1
|
Bettinger CM, Dulz S, Atiskova Y, Guerreiro H, Schön G, Guder P, Maier SL, Denecke J, Bley AE. Overview of Neuro-Ophthalmic Findings in Leukodystrophies. J Clin Med 2024; 13:5114. [PMID: 39274327 PMCID: PMC11396446 DOI: 10.3390/jcm13175114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 08/10/2024] [Accepted: 08/13/2024] [Indexed: 09/16/2024] Open
Abstract
Background: Leukodystrophies are a group of rare genetic diseases that primarily affect the white matter of the central nervous system. The broad spectrum of metabolic and pathological causes leads to manifestations at any age, most often in childhood and adolescence, and a variety of symptoms. Leukodystrophies are usually progressive, resulting in severe disabilities and premature death. Progressive visual impairment is a common symptom. Currently, no overview of the manifold neuro-ophthalmologic manifestations and visual impact of leukodystrophies exists. Methods: Data from 217 patients in the Hamburg leukodystrophy cohort were analyzed retrospectively for neuro-ophthalmologic manifestations, age of disease onset, and magnetic resonance imaging, visual evoked potential, and optical coherence tomography findings and were compared with data from the literature. Results: In total, 68% of the patients suffered from neuro-ophthalmologic symptoms, such as optic atrophy, visual neglect, strabismus, and nystagmus. Depending on the type of leukodystrophy, neuro-ophthalmologic symptoms occurred early or late during the course of the disease. Magnetic resonance imaging scans revealed pathologic alterations in the visual tract that were temporally correlated with symptoms. Conclusions: The first optical coherence tomography findings in Krabbe disease and metachromatic leukodystrophy allow retinal assessments. Comprehensive literature research supports the results of this first overview of neuro-ophthalmologic findings in leukodystrophies.
Collapse
Affiliation(s)
| | - Simon Dulz
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Yevgeniya Atiskova
- Department of Ophthalmology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Helena Guerreiro
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Gerhard Schön
- Center of Experimental Medicine, Institute for Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Philipp Guder
- Children's Hospital, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Sarah Lena Maier
- Children's Hospital, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Jonas Denecke
- Children's Hospital, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Annette E Bley
- Children's Hospital, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| |
Collapse
|
2
|
Raslan IR, Silva TYT, Kok F, Rodrigues MM, Aragão MM, Pinho RS, França MC, Barsottini OG, Pedroso JL. Clinical and Genetic Characterization of a Cohort of Brazilian Patients With Congenital Ataxia. Neurol Genet 2024; 10:e200153. [PMID: 38681507 PMCID: PMC11052569 DOI: 10.1212/nxg.0000000000200153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 02/29/2024] [Indexed: 05/01/2024]
Abstract
Background and Objectives Congenital ataxias are rare hereditary disorders characterized by hypotonia and developmental motor delay in the first few months of life, followed by cerebellar ataxia in early childhood. The course of the disease is predominantly nonprogressive, and many patients are incorrectly diagnosed with cerebral palsy. Despite significant advancements in next-generation sequencing in the past few decades, a specific genetic diagnosis is seldom obtained in cases of congenital ataxia. The aim of the study was to analyze the clinical, radiologic, and genetic features of a cohort of Brazilian patients with congenital ataxia. Methods Thirty patients with a clinical diagnosis of congenital ataxia were enrolled in this study. Clinical and demographic features and neuroimaging studies were analyzed. Genetic testing (whole-exome sequencing) was also performed. Results A heterogeneous pattern of genetic variants was detected. Eighteen genes were involved: ALDH5A1, BRF1, CACNA1A CACNA1G, CC2D2A, CWF19L1, EXOSC3, ITPR1, KIF1A, MME, PEX10, SCN2A, SNX14, SPTBN2, STXBP1, TMEM240, THG1L, and TUBB4A. Pathogenic/likely pathogenic variants involving 11 genes (ALDH5A1, CACNA1A, EXOSC3, MME, ITPR1, KIF1A, STXBP1, SNX14, SPTBN2, TMEM240, and TUBB4A) were identified in 46.7% of patients. Variants of uncertain significance involving 8 genes were detected in 33.3% of patients. Congenital ataxias were characterized by a broad phenotype. A genetic diagnosis was more often obtained in patients with cerebellar-plus syndrome than in patients with a pure cerebellar syndrome. Discussion This study re-emphasizes the genetic heterogeneity of congenital ataxias and the absence of a clear phenotype-genotype relationship. A specific genetic diagnosis was established in 46.7% of patients. Autosomal dominant, associated with sporadic cases, was recognized as an important genetic inheritance. The results of this analysis highlight the value of whole-exome sequencing as an efficient screening tool in patients with congenital ataxia.
Collapse
Affiliation(s)
- Ivana R Raslan
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Thiago Yoshinaga Tonholo Silva
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Fernando Kok
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Marcelo M Rodrigues
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Marcelo M Aragão
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Ricardo S Pinho
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Marcondes C França
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - Orlando G Barsottini
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| | - José Luiz Pedroso
- From the Department of Ataxia Unit of the Federal University of São Paulo (UNIFESP) (I.R.R., T.Y.T.S., O.G.B., J.L.P.); Neurology Department (F.K.), Hospital das Clínicas da Universidade de São Paulo and Mendelics; Department of Neurology and Neurosurgery (M.M.R., M.M.A., R.S.P.), Universidade Federal de São Paulo (UNIFESP); and Department of Neurology (M.C.F.), Universidade de Campinas (UNICAMP), Brazil
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Abstract
Leukodystrophies are a group of genetically determined disorders that affect development or maintenance of central nervous system myelin. Leukodystrophies have an incidence of at least 1 in 4700 live births and significant morbidity and elevated risk of early death. This report includes a discussion of the types of leukodystrophies; their prevalence, clinical presentation, symptoms, and diagnosis; and current and future treatments. Leukodystrophies can present at any age from infancy to adulthood, with variability in disease progression and clinical presentation, ranging from developmental delay to seizures to spasticity. Diagnosis is based on a combination of history, examination, and radiologic and laboratory findings, including genetic testing. Although there are few cures, there are significant opportunities for care and improvements in patient well-being. Rapid advances in imaging and diagnosis, the emergence of and requirement for timely treatments, and the addition of leukodystrophy screening to newborn screening, make an understanding of the leukodystrophies necessary for pediatricians and other care providers for children.
Collapse
Affiliation(s)
- Joshua L Bonkowsky
- Division of Pediatric Neurology, Department of Pediatrics, School of Medicine, University of Utah and Brain and Spine Center, Primary Children's Hospital, Salt Lake City, Utah
| | | | | |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
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.
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Smith HS, Swint JM, Lalani SR, Yamal JM, de Oliveira Otto MC, Castellanos S, Taylor A, Lee BH, Russell HV. Clinical Application of Genome and Exome Sequencing as a Diagnostic Tool for Pediatric Patients: a Scoping Review of the Literature. Genet Med 2018; 21:3-16. [PMID: 29760485 DOI: 10.1038/s41436-018-0024-6] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/20/2018] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Availability of clinical genomic sequencing (CGS) has generated questions about the value of genome and exome sequencing as a diagnostic tool. Analysis of reported CGS application can inform uptake and direct further research. This scoping literature review aims to synthesize evidence on the clinical and economic impact of CGS. METHODS PubMed, Embase, and Cochrane were searched for peer-reviewed articles published between 2009 and 2017 on diagnostic CGS for infant and pediatric patients. Articles were classified according to sample size and whether economic evaluation was a primary research objective. Data on patient characteristics, clinical setting, and outcomes were extracted and narratively synthesized. RESULTS Of 171 included articles, 131 were case reports, 40 were aggregate analyses, and 4 had a primary economic evaluation aim. Diagnostic yield was the only consistently reported outcome. Median diagnostic yield in aggregate analyses was 33.2% but varied by broad clinical categories and test type. CONCLUSION Reported CGS use has rapidly increased and spans diverse clinical settings and patient phenotypes. Economic evaluations support the cost-saving potential of diagnostic CGS. Multidisciplinary implementation research, including more robust outcome measurement and economic evaluation, is needed to demonstrate clinical utility and cost-effectiveness of CGS.
Collapse
Affiliation(s)
- Hadley Stevens Smith
- Baylor College of Medicine, The University of Texas School of Public Health, Houston, Texas, USA
| | - J Michael Swint
- The University of Texas School of Public Health, The Center for Clinical Research and Evidence-Based Medicine, The University of Texas McGovern Medical School, Houston, Texas, USA
| | - Seema R Lalani
- Baylor College of Medicine, Baylor Genetics Laboratory, Houston, Texas, USA
| | - Jose-Miguel Yamal
- The University of Texas School of Public Health, Houston, Texas, USA
| | | | | | - Amy Taylor
- Texas Medical Center Library, Houston, Texas, USA
| | | | - Heidi V Russell
- Texas Children's Hospital, Baylor College of Medicine, Houston, Texas, USA
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Abstract
During the process of neurogenesis, the stem cell committed to the neuronal cell fate starts a series of molecular and morphological changes. The understanding of the physio-pathology of mechanisms controlling the molecular and morphological changes occurring during neuronal differentiation is fundamental to the development of effective therapies for many neurologic diseases. Unfortunately, our knowledge of the biological events occurring in the cell during neuronal differentiation is still poor. In this study, we focus preliminarily on the relevance of the cytoskeletal rearrangements, which earlier drive the morphology of the neuronal precursors, and later the migrating/mature neurons. In fact, neuritogenesis, neurite branching, outgrowth and retraction are seminal to the development of a fully functional nervous system. With this in mind, we highlight the importance of iPSC technology to study the processes of cytoskeletal-driven morphological changes during neuronal differentiation.
Collapse
|
15
|
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.
Collapse
|
16
|
Duncan ID, Bugiani M, Radcliff AB, Moran JJ, Lopez-Anido C, Duong P, August BK, Wolf NI, van der Knaap MS, Svaren J. A mutation in the Tubb4a gene leads to microtubule accumulation with hypomyelination and demyelination. Ann Neurol 2017; 81:690-702. [PMID: 28393430 DOI: 10.1002/ana.24930] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 04/03/2017] [Accepted: 04/03/2017] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Our goal was to define the genetic cause of the profound hypomyelination in the taiep rat model and determine its relevance to human white matter disease. METHODS Based on previous localization of the taiep mutation to rat chromosome 9, we tested whether the mutation resided within the Tubb4a (β-tubulin 4A) gene, because mutations in the TUBB4A gene have been described in patients with central nervous system hypomyelination. To determine whether accumulation of microtubules led to progressive demyelination, we analyzed the spinal cord and optic nerves of 2-year-old rats by light and electron microscopy. Cerebral white matter from a patient with TUBB4A Asn414Lys mutation and magnetic resonance imaging evidence of severe hypomyelination were studied similarly. RESULTS As the taiep rat ages, there is progressive loss of myelin in the brain and dorsal column of the spinal cord associated with increased oligodendrocyte numbers with accumulation of microtubules. This accumulation involved the entire cell body and distal processes of oligodendrocytes, but there was no accumulation of microtubules in axons. A single point mutation in Tubb4a (p.Ala302Thr) was found in homozygous taiep samples. A similar hypomyelination associated with increased oligodendrocyte numbers and arrays of microtubules in oligodendrocytes was demonstrated in the human patient sample. INTERPRETATION The taiep rat is the first animal model of TUBB4 mutations in humans and a novel system in which to test the mechanism of microtubule accumulation. The finding of microtubule accumulation in a patient with a TUBB4A mutation and leukodystrophy confirms the usefulness of taiep as a model of the human disease. Ann Neurol 2017;81:690-702.
Collapse
Affiliation(s)
- Ian D Duncan
- Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI
| | - Marianna Bugiani
- Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands.,Center for Childhood White Matter Disorders, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, the Netherlands
| | - Abigail B Radcliff
- Department of Medical Sciences, University of Wisconsin-Madison, Madison, WI
| | - John J Moran
- Waisman Center, University of Wisconsin-Madison, Madison, WI
| | | | - Phu Duong
- Waisman Center, University of Wisconsin-Madison, Madison, WI
| | - Benjamin K August
- Electron Microscope Facility, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI
| | - Nicole I Wolf
- Center for Childhood White Matter Disorders, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, the Netherlands.,Department of Child Neurology, VU University Medical Center, Amsterdam, the Netherlands
| | - Marjo S van der Knaap
- Center for Childhood White Matter Disorders, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, the Netherlands.,Department of Child Neurology, VU University Medical Center, Amsterdam, the Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, the Netherlands
| | - John Svaren
- Waisman Center, University of Wisconsin-Madison, Madison, WI.,Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI
| |
Collapse
|
17
|
Compagnucci C, Piermarini E, Sferra A, Borghi R, Niceforo A, Petrini S, Piemonte F, Bertini E. Cytoskeletal dynamics during in vitro neurogenesis of induced pluripotent stem cells (iPSCs). Mol Cell Neurosci 2016; 77:113-124. [PMID: 27756615 DOI: 10.1016/j.mcn.2016.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 08/24/2016] [Accepted: 10/13/2016] [Indexed: 12/27/2022] Open
Abstract
Patient-derived induced pluripotent stem cells (iPSCs) provide a novel tool to investigate the pathophysiology of poorly known diseases, in particular those affecting the nervous system, which has been difficult to study for its lack of accessibility. In this emerging and promising field, recent iPSCs studies are mostly used as "proof-of-principle" experiments that are confirmatory of previous findings obtained from animal models and postmortem human studies; its promise as a discovery tool is just beginning to be realized. A recent number of studies point to the functional similarities between in vitro neurogenesis and in vivo neuronal development, suggesting that similar morphogenetic and patterning events direct neuronal differentiation. In this context, neuronal adhesion, cytoskeletal organization and cell metabolism emerge as an integrated and unexplored processes of human neurogenesis, mediated by the lack of data due to the difficult accessibility of the human neural tissue. These observations raise the necessity to understand which are the players controlling cytoskeletal reorganization and remodeling. In particular, we investigated human in vitro neurogenesis using iPSCs of healthy subjects to unveil the underpinnings of the cytoskeletal dynamics with the aim to shed light on the physiologic events controlling the development and the functionality of neuronal cells. We validate the iPSCs system to better understand the development of the human nervous system in order to set the bases for the future understanding of pathologies including developmental disorders (i.e. intellectual disability), epilepsy but also neurodegenerative disorders (i.e. Friedreich's Ataxia). We investigate the changes of the cytoskeletal components during the 30days of neuronal differentiation and we demonstrate that human neuronal differentiation requires a (time-dependent) reorganization of actin filaments, intermediate filaments and microtubules; and that immature neurons present a finely regulated localization of Glu-, Tyr- and Acet-TUBULINS. This study advances our understanding on cytoskeletal dynamics with the hope to pave the way for future therapies that could be potentially able to target cytoskeletal based neurodevelopmental and neurodegenerative diseases.
Collapse
Affiliation(s)
- Claudia Compagnucci
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Children's Research Hospital Bambino Gesù, IRCCS, Rome 00146, Italy.
| | - Emanuela Piermarini
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Children's Research Hospital Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Antonella Sferra
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Children's Research Hospital Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Rossella Borghi
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Children's Research Hospital Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Alessia Niceforo
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Children's Research Hospital Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Stefania Petrini
- Confocal Microscopy Core Facility, Research Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome 00146, Italy
| | - Fiorella Piemonte
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Children's Research Hospital Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Enrico Bertini
- Department of Neuroscience, Unit of Neuromuscular and Neurodegenerative Diseases, Children's Research Hospital Bambino Gesù, IRCCS, Rome 00146, Italy
| |
Collapse
|
18
|
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
| |
Collapse
|
19
|
Romaniello R, Arrigoni F, Bassi MT, Borgatti R. Mutations in α- and β-tubulin encoding genes: implications in brain malformations. Brain Dev 2015; 37:273-80. [PMID: 25008804 DOI: 10.1016/j.braindev.2014.06.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/26/2014] [Accepted: 06/02/2014] [Indexed: 12/24/2022]
Abstract
The tubulin gene family is mainly expressed in post-mitotic neurons during cortical development with a specific spatial and temporal expression pattern. Members of this family encode dimeric proteins consisting of two closely related subunits (α and β), representing the major constituents of microtubules. Tubulin genes play a crucial role in the mechanisms of the Central Nervous System development such as neuronal migration and axonal guidance (axon outgrowth and maintenance). Different mutations in α/β-tubulin genes (TUBA1A, TUBA8, TUBB2A, TUBB4A, TUBB2B, TUBB3, and TUBB) might alter the dynamic properties and functions of microtubules in several ways, effecting a reduction in the number of functional tubulin heterodimers and causing alterations in GTP binding and disruptions of the binding of other proteins to microtubules (motor proteins and other microtubule interacting proteins). In recent years an increasing number of brain malformations has been associated with mutations in tubulin genes: malformations of cortical development such as lissencephaly and various grades of gyral disorganization, focal or diffuse polymicrogyria and open or closed-lips schizencephaly as likely consequences of an altered neuronal migration process; abnormalities or agenesis of the midline commissural structures (anterior commissure, corpus callosum and fornix), hypoplasia of the oculomotor and optic nerves, dysmorphisms of the hind-brain as expression of axon guidance disorders. Dysmorphisms of the basal ganglia (fusion between the caudate nucleus and putamen with absence of the anterior limb of the internal capsule) and hippocampi were also observed. A rare form of leukoencephalopathy characterized by hypomyelination with atrophy of the basal ganglia an cerebellum (H-ABC) was also recently described. The present review, describing the structural and functional features of tubulin genes, aims to revise the main cerebral associated malformations and related clinical aspects, suggesting a genotype-phenotype correlation.
Collapse
Affiliation(s)
- Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Filippo Arrigoni
- Neuroimaging Unit, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Maria Teresa Bassi
- Laboratory of Molecular Biology, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Renato Borgatti
- Neuropsychiatry and Neurorehabilitation Unit, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy.
| |
Collapse
|
20
|
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
| |
Collapse
|
21
|
Torii T, Miyamoto Y, Yamauchi J, Tanoue A. Pelizaeus-Merzbacher disease: cellular pathogenesis and pharmacologic therapy. Pediatr Int 2014; 56:659-66. [PMID: 25040584 DOI: 10.1111/ped.12450] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/30/2014] [Accepted: 07/07/2014] [Indexed: 01/18/2023]
Abstract
Pelizaeus-Merzbacher disease (PMD) is a rare leukodystrophy that causes severe dysmyelination in the central nervous system in infancy and early childhood. Many previous studies showed that various proteolipid protein 1 (plp1) mutations, including duplications, point mutations, and deletions, lead to oligodendrocyte dysfunction in patients with PMD. PMD onset and clinical severity range widely, depending on the type of plp1 mutation. Patients with PMD exhibit a delayed mental and physical development phenotype, but specific pharmacological therapy and clinical treatment for PMD are not yet well established. This review describes PMD pathology and establishment of new clinical treatment for PMD. These findings support the development of a new therapy for PMD and these treatments may improve the quality of life in patients with PMD.
Collapse
Affiliation(s)
- Tomohiro Torii
- Department of Pharmacology, National Research Institute for Child Health and Development, Tokyo, Japan
| | | | | | | |
Collapse
|
22
|
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
| |
Collapse
|
23
|
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
|