATP6B1, encoding the B-subtype unit of the apical H(+) ATPase, are responsible for a group of patients with autosomal recessive dRTA associated with sensorineural deafness. Thus, the presence of deafness and the type provide an important clue to the genetic lesion underlying hereditary dRTA.
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Affiliation(s)
- D Batlle
- Division of Nephrology/Hypertension, Northwestern University Medical School, 303 E. Chicago Avenue, Chicago, Illinois 60611-3008, USA.
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