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Experimental Evidence that 3-Methylglutaric Acid Disturbs Mitochondrial Function and Induced Oxidative Stress in Rat Brain Synaptosomes: New Converging Mechanisms. Neurochem Res 2016; 41:2619-2626. [DOI: 10.1007/s11064-016-1973-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/23/2016] [Accepted: 06/01/2016] [Indexed: 12/14/2022]
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52
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Mandel H, Saita S, Edvardson S, Jalas C, Shaag A, Goldsher D, Vlodavsky E, Langer T, Elpeleg O. Deficiency of HTRA2/Omi is associated with infantile neurodegeneration and 3-methylglutaconic aciduria. J Med Genet 2016; 53:690-6. [PMID: 27208207 DOI: 10.1136/jmedgenet-2016-103922] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Accepted: 04/19/2016] [Indexed: 01/05/2023]
Abstract
BACKGROUND Cell survival critically depends on the integrity of mitochondria, which play a pivotal role during apoptosis. Extensive mitochondrial damage promotes release of pro-apoptotic factors from the intermembrane space of mitochondria. Released mitochondrial proteins include Smac/DIABLO and HTRA2/Omi, which inhibit the cytosolic E3 ubiquitin ligase XIAP and other inhibitors of apoptosis proteins. AIMS Here we investigated the cause of extreme hypertonia at birth, alternating with hypotonia, with the subsequent appearance of extrapyramidal symptoms, lack of psychomotor development, microcephaly, intractable seizures and early death in four patients from two unrelated families. The patients showed lactic acidemia, 3-methylglutaconic aciduria, intermittent neutropenia, evolving brain atrophy and disturbed cristae structure in muscle mitochondria. METHODS AND RESULTS Using whole-exome sequencing, we identified missplicing mutation and a 5 bp deletion in HTRA2, encoding HTRA2/Omi. This protein was completely absent from the patients' fibroblasts, whose growth was impaired and which were hypersensitive to apoptosis. Expression of HtrA2/Omi or of the proteolytically inactive HTRA2/Omi protein restored the cells' apoptotic resistance. However, cell growth was only restored by the proteolytically active protein. CONCLUSIONS This is the first report of recessive deleterious mutations in HTRA2 in human. The clinical phenotype, the increased apoptotic susceptibility and the impaired cell growth recapitulate those observed in the Htra2 knockout mice and in mutant mice with proteolytically inactive HTRA2/Omi. Together, they underscore the importance of both chaperone and proteolytic activities of HTRA2/Omi for balanced apoptosis sensitivity and for brain development. Absence of HTRA2/Omi is associated with severe neurodegenerative disorder of infancy, abnormal mitochondria, 3-methylglutaconic aciduria and increased sensitivity to apoptosis.
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Affiliation(s)
- Hanna Mandel
- Metabolic Unit, Rambam Health Care Center, Rappaport School of Medicine, Technion, Haifa, Israel
| | - Shotaro Saita
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Simon Edvardson
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Chaim Jalas
- Bonei Olam, Center for Rare Jewish Genetic Disorders, Brooklyn, New York, USA
| | - Avraham Shaag
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Dorit Goldsher
- MRI Unit, Rambam Medical Center, Ruth and Baruch Rappaport School of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
| | - Euvgeni Vlodavsky
- Department of Pathology, Rambam Medical Center, Ruth and Baruch Rappaport School of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
| | - Thomas Langer
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Orly Elpeleg
- The Monique and Jacques Roboh Department of Genetic Research, Hadassah Hebrew University Medical Center, Jerusalem, Israel
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53
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Benson MD, Ferreira P, MacDonald IM. Oculomotor apraxia and dilated cardiomyopathy with ataxia syndrome: A case report. Ophthalmic Genet 2016; 38:88-90. [DOI: 10.3109/13816810.2015.1137327] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Matthew D. Benson
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Patrick Ferreira
- Division of Medical Genetics, Alberta Children’s Hospital, Calgary, Alberta, Canada
| | - Ian M. MacDonald
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada
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54
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Novel CLPB mutation in a patient with 3-methylglutaconic aciduria causing severe neurological involvement and congenital neutropenia. Clin Immunol 2016; 165:1-3. [DOI: 10.1016/j.clim.2016.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 02/19/2016] [Indexed: 11/23/2022]
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55
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Brunel-Guitton C, Levtova A, Sasarman F. Mitochondrial Diseases and Cardiomyopathies. Can J Cardiol 2015; 31:1360-76. [DOI: 10.1016/j.cjca.2015.08.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/21/2015] [Accepted: 08/21/2015] [Indexed: 12/31/2022] Open
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Abstract
Mitochondrial dysfunction underlies many human disorders, including those that affect the visual system. The retinal ganglion cells, whose axons form the optic nerve, are often damaged by mitochondrial-related diseases which result in blindness. Both mitochondrial DNA (mtDNA) and nuclear gene mutations impacting many different mitochondrial processes can result in optic nerve disease. Of particular importance are mutations that impair mitochondrial network dynamics (fusion and fission), oxidative phosphorylation (OXPHOS), and formation of iron-sulfur complexes. Current genetic knowledge can inform genetic counseling and suggest strategies for novel gene-based therapies. Identifying new optic neuropathy-causing genes and defining the role of current and novel genes in disease will be important steps toward the development of effective and potentially neuroprotective therapies.
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Affiliation(s)
- Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School and Massachusetts Eye and Ear, Boston, Massachusetts 02114;
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57
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Saunders C, Smith L, Wibrand F, Ravn K, Bross P, Thiffault I, Christensen M, Atherton A, Farrow E, Miller N, Kingsmore SF, Ostergaard E. CLPB variants associated with autosomal-recessive mitochondrial disorder with cataract, neutropenia, epilepsy, and methylglutaconic aciduria. Am J Hum Genet 2015; 96:258-65. [PMID: 25597511 DOI: 10.1016/j.ajhg.2014.12.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 12/19/2014] [Indexed: 11/29/2022] Open
Abstract
3-methylglutaconic aciduria (3-MGA-uria) is a nonspecific finding associated with mitochondrial dysfunction, including defects of oxidative phosphorylation. 3-MGA-uria is classified into five groups, of which one, type IV, is genetically heterogeneous. Here we report five children with a form of type IV 3-MGA-uria characterized by cataracts, severe psychomotor regression during febrile episodes, epilepsy, neutropenia with frequent infections, and death in early childhood. Four of the individuals were of Greenlandic descent, and one was North American, of Northern European and Asian descent. Through a combination of homozygosity mapping in the Greenlandic individuals and exome sequencing in the North American, we identified biallelic variants in the caseinolytic peptidase B homolog (CLPB). The causative variants included one missense variant, c.803C>T (p.Thr268Met), and two nonsense variants, c.961A>T (p.Lys321*) and c.1249C>T (p.Arg417*). The level of CLPB protein was markedly decreased in fibroblasts and liver of affected individuals. CLPB is proposed to function as a mitochondrial chaperone involved in disaggregation of misfolded proteins, resulting from stress such as heat denaturation.
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MESH Headings
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/pathology
- Atrophy/genetics
- Atrophy/pathology
- Base Sequence
- Brain/pathology
- Cataract/genetics
- Cataract/pathology
- Child, Preschool
- Codon, Nonsense/genetics
- Endopeptidase Clp/genetics
- Endopeptidase Clp/metabolism
- Epilepsy/genetics
- Epilepsy/pathology
- Exome/genetics
- Fatal Outcome
- Female
- Fibroblasts/metabolism
- Genes, Recessive/genetics
- Greenland
- Humans
- Infant
- Infant, Newborn
- Liver/metabolism
- Male
- Metabolism, Inborn Errors/genetics
- Metabolism, Inborn Errors/pathology
- Mitochondrial Diseases/genetics
- Mitochondrial Diseases/pathology
- Molecular Sequence Data
- Movement Disorders/genetics
- Movement Disorders/pathology
- Mutation, Missense/genetics
- Neutropenia/genetics
- Neutropenia/pathology
- Sequence Analysis, DNA
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Affiliation(s)
- Carol Saunders
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA; Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA.
| | - Laurie Smith
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA; Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Flemming Wibrand
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Kirstine Ravn
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Peter Bross
- Research Unit for Molecular Medicine, Aarhus University and Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Isabelle Thiffault
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Mette Christensen
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark
| | - Andrea Atherton
- Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Emily Farrow
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA; Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Neil Miller
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Stephen F Kingsmore
- Center for Pediatric Genomic Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA; Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO 64108, USA; Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO 64108, USA
| | - Elsebet Ostergaard
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, 2100 Copenhagen, Denmark.
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58
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Wortmann SB, Ziętkiewicz S, Kousi M, Szklarczyk R, Haack TB, Gersting SW, Muntau AC, Rakovic A, Renkema GH, Rodenburg RJ, Strom TM, Meitinger T, Rubio-Gozalbo ME, Chrusciel E, Distelmaier F, Golzio C, Jansen JH, van Karnebeek C, Lillquist Y, Lücke T, Õunap K, Zordania R, Yaplito-Lee J, van Bokhoven H, Spelbrink JN, Vaz FM, Pras-Raves M, Ploski R, Pronicka E, Klein C, Willemsen MAAP, de Brouwer APM, Prokisch H, Katsanis N, Wevers RA. CLPB mutations cause 3-methylglutaconic aciduria, progressive brain atrophy, intellectual disability, congenital neutropenia, cataracts, movement disorder. Am J Hum Genet 2015; 96:245-57. [PMID: 25597510 DOI: 10.1016/j.ajhg.2014.12.013] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 12/10/2014] [Indexed: 01/04/2023] Open
Abstract
We studied a group of individuals with elevated urinary excretion of 3-methylglutaconic acid, neutropenia that can develop into leukemia, a neurological phenotype ranging from nonprogressive intellectual disability to a prenatal encephalopathy with progressive brain atrophy, movement disorder, cataracts, and early death. Exome sequencing of two unrelated individuals and subsequent Sanger sequencing of 16 individuals with an overlapping phenotype identified a total of 14 rare, predicted deleterious alleles in CLPB in 14 individuals from 9 unrelated families. CLPB encodes caseinolytic peptidase B homolog ClpB, a member of the AAA+ protein family. To evaluate the relevance of CLPB in the pathogenesis of this syndrome, we developed a zebrafish model and an in vitro assay to measure ATPase activity. Suppression of clpb in zebrafish embryos induced a central nervous system phenotype that was consistent with cerebellar and cerebral atrophy that could be rescued by wild-type, but not mutant, human CLPB mRNA. Consistent with these data, the loss-of-function effect of one of the identified variants (c.1222A>G [p.Arg408Gly]) was supported further by in vitro evidence with the mutant peptides abolishing ATPase function. Additionally, we show that CLPB interacts biochemically with ATP2A2, known to be involved in apoptotic processes in severe congenital neutropenia (SCN) 3 (Kostmann disease [caused by HAX1 mutations]). Taken together, mutations in CLPB define a syndrome with intellectual disability, congenital neutropenia, progressive brain atrophy, movement disorder, cataracts, and 3-methylglutaconic aciduria.
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Affiliation(s)
- Saskia B Wortmann
- Nijmegen Centre for Mitochondrial Disorders (NCMD), Amalia Children's Hospital, Radboudumc, 6500HB Nijmegen, the Netherlands.
| | - Szymon Ziętkiewicz
- Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Kładki str. 24, 80822 Gdańsk, Poland
| | - Maria Kousi
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27710, USA
| | - Radek Szklarczyk
- Clinical Genomics, Maastricht UMC+, PO Box 616, 6200MD Maastricht, the Netherlands
| | - Tobias B Haack
- Institute of Human Genetics, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Søren W Gersting
- Department of Molecular Pediatrics, Dr. von Hauner Children's Hospital, Ludwig-Maximilians-University, 80337 Munich, Germany
| | - Ania C Muntau
- Department of Pediatrics, University Children's Hospital, University Medical Center Eppendorf, 20246 Hamburg, Germany
| | | | - G Herma Renkema
- Nijmegen Centre for Mitochondrial Disorders (NCMD), Amalia Children's Hospital, Radboudumc, 6500HB Nijmegen, the Netherlands
| | - Richard J Rodenburg
- Nijmegen Centre for Mitochondrial Disorders (NCMD), Amalia Children's Hospital, Radboudumc, 6500HB Nijmegen, the Netherlands
| | - Tim M Strom
- Institute of Human Genetics, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - M Estela Rubio-Gozalbo
- Departments of Pediatrics and Laboratory Genetic Metabolic Diseases, Maastricht University Medical Center, 6202AZ Maastricht, the Netherlands
| | - Elzbieta Chrusciel
- Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, Kładki str. 24, 80822 Gdańsk, Poland
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, University Children's Hospital, Heinrich-Heine University, Moorenstr. 5, 40225 Düsseldorf, Germany
| | - Christelle Golzio
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27710, USA
| | - Joop H Jansen
- Department of Laboratory Medicine, Laboratory of Hematology, Radboudumc, 6525GA Nijmegen, the Netherlands
| | - Clara van Karnebeek
- Division of Biochemical Diseases, Department of Pediatrics, B.C. Children's Hospital, Treatable Intellectual Disability Endeavour, Vancouver, BC V6H 3N4, Canada; Child and Family Research Institute, Centre for Molecular Medicine & Therapeutics, University of British Columbia, Vancouver, BC V5Z 4H4, Canada
| | - Yolanda Lillquist
- Division of Biochemical Diseases, Department of Pediatrics, B.C. Children's Hospital, Treatable Intellectual Disability Endeavour, Vancouver, BC V6H 3N4, Canada
| | - Thomas Lücke
- Department of Neuropediatrics, University Children's Hospital, Ruhr University Bochum, 44791 Bochum, Germany
| | - Katrin Õunap
- Department of Genetics, United Laboratories, Tartu University Hospital, Tartu 51014, Estonia
| | - Riina Zordania
- Department of Genetics, United Laboratories, Tartu University Hospital, Tartu 51014, Estonia
| | - Joy Yaplito-Lee
- Metabolic Genetics, Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Hans van Bokhoven
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6500HB Nijmegen, the Netherlands
| | - Johannes N Spelbrink
- Nijmegen Centre for Mitochondrial Disorders (NCMD), Amalia Children's Hospital, Radboudumc, 6500HB Nijmegen, the Netherlands; BioMediTech, University of Tampere, 33014 Tampere, Finland
| | - Frédéric M Vaz
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Disease, Academic Medical Center, 1100AZ Amsterdam, the Netherlands
| | - Mia Pras-Raves
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Disease, Academic Medical Center, 1100AZ Amsterdam, the Netherlands
| | - Rafal Ploski
- Department of Medical Genetics, Warsaw Medical University, 02-106 Warsaw, Poland
| | - Ewa Pronicka
- Department of Pediatrics, Nutrition and Metabolic Diseases, Department of Medical Genetics, Children's Memorial Health Institute, 20 Aleja Dzieci Polskich, 04-730 Warsaw, Poland
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
| | | | - Arjan P M de Brouwer
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboudumc, 6500HB Nijmegen, the Netherlands
| | - Holger Prokisch
- Institute of Human Genetics, Helmholtz Zentrum Munich, 85764 Neuherberg, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27710, USA
| | - Ron A Wevers
- Department of Laboratory Medicine, Translational Metabolic Laboratory, Radboudumc, 6525GA Nijmegen, the Netherlands
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59
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Yahalom G, Anikster Y, Huna-Baron R, Hoffmann C, Blumkin L, Lev D, Tsabari R, Nitsan Z, Lerman SF, Ben-Zeev B, Pode-Shakked B, Sofer S, Schweiger A, Lerman-Sagie T, Hassin-Baer S. Costeff syndrome: clinical features and natural history. J Neurol 2014; 261:2275-82. [PMID: 25201222 DOI: 10.1007/s00415-014-7481-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Revised: 08/24/2014] [Accepted: 08/25/2014] [Indexed: 11/26/2022]
Abstract
Costeff syndrome (CS) is a rare autosomal-recessive neurological disorder, which is known almost exclusively in patients of Iraqi Jewish descent, manifesting in childhood with optic atrophy, ataxia, chorea and spastic paraparesis. Our aim was to study the clinical spectrum of CS and natural history using a cross-sectional study design. Consecutive patients with CS were recruited to the study. Patients were diagnosed based on clinical features, along with elevated urinary levels of methylglutaconic and methylglutaric acid, and by identification of the disease-causing mutation in the OPA3 gene in most. All patients were examined by a neurologist and signs and symptoms were rated. 28 patients with CS (16 males, 21 families, age at last observation 28.6 ± 16.1 years, range 0.5-68 years) were included. First signs of neurological deficit appeared in infancy or early childhood, with delayed motor milestones, choreiform movements, ataxia and visual disturbances. Ataxia and chorea were the dominant motor features in childhood, but varied in severity among patients and did not seem to worsen with age. Pyramidal dysfunction appeared later and progressed with age (r = 0.71, p < 0.001) leading to spastic paraparesis and marked gait impairment. The course of neurological deterioration was slow and the majority of patients could still walk beyond the fifth decade. While visual acuity seemed to deteriorate, it did not correlate with age. CS is a rare neurogenetic disorder that causes serious disability and worsens with age. Spasticity significantly increases over the years and is the most crucial determinant of neurological dysfunction.
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Affiliation(s)
- Gilad Yahalom
- Parkinson Disease and Movement Disorders Clinic, Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan, 52621, Israel,
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60
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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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61
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Sergouniotis PI, Perveen R, Thiselton DL, Giannopoulos K, Sarros M, Davies JR, Biswas S, Ansons AM, Ashworth JL, Lloyd IC, Black GC, Votruba M. Clinical and molecular genetic findings in autosomal dominant OPA3-related optic neuropathy. Neurogenetics 2014; 16:69-75. [PMID: 25159689 DOI: 10.1007/s10048-014-0416-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 07/28/2014] [Indexed: 10/24/2022]
Abstract
Leber hereditary optic neuropathy and autosomal dominant optic atrophy are the two most common inherited optic neuropathies. The latter has been associated with mutations in the OPA1 and OPA3 genes. To date, only six families with OPA3-associated dominant optic atrophy have been reported. In order to identify additional families, we performed Sanger sequencing of the OPA3 gene in 75 unrelated optic neuropathy patients. Affected individuals from two families were found to harbour the c.313C > G, p.(Gln105Glu) change in heterozygous state; this genetic defect has been previously reported in four dominant optic atrophy families. Intra- and interfamilial variability in age of onset and presenting symptoms was observed. Although dominant OPA3 mutations are typically associated with optic atrophy and cataracts, the former can be observed in isolation; we report a case with no lens opacities at age 38. Conversely, it is important to consider OPA3-related disease in individuals with bilateral infantile-onset cataracts and to assess optic nerve health in those whose vision fail to improve following lens surgery. The papillomacular bundle is primarily affected and vision is typically worse than 20/40. Notably, we describe one subject who retained normal acuities into the fifth decade of life. The condition can be associated with extraocular clinical features: two affected individuals in the present study had sensorineural hearing loss. The clinical heterogeneity observed in the individuals reported here (all having the same genetic defect in OPA3) suggests that the molecular pathology of the disorder is likely to be complex.
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Affiliation(s)
- Panagiotis I Sergouniotis
- Institute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
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Lumish HS, Yang Y, Xia F, Wilson A, Chung WK. The Expanding MEGDEL Phenotype: Optic Nerve Atrophy, Microcephaly, and Myoclonic Epilepsy in a Child with SERAC1 Mutations. JIMD Rep 2014; 16:75-9. [PMID: 24997715 PMCID: PMC4221303 DOI: 10.1007/8904_2014_322] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 04/03/2014] [Accepted: 05/20/2014] [Indexed: 01/30/2023] Open
Abstract
The inborn errors of metabolism associated with 3-methylglutaconic aciduria are a diverse group of disorders characterized by the excretion of 3-methylglutaconic and 3-methylglutaric acids in the urine. Mutations in several genes have been identified in association with 3-methylglutaconic aciduria. We describe a patient of Saudi Arabian descent with 3-methylglutaconic aciduria, sensorineural hearing loss, encephalopathy, and Leigh-like pattern on MRI (MEGDEL syndrome), as well as developmental delay and developmental regression, bilateral optic nerve atrophy, microcephaly, and myoclonic epilepsy. The patient had an earlier age of onset of optic atrophy than previously described in other MEGDEL syndrome patients. Whole exome sequencing revealed two loss-of-function mutations in SERAC1 in trans: c.438delC (p.T147Rfs*22) and c.442C>T (p.R148X), confirmed by Sanger sequencing. One of these mutations is novel (c.438delC). This case contributes to refining the MEGDEL phenotype.
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Affiliation(s)
- Heidi S. Lumish
- />College of Physicians and Surgeons, Columbia University, New York, NY USA
| | - Yaping Yang
- />Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX USA
| | - Fan Xia
- />Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX USA
| | - Ashley Wilson
- />Division of Clinical Genetics, New York Presbyterian Hospital, New York, NY USA
| | - Wendy K. Chung
- />Department of Pediatrics and Medicine, Columbia University, New York, NY USA
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Diagnosis by whole exome sequencing of atypical infantile onset Alexander disease masquerading as a mitochondrial disorder. Eur J Paediatr Neurol 2014; 18:495-501. [PMID: 24742911 DOI: 10.1016/j.ejpn.2014.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 03/25/2014] [Accepted: 03/28/2014] [Indexed: 11/24/2022]
Abstract
INTRODUCTION There are many similarities, both clinical and radiological, between mitochondrial leukoencephalopathies and Alexander disease, an astrogliopathy. Clinically, both can manifest with a myriad of symptoms and signs, arising from the neonatal period to adulthood. Radiologically, both can demonstrate white matter changes, signal abnormalities of basal ganglia or thalami, brainstem abnormalities and contrast enhancement of white matter structures. Magnetic resonance spectroscopy may reveal elevation of lactate in the abnormal white matter in Alexander disease making the distinction even more challenging. PATIENT AND METHODS We present a child who was considered to have an infantile onset mitochondrial disorder due to a combination of neurological symptoms and signs (developmental regression, failure to thrive, episodic deterioration, abnormal eye movements, pyramidal and cerebellar signs), urinary excretion of 3-methyl-glutaconic acid and imaging findings (extensive white matter changes and cerebellar atrophy) with a normal head circumference. Whole exome sequence analysis was performed. RESULTS The child was found to harbor the R416W mutation, one of the most prevalent mutations in the glial fibrillary acidic protein (GFAP) gene that causes Alexander disease. CONCLUSIONS Alexander disease should be considered in the differential diagnosis of infantile leukoencephalopathy, even when no macrocephaly is present. Next generation sequencing is a useful aid in unraveling the molecular etiology of leukoencephalopathies.
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64
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Su B, Ryan RO. Metabolic biology of 3-methylglutaconic acid-uria: a new perspective. J Inherit Metab Dis 2014; 37:359-68. [PMID: 24407466 PMCID: PMC4016128 DOI: 10.1007/s10545-013-9669-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 11/20/2013] [Accepted: 11/26/2013] [Indexed: 10/25/2022]
Abstract
Over the past 25 years a growing number of distinct syndromes/mutations associated with compromised mitochondrial function have been identified that share a common feature: urinary excretion of 3-methylglutaconic acid (3MGA). In the leucine degradation pathway, carboxylation of 3-methylcrotonyl CoA leads to formation of 3-methylglutaconyl CoA while 3-methylglutaconyl CoA hydratase converts this metabolite to 3-hydroxy-3-methylglutaryl CoA (HMG CoA). In "primary" 3MGA-uria, mutations in the hydratase are directly responsible for the accumulation of 3MGA. On the other hand, in all "secondary" 3MGA-urias, no defect in leucine catabolism exists and the metabolic origin of 3MGA is unknown. Herein, a path to 3MGA from mitochondrial acetyl CoA is proposed. The pathway is initiated when syndrome-associated mutations/DNA deletions result in decreased Krebs cycle flux. When this occurs, acetoacetyl CoA thiolase condenses two acetyl CoA into acetoacetyl CoA plus CoASH. Subsequently, HMG CoA synthase 2 converts acetoacetyl CoA and acetyl CoA to HMG CoA. Under syndrome-specific metabolic conditions, 3-methylglutaconyl CoA hydratase converts HMG CoA into 3-methylglutaconyl CoA in a reverse reaction of the leucine degradation pathway. This metabolite fails to proceed further up the leucine degradation pathway owing to the kinetic properties of 3-methylcrotonyl CoA carboxylase. Instead, hydrolysis of the CoA moiety of 3-methylglutaconyl CoA generates 3MGA, which appears in urine. If experimentally confirmed, this pathway provides an explanation for the occurrence of 3MGA in multiple disorders associated with compromised mitochondrial function.
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Affiliation(s)
- Betty Su
- Children's Hospital Oakland Research Institute, 5700 Martin Luther King Jr. Way, Oakland, CA, 94609, USA
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Wortmann SB, Kluijtmans LAJ, Sequeira S, Wevers RA, Morava E. Leucine Loading Test is Only Discriminative for 3-Methylglutaconic Aciduria Due to AUH Defect. JIMD Rep 2014; 16:1-6. [PMID: 24757000 DOI: 10.1007/8904_2014_309] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 03/07/2014] [Accepted: 03/11/2014] [Indexed: 12/03/2022] Open
Abstract
Currently, six inborn errors of metabolism with 3-methylglutaconic aciduria as discriminative feature are known. The "Primary 3-methylglutaconic aciduria," 3-methylglutaconyl-CoA hydratase deficiency or AUH defect, is a disorder of leucine catabolism. For all other subtypes, also denoted "Secondary 3-methylglutaconic acidurias" (TAZ defect or Barth syndrome, SERAC1 defect or MEGDEL syndrome, OPA3 defect or Costeff syndrome, DNAJC19 defect or DCMA syndrome, TMEM70 defect, "not otherwise specified (NOS) 3-MGA-uria"), the origin of 3-methylglutaconic aciduria remains enigmatic but is hypothesized to be independent from leucine catabolism. Here we show the results of leucine loading test in 21 patients with different inborn errors of metabolism who present with 3-methylglutaconic aciduria. After leucine loading urinary 3-methylglutaconic acid levels increased only in the patients with an AUH defect. This strongly supports the hypothesis that 3-methylglutaconic aciduria is independent from leucine breakdown in other inborn errors of metabolism with 3-methylglutaconic aciduria and also provides a simple test to discriminate between primary and secondary 3-methylglutaconic aciduria in regular patient care.
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Affiliation(s)
- Saskia B Wortmann
- Department of Pediatrics, Nijmegen Centre for Mitochondrial Disorders (NCMD), Amalia Children's Hospital, Radboud University Medical Centre, 9101, 6500 HB, Nijmegen, The Netherlands,
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Diodato D, Invernizzi F, Lamantea E, Fagiolari G, Parini R, Menni F, Parenti G, Bollani L, Pasquini E, Donati MA, Cassandrini D, Santorelli FM, Haack TB, Prokisch H, Ghezzi D, Lamperti C, Zeviani M. Common and Novel TMEM70 Mutations in a Cohort of Italian Patients with Mitochondrial Encephalocardiomyopathy. JIMD Rep 2014; 15:71-8. [PMID: 24740313 PMCID: PMC4270871 DOI: 10.1007/8904_2014_300] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/31/2014] [Accepted: 02/07/2014] [Indexed: 12/21/2022] Open
Abstract
ATP synthase or complex V (cV) of the oxidative phosphorylation system is responsible for the production of ATP, dissipating the electrochemical gradient generated by the mitochondrial respiratory chain. In addition to maternally transmitted cV dysfunction caused by mutations in mtDNA genes (MT-ATP6 or MT-ATP8), encoding cV subunits, recessive mutations in the nuclear TMEM70 are the most frequent cause of ATP synthase deficiency.We report on a cohort of ten Italian patients presenting with neonatal lactic acidosis, respiratory distress, hypotonia, cardiomyopathy and psychomotor delay and harbouring mutations in TMEM70, including the common splice mutation and four novel variants. TMEM70 protein was virtually absent in all tested TMEM70 patients' specimens.The exact function of TMEM70 is not known, but it is considered to impact on cV assembly since TMEM70 mutations have been associated with isolated cV activity reduction. We detected a clear cV biochemical defect in TMEM70 patients' fibroblasts, whereas the assay was not reliable in frozen muscle. Nevertheless, the evaluation of the amount of holocomplexes in patients with TMEM70 mutations showed a nearly absent cV in muscles and a strong decrease of cV with accumulation of sub-assembly species in fibroblasts. In our cohort we found not only cV deficiencies but also impairment of other OXPHOS complexes. By ultrastructural analysis of muscle tissue from one patient with isolated cV deficiency, we found a severely impaired mitochondrial morphology with loss of the cristae. These findings indicate that cV impairment could indirectly alter other respiratory chain complex activities by disrupting the mitochondrial cristae structure.
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Affiliation(s)
- Daria Diodato
- />Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico “Carlo Besta”, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), via Temolo 4, 20126 Milan, Italy
| | - Federica Invernizzi
- />Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico “Carlo Besta”, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), via Temolo 4, 20126 Milan, Italy
| | - Eleonora Lamantea
- />Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico “Carlo Besta”, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), via Temolo 4, 20126 Milan, Italy
| | - Gigliola Fagiolari
- />Neuromuscular Unit, Department of Neurology, Centro Dino Ferrari, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, University of Milan, 20122 Milan, Italy
| | - Rossella Parini
- />Unit of Metabolic Disorders, Department of Pediatrics, Foundation MBBM/San Gerardo University Hospital, 20900 Monza, Italy
| | - Francesca Menni
- />Pediatric Clinic, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, University of Milan, 20122 Milan, Italy
| | - Giancarlo Parenti
- />Department of Metabolic Diseases, University of Naples “Federico II”, 80138 Naples, Italy
| | - Lina Bollani
- />Neonatal Intensive Care Unit, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy
| | - Elisabetta Pasquini
- />Unit of Metabolic and Muscular Diseases, Meyer Children Hospital, 50132 Florence, Italy
| | - Maria A. Donati
- />Unit of Metabolic and Muscular Diseases, Meyer Children Hospital, 50132 Florence, Italy
| | | | | | - Tobias B. Haack
- />Institute of Human Genetics, Technical University, 81675 Munich, Germany
- />Helmholtz Zentrum München, 81675 Munich, Germany
| | - Holger Prokisch
- />Institute of Human Genetics, Technical University, 81675 Munich, Germany
- />Helmholtz Zentrum München, 81675 Munich, Germany
| | - Daniele Ghezzi
- />Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico “Carlo Besta”, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), via Temolo 4, 20126 Milan, Italy
| | - Costanza Lamperti
- />Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico “Carlo Besta”, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), via Temolo 4, 20126 Milan, Italy
| | - Massimo Zeviani
- />Unit of Molecular Neurogenetics, Fondazione Istituto Neurologico “Carlo Besta”, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), via Temolo 4, 20126 Milan, Italy
- />Mitochondrial Biology Unit, MRC, Wellcome Trust/MRC Building, Hills Road, CB2 0XY Cambridge, UK
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Lam C, Gallo LK, Dineen R, Ciccone C, Dorward H, Hoganson GE, Wolfe L, Gahl WA, Huizing M. Two novel compound heterozygous mutations in OPA3 in two siblings with OPA3-related 3-methylglutaconic aciduria. Mol Genet Metab Rep 2014; 1:114-123. [PMID: 24749080 PMCID: PMC3987911 DOI: 10.1016/j.ymgmr.2014.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
OPA3-related 3-methylglutaconic aciduria, or Costeff Optic Atrophy syndrome, is a neuro-ophthalmologic syndrome of early-onset bilateral optic atrophy and later-onset spasticity, and extrapyramidal dysfunction. Urinary excretion of 3-methylglutaconic acid and of 3-methylglutaric acid is markedly increased. OPA3-related 3-methylglutaconic aciduria is due to mutations in the OPA3 gene located at 19q13.2-13.3. Here we describe two siblings with novel compound heterozygous variants in OPA3: c.1A>G (p.1M>V) in the translation initiation codon in exon 1 and a second variant, c.142+5G>C in intron 1. On cDNA sequencing the c.1A>G appeared homozygous, indicating that the allele without the c.1A>G variant is degraded. This is likely due to an intronic variant; possibly the IVS1+5 splice site variant. The older female sibling initially presented with motor developmental delay and vertical nystagmus during her first year of life and was diagnosed subsequently with optic atrophy. Her brother presented with mildly increased hip muscle tone followed by vertical nystagmus within the first 6 months of life, and was found to have elevated urinary excretion of 3-methylglutaconic acid and 3-methylglutaric acid, and optic atrophy by 1.5 years of age. Currently, ages 16 and 7, both children exhibit ataxic gaits and dysarthric speech. Immunofluorescence studies on patient's cells showed fragmented mitochondrial morphology. Thus, though the exact function of OPA3 remains unknown, our experimental results and clinical summary provide evidence for the pathogenicity of the identified OPA3 variants and provide further evidence for a mitochondrial pathology in this disease.
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Affiliation(s)
- Christina Lam
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Linda K Gallo
- Department of Pediatrics, Edward Hospital, Naperville, Illinois, USA
| | - Richard Dineen
- Department of Pediatrics, University of Illinois, Chicago, Illinois, USA
| | - Carla Ciccone
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Heidi Dorward
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - George E Hoganson
- Department of Pediatrics, University of Illinois, Chicago, Illinois, USA
| | - Lynne Wolfe
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - William A Gahl
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marjan Huizing
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Wortmann SB, Kluijtmans LAJ, Rodenburg RJ, Sass JO, Nouws J, van Kaauwen EP, Kleefstra T, Tranebjaerg L, de Vries MC, Isohanni P, Walter K, Alkuraya FS, Smuts I, Reinecke CJ, van der Westhuizen FH, Thorburn D, Smeitink JAM, Morava E, Wevers RA. 3-Methylglutaconic aciduria--lessons from 50 genes and 977 patients. J Inherit Metab Dis 2013; 36:913-21. [PMID: 23355087 DOI: 10.1007/s10545-012-9579-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Revised: 12/18/2012] [Accepted: 12/20/2012] [Indexed: 10/27/2022]
Abstract
Elevated urinary excretion of 3-methylglutaconic acid is considered rare in patients suspected of a metabolic disorder. In 3-methylglutaconyl-CoA hydratase deficiency (mutations in AUH), it derives from leucine degradation. In all other disorders with 3-methylglutaconic aciduria the origin is unknown, yet mitochondrial dysfunction is thought to be the common denominator. We investigate the biochemical, clinical and genetic data of 388 patients referred to our centre under suspicion of a metabolic disorder showing 3-methylglutaconic aciduria in routine metabolic screening. Furthermore, we investigate 591 patients with 50 different, genetically proven, mitochondrial disorders for the presence of 3-methylglutaconic aciduria. Three percent of all urine samples of the patients referred showed 3-methylglutaconic aciduria, often in correlation with disorders not reported earlier in association with 3-methylglutaconic aciduria (e.g. organic acidurias, urea cycle disorders, haematological and neuromuscular disorders). In the patient cohort with genetically proven mitochondrial disorders 11% presented 3-methylglutaconic aciduria. It was more frequently seen in ATPase related disorders, with mitochondrial DNA depletion or deletion, but not in patients with single respiratory chain complex deficiencies. Besides, it was a consistent feature of patients with mutations in TAZ, SERAC1, OPA3, DNAJC19 and TMEM70 accounting for mitochondrial membrane related pathology. 3-methylglutaconic aciduria is found quite frequently in patients suspected of a metabolic disorder, and mitochondrial dysfunction is indeed a common denominator. It is only a discriminative feature of patients with mutations in AUH, TAZ, SERAC1, OPA3, DNAJC19 TMEM70. These conditions should therefore be referred to as inborn errors of metabolism with 3-methylglutaconic aciduria as discriminative feature.
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Affiliation(s)
- Saskia B Wortmann
- Nijmegen Center for Mitochondrial Disorders (NCMD) at the Department of Pediatrics and the Institute of Genetic and Metabolic Disease (IGMD), Radboud University Medical Centre, P.O Box 9101, 6500 HB, Nijmegen, The Netherlands,
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Tort F, García-Silva MT, Ferrer-Cortès X, Navarro-Sastre A, Garcia-Villoria J, Coll MJ, Vidal E, Jiménez-Almazán J, Dopazo J, Briones P, Elpeleg O, Ribes A. Exome sequencing identifies a new mutation in SERAC1 in a patient with 3-methylglutaconic aciduria. Mol Genet Metab 2013; 110:73-7. [PMID: 23707711 DOI: 10.1016/j.ymgme.2013.04.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 04/29/2013] [Indexed: 12/11/2022]
Abstract
3-Methylglutaconic aciduria (3-MGA-uria) is a heterogeneous group of syndromes characterized by an increased excretion of 3-methylglutaconic and 3-methylglutaric acids. Five types of 3-MGA-uria (I to V) with different clinical presentations have been described. Causative mutations in TAZ, OPA3, DNAJC19, ATP12, ATP5E, and TMEM70 have been identified. After excluding the known genetic causes of 3-MGA-uria we used exome sequencing to investigate a patient with Leigh syndrome and 3-MGA-uria. We identified a homozygous variant in SERAC1 (c.202C>T; p.Arg68*), that generates a premature stop codon at position 68 of SERAC1 protein. Western blot analysis in patient's fibroblasts showed a complete absence of SERAC1 that was consistent with the prediction of a truncated protein and supports the pathogenic role of the mutation. During the course of this project a parallel study identified mutations in SERAC1 as the genetic cause of the disease in 15 patients with MEGDEL syndrome, which was compatible with the clinical and biochemical phenotypes of the patient described here. In addition, our patient developed microcephaly and optic atrophy, two features not previously reported in MEGDEL syndrome. We highlight the usefulness of exome sequencing to reveal the genetic bases of human rare diseases even if only one affected individual is available.
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Affiliation(s)
- Frederic Tort
- Secció d'Errors Congènits del Metabolisme, Servei de Bioquímica i Genètica Molecular, Hospital Clinic, IDIBAPS, 08028, Barcelona, Spain
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