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Ben Jdila M, Kammoun F, Abdelmaksoud-Dammak R, Triki C, Fakhfakh F. Mutation in the β-tubulin gene TUBB4A results in epileptic encephalopathy associated with hypomyelinated leucodystrophy: Unexpected findings reveal genetic mosaicism. Int J Dev Neurosci 2023; 83:532-545. [PMID: 37529938 DOI: 10.1002/jdn.10284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 05/10/2023] [Accepted: 06/15/2023] [Indexed: 08/03/2023] Open
Abstract
INTRODUCTION Epileptic encephalopathies (EEs) are a group of heterogeneous epileptic syndromes characterized by early-onset refractory seizures, specific EEG abnormalities, developmental delay or regression and intellectual disability. The genetic spectrum of EE is very wide with mutations in a number of genes having various functions, such as those encoding AMPA ionotropic and glutamate receptors as well as voltage-gated ion channels. However, the list of EE-responsible genes could certainly be enlarged by next-generation sequencing. PATIENTS AND METHODS The present study reports a clinical investigation and a molecular analysis by the whole exome sequencing (WES) and pyrosequencing of a patient's family affected by epileptic spasms and severe psychomotor delay. RESULTS Clinical and radiological investigations revealed that the patient presented clinical features of severe and drug-resistant EE-type infantile epileptic spasm syndrome that evolved to Lennox Gastaut syndrome with radiological findings of hypomyelinated leukodystrophy. The results of WES revealed the presence of a novel heterozygous c.466C>T mutation in exon 4 of the TUBB4A gene in the patient. This transition led to the replacement of arginine by cysteine at position 156 (p.R156C) of the conserved helix 4 among the N-terminal domain of the TUBB4A protein. Bioinformatic tools predicted its deleterious effects on the structural arrangement and stability of the protein. The presence of the mutation in the asymptomatic father suggested the hypothesis of somatic mosaicism that was tested by pyrosequencing of DNA from two tissues of the patient and her father. The obtained results showed a lower rate of mutated alleles in the asymptomatic father compared with the affected daughter in both lymphocytes and buccal mucosa cells, confirming the occurrence of paternal mosaicism. The phenotypic features of the patient were also compared with those of previously described patients presenting TUBB4A mutations. CONCLUSIONS Our study is the first to report a disease-causing variant in the TUBB4A gene in a patient with EE associated with hypomyelinated leucodystrophy. In addition, we expanded the phenotypic spectrum associated with the TUBB4A gene.
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Affiliation(s)
- Marwa Ben Jdila
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
- Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, Sfax University, Sfax, Tunisia
| | - Fatma Kammoun
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
- Child Neurology Department, Hedi Chaker University Hospital of Sfax, Sfax, Tunisia
| | - Rania Abdelmaksoud-Dammak
- Center of Biotechnology of Sfax, Laboratory of Eucaryotes Molecular Biotechnology, University of Sfax, Sfax, Tunisia
| | - Chahnez Triki
- Research Laboratory 'NeuroPédiatrie' (LR19ES15), Sfax Medical School, Sfax University, Sfax, Tunisia
- Child Neurology Department, Hedi Chaker University Hospital of Sfax, Sfax, Tunisia
| | - Faiza Fakhfakh
- Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, Sfax University, Sfax, Tunisia
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Perrier S, Guerrero K, Tran LT, Michell-Robinson MA, Legault G, Brais B, Sylvain M, Dorman J, Demos M, Köhler W, Pastinen T, Thiffault I, Bernard G. Solving inherited white matter disorder etiologies in the neurology clinic: Challenges and lessons learned using next-generation sequencing. Front Neurol 2023; 14:1148377. [PMID: 37077564 PMCID: PMC10108901 DOI: 10.3389/fneur.2023.1148377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 02/23/2023] [Indexed: 04/05/2023] Open
Abstract
IntroductionRare neurodevelopmental disorders, including inherited white matter disorders or leukodystrophies, often present a diagnostic challenge on a genetic level given the large number of causal genes associated with a range of disease subtypes. This study aims to demonstrate the challenges and lessons learned in the genetic investigations of leukodystrophies through presentation of a series of cases solved using exome or genome sequencing.MethodsEach of the six patients had a leukodystrophy associated with hypomyelination or delayed myelination on MRI, and inconclusive clinical diagnostic genetic testing results. We performed next generation sequencing (case-based exome or genome sequencing) to further investigate the genetic cause of disease.ResultsFollowing different lines of investigation, molecular diagnoses were obtained for each case, with patients harboring pathogenic variants in a range of genes including TMEM106B, GJA1, AGA, POLR3A, and TUBB4A. We describe the lessons learned in reaching the genetic diagnosis, including the importance of (a) utilizing proper multi-gene panels in clinical testing, (b) assessing the reliability of biochemical assays in supporting diagnoses, and (c) understanding the limitations of exome sequencing methods in regard to CNV detection and region coverage in GC-rich areas.DiscussionThis study illustrates the importance of applying a collaborative diagnostic approach by combining detailed phenotyping data and metabolic results from the clinical environment with advanced next generation sequencing analysis techniques from the research environment to increase the diagnostic yield in patients with genetically unresolved leukodystrophies.
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Affiliation(s)
- Stefanie Perrier
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Kether Guerrero
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Luan T. Tran
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Mackenzie A. Michell-Robinson
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Geneviève Legault
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Department of Pediatrics, McGill University, Montreal, QC, Canada
| | - Bernard Brais
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Michel Sylvain
- Division of Pediatric Neurology, Centre Mère-Enfant Soleil du CHU de Québec - Université Laval, Québec City, QC, Canada
| | - James Dorman
- John H. Stroger Jr. Hospital of Cook County, Chicago, IL, United States
- Department of Neurological Sciences, Rush Medical College, Chicago, IL, United States
| | - Michelle Demos
- Division of Neurology, Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| | - Wolfgang Köhler
- Leukodystrophy Center, University of Leipzig Medical Center, Leipzig, Germany
| | - Tomi Pastinen
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, United States
- University of Missouri Kansas City School of Medicine, Kansas City, MO, United States
| | - Isabelle Thiffault
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, United States
- University of Missouri Kansas City School of Medicine, Kansas City, MO, United States
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, United States
- Isabelle Thiffault
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Department of Pediatrics, McGill University, Montreal, QC, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, QC, Canada
- *Correspondence: Geneviève Bernard
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Attard TJ, Welburn JPI, Marsh JA. Understanding molecular mechanisms and predicting phenotypic effects of pathogenic tubulin mutations. PLoS Comput Biol 2022; 18:e1010611. [PMID: 36206299 PMCID: PMC9581425 DOI: 10.1371/journal.pcbi.1010611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/19/2022] [Accepted: 09/28/2022] [Indexed: 11/21/2022] Open
Abstract
Cells rely heavily on microtubules for several processes, including cell division and molecular trafficking. Mutations in the different tubulin-α and -β proteins that comprise microtubules have been associated with various diseases and are often dominant, sporadic and congenital. While the earliest reported tubulin mutations affect neurodevelopment, mutations are also associated with other disorders such as bleeding disorders and infertility. We performed a systematic survey of tubulin mutations across all isotypes in order to improve our understanding of how they cause disease, and increase our ability to predict their phenotypic effects. Both protein structural analyses and computational variant effect predictors were very limited in their utility for differentiating between pathogenic and benign mutations. This was even worse for those genes associated with non-neurodevelopmental disorders. We selected tubulin-α and -β disease mutations that were most poorly predicted for experimental characterisation. These mutants co-localise to the mitotic spindle in HeLa cells, suggesting they may exert dominant-negative effects by altering microtubule properties. Our results show that tubulin mutations represent a blind spot for current computational approaches, being much more poorly predicted than mutations in most human disease genes. We suggest that this is likely due to their strong association with dominant-negative and gain-of-function mechanisms.
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Affiliation(s)
- Thomas J. Attard
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Julie P. I. Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Joseph A. Marsh
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
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Novel TUBB4A mutation in a family with hereditary spastic paraplegia. Acta Neurol Belg 2022:10.1007/s13760-022-02032-w. [DOI: 10.1007/s13760-022-02032-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 07/10/2022] [Indexed: 11/01/2022]
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Xiao H, He H, Wu T, Ni X, Liu F, Yin F, Peng J. Functional Investigation of TUBB4A Variants Associated with Different Clinical Phenotypes. Mol Neurobiol 2022; 59:5056-5069. [PMID: 35668344 DOI: 10.1007/s12035-022-02900-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022]
Abstract
Dominant TUBB4A variants result in different phenotypes, including hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC), dystonia type 4 (DYT4), and isolated hypomyelination. Here, we report four new patients with a novel TUBB4A variant (p.K324T) and three new patients with previously reported variants (p.Q292K, p.V255I, p.E410K). The individual carrying the novel p.K324T variant exhibits epilepsy of infancy with migrating focal seizures (EIMFS), while the other three have isolated hypomyelination phenotype. We also present a study of the cellular effects of TUBB4A variants responsible for H-ABC (p.D249N), DYT4 (p.R2G), a severe combined phenotype with combination of hypomyelination and EIMFS (p.K324T), and isolated hypomyelination (p.Q292K and p.E410K) on microtubule stability and dynamics, neurite outgrowth, dendritic spine development, and kinesin binding. Cellular-based assays reveal that all variants except p.R2G increase microtubule stability, decrease microtubule polymerization rates, reduce axonal outgrowth, and alter the density and shape of dendritic spines. We also find that the p.K324T and p.E410K variants perturb the binding of TUBB4A to KIF1A, a neuron-specific kinesin required for transport of synaptic vesicle precursors. Taken together, our data suggest that impaired microtubule stability and dynamics, defected axonal growth, and dendritic spine development form the common molecular basis of TUBB4A-related leukodystrophy. Impairment of TUBB4A binding to KIF1A is more likely to be involved in the isolated hypomyelination phenotype, which suggests that alterations in kinesin binding may cause different phenotypes. In conclusion, our study extends the spectrum of TUBB4A mutations and related phenotypes and provides insight into why different TUBB4A variants cause distinct clinical phenotypes.
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Affiliation(s)
- Hui Xiao
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Hailan He
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Tenghui Wu
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Xiaoyuan Ni
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Fangyun Liu
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China.
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, 410005, China.
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Hashiguchi M, Monden Y, Nozaki Y, Watanabe K, Nakashima M, Saitsu H, Yamagata T, Osaka H. A TUBB4A Met363Thr variant in pediatric hypomyelination without atrophy of the basal ganglia. Hum Genome Var 2022; 9:19. [PMID: 35661708 PMCID: PMC9166743 DOI: 10.1038/s41439-022-00198-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/21/2022] [Accepted: 05/02/2022] [Indexed: 01/11/2023] Open
Abstract
TUBB4A gene variants cause dystonia type 4 and hypomyelination with atrophy of the basal ganglia and cerebellum. We report the case of a child with delayed motor development, intellectual disability, and dystonia. Magnetic resonance imaging revealed hypomyelination and progressive cerebellar atrophy without atrophy of the basal ganglia. Whole-exome sequencing revealed a de novo heterozygous variant, c.1088T > C, p.(Met363Thr), in TUBB4A. The present case further supports the vulnerability of the cerebellum in patients with TUBB4A pathogenic variants.
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Affiliation(s)
- Marina Hashiguchi
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yukifumi Monden
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yasuyuki Nozaki
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan ,Department of Pediatrics, Shin-Oyama City Hospital, Tochigi, Japan
| | - Kazuki Watanabe
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Mitsuko Nakashima
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Hirotomo Saitsu
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Takanori Yamagata
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Hitoshi Osaka
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
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Krajka V, Vulinovic F, Genova M, Tanzer K, Jijumon AS, Bodakuntla S, Tennstedt S, Mueller-Fielitz H, Meier B, Janke C, Klein C, Rakovic A. H-ABC- and dystonia-causing TUBB4A mutations show distinct pathogenic effects. SCIENCE ADVANCES 2022; 8:eabj9229. [PMID: 35275727 PMCID: PMC8916731 DOI: 10.1126/sciadv.abj9229] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
Mutations in the brain-specific β-tubulin 4A (TUBB4A) gene cause a broad spectrum of diseases, ranging from dystonia (DYT-TUBB4A) to hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). Currently, the mechanisms of how TUBB4A variants lead to this pleiotropic manifestation remain elusive. Here, we investigated whether TUBB4A mutations causing either DYT-TUBB4A (p.R2G and p.Q424H) or H-ABC (p.R2W and p.D249N) exhibit differential effects at the molecular and cellular levels. Using live-cell imaging of disease-relevant oligodendrocytes and total internal reflection fluorescence microscopy of whole-cell lysates, we observed divergent impact on microtubule polymerization and microtubule integration, partially reflecting the observed pleiotropy. Moreover, in silico simulations demonstrated that the mutants rarely adopted a straight heterodimer conformation in contrast to wild type. In conclusion, for most of the examined variants, we deciphered potential molecular disease mechanisms that may lead to the diverse clinical manifestations and phenotype severity across and within each TUBB4A-related disease.
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Affiliation(s)
- Victor Krajka
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
- Institute of Microtechnology (IMT), Technische Universität Braunschweig, Braunschweig 38124, Germany
| | - Franca Vulinovic
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Mariya Genova
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Kerstin Tanzer
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - A. S. Jijumon
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Satish Bodakuntla
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Stephanie Tennstedt
- Institute for Cardiogenetics, University of Lübeck, 23562 Lübeck, Germany
- DZHK (German Research Centre for Cardiovascular Research), partner site Hamburg/Lübeck/Kiel, 23562 Lübeck, Germany
- University Heart Center Lübeck, 23562 Lübeck, Germany
| | - Helge Mueller-Fielitz
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Britta Meier
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Aleksandar Rakovic
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
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Fellner A, Goldberg Y, Lev D, Basel-Salmon L, Shor O, Benninger F. In-silico phenotype prediction by normal mode variant analysis in TUBB4A-related disease. Sci Rep 2022; 12:58. [PMID: 34997144 PMCID: PMC8741991 DOI: 10.1038/s41598-021-04337-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 12/21/2021] [Indexed: 11/09/2022] Open
Abstract
TUBB4A-associated disorder is a rare condition affecting the central nervous system. It displays a wide phenotypic spectrum, ranging from isolated late-onset torsion dystonia to a severe early-onset disease with developmental delay, neurological deficits, and atrophy of the basal ganglia and cerebellum, therefore complicating variant interpretation and phenotype prediction in patients carrying TUBB4A variants. We applied entropy-based normal mode analysis (NMA) to investigate genotype–phenotype correlations in TUBB4A-releated disease and to develop an in-silico approach to assist in variant interpretation and phenotype prediction in this disorder. Variants included in our analysis were those reported prior to the conclusion of data collection for this study in October 2019. All TUBB4A pathogenic missense variants reported in ClinVar and Pubmed, for which associated clinical information was available, and all benign/likely benign TUBB4A missense variants reported in ClinVar, were included in the analysis. Pathogenic variants were divided into five phenotypic subgroups. In-silico point mutagenesis in the wild-type modeled protein structure was performed for each variant. Wild-type and mutated structures were analyzed by coarse-grained NMA to quantify protein stability as entropy difference value (ΔG) for each variant. Pairwise ΔG differences between all variant pairs in each structural cluster were calculated and clustered into dendrograms. Our search yielded 41 TUBB4A pathogenic variants in 126 patients, divided into 11 partially overlapping structural clusters across the TUBB4A protein. ΔG-based cluster analysis of the NMA results revealed a continuum of genotype–phenotype correlation across each structural cluster, as well as in transition areas of partially overlapping structural clusters. Benign/likely benign variants were integrated into the genotype–phenotype continuum as expected and were clearly separated from pathogenic variants. We conclude that our results support the incorporation of the NMA-based approach used in this study in the interpretation of variant pathogenicity and phenotype prediction in TUBB4A-related disease. Moreover, our results suggest that NMA may be of value in variant interpretation in additional monogenic conditions.
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Affiliation(s)
- Avi Fellner
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel. .,Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.
| | - Yael Goldberg
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel
| | - Dorit Lev
- Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Metabolic-Neurogenetic Clinic, Wolfson Medical Center, 58220, Holon, Israel.,Rina Mor Institute of Medical Genetics, Wolfson Medical Center, 58220, Holon, Israel
| | - Lina Basel-Salmon
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
| | - Oded Shor
- Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
| | - Felix Benninger
- Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
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9
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Park K, Hoff KJ, Wethekam L, Stence N, Saenz M, Moore JK. Kinetically Stabilizing Mutations in Beta Tubulins Create Isotype-Specific Brain Malformations. Front Cell Dev Biol 2021; 9:765992. [PMID: 34869359 PMCID: PMC8637541 DOI: 10.3389/fcell.2021.765992] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 10/29/2021] [Indexed: 11/13/2022] Open
Abstract
Mutations in the family of genes encoding the tubulin subunits of microtubules are associated with a spectrum of human brain malformations known as tubulinopathies. How these mutations impact tubulin activity to give rise to distinct developmental consequences is poorly understood. Here we report two patients exhibiting brain malformations characteristic of tubulinopathies and heterozygous T178M missense mutations in different β-tubulin genes, TUBB2A or TUBB3. RNAseq analysis indicates that both TUBB2A and TUBB3 are expressed in the brain during development, but only TUBB2A maintains high expression in neurons into adulthood. The T178 residue is highly conserved in β-tubulins and located in the exchangeable GTP-binding pocket of β-tubulin. To determine the impact of T178M on β-tubulin function we created an analogous mutation in the β-tubulin of budding yeast and show that the substitution acts dominantly to produce kinetically stabilized microtubules that assemble and disassemble slowly, with fewer transitions between these states. In vitro experiments with purified mutant tubulin demonstrate that T178M decreases the intrinsic assembly activity of β-tubulin and forms microtubules that rarely transition to disassembly. We provide evidence that the T178M substitution disrupts GTPase-dependent conformational changes in tubulin, providing a mechanistic explanation for kinetic stabilization. Our findings demonstrate the importance of tubulin’s GTPase activity during brain development, and indicate that tubulin isotypes play different, important roles during brain development.
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Affiliation(s)
- Kristen Park
- Department of Pediatrics and Neurology, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Katelyn J Hoff
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Linnea Wethekam
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Nicholas Stence
- Section of Pediatric Radiology, Department of Radiology, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Margarita Saenz
- Section of Genetics, Department of Pediatrics, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Jeffrey K Moore
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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Alata M, González-Vega A, Piazza V, Kleinert-Altamirano A, Cortes C, Ahumada-Juárez JC, Eguibar JR, López-Juárez A, Hernandez VH. Longitudinal Evaluation of Cerebellar Signs of H-ABC Tubulinopathy in a Patient and in the taiep Model. Front Neurol 2021; 12:702039. [PMID: 34335454 PMCID: PMC8317997 DOI: 10.3389/fneur.2021.702039] [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: 04/28/2021] [Accepted: 06/08/2021] [Indexed: 01/20/2023] Open
Abstract
Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a central neurodegenerative disease due to mutations in the tubulin beta-4A (TUBB4A) gene, characterized by motor development delay, abnormal movements, ataxia, spasticity, dysarthria, and cognitive deficits. Diagnosis is made by integrating clinical data and radiological signs. Differences in MRIs have been reported in patients that carry the same mutation; however, a quantitative study has not been performed so far. Our study aimed to provide a longitudinal analysis of the changes in the cerebellum (Cb), corpus callosum (CC), ventricular system, and striatum in a patient suffering from H-ABC and in the taiep rat. We correlated the MRI signs of the patient with the results of immunofluorescence, gait analysis, segmentation of cerebellum, CC, and ventricular system, performed in the taiep rat. We found that cerebellar and callosal changes, suggesting a potential hypomyelination, worsened with age, in concomitance with the emergence of ataxic gait. We also observed a progressive lateral ventriculomegaly in both patient and taiep, possibly secondary to the atrophy of the white matter. These white matter changes are progressive and can be involved in the clinical deterioration. Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) gives rise to a spectrum of clinical signs whose pathophysiology still needs to be understood.
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Affiliation(s)
| | - Arturo González-Vega
- Department of Chemical, Electronic and Biomedical Engineering, Division of Sciences and Engineering, University of Guanajuato, Guanajuato, Mexico
| | | | | | - Carmen Cortes
- Behavioral Neurophysiology Lab, Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Juan C Ahumada-Juárez
- Behavioral Neurophysiology Lab, Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Jose R Eguibar
- Behavioral Neurophysiology Lab, Institute of Physiology, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico.,Research Office, Vicerrectory of Research and Postgraduate Studies, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Alejandra López-Juárez
- Department of Chemical, Electronic and Biomedical Engineering, Division of Sciences and Engineering, University of Guanajuato, Guanajuato, Mexico
| | - Victor H Hernandez
- Department of Chemical, Electronic and Biomedical Engineering, Division of Sciences and Engineering, University of Guanajuato, Guanajuato, Mexico
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11
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Microtubule Dysfunction: A Common Feature of Neurodegenerative Diseases. Int J Mol Sci 2020; 21:ijms21197354. [PMID: 33027950 PMCID: PMC7582320 DOI: 10.3390/ijms21197354] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 12/13/2022] Open
Abstract
Neurons are particularly susceptible to microtubule (MT) defects and deregulation of the MT cytoskeleton is considered to be a common insult during the pathogenesis of neurodegenerative disorders. Evidence that dysfunctions in the MT system have a direct role in neurodegeneration comes from findings that several forms of neurodegenerative diseases are associated with changes in genes encoding tubulins, the structural units of MTs, MT-associated proteins (MAPs), or additional factors such as MT modifying enzymes which modulating tubulin post-translational modifications (PTMs) regulate MT functions and dynamics. Efforts to use MT-targeting therapeutic agents for the treatment of neurodegenerative diseases are underway. Many of these agents have provided several benefits when tested on both in vitro and in vivo neurodegenerative model systems. Currently, the most frequently addressed therapeutic interventions include drugs that modulate MT stability or that target tubulin PTMs, such as tubulin acetylation. The purpose of this review is to provide an update on the relevance of MT dysfunctions to the process of neurodegeneration and briefly discuss advances in the use of MT-targeting drugs for the treatment of neurodegenerative disorders.
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12
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Sase S, Almad AA, Boecker CA, Guedes-Dias P, Li JJ, Takanohashi A, Patel A, McCaffrey T, Patel H, Sirdeshpande D, Curiel J, Shih-Hwa Liu J, Padiath Q, Holzbaur EL, Scherer SS, Vanderver A. TUBB4A mutations result in both glial and neuronal degeneration in an H-ABC leukodystrophy mouse model. eLife 2020; 9:52986. [PMID: 32463361 PMCID: PMC7255805 DOI: 10.7554/elife.52986] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/13/2020] [Indexed: 12/20/2022] Open
Abstract
Mutations in TUBB4A result in a spectrum of leukodystrophy including Hypomyelination with Atrophy of Basal Ganglia and Cerebellum (H-ABC), a rare hypomyelinating leukodystrophy, often associated with a recurring variant p.Asp249Asn (D249N). We have developed a novel knock-in mouse model harboring heterozygous (Tubb4aD249N/+) and the homozygous (Tubb4aD249N/D249N) mutation that recapitulate the progressive motor dysfunction with tremor, dystonia and ataxia seen in H-ABC. Tubb4aD249N/D249N mice have myelination deficits along with dramatic decrease in mature oligodendrocytes and their progenitor cells. Additionally, a significant loss occurs in the cerebellar granular neurons and striatal neurons in Tubb4aD249N/D249N mice. In vitro studies show decreased survival and dysfunction in microtubule dynamics in neurons from Tubb4aD249N/D249N mice. Thus Tubb4aD249N/D249N mice demonstrate the complex cellular physiology of H-ABC, likely due to independent effects on oligodendrocytes, striatal neurons, and cerebellar granule cells in the context of altered microtubule dynamics, with profound neurodevelopmental deficits.
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Affiliation(s)
- Sunetra Sase
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Akshata A Almad
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - C Alexander Boecker
- Department of Physiology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Pedro Guedes-Dias
- Department of Physiology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Jian J Li
- Department of Neurology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Asako Takanohashi
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Akshilkumar Patel
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Tara McCaffrey
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Heta Patel
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Divya Sirdeshpande
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Julian Curiel
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Judy Shih-Hwa Liu
- Department of Neurology, Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States
| | - Quasar Padiath
- Department of Human Genetics and Neurobiology, University of Pittsburgh, Pittsburgh, United States
| | - Erika Lf Holzbaur
- Department of Physiology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Steven S Scherer
- Department of Neurology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Adeline Vanderver
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States.,Department of Neurology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
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13
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Joyal KM, Michaud J, van der Knaap MS, Bugiani M, Venkateswaran S. Severe TUBB4A-Related Hypomyelination With Atrophy of the Basal Ganglia and Cerebellum: Novel Neuropathological Findings. J Neuropathol Exp Neurol 2019; 78:3-9. [PMID: 30476126 DOI: 10.1093/jnen/nly105] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a rare hypomyelinating leukodystrophy characterized by infantile or childhood onset of motor developmental delay, progressive rigidity and spasticity, with hypomyelination and progressive atrophy of the basal ganglia and cerebellum due to a genetic mutation of the TUBB4A gene. It has only been recognized since 2002 and the full spectrum of the disorder is still being delineated. Here, we review a case report of a severely affected girl with a thorough neuropathological evaluation demonstrating novel clinical and pathological findings. Clinically, our patient demonstrated visual dysfunction and hypodontia in addition to the typical phenotype. Morphologically, more severe and widespread changes in the white matter were observed, including to the optic tracts; in gray structures such as the caudate nucleus, thalamus, globus pallidus, and substantia nigra; as well as an area of focal cortical dysplasia. Overall this case offers further insight into the broad range of clinical and neuropathological findings that may be associated with H-ABC and related TUBB4A gene mutations.
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Affiliation(s)
- Kristina M Joyal
- Division of Pediatric Neurology, Children's Hospital of Eastern Ontario, Ottawa, Ontario Canada
| | - Jean Michaud
- Department of Pathology and Laboratory Medicine, Children's Hospital of Eastern Ontario and University of Ottawa, Ottawa, Ontario, Canada
| | - Marjo S van der Knaap
- Department of Child Neurology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, Netherlands
| | - Marianna Bugiani
- Department of Neuropathology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, Netherlands
| | - Sunita Venkateswaran
- Division of Pediatric Neurology, Children's Hospital of Eastern Ontario, Ottawa, Ontario Canada
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14
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Owczarek-Lipska M, Mulahasanovic L, Obermaier CD, Hörtnagel K, Neubauer BA, Korenke GC, Biskup S, Neidhardt J. Novel mutations in the GJC2 gene associated with Pelizaeus–Merzbacher-like disease. Mol Biol Rep 2019; 46:4507-4516. [DOI: 10.1007/s11033-019-04906-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/01/2019] [Indexed: 12/15/2022]
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15
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Vulinovic F, Krajka V, Hausrat TJ, Seibler P, Alvarez-Fischer D, Madoev H, Park JS, Kumar KR, Sue CM, Lohmann K, Kneussel M, Klein C, Rakovic A. Motor protein binding and mitochondrial transport are altered by pathogenic TUBB4A variants. Hum Mutat 2018; 39:1901-1915. [PMID: 30079973 DOI: 10.1002/humu.23602] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/05/2018] [Accepted: 07/29/2018] [Indexed: 12/21/2022]
Abstract
Mutations in TUBB4A have been identified to cause a wide phenotypic spectrum of diseases ranging from hereditary generalized dystonia with whispering dysphonia (DYT-TUBB4A) and hereditary spastic paraplegia (HSP) to leukodystrophy hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). TUBB4A encodes the brain-specific β-tubulin isotype, β-tubulin 4A. To elucidate the pathogenic mechanisms conferred by TUBB4A mutations leading to the different phenotypes, we functionally characterized three pathogenic TUBB4A variants (c.4C>G,p.R2G; c.745G>A,p.D249N; c.811G>A, p.A271T) as representatives of the mutational and disease spectrum) in human neuroblastoma cells and human induced pluripotent stem cell (iPSC)-derived neurons. We showed that mRNA stability was not affected by any of the TUBB4A variants. Although two mutations (p.R2G and p.D249N) are located at the α/β-tubulin interdimer interface, we confirmed incorporation of all TUBB4A mutants into the microtubule network. However, we showed that the mutations p.D249N and p.A271T interfered with motor protein binding to microtubules and impaired neurite outgrowth and microtubule dynamics. Finally, TUBB4A mutations, as well as heterozygous knockout of TUBB4A, disrupted mitochondrial transport in iPSC-derived neurons. Taken together, our findings suggest that functional impairment of microtubule-associated transport is a shared pathogenic mechanism by which the TUBB4A mutations studied here cause a spectrum of diseases.
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Affiliation(s)
- Franca Vulinovic
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Victor Krajka
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Torben J Hausrat
- Institute of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Philip Seibler
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | | | - Harutyun Madoev
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Jin-Sung Park
- Department of Neurogenetics, Kolling Institute, Royal North Shore Hospital and the University of Sydney, St. Leonards, New South Wales, Australia
| | - Kishore R Kumar
- Department of Neurogenetics, Kolling Institute, Royal North Shore Hospital and the University of Sydney, St. Leonards, New South Wales, Australia
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, Australia
| | - Carolyn M Sue
- Department of Neurogenetics, Kolling Institute, Royal North Shore Hospital and the University of Sydney, St. Leonards, New South Wales, Australia
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Matthias Kneussel
- Institute of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
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16
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Clinical and Functional Characterization of the Recurrent TUBA1A p.(Arg2His) Mutation. Brain Sci 2018; 8:brainsci8080145. [PMID: 30087272 PMCID: PMC6119949 DOI: 10.3390/brainsci8080145] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/06/2018] [Accepted: 07/17/2018] [Indexed: 12/25/2022] Open
Abstract
The TUBA1A gene encodes tubulin alpha-1A, a protein that is highly expressed in the fetal brain. Alpha- and beta-tubulin subunits form dimers, which then co-assemble into microtubule polymers: dynamic, scaffold-like structures that perform key functions during neurogenesis, neuronal migration, and cortical organisation. Mutations in TUBA1A have been reported to cause a range of brain malformations. We describe four unrelated patients with the same de novo missense mutation in TUBA1A, c.5G>A, p.(Arg2His), as found by next generation sequencing. Detailed comparison revealed similar brain phenotypes with mild variability. Shared features included developmental delay, microcephaly, hypoplasia of the cerebellar vermis, dysplasia or thinning of the corpus callosum, small pons, and dysmorphic basal ganglia. Two of the patients had bilateral perisylvian polymicrogyria. We examined the effects of the p.(Arg2His) mutation by computer-based protein structure modelling and heterologous expression in HEK-293 cells. The results suggest the mutation subtly impairs microtubule function, potentially by affecting inter-dimer interaction. Based on its sequence context, c.5G>A is likely to be a common recurrent mutation. We propose that the subtle functional effects of p.(Arg2His) may allow for other factors (such as genetic background or environmental conditions) to influence phenotypic outcome, thus explaining the mild variability in clinical manifestations.
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17
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Curiel J, Rodríguez Bey G, Takanohashi A, Bugiani M, Fu X, Wolf NI, Nmezi B, Schiffmann R, Bugaighis M, Pierson T, Helman G, Simons C, van der Knaap MS, Liu J, Padiath Q, Vanderver A. TUBB4A mutations result in specific neuronal and oligodendrocytic defects that closely match clinically distinct phenotypes. Hum Mol Genet 2018; 26:4506-4518. [PMID: 28973395 DOI: 10.1093/hmg/ddx338] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/24/2017] [Indexed: 12/16/2022] Open
Abstract
Hypomyelinating leukodystrophies are heritable disorders defined by lack of development of brain myelin, but the cellular mechanisms of hypomyelination are often poorly understood. Mutations in TUBB4A, encoding the tubulin isoform tubulin beta class IVA (Tubb4a), result in the symptom complex of hypomyelination with atrophy of basal ganglia and cerebellum (H-ABC). Additionally, TUBB4A mutations are known to result in a broad phenotypic spectrum, ranging from primary dystonia (DYT4), isolated hypomyelination with spastic quadriplegia, and an infantile onset encephalopathy, suggesting multiple cell types may be involved. We present a study of the cellular effects of TUBB4A mutations responsible for H-ABC (p.Asp249Asn), DYT4 (p.Arg2Gly), a severe combined phenotype with hypomyelination and encephalopathy (p.Asn414Lys), as well as milder phenotypes causing isolated hypomyelination (p.Val255Ile and p.Arg282Pro). We used a combination of histopathological, biochemical and cellular approaches to determine how these different mutations may have variable cellular effects in neurons and/or oligodendrocytes. Our results demonstrate that specific mutations lead to either purely neuronal, combined neuronal and oligodendrocytic or purely oligodendrocytic defects that closely match their respective clinical phenotypes. Thus, the DYT4 mutation that leads to phenotypes attributable to neuronal dysfunction results in altered neuronal morphology, but with unchanged tubulin quantity and polymerization, with normal oligodendrocyte morphology and myelin gene expression. Conversely, mutations associated with isolated hypomyelination (p.Val255Ile and p.Arg282Pro) and the severe combined phenotype (p.Asn414Lys) resulted in normal neuronal morphology but were associated with altered oligodendrocyte morphology, myelin gene expression, and microtubule dysfunction. The H-ABC mutation (p.Asp249Asn) that exhibits a combined neuronal and myelin phenotype had overlapping cellular defects involving both neuronal and oligodendrocyte cell types in vitro. Only mutations causing hypomyelination phenotypes showed altered microtubule dynamics and acted through a dominant toxic gain of function mechanism. The DYT4 mutation had no impact on microtubule dynamics suggesting a distinct mechanism of action. In summary, the different clinical phenotypes associated with TUBB4A reflect the selective and specific cellular effects of the causative mutations. Cellular specificity of disease pathogenesis is relevant to developing targeted treatments for this disabling condition.
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Affiliation(s)
- Julian Curiel
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | | | - Asako Takanohashi
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA.,Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | | | - Xiaoqin Fu
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Nicole I Wolf
- VU University Medical Center, Amsterdam, The Netherlands
| | - Bruce Nmezi
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75204, USA
| | - Mona Bugaighis
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Tyler Pierson
- Departments of Pediatrics and Neurology, Cedar Sinai Medical Center, Board of Governors Regenerative Medicine Institute, Los Angeles, CA 90048, USA
| | - Guy Helman
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA.,Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia.,Department of Neurology, Children's National Health System, Washington, DC 20010, USA
| | - Cas Simons
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | | | - Judy Liu
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Quasar Padiath
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Adeline Vanderver
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA.,Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Neurology, Children's National Health System, Washington, DC 20010, USA.,Perlman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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18
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A novel TUBB4A mutation G96R identified in a patient with hypomyelinating leukodystrophy onset beyond adolescence. Hum Genome Var 2017; 4:17035. [PMID: 28791129 PMCID: PMC5540734 DOI: 10.1038/hgv.2017.35] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/26/2017] [Accepted: 06/26/2017] [Indexed: 12/22/2022] Open
Abstract
The tubulin beta-4A gene (TUBB4A) is associated with two different clinical conditions, dystonia type 4 (DYT4) and hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). We identified a novel TUBB4A mutation, c.286G>A (p.G96R), in an adult male patient who suffered neurological symptoms beyond adolescence. This patient shows intermediate clinical features between DYT4 and H-ABC, suggesting that the TUBB4A disorder would constitute a spectrum disorder.
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19
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Synofzik M, Schüle R. Overcoming the divide between ataxias and spastic paraplegias: Shared phenotypes, genes, and pathways. Mov Disord 2017; 32:332-345. [PMID: 28195350 PMCID: PMC6287914 DOI: 10.1002/mds.26944] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/07/2017] [Accepted: 01/15/2017] [Indexed: 12/11/2022] Open
Abstract
Autosomal-dominant spinocerebellar ataxias, autosomal-recessive spinocerebellar ataxias, and hereditary spastic paraplegias have traditionally been designated in separate clinicogenetic disease classifications. This classification system still largely frames clinical thinking and genetic workup in clinical practice. Yet, with the advent of next-generation sequencing, phenotypically unbiased studies have revealed the limitations of this classification system. Various genes (eg, SPG7, SYNE1, PNPLA6) traditionally rooted in either the ataxia or hereditary spastic paraplegia classification system have now been shown to cause ataxia on the one end of the disease continuum and hereditary spastic paraplegia on the other. Other genes such as GBA2 and KIF1C were almost simultaneously published as both a hereditary spastic paraplegia and an ataxia gene. The variability and fluidity of observed phenotypes along the ataxia-spasticity spectrum warrants a rethinking of the traditional classification system. We propose to replace this divisive diagnosis-driven ataxia and hereditary spastic paraplegia classification system by a descriptive, unbiased approach of modular phenotyping. This approach is also open to expansion of the phenotype beyond ataxia and spasticity, which often occur as part of broader multisystem neuronal dysfunction. The concept of a continuous ataxia-spasticity disease spectrum is further supported by ataxias and hereditary spastic paraplegias sharing not only overlapping phenotypes and underlying genes, but also common cellular pathways and disease mechanisms. This suggests a shared vulnerability of cerebellar and corticospinal neurons for common pathophysiological processes. It might be this mechanistic overlap that drives their clinical overlap. A mechanistically inspired classification system will help to pave the way for mechanism-based strategies for drug development. © 2017 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Matthis Synofzik
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Rebecca Schüle
- Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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20
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de Gusmão CM, Fuchs T, Moses A, Multhaupt-Buell T, Song PC, Ozelius LJ, Franco RA, Sharma N. Dystonia-Causing Mutations as a Contribution to the Etiology of Spasmodic Dysphonia. Otolaryngol Head Neck Surg 2016; 155:624-8. [PMID: 27188707 DOI: 10.1177/0194599816648293] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 04/15/2016] [Indexed: 01/26/2023]
Abstract
OBJECTIVE Spasmodic dysphonia is a focal dystonia of the larynx with heterogeneous manifestations and association with familial risk factors. There are scarce data to allow precise understanding of etiology and pathophysiology. Screening for dystonia-causing genetic mutations has the potential to allow accurate diagnosis, inform about genotype-phenotype correlations, and allow a better understanding of mechanisms of disease. STUDY DESIGN Cross-sectional study. SETTING Tertiary academic medical center. SUBJECTS AND METHODS We enrolled patients presenting with spasmodic dysphonia to the voice clinic of our academic medical center. Data included demographics, clinical features, family history, and treatments administered. The following genes with disease-causing mutations previously associated with spasmodic dysphonia were screened: TOR1A (DYT1), TUBB4 (DYT4), and THAP1 (DYT6). RESULTS Eighty-six patients were recruited, comprising 77% females and 23% males. A definite family history of neurologic disorder was present in 15% (13 of 86). Average age (± standard deviation) of symptom onset was 42.1 ± 15.7 years. Most (99%; 85 of 86) were treated with botulinum toxin, and 12% (11 of 86) received oral medications. Genetic screening was negative in all patients for the GAG deletion in TOR1A (DYT1) and in the 5 exons currently associated with disease-causing mutations in TUBB4 (DYT4). Two patients tested positive for novel/rare variants in THAP1 (DYT6). CONCLUSION Genetic screening targeted at currently known disease-causing mutations in TOR1A, THAP1, and TUBB4 appears to have low diagnostic yield in sporadic spasmodic dysphonia. In our cohort, only 2 patients tested positive for novel/rare variants in THAP1. Clinicians should make use of genetic testing judiciously and in cost-effective ways.
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Affiliation(s)
- Claudio M de Gusmão
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Tania Fuchs
- Department of Genetics and Genomics, Icahn School of Medicine at Mt Sinai, New York, New York, USA
| | - Andrew Moses
- Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA
| | | | - Phillip C Song
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Laurie J Ozelius
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Ramon A Franco
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - Nutan Sharma
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
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21
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Chakraborti S, Natarajan K, Curiel J, Janke C, Liu J. The emerging role of the tubulin code: From the tubulin molecule to neuronal function and disease. Cytoskeleton (Hoboken) 2016; 73:521-550. [PMID: 26934450 DOI: 10.1002/cm.21290] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/18/2016] [Accepted: 02/26/2016] [Indexed: 11/11/2022]
Abstract
Across different cell types and tissues, microtubules are assembled from highly conserved dimers of α- and β-tubulin. Despite their highly similar structures, microtubules have functional heterogeneity, generated either by the expression of different tubulin genes, encoding distinct isotypes, or by posttranslational modifications of tubulin. This genetically encoded and posttranslational generated heterogeneity of tubulin-the "tubulin code"-has the potential to modulate microtubule structure, dynamics, and interactions with associated proteins. The tubulin code is therefore believed to regulate microtubule functions on a cellular and sub-cellular level. This review highlights the importance of the tubulin code for tubulin structure, as well as on microtubule dynamics and functions in neurons. It further summarizes recent developments in the understanding of mutations in tubulin genes, and how they are linked to neurodegenerative and neurodevelopmental disorders. The current advances in the knowledge of the tubulin code on the molecular and the functional level will certainly lead to a better understanding of how complex signaling events control microtubule functions, especially in cells of the nervous system. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Soumyananda Chakraborti
- Institut Curie, PSL Research University, CNRS, INSERM, UMR 3348, Orsay, F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS, UMR 3348, Orsay, F-91405, France
| | - Kathiresan Natarajan
- Institut Curie, PSL Research University, CNRS, INSERM, UMR 3348, Orsay, F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS, UMR 3348, Orsay, F-91405, France
| | - Julian Curiel
- Children's National Health System, Center for Neuroscience Research, Washington, District of Columbia
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS, INSERM, UMR 3348, Orsay, F-91405, France. .,Université Paris Sud, Université Paris-Saclay, CNRS, UMR 3348, Orsay, F-91405, France.
| | - Judy Liu
- Children's National Health System, Center for Neuroscience Research, Washington, District of Columbia.
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22
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Brugger F, Balint B, Antelmi E, Bhatia KP. Hypomyelination with Atrophy of the Basal Ganglia and Cerebellum (H-ABC) is a Differential Diagnosis for Pallidopyramidal Syndromes with Thin Corpus Callosum. Mov Disord Clin Pract 2016; 4:150-151. [PMID: 30713963 DOI: 10.1002/mdc3.12367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/16/2016] [Accepted: 03/16/2016] [Indexed: 12/13/2022] Open
Affiliation(s)
- Florian Brugger
- Sobell Department of Motor Neuroscience and Movement Disorders Institute of Neurology University College London London United Kingdom.,Department of Neurology Kantonsspital St. Gallen St. Gallen Switzerland
| | - Bettina Balint
- Sobell Department of Motor Neuroscience and Movement Disorders Institute of Neurology University College London London United Kingdom.,Department of Neurology University Hospital Heidelberg Heidelberg Germany
| | - Elena Antelmi
- Sobell Department of Motor Neuroscience and Movement Disorders Institute of Neurology University College London London United Kingdom.,Department of Biomedical and Neuromotor Sciences Alma Mater Studiorum University of Bologna Bologna Italy
| | - Kailash P Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders Institute of Neurology University College London London United Kingdom
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23
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Tonduti D, Aiello C, Renaldo F, Dorboz I, Saaman S, Rodriguez D, Fettah H, Elmaleh M, Biancheri R, Barresi S, Boccone L, Orcesi S, Pichiecchio A, Zangaglia R, Maurey H, Rossi A, Boespflug-Tanguy O, Bertini E. TUBB4A-related hypomyelinating leukodystrophy: New insights from a series of 12 patients. Eur J Paediatr Neurol 2016; 20:323-330. [PMID: 26643067 DOI: 10.1016/j.ejpn.2015.11.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 10/23/2015] [Accepted: 11/05/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) was first described in 2002. After the recent identification of TUBB4A mutation as the genetic basis of the disease, the clinical and neuroimaging phenotype related to TUBB4A mutations expanded, ranging from primary dystonia type 4 with normal MRI to severe H-ABC cases. PATIENTS AND METHODS The study included patients referred to us for an unclassified hypomyelinating leukodystrophy. We selected patients with deleterious heterozygous TUBB4A mutations. Molecular analysis of TUBB4A was performed on genomic DNA extracted from peripheral blood. RESULTS The series included 12 patients (5 females and 7 males). Five patients carried the common mutation c.745G > A (p.Asp249Asn), while the remaining harbored different mutations. Three new mutations were found in 5 patients. Clinical and neuroimaging observations are described. A clear correlation between the clinical presentation and the genotype seems to be absent in our group of 12 patients. CONCLUSIONS TUBB4A-mutated patients manifest a comparable clinical and neuroimaging picture but they can differ from each other in terms of rate of disease progression. Extrapyramidal signs can be absent in the first stages of the disease, and a careful evaluation of MRI is fundamental to obtain the final diagnosis. From a therapeutic perspective a trial with l-dopa should be considered in all patients presenting extrapyramidal symptoms.
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Affiliation(s)
- Davide Tonduti
- Department of Child Neurology, Neurological Institute C. Besta Foundation IRCCS, Milan, Italy; INSERM UMR1141, Paris Diderot University, Sorbonne Paris Cité, DHU PROTECT, France.
| | - Chiara Aiello
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, Rome, Italy
| | - Florence Renaldo
- INSERM UMR1141, Paris Diderot University, Sorbonne Paris Cité, DHU PROTECT, France; AP-HP, Departement of Neuropediatrics and Metabolic Diseases, National Reference Center for Leukodystrophies, Robert Debré Hospital, Paris, France
| | - Imen Dorboz
- INSERM UMR1141, Paris Diderot University, Sorbonne Paris Cité, DHU PROTECT, France
| | - Simon Saaman
- AP-HP, Department of Human Genetic, Molecular Biology Unit, Robert Debré Hospital, Paris, France
| | - Diana Rodriguez
- INSERM UMR1141, Paris Diderot University, Sorbonne Paris Cité, DHU PROTECT, France; AP-HP, Department of Child Neurology, Hôpital Armand-Trousseau, GHUEP, Paris, France
| | - Houda Fettah
- AP-HP, Departement of Neuropediatrics and Metabolic Diseases, National Reference Center for Leukodystrophies, Robert Debré Hospital, Paris, France; INSERM UMR1141, Paris Diderot University, Sorbonne Paris Cité, DHU PROTECT, France
| | | | - Roberta Biancheri
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, London, UK
| | - Sabina Barresi
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, Rome, Italy
| | - Loredana Boccone
- Genetics and Rare Diseases Unit, II Division of Pediatrics, Ospedale Microcitemico, Cagliari, Italy
| | - Simona Orcesi
- Child Neurology and Psychiatry Unit, C. Mondino National Neurological Institute, Pavia, Italy
| | - Anna Pichiecchio
- Department of Neuroradiology, C. Mondino National Neurological Institute, Pavia, Italy
| | - Roberta Zangaglia
- Movement Disorders Unit, C. Mondino National Neurological Institute, Pavia, Italy
| | - Hélène Maurey
- AP-HP, Neuropediatric Departement, Reference Center for Leukodystrophies Kremlin Bicêtre Hospital, Paris, France
| | - Andrea Rossi
- Department of Child Neurology, Neurological Institute C. Besta Foundation IRCCS, Milan, Italy
| | - Odile Boespflug-Tanguy
- INSERM UMR1141, Paris Diderot University, Sorbonne Paris Cité, DHU PROTECT, France; AP-HP, Departement of Neuropediatrics and Metabolic Diseases, National Reference Center for Leukodystrophies, Robert Debré Hospital, Paris, France
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesu' Children's Research Hospital, Rome, Italy
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24
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Early-onset progressive spastic paraplegia caused by a novel TUBB4A mutation: brain MRI and FDG-PET findings. J Neurol 2016; 263:591-3. [DOI: 10.1007/s00415-016-8020-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 12/30/2015] [Accepted: 12/31/2015] [Indexed: 11/25/2022]
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25
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Yuvaraj P, Jayaram M, Abubacker R, Bindu PS. Auditory neuropathy spectrum disorder in hypomyelinating leukodystrophy--A case study. Int J Pediatr Otorhinolaryngol 2015; 79:2479-83. [PMID: 26611342 DOI: 10.1016/j.ijporl.2015.10.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 10/26/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Affiliation(s)
- Pradeep Yuvaraj
- Department of Speech Pathology and Audiology, National Institute of Mental Health and Neurosciences, Bangalore 560029, Karnataka, India.
| | - M Jayaram
- Department of Speech Pathology and Audiology, National Institute of Mental Health and Neurosciences, Bangalore 560029, Karnataka, India.
| | - Rahina Abubacker
- Department of Speech Pathology and Audiology, National Institute of Mental Health and Neurosciences, Bangalore 560029, Karnataka, India.
| | - P S Bindu
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore 560029, Karnataka, India.
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26
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Arai-Ichinoi N, Uematsu M, Sato R, Suzuki T, Kudo H, Kikuchi A, Hino-Fukuyo N, Matsumoto M, Igarashi K, Haginoya K, Kure S. Genetic heterogeneity in 26 infants with a hypomyelinating leukodystrophy. Hum Genet 2015; 135:89-98. [DOI: 10.1007/s00439-015-1617-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 11/13/2015] [Indexed: 02/06/2023]
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27
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Chamova T, Kancheva D, Guergueltcheva V, Mitev V, Azmanov DN, Kalaydjieva L, Jordanova A, Tournev I. Reply: Mutations in TUBB4A and spastic paraplegia. Mov Disord 2015; 30:1858-9. [PMID: 26477690 DOI: 10.1002/mds.26442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 09/07/2015] [Indexed: 11/06/2022] Open
Affiliation(s)
- Teodora Chamova
- Medical University of Sofia, Faculty of Medicine, Department of Neurology, Clinic of Neurology, University Hospital Alexandrovska, Sofia, Bulgaria
| | - Dahlia Kancheva
- Molecular Neurogenomics Group, Department of Molecular Genetics, Antwerp, Belgium.,Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium.,Department of Medical Chemistry and Biochemistry, Molecular Medicine Center, Medical University-Sofia, Sofia, Bulgaria
| | | | - Vanio Mitev
- Department of Medical Chemistry and Biochemistry, Molecular Medicine Center, Medical University-Sofia, Sofia, Bulgaria
| | - Dimitar N Azmanov
- Department of Diagnostic Genomics, PathWest, QEII Medical Centre, Nedlands, WA, Australia.,Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Luba Kalaydjieva
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Albena Jordanova
- Molecular Neurogenomics Group, Department of Molecular Genetics, Antwerp, Belgium.,Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium.,Department of Medical Chemistry and Biochemistry, Molecular Medicine Center, Medical University-Sofia, Sofia, Bulgaria
| | - Ivailo Tournev
- Medical University of Sofia, Faculty of Medicine, Department of Neurology, Clinic of Neurology, University Hospital Alexandrovska, Sofia, Bulgaria.,Department of Cognitive Science and Psychology, New Bulgarian University, Sofia, Bulgaria
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28
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Dubey J, Ratnakaran N, Koushika SP. Neurodegeneration and microtubule dynamics: death by a thousand cuts. Front Cell Neurosci 2015; 9:343. [PMID: 26441521 PMCID: PMC4563776 DOI: 10.3389/fncel.2015.00343] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 08/18/2015] [Indexed: 12/11/2022] Open
Abstract
Microtubules form important cytoskeletal structures that play a role in establishing and maintaining neuronal polarity, regulating neuronal morphology, transporting cargo, and scaffolding signaling molecules to form signaling hubs. Within a neuronal cell, microtubules are found to have variable lengths and can be both stable and dynamic. Microtubule associated proteins, post-translational modifications of tubulin subunits, microtubule severing enzymes, and signaling molecules are all known to influence both stable and dynamic pools of microtubules. Microtubule dynamics, the process of interconversion between stable and dynamic pools, and the proportions of these two pools have the potential to influence a wide variety of cellular processes. Reduced microtubule stability has been observed in several neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic Lateral Sclerosis (ALS), and tauopathies like Progressive Supranuclear Palsy. Hyperstable microtubules, as seen in Hereditary Spastic Paraplegia (HSP), also lead to neurodegeneration. Therefore, the ratio of stable and dynamic microtubules is likely to be important for neuronal function and perturbation in microtubule dynamics might contribute to disease progression.
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Affiliation(s)
- Jyoti Dubey
- Department of Biological Sciences, Tata Institute of Fundamental Research Mumbai, India ; InStem Bangalore, India
| | - Neena Ratnakaran
- Department of Biological Sciences, Tata Institute of Fundamental Research Mumbai, India
| | - Sandhya P Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research Mumbai, India
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29
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Zech M, Boesch S, Jochim A, Graf S, Lichtner P, Peters A, Gieger C, Mueller J, Poewe W, Haslinger B, Winkelmann J. Large-scale TUBB4A mutational screening in isolated dystonia and controls. Parkinsonism Relat Disord 2015; 21:1278-81. [PMID: 26318963 DOI: 10.1016/j.parkreldis.2015.08.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/05/2015] [Accepted: 08/17/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Mutations in TUBB4A have recently been implicated in two seemingly different disease entities, namely DYT4-isolated dystonia and hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC), a disorder characterized by considerable clinical variability. While several follow-up studies confirmed the importance of TUBB4A mutations in the development of H-ABC, their contribution to isolated dystonia remains uncertain. METHODS We screened the TUBB4A coding regions in a large population of 709 isolated dystonia patients of German/Austrian ancestry as well as in 376 ancestry-matched control subjects by means of Sanger sequencing and high-resolution melting. In addition, we assessed the overall frequency of rare non-synonymous TUBB4A genetic variation in the huge exome dataset released by the Exome Aggregation Consortium (ExAC). RESULTS We were unable to identify any possibly pathogenic sequence alteration in either patients or controls. According to ExAC, the overall prevalence of rare missense and loss-of-function alleles in the TUBB4A gene can be estimated at ∼1:706. CONCLUSIONS In accordance with previous work, our data indicate that TUBB4A coding mutations do not play a critical role in the broad population of isolated dystonia patients. Rather, isolated dystonia as seen in DYT4 might be an exceptional feature occurring in the heterogeneous phenotypic spectrum due to TUBB4A mutations.
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Affiliation(s)
- Michael Zech
- Neurologische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany; Institut für Neurogenomik, Helmholtz Zentrum München, Munich, Germany
| | - Sylvia Boesch
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Angela Jochim
- Neurologische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Sebastian Graf
- Neurologische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Peter Lichtner
- Institut für Humangenetik, Helmholtz Zentrum München, Munich, Germany; Institut für Humangenetik, Technische Universität München, Munich, Germany
| | - Annette Peters
- Institute of Epidemiology II, Helmholtz Zentrum München, Munich, Germany
| | - Christian Gieger
- Institute of Genetic Epidemiology, Helmholtz Zentrum München, Munich, Germany
| | - Joerg Mueller
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria; Vivantes Klinikum Spandau, Berlin, Germany
| | - Werner Poewe
- Department of Neurology, Medical University Innsbruck, Innsbruck, Austria
| | - Bernhard Haslinger
- Neurologische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Juliane Winkelmann
- Neurologische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany; Institut für Neurogenomik, Helmholtz Zentrum München, Munich, Germany; Munich Cluster for Systems Neurology, SyNergy, Munich, Germany.
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30
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31
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Lossos A, Elazar N, Lerer I, Schueler-Furman O, Fellig Y, Glick B, Zimmerman BE, Azulay H, Dotan S, Goldberg S, Gomori JM, Ponger P, Newman JP, Marreed H, Steck AJ, Schaeren-Wiemers N, Mor N, Harel M, Geiger T, Eshed-Eisenbach Y, Meiner V, Peles E. Myelin-associated glycoprotein gene mutation causes Pelizaeus-Merzbacher disease-like disorder. Brain 2015; 138:2521-36. [PMID: 26179919 DOI: 10.1093/brain/awv204] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 05/27/2015] [Indexed: 01/07/2023] Open
Abstract
Pelizaeus-Merzbacher disease is an X-linked hypomyelinating leukodystrophy caused by mutations or rearrangements in PLP1. It presents in infancy with nystagmus, jerky head movements, hypotonia and developmental delay evolving into spastic tetraplegia with optic atrophy and variable movement disorders. A clinically similar phenotype caused by recessive mutations in GJC2 is known as Pelizaeus-Merzbacher-like disease. Both genes encode proteins associated with myelin. We describe three siblings of a consanguineous family manifesting the typical infantile-onset Pelizaeus-Merzbacher disease-like phenotype slowly evolving into a form of complicated hereditary spastic paraplegia with mental retardation, dysarthria, optic atrophy and peripheral neuropathy in adulthood. Magnetic resonance imaging and spectroscopy were consistent with a demyelinating leukodystrophy. Using genetic linkage and exome sequencing, we identified a homozygous missense c.399C>G; p.S133R mutation in MAG. This gene, previously associated with hereditary spastic paraplegia, encodes myelin-associated glycoprotein, which is involved in myelin maintenance and glia-axon interaction. This mutation is predicted to destabilize the protein and affect its tertiary structure. Examination of the sural nerve biopsy sample obtained in childhood in the oldest sibling revealed complete absence of myelin-associated glycoprotein accompanied by ill-formed onion-bulb structures and a relatively thin myelin sheath of the affected axons. Immunofluorescence, cell surface labelling, biochemical analysis and mass spectrometry-based proteomics studies in a variety of cell types demonstrated a devastating effect of the mutation on post-translational processing, steady state expression and subcellular localization of myelin-associated glycoprotein. In contrast to the wild-type protein, the p.S133R mutant was retained in the endoplasmic reticulum and was subjected to endoplasmic reticulum-associated protein degradation by the proteasome. Our findings identify involvement of myelin-associated glycoprotein in this family with a disorder affecting the central and peripheral nervous system, and suggest that loss of the protein function is responsible for the unique clinical phenotype.
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Affiliation(s)
- Alexander Lossos
- 1 Department of Neurology and Agnes Ginges Centre for Human Neurogenetics, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Nimrod Elazar
- 2 Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Israela Lerer
- 3 Department of Genetics and Metabolic Diseases, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Ora Schueler-Furman
- 4 Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Yakov Fellig
- 5 Department of Pathology, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Benjamin Glick
- 6 Paediatric Neuromuscular Service, Alyn Paediatric Rehabilitation Centre, Jerusalem, Israel
| | - Bat-El Zimmerman
- 3 Department of Genetics and Metabolic Diseases, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Haim Azulay
- 5 Department of Pathology, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Shlomo Dotan
- 7 Department of Ophthalmology, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Sharon Goldberg
- 7 Department of Ophthalmology, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - John M Gomori
- 8 Department of Radiology, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Penina Ponger
- 1 Department of Neurology and Agnes Ginges Centre for Human Neurogenetics, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - J P Newman
- 1 Department of Neurology and Agnes Ginges Centre for Human Neurogenetics, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Hodaifah Marreed
- 3 Department of Genetics and Metabolic Diseases, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Andreas J Steck
- 9 Department of Biomedicine, University Hospital Basel, University of Basel, Switzerland
| | | | - Nofar Mor
- 2 Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Michal Harel
- 10 Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tamar Geiger
- 10 Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yael Eshed-Eisenbach
- 2 Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Vardiella Meiner
- 3 Department of Genetics and Metabolic Diseases, Hebrew University-Hadassah Medical Centre, Jerusalem, Israel
| | - Elior Peles
- 2 Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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32
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Salsano E. Leukodystrophy or genetic leukoencephalopathy? Nature does not make leaps. Mol Genet Metab 2015; 114:491-3. [PMID: 25748346 DOI: 10.1016/j.ymgme.2015.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 02/19/2015] [Indexed: 12/28/2022]
Affiliation(s)
- Ettore Salsano
- Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico "Carlo Besta," via Celoria 11, Milano 20133, Italy.
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33
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Kancheva D, Chamova T, Guergueltcheva V, Mitev V, Azmanov DN, Kalaydjieva L, Tournev I, Jordanova A. Mosaic dominant TUBB4A
mutation in an inbred family with complicated hereditary spastic paraplegia. Mov Disord 2015; 30:854-8. [DOI: 10.1002/mds.26196] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/20/2015] [Accepted: 01/26/2015] [Indexed: 11/06/2022] Open
Affiliation(s)
- Dahlia Kancheva
- Molecular Neurogenomics Group; Department of Molecular Genetics; VIB Antwerp Belgium
- Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp; Antwerp Belgium
- Department of Medical Chemistry and Biochemistry; Molecular Medicine Center, Medical University-Sofia; Sofia Bulgaria
| | - Teodora Chamova
- Department of Neurology; Medical University-Sofia; Sofia Bulgaria
| | | | - Vanio Mitev
- Department of Medical Chemistry and Biochemistry; Molecular Medicine Center, Medical University-Sofia; Sofia Bulgaria
| | - Dimitar N. Azmanov
- Department of Diagnostic Genomics; PathWest, QEII Medical Centre; Nedlands WA Australia
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia; Perth Australia
| | - Luba Kalaydjieva
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia; Perth Australia
| | - Ivailo Tournev
- Department of Neurology; Medical University-Sofia; Sofia Bulgaria
- Department of Cognitive Science and Psychology; New Bulgarian University; Sofia Bulgaria
| | - Albena Jordanova
- Molecular Neurogenomics Group; Department of Molecular Genetics; VIB Antwerp Belgium
- Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp; Antwerp Belgium
- Department of Medical Chemistry and Biochemistry; Molecular Medicine Center, Medical University-Sofia; Sofia Bulgaria
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34
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Balint B, Bhatia KP. Isolated and combined dystonia syndromes - an update on new genes and their phenotypes. Eur J Neurol 2015; 22:610-7. [DOI: 10.1111/ene.12650] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 11/12/2014] [Indexed: 11/27/2022]
Affiliation(s)
- B. Balint
- Sobell Department of Motor Neuroscience and Movement Disorders; UCL Institute of Neurology; London UK
- Department of Neurology; University Hospital Heidelberg; Heidelberg Germany
| | - K. P. Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders; UCL Institute of Neurology; London UK
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35
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Erro R, Hersheson J, Houlden H, Bhatia KP. A novel TUBB4A mutation suggests that genotype-phenotype correlation of H-ABC syndrome needs to be revisited. Brain 2015; 138:e370. [PMID: 25614026 DOI: 10.1093/brain/awu403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Roberto Erro
- 1 Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, UK 2 Dipartimento di Scienze Neurologiche e del Movimento, Università di Verona, Verona, Italy
| | - Joshua Hersheson
- 3 Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Henry Houlden
- 3 Department of Molecular Neuroscience, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Kailash P Bhatia
- 1 Sobell Department of Motor Neuroscience and Movement Disorders, University College London (UCL) Institute of Neurology, London, UK
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Isakov O, Lev D, Blumkin L, Celniker G, Leshinsky-Silver E, Shomron N. Crowdfunding effort identifies the causative mutation in a patient with nystagmus, microcephaly, dystonia and hypomyelination. J Genet Genomics 2015; 42:79-81. [PMID: 25697102 DOI: 10.1016/j.jgg.2014.12.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Revised: 12/26/2014] [Accepted: 12/30/2014] [Indexed: 10/24/2022]
Affiliation(s)
- Ofer Isakov
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Dorit Lev
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Metabolic-Neurogenetic Clinic, Wolfson Medical Center, Holon 58100, Israel; Institute of Medical Genetics, Wolfson Medical Center, Holon 58100, Israel
| | - Lubov Blumkin
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Metabolic-Neurogenetic Clinic, Wolfson Medical Center, Holon 58100, Israel; Pediatric Neurology Unit, Wolfson Medical Center, Holon 58100, Israel
| | - Gershon Celniker
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Esther Leshinsky-Silver
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Metabolic-Neurogenetic Clinic, Wolfson Medical Center, Holon 58100, Israel; Molecular Genetic Laboratory, Wolfson Medical Center, Holon 58100, Israel
| | - Noam Shomron
- Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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Erro R, Hersheson J, Ganos C, Mencacci NE, Stamelou M, Batla A, Thust SC, Bras JM, Guerreiro RJ, Hardy J, Quinn NP, Houlden H, Bhatia KP. H-ABC syndrome and DYT4: Variable expressivity or pleiotropy of TUBB4 mutations? Mov Disord 2014; 30:828-33. [DOI: 10.1002/mds.26129] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 10/27/2014] [Accepted: 10/29/2014] [Indexed: 12/21/2022] Open
Affiliation(s)
- Roberto Erro
- Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
- Dipartimento di Scienze Neurologiche e del Movimento; Università di Verona; Verona Italy
| | - Joshua Hersheson
- Department of Molecular Neuroscience; UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery; London United Kingdom
| | - Christos Ganos
- Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
- University Medical Center Hamburg-Eppendorf (UKE); Neurology Hamburg Germany
| | - Niccoló E. Mencacci
- Department of Molecular Neuroscience; UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery; London United Kingdom
| | - Maria Stamelou
- Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
- Second Department of Neurology; Kapodistrian University of Athens; Greece
- Neurology Clinic; Philipps University; Marburg Germany
| | - Amit Batla
- Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
| | - Stefanie Catherine Thust
- The Lysholm Department of Neuroradiology; National Hospital for Neurology and Neurosurgery; London United Kingdom
| | - Jose M. Bras
- Department of Molecular Neuroscience; UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery; London United Kingdom
| | - Rita J. Guerreiro
- Department of Molecular Neuroscience; UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery; London United Kingdom
| | - John Hardy
- Department of Molecular Neuroscience; UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery; London United Kingdom
| | - Niall P. Quinn
- Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
| | - Henry Houlden
- Department of Molecular Neuroscience; UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery; London United Kingdom
| | - Kailash P. Bhatia
- Sobell Department of Motor Neuroscience and Movement Disorders; University College London (UCL) Institute of Neurology; London United Kingdom
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Hamilton EM, Wolf NI, van der Knaap MS. Reply: TUBB4A novel mutation reinforces the genotype-phenotype correlation of hypomyelination with atrophy of the basal ganglia and cerebellum. ACTA ACUST UNITED AC 2014; 138:e328. [PMID: 25168211 DOI: 10.1093/brain/awu243] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Eline M Hamilton
- 1 Department of Child Neurology and Neuroscience Campus Amsterdam, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Nicole I Wolf
- 1 Department of Child Neurology and Neuroscience Campus Amsterdam, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Marjo S van der Knaap
- 1 Department of Child Neurology and Neuroscience Campus Amsterdam, VU University Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands 2 Department of Functional Genomics, VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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39
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Carvalho D, Santos S, Martins B, Pinto Marques F. TUBB4A novel mutation reinforces the genotype–phenotype correlation of hypomyelination with atrophy of the basal ganglia and cerebellum. Brain 2014; 138:e327. [DOI: 10.1093/brain/awu242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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