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Capacci E, Bagnoli S, Giacomucci G, Rapillo CM, Govoni A, Bessi V, Polito C, Giotti I, Brogi A, Pelo E, Sorbi S, Nacmias B, Ferrari C. The Frequency of Intermediate Alleles in Patients with Cerebellar Phenotypes. CEREBELLUM (LONDON, ENGLAND) 2024; 23:1135-1145. [PMID: 37906407 PMCID: PMC11102406 DOI: 10.1007/s12311-023-01620-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/13/2023] [Indexed: 11/02/2023]
Abstract
Cerebellar syndromes are clinically and etiologically heterogeneous and can be classified as hereditary, neurodegenerative non-hereditary, or acquired. Few data are available on the frequency of each form in the clinical setting. Growing interest is emerging regarding the genetic forms caused by triplet repeat expansions. Alleles with repeat expansion lower than the pathological threshold, termed intermediate alleles (IAs), have been found to be associated with disease manifestation. In order to assess the relevance of IAs as a cause of cerebellar syndromes, we enrolled 66 unrelated Italian ataxic patients and described the distribution of the different etiology of their syndromes and the frequency of IAs. Each patient underwent complete clinical, hematological, and neurophysiological assessments, neuroimaging evaluations, and genetic tests for autosomal dominant cerebellar ataxia (SCA) and fragile X-associated tremor/ataxia syndrome (FXTAS). We identified the following diagnostic categories: 28% sporadic adult-onset ataxia, 18% cerebellar variant of multiple system atrophy, 9% acquired forms, 9% genetic forms with full-range expansion, and 12% cases with intermediate-range expansion. The IAs were six in the FMR1 gene, two in the gene responsible for SCA8, and one in the ATXN2 gene. The clinical phenotype of patients carrying the IAs resembles, in most of the cases, the one associated with full-range expansion. Our study provides an exhaustive description of the causes of cerebellar ataxia, estimating for the first time the frequency of IAs in SCAs- and FXTAS-associated genes. The high percentage of cases with IAs supports further screening among patients with cerebellar syndromes.
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Affiliation(s)
- Elena Capacci
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Silvia Bagnoli
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Giulia Giacomucci
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Costanza Maria Rapillo
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Alessandra Govoni
- Neuromuscular-Skeletal and Sensory Organs Department, AOU Careggi, Florence, Italy
| | - Valentina Bessi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | | | - Irene Giotti
- SODc Diagnostica Genetica, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
| | - Alice Brogi
- SODc Diagnostica Genetica, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
| | - Elisabetta Pelo
- SODc Diagnostica Genetica, Azienda Ospedaliero Universitaria Careggi, Florence, Italy
| | - Sandro Sorbi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
- IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | - Benedetta Nacmias
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
- IRCCS Fondazione Don Carlo Gnocchi, Florence, Italy
| | - Camilla Ferrari
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy.
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Zheng Z, Zhu Z, Pu J, Zhou C, Cao L, Lv D, Lu J, Zhao G, Chen Y, Tian J, Yin X, Zhang B, Yan Y, Zhao G. Early-onset familial essential tremor is associated with nucleotide expansions of spinocerebellar ataxia in China. Mol Biol Rep 2024; 51:113. [PMID: 38227102 DOI: 10.1007/s11033-023-09023-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 10/23/2023] [Indexed: 01/17/2024]
Abstract
BACKGROUND Essential tremor (ET) is a neurological disease characterized by action tremor in upper arms. Although its high heritability and prevalence worldwide, its etiology and association with other diseases are still unknown. METHOD We investigated 10 common spinocerebellar ataxias (SCAs), including SCA1, SCA2, SCA3, SCA6, SCA7, SCA8, SCA12, SCA17, SCA36, dentatorubral-pallidoluysian atrophy (DRPLA) in 92 early-onset familial ET pedigrees in China collected from 2016 to 2022. RESULT We found one SCA12 proband carried 51 CAG repeats within PPP2R2B gene and one SCA3 proband with intermediate CAG repeats (55) with ATXN3 gene. The other 90 ET probands all had normal repeat expansions. CONCLUSION Tremor can be the initial phenotype of certain SCA. For early-onset, familial ET patients, careful physical examinations are needed before genetic SCA screening.
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Affiliation(s)
- Zhilin Zheng
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Zeyu Zhu
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Jiali Pu
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chen Zhou
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Lanxiao Cao
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Dayao Lv
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Jinyu Lu
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Gaohua Zhao
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Yanxing Chen
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jun Tian
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xinzhen Yin
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Baorong Zhang
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Yaping Yan
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Guohua Zhao
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China.
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
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Tseng FS, Foo JQX, Mai AS, Tan EK. The genetic basis of multiple system atrophy. J Transl Med 2023; 21:104. [PMID: 36765380 PMCID: PMC9912584 DOI: 10.1186/s12967-023-03905-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/19/2023] [Indexed: 02/12/2023] Open
Abstract
Multiple system atrophy (MSA) is a heterogenous, uniformly fatal neurodegenerative ɑ-synucleinopathy. Patients present with varying degrees of dysautonomia, parkinsonism, cerebellar dysfunction, and corticospinal degeneration. The underlying pathophysiology is postulated to arise from aberrant ɑ-synuclein deposition, mitochondrial dysfunction, oxidative stress and neuroinflammation. Although MSA is regarded as a primarily sporadic disease, there is a possible genetic component that is poorly understood. This review summarizes current literature on genetic risk factors and potential pathogenic genes and loci linked to both sporadic and familial MSA, and underlines the biological mechanisms that support the role of genetics in MSA. We discuss a broad range of genes that have been associated with MSA including genes related to Parkinson's disease (PD), oxidative stress, inflammation, and tandem gene repeat expansions, among several others. Furthermore, we highlight various genetic polymorphisms that modulate MSA risk, including complex gene-gene and gene-environment interactions, which influence the disease phenotype and have clinical significance in both presentation and prognosis. Deciphering the exact mechanism of how MSA can result from genetic aberrations in both experimental and clinical models will facilitate the identification of novel pathophysiologic clues, and pave the way for translational research into the development of disease-modifying therapeutic targets.
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Affiliation(s)
- Fan Shuen Tseng
- grid.163555.10000 0000 9486 5048Division of Medicine, Singapore General Hospital, Singapore, Singapore
| | - Joel Qi Xuan Foo
- grid.276809.20000 0004 0636 696XDepartment of Neurosurgery, National Neuroscience Institute, Singapore, Singapore
| | - Aaron Shengting Mai
- grid.4280.e0000 0001 2180 6431Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Eng-King Tan
- Department of Neurology, National Neuroscience Institute, Singapore, 169856, Singapore. .,Duke-NUS Medical School, Singapore, Singapore.
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Mohamed Ibrahim N. An atypical course of a 71-year old man with right arm weakness and ataxia: Expert commentary. Parkinsonism Relat Disord 2022; 105:157-158. [PMID: 36274018 DOI: 10.1016/j.parkreldis.2022.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Norlinah Mohamed Ibrahim
- Department of Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Center, 56000, Bandar Tun Razak, Kuala Lumpur, Malaysia.
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Wernick AI, Walton RL, Soto-Beasley AI, Koga S, Heckman MG, Valentino RR, Milanowski LM, Hoffman-Zacharska D, Koziorowski D, Hassan A, Uitti RJ, Cheshire WP, Singer W, Wszolek ZK, Dickson DW, Low PA, Ross OA. Frequency of spinocerebellar ataxia mutations in patients with multiple system atrophy. Clin Auton Res 2021; 31:117-125. [PMID: 33502644 DOI: 10.1007/s10286-020-00759-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/18/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE Investigate single nucleotide variants and short tandem repeats in 39 genes related to spinocerebellar ataxia in clinical and pathologically defined cohorts of multiple system atrophy. METHODS Exome sequencing was conducted in 28 clinical multiple system atrophy patients to identify single nucleotide variants in spinocerebellar ataxia-related genes. Novel variants were validated in two independent disease cohorts: 86 clinically diagnosed multiple system atrophy patients and 166 pathological multiple system atrophy cases. Expanded repeat alleles in spinocerebellar ataxia genes were evaluated in 36 clinically diagnosed multiple system atrophy patients, and CAG/CAA repeats in TATA-Box Binding Protein (TBP, causative of SCA17) were screened in 216 clinical and pathological multiple system atrophy patients and 346 controls. RESULTS No known pathogenic spinocerebellar ataxia single nucleotide variants or pathogenic range expanded repeat alleles of ATXN1, ATXN2, ATXN3, CACNA1A, AXTN7, ATXN8OS, ATXN10, PPP2R2B, and TBP were detected in any clinical multiple system atrophy patients. However, four novel variants were identified in four spinocerebellar ataxia-related genes across three multiple system atrophy patients. Additionally, four multiple system atrophy patients (1.6%) and one control (0.3%) carried an intermediate length 41 TBP CAG/CAA repeat allele (OR = 4.11, P = 0.21). There was a significant association between the occurrence of a repeat length of longer alleles (> 38 repeats) and an increased risk of multiple system atrophy (OR = 1.64, P = 0.03). CONCLUSION Occurrence of TBP CAG/CAA repeat length of longer alleles (> 38 repeats) is significantly associated with increased multiple system atrophy risk. This discovery warrants further investigation and supports a possible genetic overlap of multiple system atrophy with SCA17.
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Affiliation(s)
- Anna I Wernick
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- School of Biological Sciences, University of Manchester, Manchester, UK
- Queen Square Institute of Neurology, University College London, London, UK
| | - Ronald L Walton
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Alexandra I Soto-Beasley
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Shunsuke Koga
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Michael G Heckman
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Jacksonville, FL, USA
| | - Rebecca R Valentino
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Lukasz M Milanowski
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
- Department of Neurology, Faculty of Health Science, Medical University of Warsaw, Warsaw, Poland
| | | | - Dariusz Koziorowski
- Department of Neurology, Faculty of Health Science, Medical University of Warsaw, Warsaw, Poland
| | - Anhar Hassan
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Ryan J Uitti
- Department of Neurology, Mayo Clinic, Jacksonville, FL, USA
| | | | | | | | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA
| | - Phillip A Low
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Owen A Ross
- Department of Neuroscience, Mayo Clinic Jacksonville, 4500 San Pablo Road, Jacksonville, FL, 32224, USA.
- Mayo Graduate School, Neuroscience Track, Mayo Clinic, Jacksonville, FL, USA.
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, USA.
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Magri S, Nanetti L, Mongelli A, Rizzo E, Taroni F, Mariotti C, Gellera C. Missing the pathological expansion in Huntington disease: de novo c.51C>G variant on the expanded allele causing intrafamilial allele dropout. Am J Med Genet A 2020; 185:397-400. [PMID: 33247537 DOI: 10.1002/ajmg.a.61973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/08/2020] [Accepted: 10/25/2020] [Indexed: 11/08/2022]
Abstract
Huntington disease (HD) is an autosomal dominant disease characterized by motor, behavioral, and cognitive symptoms, caused by the pathological expansion of more than 35 CAG/CAA repeats in the HTT gene. We describe the phenotype of a patient compatible with HD. Several family members were reported as affected, and a paternal cousin and his daughter carried 39 and 42 CAG/CAA. HD genetic testing in proband showed homozygosity for a 14 CAG/CAA allele. Considering the phenotype and family history, HTT gene sequence was performed, revealing heterozygosity for the c.51C>G variant that changes the last nucleotide before the CAG tract, causing misannealing of forward primer (HD344) and dropout of the expanded allele. Polymerase chain reaction (PCR) analysis performed with an alternative forward primer demonstrated a 41 CAG/CAA allele. The c.51C>G variant was not detected in the affected cousin, thus suggesting a de novo occurrence. The lack of biological samples from the proband father and grandmother prevented further investigations to establish in which family member the variant occurred. These data indicate that patients presenting HD phenotype, and homozygous for a normal HTT CAG/CAA allele should be thoroughly evaluated for the presence of a genetic variant, even de novo, within the repeat region that may hamper genetic diagnosis.
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Affiliation(s)
- Stefania Magri
- Unit of Medical Genetics and Neurogenetics, Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Lorenzo Nanetti
- Unit of Medical Genetics and Neurogenetics, Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alessia Mongelli
- Unit of Medical Genetics and Neurogenetics, Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elena Rizzo
- Unit of Medical Genetics and Neurogenetics, Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Franco Taroni
- Unit of Medical Genetics and Neurogenetics, Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Caterina Mariotti
- Unit of Medical Genetics and Neurogenetics, Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Cinzia Gellera
- Unit of Medical Genetics and Neurogenetics, Department of Diagnostics and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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7
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Frequency and distribution of polyQ disease intermediate-length repeat alleles in healthy Italian population. Neurol Sci 2020; 41:1475-1482. [PMID: 31940111 DOI: 10.1007/s10072-019-04233-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/30/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Huntington disease (HD) and spinocerebellar ataxia type 1-2-17 (SCA1-2-17) are adult-onset autosomal dominant diseases, caused by triplet repeat expansions in the HTT, ATXN1, ATXN2, and TBP genes. Alleles with a repeat number just below the pathological threshold are associated with reduced penetrance and meiotic instability and are defined as intermediate alleles (IAs). OBJECTIVES We aimed to determine the frequencies of IAs in healthy Italian subjects and to compare the proportion of the IAs with the prevalence of the respective diseases. METHODS We analyzed the triplet repeat size in HTT, ATXN1, ATXN2, and TBP genes in the DNA samples from 729 consecutive adult healthy Italian subjects. RESULTS IAs associated with reduced penetrance were found in ATXN2 gene (1 subject, 0.1%) and TBP gene (0.82%). IAs at risk for meiotic instability were found in HTT (5.3%) and ATXN2 genes (2.7%). In ATXN1, we found a low percentage of IAs (0.4%). Alleles lacking the common CAT interruption within the CAG sequence were also rare (0.3%). CONCLUSIONS The high frequencies of IAs in HTT and ATXN2 genes suggest a correlation with the prevalence of the diseases in our population and support the hypothesis that IAs could represent a reservoir of new pathological expansions. On the opposite, ATXN1-IA were very rare in respect to the prevalence of SCA1 in our country, and TBP- IA were more frequent than expected, suggesting that other mechanisms could influence the occurrence of novel pathological expansions.
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Demir G, Alkan C. Characterizing microsatellite polymorphisms using assembly-based and mapping-based tools. ACTA ACUST UNITED AC 2019; 43:264-273. [PMID: 31496881 PMCID: PMC6710001 DOI: 10.3906/biy-1903-16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Microsatellite polymorphism has always been a challenge for genome assembly and sequence alignment due to sequencing errors, short read lengths, and high incidence of polymerase slippage in microsatellite regions. Despite the information they carry being very valuable, microsatellite variations have not gained enough attention to be a routine step in genome sequence analysis pipelines. After the completion of the 1000 Genomes Project, which aimed to establish the most detailed genetic variation catalog for humans, the consortium released only two microsatellite prediction sets generated by two tools. Many other large research efforts have failed to shed light on microsatellite variations. We evaluated the performance of three different local assembly methods on three different experimental settings, focusing on genotype-based performance, coverage impact, and preprocessing including flanking regions. All these experiments supported our initial expectations on assembly. We also demonstrate that overlap-layout-consensus (OLC)-basedassembly methods show higher sensitivity to microsatellite variant calling when compared to a de Bruijn graph-based approach. We conclude that assembly with OLC is the better method for genotyping microsatellites. Our pipeline is available at https://github.com/gulfemd/STRAssembly.
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Affiliation(s)
- Gülfem Demir
- Department of Computer Engineering, Faculty of Engineering, Bilkent University, Bilkent, Ankara Turkey
| | - Can Alkan
- Department of Computer Engineering, Faculty of Engineering, Bilkent University, Bilkent, Ankara Turkey
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Katzeff JS, Phan K, Purushothuman S, Halliday GM, Kim WS. Cross-examining candidate genes implicated in multiple system atrophy. Acta Neuropathol Commun 2019; 7:117. [PMID: 31340844 PMCID: PMC6651992 DOI: 10.1186/s40478-019-0769-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 07/14/2019] [Indexed: 12/26/2022] Open
Abstract
Multiple system atrophy (MSA) is a devastating neurodegenerative disease characterized by the clinical triad of parkinsonism, cerebellar ataxia and autonomic failure, impacting on striatonigral, olivopontocerebellar and autonomic systems. At early stage of the disease, the clinical symptoms of MSA can overlap with those of Parkinson's disease (PD). The key pathological hallmark of MSA is the presence of glial cytoplasmic inclusions (GCI) in oligodendrocytes. GCI comprise insoluble proteinaceous filaments composed chiefly of α-synuclein aggregates, and therefore MSA is regarded as an α-synucleinopathy along with PD and dementia with Lewy bodies. The etiology of MSA is unknown, and the pathogenesis of MSA is still largely speculative. Much data suggests that MSA is a sporadic disease, although some emerging evidence suggests rare genetic variants increase susceptibility. Currently, there is no general consensus on the susceptibility genes as there have been differences due to geographical distribution or ethnicity. Furthermore, many of the reported studies have been conducted on patients that were only clinically diagnosed without pathological verification. The purpose of this review is to bring together available evidence to cross-examine the susceptibility genes and genetic pathomechanisms implicated in MSA. We explore the possible involvement of the SNCA, COQ2, MAPT, GBA1, LRRK2 and C9orf72 genes in MSA pathogenesis, highlight the under-explored areas of MSA genetics, and discuss future directions of research in MSA.
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