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Sena LS, Furtado GV, Pedroso JL, Barsottini O, Cornejo-Olivas M, Nóbrega PR, Braga Neto P, Soares DMB, Vargas FR, Godeiro C, Medeiros PFVD, Camejo C, Toralles MBP, Fagundes NJR, Jardim LB, Saraiva-Pereira ML. Spinocerebellar ataxia type 2 has multiple ancestral origins. Parkinsonism Relat Disord 2024; 120:105985. [PMID: 38181536 DOI: 10.1016/j.parkreldis.2023.105985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/13/2023] [Accepted: 12/28/2023] [Indexed: 01/07/2024]
Abstract
INTRODUCTION Spinocerebellar ataxia type 2 (SCA2) is a dominant neurodegenerative disorder due to expansions of a CAG repeat tract (CAGexp) at the ATXN2 gene. Previous studies found only one ancestral haplotype worldwide, with a C allele at rs695871. This homogeneity was unexpected, given the severe anticipations related to SCA2. We aimed to describe informative ancestral haplotypes found in South American SCA2 families. METHODS Seventy-seven SCA2 index cases were recruited from Brazil, Peru, and Uruguay; 263 normal chromosomes were used as controls. The SNPs rs9300319, rs3809274, rs695871, rs1236900 and rs593226, and the STRs D12S1329, D12S1333, D12S1672 and D12S1332, were used to reconstruct haplotypes. RESULTS Eleven ancestral haplotypes were found in SCA2 families. The most frequent ones were A-G-C-C-C (46.7 % of families), G-C-C-C-C (24.6 %) and A-C-C-C-C (10.3 %) and their mean (sd) CAGexp were 41.68 (3.55), 40.42 (4.11) and 45.67 (9.70) (p = 0.055), respectively. In contrast, the mean (sd) CAG lengths at normal alleles grouped per haplotypes G-C-G-A-T, A-G-C-C-C and G-C-C-C-C were 22.97 (3.93), 23.85 (3.59), and 30.81 (4.27) (p < 0.001), respectively. The other SCA2 haplotypes were rare: among them, a G-C-G-A-T lineage was found, evidencing a G allele in rs695871. CONCLUSION We identified several distinct ancestral haplotypes in SCA2 families, including an unexpected lineage with a G allele at rs695871, a variation never found in hundreds of SCA2 patients studied worldwide. SCA2 has multiple origins in South America, and more studies should be done in other regions of the world.
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Affiliation(s)
- Lucas Schenatto Sena
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Brazil; Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2340, 90035-903, Porto Alegre, Brazil.
| | - Gabriel Vasata Furtado
- Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2340, 90035-903, Porto Alegre, Brazil
| | - José Luiz Pedroso
- Universidade Federal do Estado de São Paulo, Rua Pedro de Toledo 650, 04039-031, São Paulo, Brazil
| | - Orlando Barsottini
- Universidade Federal do Estado de São Paulo, Rua Pedro de Toledo 650, 04039-031, São Paulo, Brazil
| | - Mario Cornejo-Olivas
- Neurogenetics Working Group, Universidad Cientifica del Sur, 19 Panamericana S Avenue, 15067, Lima, 15067, Peru; Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, 1271 Ancas St, 15003, Lima, Peru
| | - Paulo Ribeiro Nóbrega
- Setor de Neurologia, Departamento de Medicina Clínica, Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, 60430-140, Fortaleza, CE, Brazil; Centro Universitário Christus, Rua Alexandre Baraúna 949, 60430-160, Fortaleza, CE, Brazil
| | - Pedro Braga Neto
- Setor de Neurologia, Departamento de Medicina Clínica, Faculdade de Medicina, Universidade Federal do Ceará, Rua Professor Costa Mendes, 1608, 60430-140, Fortaleza, CE, Brazil; Curso de Medicina, Centro de Ciências da Saúde, Universidade Estadual do Ceará, Avenida Dr. Silas Munguba, 1700, 60714-903, Fortaleza, CE, Brazil
| | - Danyela Martins Bezerra Soares
- Curso de Medicina, Centro de Ciências da Saúde, Universidade Estadual do Ceará, Avenida Dr. Silas Munguba, 1700, 60714-903, Fortaleza, CE, Brazil
| | - Fernando Regla Vargas
- Departamento de Genética e Biologia Molecular, Universidade Federal do Estado do Rio de Janeiro, Rua Frei Caneca 94, 20211-010, Rio de Janeiro, Brazil; Laboratório de Epidemiologia de Malformações Congênitas, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Avenida Brasil 4365, 21040-900, Rio de Janeiro, Brazil
| | - Clecio Godeiro
- Departamento de Medicina Integrada, Hospital Universitário Onofre Lopes, Avenida Nilo Peçanha, 59012-300, Natal, Brazil
| | - Paula Frassinetti Vasconcelos de Medeiros
- Unidade Acadêmica de Medicina, Hospital Universitário Alcides Carneiro, Universidade Federal de Campina Grande, Rua Carlos Chagas S/n, 58107-670, Campina Grande, Brazil
| | - Claudia Camejo
- Facultad de Medicina. Universidad de La República, Avenida General Flores 3461, 11700, Montevideo, Uruguay
| | | | - Nelson Jurandi Rosa Fagundes
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Brazil; Departamento de Genética, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Brazil
| | - Laura Bannach Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Brazil; Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2340, 90035-903, Porto Alegre, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2340, 90.035-903, Brazil; Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2400, 90035-002, Porto Alegre, Brazil
| | - Maria Luiza Saraiva-Pereira
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Brazil; Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2340, 90035-903, Porto Alegre, Brazil; Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2340, 90.035-903, Brazil; Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, 90035-003, Porto Alegre, Brazil
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Sena LS, Lemes RB, Furtado GV, Saraiva-Pereira ML, Jardim LB. A model for the dynamics of expanded CAG repeat alleles: ATXN2 and ATXN3 as prototypes. Front Genet 2023; 14:1296614. [PMID: 38034492 PMCID: PMC10682950 DOI: 10.3389/fgene.2023.1296614] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 10/27/2023] [Indexed: 12/02/2023] Open
Abstract
Background: Spinocerebellar ataxia types 2 (SCA2) and 3 (SCA3/MJD) are diseases due to dominant unstable expansions of CAG repeats (CAGexp). Age of onset of symptoms (AO) correlates with the CAGexp length. Repeat instability leads to increases in the expanded repeats, to important AO anticipations and to the eventual extinction of lineages. Because of that, compensatory forces are expected to act on the maintenance of expanded alleles, but they are poorly understood. Objectives: we described the CAGexp dynamics, adapting a classical equation and aiming to estimate for how many generations will the descendants of a de novo expansion last. Methods: A mathematical model was adapted to encompass anticipation, fitness, and allelic segregation; and empirical data fed the model. The arbitrated ancestral mutations included in the model had the lowest CAGexp and the highest AO described in the literature. One thousand generations were simulated until the alleles were eliminated, fixed, or 650 generations had passed. Results: All SCA2 lineages were eliminated in a median of 10 generations. In SCA3/MJD lineages, 593 were eliminated in a median of 29 generations. The other ones were eliminated due to anticipation after the 650th generation or remained indefinitely with CAG repeats transitioning between expanded and unexpanded ranges. Discussion: the model predicted outcomes compatible with empirical data - the very old ancestral SCA3/MJD haplotype, and the de novo SCA2 expansions -, which previously seemed to be contradictory. This model accommodates these data into understandable dynamics and might be useful for other CAGexp disorders.
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Affiliation(s)
- Lucas Schenatto Sena
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | | | - Gabriel Vasata Furtado
- Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Maria Luiza Saraiva-Pereira
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Laura Bannach Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
- Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Loureiro JR, Castro AF, Figueiredo AS, Silveira I. Molecular Mechanisms in Pentanucleotide Repeat Diseases. Cells 2022; 11:cells11020205. [PMID: 35053321 PMCID: PMC8773600 DOI: 10.3390/cells11020205] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 02/01/2023] Open
Abstract
The number of neurodegenerative diseases resulting from repeat expansion has increased extraordinarily in recent years. In several of these pathologies, the repeat can be transcribed in RNA from both DNA strands producing, at least, one toxic RNA repeat that causes neurodegeneration by a complex mechanism. Recently, seven diseases have been found caused by a novel intronic pentanucleotide repeat in distinct genes encoding proteins highly expressed in the cerebellum. These disorders are clinically heterogeneous being characterized by impaired motor function, resulting from ataxia or epilepsy. The role that apparently normal proteins from these mutant genes play in these pathologies is not known. However, recent advances in previously known spinocerebellar ataxias originated by abnormal non-coding pentanucleotide repeats point to a gain of a toxic function by the pathogenic repeat-containing RNA that abnormally forms nuclear foci with RNA-binding proteins. In cells, RNA foci have been shown to be formed by phase separation. Moreover, the field of repeat expansions has lately achieved an extraordinary progress with the discovery that RNA repeats, polyglutamine, and polyalanine proteins are crucial for the formation of nuclear membraneless organelles by phase separation, which is perturbed when they are expanded. This review will cover the amazing advances on repeat diseases.
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Affiliation(s)
- Joana R. Loureiro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana F. Castro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Ana S. Figueiredo
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Isabel Silveira
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (J.R.L.); (A.F.C.); (A.S.F.)
- Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal
- Correspondence: ; Tel.: +351-2240-8800
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Abstract
PURPOSE OF REVIEW To provide an update on the role of Ataxin-2 gene (ATXN2) in health and neurological diseases. RECENT FINDINGS There is a growing complexity emerging on the role of ATXN2 and its variants in association with SCA2 and several other neurological diseases. Polymorphisms and intermediate alleles in ATXN2 establish this gene as a powerful modulator of neurological diseases including lethal neurodegenerative conditions such as motor neuron disease, spinocerebellar ataxia 3 (SCA3), and peripheral nerve disease such as familial amyloidosis polyneuropathy. This role is in fact far wider than the previously described for polymorphism in the prion protein (PRNP) gene. Positive data from antisense oligo therapy in a murine model of SCA2 suggest that similar approaches may be feasible in humans SCA2 patients. SUMMARY ATXN2 is one of the few genes where a single gene causes several diseases and/or modifies several and disparate neurological disorders. Hence, understanding mutagenesis, genetic variants, and biological functions will help managing SCA2, and several human diseases connected with dysfunctional pathways in the brain, innate immunity, autophagy, cellular, lipid, and RNA metabolism.
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Affiliation(s)
- Jose Miguel Laffita-Mesa
- Department of Clinical Neuroscience (CNS), J5:20 Bioclinicum, Karolinska University Hospital, Stockholm, Sweden
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Sonakar AK, Shamim U, Srivastava MP, Faruq M, Srivastava AK. SCA2 in the Indian population: Unified haplotype and variable phenotypic patterns in a large case series. Parkinsonism Relat Disord 2021; 89:139-145. [PMID: 34298214 DOI: 10.1016/j.parkreldis.2021.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 07/06/2021] [Accepted: 07/10/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND Spinocerebellar ataxia-2 is one of the most prevalent SCA type across the world and one of the commonest in India. We aimed to characterize SCA2 patients both clinically and genetically (ATXN2-CAG repeats and its haplotypic background). METHODS A total of 436 SCA2 patients were recruited consecutively comprising individuals of multiple ethnicities and two large multigenerational families. A detailed clinical evaluation and genetic analysis for CAG repeat length estimation and two marker based haplotype analysis [rs695871 and rs695872 located 177 bp and 106 bp upstream of CAG sequence in Exon 1 of ATXN2] was performed. RESULTS Generalized limb ataxia and slow saccades were prevalent features in majority of our patients, while hyporeflexia and extrapyramidal features were less commonly observed manifestations. Slow ocular saccades, upper limb ataxia and tremor showed significant associations with age of onset, CAG repeat length and disease duration. We observed a 100% association of C-C haplotype with the expanded ATXN2 repeats. CONCLUSION This study represents the largest study of SCA2 Indian patients that highlights the clinico-genetic manifestations and haplotype analysis. A significant proportion of patients have not shown the characteristic slow saccades and hyporeflexia thus indicating the influences of other factors in modulation of the disease which warrants further investigations. The observation of CC haplotype in all our SCA2 patients indicates a common origin across all Indian sub populations and that also indicate a common global founder event in the past.
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Affiliation(s)
- Akhilesh K Sonakar
- Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Uzma Shamim
- Genomics and Molecular Medicine, CSIR - Institute of Genomics and Integrative Biology, Delhi, 110007, India
| | - Mv Padma Srivastava
- Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Mohd Faruq
- Genomics and Molecular Medicine, CSIR - Institute of Genomics and Integrative Biology, Delhi, 110007, India.
| | - Achal K Srivastava
- Department of Neurology, Neuroscience Centre, All India Institute of Medical Sciences, New Delhi, 110029, India.
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Sena LS, Dos Santos Pinheiro J, Hasan A, Saraiva-Pereira ML, Jardim LB. Spinocerebellar ataxia type 2 from an evolutionary perspective: Systematic review and meta-analysis. Clin Genet 2021; 100:258-267. [PMID: 33960424 DOI: 10.1111/cge.13978] [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: 03/02/2021] [Revised: 04/19/2021] [Accepted: 05/05/2021] [Indexed: 01/27/2023]
Abstract
Dominant diseases due to expanded CAG repeat tracts, such as spinocerebellar ataxia type 2 (SCA2), are prone to anticipation and worsening of clinical picture in subsequent generations. There is insufficient data about selective forces acting on the maintenance of these diseases in populations. We made a systematic review and meta-analysis on the effect of the CAG length over age at onset, instability of transmissions, anticipation, de novo or sporadic cases, fitness, segregation of alleles, and ancestral haplotypes. The correlation between CAG expanded and age at onset was r2 = 0.577, and transmission of the mutant allele was associated with an increase of 2.42 CAG repeats in the next generation and an anticipation of 14.62 years per generation, on average. One de novo and 18 sporadic cases were detected. Affected SCA2 individuals seem to have more children than controls. The expanded allele was less segregated than the 22-repeat allele in children of SCA2 subjects. Several ancestral SCA2 haplotypes were published. Data suggest that SCA2 lineages may tend to disappear eventually, due to strong anticipation phenomena. Whether or not the novel cases come from common haplotypes associated with a predisposition to further expansions is a question that needs to be addressed by future studies.
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Affiliation(s)
- Lucas Schenatto Sena
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Jordânia Dos Santos Pinheiro
- Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Ali Hasan
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Maria Luiza Saraiva-Pereira
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Instituto de Genética Médica Populacional, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Laura Bannach Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Instituto de Genética Médica Populacional, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.,Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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Rodríguez-Labrada R, Martins AC, Magaña JJ, Vazquez-Mojena Y, Medrano-Montero J, Fernandez-Ruíz J, Cisneros B, Teive H, McFarland KN, Saraiva-Pereira ML, Cerecedo-Zapata CM, Gomez CM, Ashizawa T, Velázquez-Pérez L, Jardim LB. Founder Effects of Spinocerebellar Ataxias in the American Continents and the Caribbean. THE CEREBELLUM 2021; 19:446-458. [PMID: 32086717 DOI: 10.1007/s12311-020-01109-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Spinocerebellar ataxias (SCAs) comprise a heterogeneous group of autosomal dominant disorders. The relative frequency of the different SCA subtypes varies broadly among different geographical and ethnic groups as result of genetic drifts. This review aims to provide an update regarding SCA founders in the American continents and the Caribbean as well as to discuss characteristics of these populations. Clusters of SCAs were detected in Eastern regions of Cuba for SCA2, in South Brazil for SCA3/MJD, and in Southeast regions of Mexico for SCA7. Prevalence rates were obtained and reached 154 (municipality of Báguano, Cuba), 166 (General Câmara, Brazil), and 423 (Tlaltetela, Mexico) patients/100,000 for SCA2, SCA3/MJD, and SCA7, respectively. In contrast, the scattered families with spinocerebellar ataxia type 10 (SCA10) reported all over North and South Americas have been associated to a common Native American ancestry that may have risen in East Asia and migrated to Americas 10,000 to 20,000 years ago. The comprehensive review showed that for each of these SCAs corresponded at least the development of one study group with a large production of scientific evidence often generalizable to all carriers of these conditions. Clusters of SCA populations in the American continents and the Caribbean provide unusual opportunity to gain insights into clinical and genetic characteristics of these disorders. Furthermore, the presence of large populations of patients living close to study centers can favor the development of meaningful clinical trials, which will impact on therapies and on quality of life of SCA carriers worldwide.
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Affiliation(s)
| | - Ana Carolina Martins
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 91540-070, Brazil
| | - Jonathan J Magaña
- Department of Genetics, Laboratory of Genomic Medicine, National Rehabilitation Institute (INR-LGII), 14389, Mexico City, Mexico
| | - Yaimeé Vazquez-Mojena
- Centre for the Research and Rehabilitation of Hereditary Ataxias, 80100, Holguín, Cuba
| | | | - Juan Fernandez-Ruíz
- Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, 04510, Mexico City, Mexico
| | - Bulmaro Cisneros
- Department of Genetics and Molecular Biology, Center of Research and Advanced Studies (CINVESTAV-IPN), 07360, Mexico City, Mexico
| | - Helio Teive
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas Federal University of Paraná, Curitiba, PR, 80240-440, Brazil
| | | | - Maria Luiza Saraiva-Pereira
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 91540-070, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, 90035-903, Brazil
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-903, Brazil
| | - César M Cerecedo-Zapata
- Department of Genetics, Laboratory of Genomic Medicine, National Rehabilitation Institute (INR-LGII), 14389, Mexico City, Mexico
- Rehabilitation and Social Inclusion Center of Veracruz (CRIS-DIF), Xalapa, 91070, Veracruz, Mexico
| | | | - Tetsuo Ashizawa
- Program of Neuroscience, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Luis Velázquez-Pérez
- Centre for the Research and Rehabilitation of Hereditary Ataxias, 80100, Holguín, Cuba.
- Cuban Academy of Sciences, 10100, La Havana, Cuba.
| | - Laura Bannach Jardim
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 91540-070, Brazil
- Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, 90035-903, Brazil
- Departamento de Medicina Interna, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-903, Brazil
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Yu J, Deng J, Guo X, Shan J, Luan X, Cao L, Zhao J, Yu M, Zhang W, Lv H, Xie Z, Meng L, Zheng Y, Zhao Y, Gang Q, Wang Q, Liu J, Zhu M, Zhou B, Li P, Liu Y, Wang Y, Yan C, Hong D, Yuan Y, Wang Z. The GGC repeat expansion in NOTCH2NLC is associated with oculopharyngodistal myopathy type 3. Brain 2021; 144:1819-1832. [PMID: 33693509 PMCID: PMC8320266 DOI: 10.1093/brain/awab077] [Citation(s) in RCA: 82] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 11/12/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022] Open
Abstract
Oculopharyngodistal myopathy (OPDM) is an adult-onset neuromuscular disease characterized
by progressive ocular, facial, pharyngeal and distal limb muscle involvement.
Trinucleotide repeat expansions in LRP12 or GIPC1 were
recently reported to be associated with OPDM. However, a significant portion of OPDM
patients have unknown genetic causes. In this study, long-read whole-genome sequencing and
repeat-primed PCR were performed and we identified GGC repeat expansions in the
NOTCH2NLC gene in 16.7% (4/24) of a cohort of Chinese OPDM patients,
designated as OPDM type 3 (OPDM3). Methylation analysis indicated that methylation levels
of the NOTCH2NLC gene were unaltered in OPDM3 patients, but increased
significantly in asymptomatic carriers. Quantitative real-time PCR analysis indicated that
NOTCH2NLC mRNA levels were increased in muscle but not in blood of
OPDM3 patients. Immunofluorescence on OPDM muscle samples and expressing mutant NOTCH2NLC
with (GGC)69 repeat expansions in HEK293 cells indicated that mutant
NOTCH2NLC-polyglycine protein might be a major component of intranuclear inclusions, and
contribute to toxicity in cultured cells. In addition, two RNA-binding proteins, hnRNP A/B
and MBNL1, were both co-localized with p62 in intranuclear inclusions in OPDM muscle
samples. These results indicated that a toxic protein gain-of-function mechanism and RNA
gain-of-function mechanism may both play a vital role in the pathogenic processes of
OPDM3. This study extended the spectrum of NOTCH2NLC repeat expansion-related diseases to
a predominant myopathy phenotype presenting as OPDM, and provided evidence for possible
pathogenesis of these diseases.
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Affiliation(s)
- Jiaxi Yu
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Jianwen Deng
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Xueyu Guo
- Grandomics Biosciences, Beijing 100176, China
| | - Jingli Shan
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan 250000, Shandong, China.,Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Shandong University, Qingdao 266035, Shandong, China.,Brain Science Research Institute, Shandong University, Jinan 250000, Shandong, China
| | - Xinghua Luan
- Department of Neurology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200030, China
| | - Li Cao
- Department of Neurology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200030, China
| | - Juan Zhao
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Meng Yu
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Wei Zhang
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - He Lv
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Zhiying Xie
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - LingChao Meng
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Yiming Zheng
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Yawen Zhao
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Qiang Gang
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Qingqing Wang
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Jing Liu
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Min Zhu
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Binbin Zhou
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Pidong Li
- Grandomics Biosciences, Beijing 100176, China
| | - Yinzhe Liu
- Grandomics Biosciences, Beijing 100176, China
| | - Yang Wang
- Grandomics Biosciences, Beijing 100176, China
| | - Chuanzhu Yan
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan 250000, Shandong, China.,Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Shandong University, Qingdao 266035, Shandong, China.,Brain Science Research Institute, Shandong University, Jinan 250000, Shandong, China
| | - Daojun Hong
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Yun Yuan
- Department of Neurology, Peking University First Hospital, Beijing 100034, China
| | - Zhaoxia Wang
- Department of Neurology, Peking University First Hospital, Beijing 100034, China.,Beijing Key Laboratory of Neurovascular Disease Discovery, Beijing 100034, China
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9
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Donaldson J, Powell S, Rickards N, Holmans P, Jones L. What is the Pathogenic CAG Expansion Length in Huntington's Disease? J Huntingtons Dis 2021; 10:175-202. [PMID: 33579866 PMCID: PMC7990448 DOI: 10.3233/jhd-200445] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Huntington's disease (HD) (OMIM 143100) is caused by an expanded CAG repeat tract in the HTT gene. The inherited CAG length is known to expand further in somatic and germline cells in HD subjects. Age at onset of the disease is inversely correlated with the inherited CAG length, but is further modulated by a series of genetic modifiers which are most likely to act on the CAG repeat in HTT that permit it to further expand. Longer repeats are more prone to expansions, and this expansion is age dependent and tissue-specific. Given that the inherited tract expands through life and most subjects develop disease in mid-life, this implies that in cells that degenerate, the CAG length is likely to be longer than the inherited length. These findings suggest two thresholds- the inherited CAG length which permits further expansion, and the intracellular pathogenic threshold, above which cells become dysfunctional and die. This two-step mechanism has been previously proposed and modelled mathematically to give an intracellular pathogenic threshold at a tract length of 115 CAG (95% confidence intervals 70- 165 CAG). Empirically, the intracellular pathogenic threshold is difficult to determine. Clues from studies of people and models of HD, and from other diseases caused by expanded repeat tracts, place this threshold between 60- 100 CAG, most likely towards the upper part of that range. We assess this evidence and discuss how the intracellular pathogenic threshold in manifest disease might be better determined. Knowing the cellular pathogenic threshold would be informative for both understanding the mechanism in HD and deploying treatments.
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Affiliation(s)
- Jasmine Donaldson
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, UK
| | - Sophie Powell
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, UK
| | - Nadia Rickards
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, UK
| | - Peter Holmans
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, UK
| | - Lesley Jones
- MRC Centre for Neuropsychiatric Genetics and Genomics, School of Medicine, Cardiff University, Cardiff, UK
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10
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Castro AF, Loureiro JR, Bessa J, Silveira I. Antisense Transcription across Nucleotide Repeat Expansions in Neurodegenerative and Neuromuscular Diseases: Progress and Mysteries. Genes (Basel) 2020; 11:E1418. [PMID: 33261024 PMCID: PMC7760973 DOI: 10.3390/genes11121418] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Unstable repeat expansions and insertions cause more than 30 neurodegenerative and neuromuscular diseases. Remarkably, bidirectional transcription of repeat expansions has been identified in at least 14 of these diseases. More remarkably, a growing number of studies has been showing that both sense and antisense repeat RNAs are able to dysregulate important cellular pathways, contributing together to the observed clinical phenotype. Notably, antisense repeat RNAs from spinocerebellar ataxia type 7, myotonic dystrophy type 1, Huntington's disease and frontotemporal dementia/amyotrophic lateral sclerosis associated genes have been implicated in transcriptional regulation of sense gene expression, acting either at a transcriptional or posttranscriptional level. The recent evidence that antisense repeat RNAs could modulate gene expression broadens our understanding of the pathogenic pathways and adds more complexity to the development of therapeutic strategies for these disorders. In this review, we cover the amazing progress made in the understanding of the pathogenic mechanisms associated with repeat expansion neurodegenerative and neuromuscular diseases with a focus on the impact of antisense repeat transcription in the development of efficient therapies.
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Affiliation(s)
- Ana F. Castro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (A.F.C.); (J.R.L.)
- IBMC-Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal;
- ICBAS, Universidade do Porto, 4050-313 Porto, Portugal
| | - Joana R. Loureiro
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (A.F.C.); (J.R.L.)
- IBMC-Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal;
| | - José Bessa
- IBMC-Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal;
- Vertebrate Development and Regeneration Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Isabel Silveira
- Genetics of Cognitive Dysfunction Laboratory, i3S- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; (A.F.C.); (J.R.L.)
- IBMC-Institute for Molecular and Cell Biology, Universidade do Porto, 4200-135 Porto, Portugal;
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11
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Costa IPD, Almeida BC, Sequeiros J, Amorim A, Martins S. A Pipeline to Assess Disease-Associated Haplotypes in Repeat Expansion Disorders: The Example of MJD/SCA3 Locus. Front Genet 2019; 10:38. [PMID: 30804982 PMCID: PMC6370646 DOI: 10.3389/fgene.2019.00038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/18/2019] [Indexed: 12/13/2022] Open
Abstract
At least 40 human diseases are associated with repeat expansions; yet, the mutational origin and instability mechanisms remain unknown for most of them. Previously, genetic epidemiology and predisposing backgrounds for the instability of some expanding loci have been studied in different populations through the analysis of diversity flanking the respective pathogenic repeats. Here, we aimed at developing a pipeline to assess disease-associated haplotypes at oligonucleotide repeat loci, combining analysis of single nucleotide polymorphisms (SNPs) and short tandem repeats (STRs). Machado-Joseph disease (MJD/SCA3), the most frequent dominant ataxia worldwide, was used as an example of a detailed procedure. Thus, to identify genetic backgrounds that segregate with expanded/mutated alleles in MJD, we selected a set of 26 SNPs and 7 STRs flanking the causative CAG repeat. Key criteria and steps for this selection are described, and included (1) haplotype blocks minimizing the occurrence of recombination (for SNPs); and (2) match scores to increase potential for polymorphic information content of repetitive sequences found in Tandem Repeats Finder (for STRs). To directly assess SNP haplotypes in phase with MJD expansions, we optimized a strategy with preferential amplification of normal over expanded alleles, in addition to SNP allele-specific amplifications; this allowed the identification of disease-associated SNP haplotypes, even when only the proband is available in a given family. To infer STR haplotypes, we optimized a multiplex PCR, including 7 STRs plus the MJD_CAG repeat, followed by analysis of segregation or the use of the PHASE software. This protocol is a ready-to-use tool to assess MJD haplotypes in different populations. The pipeline designed can be used to assess disease-associated haplotypes in other repeat-expansion diseases. This should be of great utility to study (1) genetic epidemiology (population-of-origin, age and spreading routes of mutations) and (2) mechanisms responsible for de novo expansions, in these neurological diseases; (3) to detect predisposing haplotypes and (4) phenotype modifiers; (5) to help solving cases of apparent homoallelism (two same-size normal alleles) in diagnosis; and (6) to identify the best targets for the development of allele-specific therapies in ethnically diverse patient populations.
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Affiliation(s)
- Inês P. D. Costa
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP – Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
| | - Beatriz C. Almeida
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP – Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
- Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Jorge Sequeiros
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IBMC – Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS – Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - António Amorim
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP – Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
- Faculdade de Ciências da Universidade do Porto, Porto, Portugal
| | - Sandra Martins
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IPATIMUP – Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
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12
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Santos D, Coelho T, Alves-Ferreira M, Sequeiros J, Mendonça D, Alonso I, Sousa A, Lemos C. Large normal alleles of ATXN2
decrease age at onset in transthyretin familial amyloid polyneuropathy Val30Met patients. Ann Neurol 2019; 85:251-258. [DOI: 10.1002/ana.25409] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 01/04/2019] [Accepted: 01/04/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Diana Santos
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Teresa Coelho
- UCA, Unidade Corino de Andrade; Centro Hospitalar do Porto (CHP)
| | - Miguel Alves-Ferreira
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Jorge Sequeiros
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Denisa Mendonça
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
- ISPUP, Instituto de Saúde Pública; Universidade do Porto; Porto Portugal
| | - Isabel Alonso
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Alda Sousa
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
| | - Carolina Lemos
- i3S, Instituto de Investigação e Inovação em Saúde; Universidade do Porto
- UnIGENe, IBMC, Institute for Molecular and Cell Biology; Universidade do Porto
- ICBAS, Instituto de Ciências Biomédicas Abel Salazar; Universidade do Porto
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13
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Loureiro JR, Oliveira CL, Mota C, Castro AF, Costa C, Loureiro JL, Coutinho P, Martins S, Sequeiros J, Silveira I. Mutational mechanism for DAB1 (ATTTC) n insertion in SCA37: ATTTT repeat lengthening and nucleotide substitution. Hum Mutat 2019; 40:404-412. [PMID: 30588707 DOI: 10.1002/humu.23704] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/28/2018] [Accepted: 12/22/2018] [Indexed: 12/20/2022]
Abstract
Dynamic mutations by microsatellite instability are the molecular basis of a growing number of neuromuscular and neurodegenerative diseases. Repetitive stretches in the human genome may drive pathogenicity, either by expansion above a given threshold, or by insertion of abnormal tracts in nonpathogenic polymorphic repetitive regions, as is the case in spinocerebellar ataxia type 37 (SCA37). We have recently established that this neurodegenerative disease is caused by an (ATTTC)n insertion within an (ATTTT)n in a noncoding region of DAB1. We now investigated the mutational mechanism that originated the (ATTTC)n insertion within an ancestral (ATTTT)n . Approximately 3% of nonpathogenic (ATTTT)n alleles are interspersed by AT-rich motifs, contrarily to mutant alleles that are composed of pure (ATTTT)n and (ATTTC)n stretches. Haplotype studies in unaffected chromosomes suggested that the primary mutational mechanism, leading to the (ATTTC)n insertion, was likely one or more T>C substitutions in an (ATTTT)n pure allele of approximately 200 repeats. Then, the (ATTTC)n expanded in size, originating a deleterious allele in DAB1 that leads to SCA37. This is likely the mutational mechanism in three similar (TTTCA)n insertions responsible for familial myoclonic epilepsy. Because (ATTTT)n tracts are frequent in the human genome, many loci could be at risk for this mutational process.
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Affiliation(s)
- Joana R Loureiro
- Genetics of Cognitive Dysfunction Laboratory, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal.,ICBAS, Universidade do Porto, Porto, Portugal
| | - Cláudia L Oliveira
- Genetics of Cognitive Dysfunction Laboratory, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
| | - Carolina Mota
- Genetics of Cognitive Dysfunction Laboratory, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
| | - Ana F Castro
- Genetics of Cognitive Dysfunction Laboratory, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
| | - Cristina Costa
- Department of Neurology, Hospital Prof. Doutor Fernando Fonseca, Amadora, Portugal
| | - José L Loureiro
- IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal.,UnIGENe, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Department of Neurology, Hospital São Sebastião, Feira, Portugal
| | - Paula Coutinho
- IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal.,UnIGENe, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Sandra Martins
- Population Genetics & Evolution, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IPATIMUP - Institute of Molecular Pathology and Immunology, University of Porto, Porto, Portugal
| | - Jorge Sequeiros
- IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal.,ICBAS, Universidade do Porto, Porto, Portugal.,UnIGENe, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Isabel Silveira
- Genetics of Cognitive Dysfunction Laboratory, i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC- Institute for Molecular and Cell Biology, Universidade do Porto, Porto, Portugal
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14
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Almaguer-Mederos L, Mesa J, González-Zaldívar Y, Almaguer-Gotay D, Cuello-Almarales D, Aguilera-Rodríguez R, Falcón N, Gispert S, Auburger G, Velázquez-Pérez L. Factors associated with ATXN2
CAG/CAA repeat intergenerational instability in Spinocerebellar ataxia type 2. Clin Genet 2018; 94:346-350. [DOI: 10.1111/cge.13380] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 05/01/2018] [Indexed: 12/13/2022]
Affiliation(s)
- L.E. Almaguer-Mederos
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
- Medical University of Holguín; Holguín Cuba
| | - J.M.L. Mesa
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
| | - Y. González-Zaldívar
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
- Medical University of Holguín; Holguín Cuba
| | - D. Almaguer-Gotay
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
- Medical University of Holguín; Holguín Cuba
| | - D. Cuello-Almarales
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
| | - R. Aguilera-Rodríguez
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
- Medical University of Holguín; Holguín Cuba
| | - N.S. Falcón
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
| | - S. Gispert
- Experimental Neurology; Goethe University Medical School; Frankfurt am Main Germany
| | - G. Auburger
- Experimental Neurology; Goethe University Medical School; Frankfurt am Main Germany
| | - L. Velázquez-Pérez
- Center for Investigation and Rehabilitation of Hereditary Ataxias; Holguín Cuba
- Medical University of Holguín; Holguín Cuba
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15
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Tomé S, Dandelot E, Dogan C, Bertrand A, Geneviève D, Péréon Y, Simon M, Bonnefont JP, Bassez G, Gourdon G. Unusual association of a unique CAG interruption in 5' of DM1 CTG repeats with intergenerational contractions and low somatic mosaicism. Hum Mutat 2018; 39:970-982. [PMID: 29664219 DOI: 10.1002/humu.23531] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/23/2018] [Accepted: 04/10/2018] [Indexed: 11/11/2022]
Abstract
Myotonic dystrophy type 1 (DM1) is a dominant multisystemic disorder associated with high variability of symptoms and anticipation. DM1 is caused by an unstable CTG repeat expansion that usually increases in successive generations and tissues. DM1 family pedigrees have shown that ∼90% and 10% of transmissions result in expansions and contractions of the CTG repeat, respectively. To date, the mechanisms of CTG repeat contraction remain poorly documented in DM1. In this report, we identified two new DM1 families with apparent contractions and no worsening of DM1 symptoms in two and three successive maternal transmissions. A new and unique CAG interruption was found in 5' of the CTG expansion in one family, whereas multiple 5' CCG interruptions were detected in the second family. We showed that these interruptions are associated with maternal intergenerational contractions and low somatic mosaicism in blood. By specific triplet-prime PCR, we observed that CTG repeat changes (contractions/expansions) occur preferentially in 3' of the interruptions for both families.
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Affiliation(s)
- Stéphanie Tomé
- Laboratory CTGDM, Inserm UMR1163, Paris, France; Institut Imagine, Université Paris-Descartes-Sorbonne Paris-Cité, Paris, France
| | - Elodie Dandelot
- Laboratory CTGDM, Inserm UMR1163, Paris, France; Institut Imagine, Université Paris-Descartes-Sorbonne Paris-Cité, Paris, France
| | - Céline Dogan
- Neuromuscular Reference Center, AP-HP, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Alexis Bertrand
- Laboratory CTGDM, Inserm UMR1163, Paris, France; Institut Imagine, Université Paris-Descartes-Sorbonne Paris-Cité, Paris, France
| | - David Geneviève
- Molecular Genetic Laboratory, Necker Hospital, Paris, France.,Département de Génétique Médicale, Maladies Rares et Médecine Personnalisée, CHU Montpellier, Université Montpellier, Montpellier, France
| | - Yann Péréon
- Centre for Neuromuscular Diseases, Hôtel-Dieu Hospital, Nantes, France
| | -
- Pauline Arnaud: Department of genetic, Bichat Hospital, Paris, France, Raphaële Chasserieau: Centre for Neuromuscular Diseases, Hôtel-Dieu Hospital, Nantes, France, Pascal Cintas: Neuromuscular Reference Center, Purpan Hospital, Toulouse, France, Ana-maria Cobo Esteban: Neuromuscular Reference Center, Marin Hospital, Hendaye, France, Marie-Carmen Cruz: Neuromuscular Reference Center, Purpan Hospital, Toulouse, France, Dalil Hamroun: Centre Hospitalo-Universitaire de Montpellier, Montpellier, France, Armelle Magot: Neuromuscular Reference Center, Hôtel-Dieu Hospital, Nantes, France, Alexandra Nadaj-Pakleza Neuromuscular Reference Center, Larrey Hospital, Angers, France, Anne-catherine Aube-Gauthier Neuromuscular Reference Center, Larrey Hospital, Angers, France, Andoni Urtizberea: Neuromuscular Reference Center, Marin Hospital, Hendaye, France
| | - Marie Simon
- Molecular Genetic Laboratory, Necker Hospital, Paris, France
| | | | - Guillaume Bassez
- Sorbonne Université, Inserm, UMRS974, Neuromuscular Reference center, AP-HP, Hôpital Pitié-Salpêtrière, F-75013, Paris, France
| | - Geneviève Gourdon
- Laboratory CTGDM, Inserm UMR1163, Paris, France; Institut Imagine, Université Paris-Descartes-Sorbonne Paris-Cité, Paris, France
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16
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Landrian I, McFarland KN, Liu J, Mulligan CJ, Rasmussen A, Ashizawa T. Inheritance patterns of ATCCT repeat interruptions in spinocerebellar ataxia type 10 (SCA10) expansions. PLoS One 2017; 12:e0175958. [PMID: 28423040 PMCID: PMC5397023 DOI: 10.1371/journal.pone.0175958] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 04/03/2017] [Indexed: 11/18/2022] Open
Abstract
Spinocerebellar ataxia type 10 (SCA10), an autosomal dominant cerebellar ataxia disorder, is caused by a non-coding ATTCT microsatellite repeat expansion in the ataxin 10 gene. In a subset of SCA10 families, the 5’-end of the repeat expansion contains a complex sequence of penta- and heptanucleotide interruption motifs which is followed by a pure tract of tandem ATCCT repeats of unknown length at its 3’-end. Intriguingly, expansions that carry these interruption motifs correlate with an epileptic seizure phenotype and are unstable despite the theory that interruptions are expected to stabilize expanded repeats. To examine the apparent contradiction of unstable, interruption-positive SCA10 expansion alleles and to determine whether the instability originates outside of the interrupted region, we sequenced approximately 1 kb of the 5’-end of SCA10 expansions using the ATCCT-PCR product in individuals across multiple generations from four SCA10 families. We found that the greatest instability within this region occurred in paternal transmissions of the allele in stretches of pure ATTCT motifs while the intervening interrupted sequences were stable. Overall, the ATCCT interruption changes by only one to three repeat units and therefore cannot account for the instability across the length of the disease allele. We conclude that the AT-rich interruptions locally stabilize the SCA10 expansion at the 5’-end but do not completely abolish instability across the entire span of the expansion. In addition, analysis of the interruption alleles across these families support a parsimonious single origin of the mutation with a shared distant ancestor.
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Affiliation(s)
- Ivette Landrian
- Department of Neurology, College of Medicine, and the McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America
| | - Karen N. McFarland
- Department of Neurology, College of Medicine, and the McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America
- Center for Translational Research in Neurodegenerative Disease, The University of Florida, Gainesville, Florida, United States of America
- * E-mail:
| | - Jilin Liu
- Department of Neurology, College of Medicine, and the McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America
| | - Connie J. Mulligan
- Department of Anthropology, College of Liberal Arts and Sciences, University of Florida, Gainesville, Florida, United States of America
- Genetics Institute, University of Florida, Gainesville, Florida, United States of America
| | - Astrid Rasmussen
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Tetsuo Ashizawa
- Department of Neurology, College of Medicine, and the McKnight Brain Institute, University of Florida, Gainesville, Florida, United States of America
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17
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Loureiro JR, Oliveira CL, Silveira I. Unstable repeat expansions in neurodegenerative diseases: nucleocytoplasmic transport emerges on the scene. Neurobiol Aging 2015; 39:174-83. [PMID: 26923414 DOI: 10.1016/j.neurobiolaging.2015.12.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 12/07/2015] [Accepted: 12/15/2015] [Indexed: 12/12/2022]
Abstract
An astonishing number of neurological diseases result from expansion of unstable repetitive sequences causing alterations in key neuronal processes. Some are progressive late-onset conditions related to aging, such as the spinocerebellar ataxias. In several of these pathologies, the expanded repeat is transcribed, producing an expanded RNA repeat that causes neurodegeneration by a complex mechanism, comprising 3 main pathways. These include (1) accumulation in the nucleus of RNA foci, resulting from sequestration of RNA-binding proteins functioning in important neuronal cascades; (2) decrease in availability of RNA-binding proteins, such as splicing factors, causing alternative splicing misregulation with imbalance in the expression ratio of neuronal isoforms; and (3) generation of neurotoxic peptides, produced from repeat-associated non-ATG-initiated translation across the RNA repeat, in all reading frames. Recently, 2 pathologies characterized by impaired motor function, cognitive decline, or/and degeneration of motor neurons have been found that have broaden our understanding of these diseases. Moreover, the finding of compromised nucleocytoplasmic transport opens new avenues for research. This review will cover the amazing progress regarding these conditions.
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Affiliation(s)
- Joana R Loureiro
- Group Genetics of Cognitive Dysfunction, i3s- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal; ICBAS, Universidade do Porto, Portugal
| | - Claudia L Oliveira
- Group Genetics of Cognitive Dysfunction, i3s- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal; ICBAS, Universidade do Porto, Portugal
| | - Isabel Silveira
- Group Genetics of Cognitive Dysfunction, i3s- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Portugal; ICBAS, Universidade do Porto, Portugal.
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18
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Santos D, Pimenta J, Wong VCN, Amorim A, Martins S. Diversity in the androgen receptor CAG repeat has been shaped by a multistep mutational mechanism. Am J Med Genet B Neuropsychiatr Genet 2014; 165B:581-6. [PMID: 25078541 DOI: 10.1002/ajmg.b.32261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 06/26/2014] [Indexed: 02/06/2023]
Abstract
The androgen receptor (AR) gene encodes a type of nuclear receptor that functions as a steroid-hormone activated transcription factor. In its coding region, AR includes a CAG repeat, which has been intensely studied due to the inverse correlation between repeat size and AR transcriptional activity. Several studies have reported different (CAG)n sizes associated with the risk of androgen-linked diseases. We aimed at clarifying the mechanisms on the origin of newly CAG sized alleles through a strategy involving the analysis of the associated haplotype diversity. We genotyped 374 control individuals of European and Asian ancestry, and reconstructed the haplotypes associated with the CAG repeat, defined by 10 SNPs and 6 flanking STRs. The most powerful SNPs to tag AR lineages are rs7061037-rs12012620 and rs34191540-rs6625187-rs2768578 in Europeans and Asians, respectively. In the most frequent AR lineage, (CAG)18 alleles seem to have been generated by a multistep mutation mechanism, most probably from longer alleles. We further noticed that the DXS1194-DXS1111 haplotype, in linkage disequilibrium with AR-(CAG)n expanded alleles responsible for spinal bulbar muscular atrophy (SBMA), is rare among our controls; however, the haplotype strategy here described may be used to clarify the origin of expansions in other populations, as in future association studies.
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Affiliation(s)
- Diana Santos
- IPATIMUP, Institute of Molecular Pathology and Immunology of the University of Porto, Porto, Portugal
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19
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Wang MD, Gomes J, Cashman NR, Little J, Krewski D. Intermediate CAG repeat expansion in the ATXN2 gene is a unique genetic risk factor for ALS--a systematic review and meta-analysis of observational studies. PLoS One 2014; 9:e105534. [PMID: 25148523 PMCID: PMC4141758 DOI: 10.1371/journal.pone.0105534] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/24/2014] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rare degenerative condition of the motor neurons. Over 10% of ALS cases are linked to monogenic mutations, with the remainder thought to be due to other risk factors, including environmental factors, genetic polymorphisms, and possibly gene-environmental interactions. We examined the association between ALS and an intermediate CAG repeat expansion in the ATXN2 gene using a meta-analytic approach. Observational studies were searched with relevant disease and gene terms from MEDLINE, EMBASE, and PsycINFO from January 2010 through to January 2014. All identified articles were screened using disease terms, gene terms, population information, and CAG repeat information according to PRISMA guidelines. The final list of 17 articles was further evaluated based on the study location, time period, and authors to exclude multiple usage of the same study populations: 13 relevant articles were retained for this study. The range 30-33 CAG repeats in the ATXN2 gene was most strongly associated with ALS. The meta-analysis revealed that the presence of an intermediate CAG repeat (30-33) in the ATXN2 gene was associated with an increased risk of ALS [odds ratio (OR) = 4.44, 95%CI: 2.91-6.76)] in Caucasian ALS patients. There was no significant difference in the association of this CAG intermediate repeat expansion in the ATXN2 gene between familial ALS cases (OR = 3.59, 1.58-8.17) and sporadic ALS cases (OR = 3.16, 1.88-5.32). These results indicate that the presence of intermediate CAG repeat expansion in the ATXN2 gene is a specific genetic risk factor for ALS, unlike monogenic mutations with an autosomal dominant transmission mode, which cause a more severe phenotype of ALS, with a higher prevalence in familial ALS.
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Affiliation(s)
- Ming-Dong Wang
- Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - James Gomes
- Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Neil R. Cashman
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Julian Little
- Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Daniel Krewski
- Department of Epidemiology and Community Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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20
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Ananda G, Hile SE, Breski A, Wang Y, Kelkar Y, Makova KD, Eckert KA. Microsatellite interruptions stabilize primate genomes and exist as population-specific single nucleotide polymorphisms within individual human genomes. PLoS Genet 2014; 10:e1004498. [PMID: 25033203 PMCID: PMC4102424 DOI: 10.1371/journal.pgen.1004498] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 05/28/2014] [Indexed: 01/01/2023] Open
Abstract
Interruptions of microsatellite sequences impact genome evolution and can alter disease manifestation. However, human polymorphism levels at interrupted microsatellites (iMSs) are not known at a genome-wide scale, and the pathways for gaining interruptions are poorly understood. Using the 1000 Genomes Phase-1 variant call set, we interrogated mono-, di-, tri-, and tetranucleotide repeats up to 10 units in length. We detected ∼26,000–40,000 iMSs within each of four human population groups (African, European, East Asian, and American). We identified population-specific iMSs within exonic regions, and discovered that known disease-associated iMSs contain alleles present at differing frequencies among the populations. By analyzing longer microsatellites in primate genomes, we demonstrate that single interruptions result in a genome-wide average two- to six-fold reduction in microsatellite mutability, as compared with perfect microsatellites. Centrally located interruptions lowered mutability dramatically, by two to three orders of magnitude. Using a biochemical approach, we tested directly whether the mutability of a specific iMS is lower because of decreased DNA polymerase strand slippage errors. Modeling the adenomatous polyposis coli tumor suppressor gene sequence, we observed that a single base substitution interruption reduced strand slippage error rates five- to 50-fold, relative to a perfect repeat, during synthesis by DNA polymerases α, β, or η. Computationally, we demonstrate that iMSs arise primarily by base substitution mutations within individual human genomes. Our biochemical survey of human DNA polymerase α, β, δ, κ, and η error rates within certain microsatellites suggests that interruptions are created most frequently by low fidelity polymerases. Our combined computational and biochemical results demonstrate that iMSs are abundant in human genomes and are sources of population-specific genetic variation that may affect genome stability. The genome-wide identification of iMSs in human populations presented here has important implications for current models describing the impact of microsatellite polymorphisms on gene expression. Microsatellites are short tandem repeat DNA sequences located throughout the human genome that display a high degree of inter-individual variation. This characteristic makes microsatellites an attractive tool for population genetics and forensics research. Some microsatellites affect gene expression, and mutations within such microsatellites can cause disease. Interruption mutations disrupt the perfect repeated array and are frequently associated with altered disease risk, but they have not been thoroughly studied in human genomes. We identified interrupted mono-, di-, tri- and tetranucleotide MSs (iMS) within individual genomes from African, European, Asian and American population groups. We show that many iMSs, including some within disease-associated genes, are unique to a single population group. By measuring the conservation of microsatellites between human and chimpanzee genomes, we demonstrate that interruptions decrease the probability of microsatellite mutations throughout the genome. We demonstrate that iMSs arise in the human genome by single base changes within the DNA, and provide biochemical data suggesting that these stabilizing changes may be created by error-prone DNA polymerases. Our genome-wide study supports the model in which iMSs act to stabilize individual genomes, and suggests that population-specific differences in microsatellite architecture may be an avenue by which genetic ancestry impacts individual disease risk.
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Affiliation(s)
- Guruprasad Ananda
- Department of Biology, Penn State University, University Park, Pennsylvania, United States of America
| | - Suzanne E. Hile
- Department of Pathology, Gittlen Cancer Research Foundation, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Amanda Breski
- Department of Pathology, Gittlen Cancer Research Foundation, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
| | - Yanli Wang
- Department of Biology, Penn State University, University Park, Pennsylvania, United States of America
| | - Yogeshwar Kelkar
- Department of Biology, Penn State University, University Park, Pennsylvania, United States of America
| | - Kateryna D. Makova
- Department of Biology, Penn State University, University Park, Pennsylvania, United States of America
- Center for Medical Genomics, Penn State University, University Park, Pennsylvania, United States of America
- * E-mail: (KDM); (KAE)
| | - Kristin A. Eckert
- Department of Pathology, Gittlen Cancer Research Foundation, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania, United States of America
- Center for Medical Genomics, Penn State University, University Park, Pennsylvania, United States of America
- * E-mail: (KDM); (KAE)
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21
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Abstract
Pathogenic CAG repeat expansion in the ataxin-2 gene (ATXN2) is the genetic cause of spinocerebellar ataxia type 2 (SCA2). Recently, it has been associated with Parkinsonism and increased genetic risk for amyotrophic lateral sclerosis (ALS). Here we report the association of de novo mutations in ATXN2 with autosomal dominant ALS. These findings support our previous conjectures based on population studies on the role of large normal ATXN2 alleles as the source for new mutations being involved in neurodegenerative pathologies associated with CAG expansions. The de novo mutations expanded from ALS/SCA2 non-risk alleles as proven by meta-analysis method. The ALS risk was associated with SCA2 alleles as well as with intermediate CAG lengths in the ATXN2. Higher risk for ALS was associated with pathogenic CAG repeat as revealed by meta-analysis.
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22
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Di Fabio R, Santorelli F, Bertini E, Balestri M, Cursi L, Tessa A, Pierelli F, Casali C. Infantile childhood onset of spinocerebellar ataxia type 2. THE CEREBELLUM 2012; 11:526-30. [PMID: 21975856 DOI: 10.1007/s12311-011-0315-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Spinocerebellar ataxia type 2 (SCA2) is a late-onset autosomal dominant cerebellar ataxia caused by triplet CAG/CTG expansion in the ATX2 gene. The initial symptoms usually appear when subjects are in their 30s.Pediatric onset is less common and usually associated with larger triplet expansions. We here report the case of a 1-year-old girl who presented with facial dysmorphism,dystonic features, developmental delay, and retinitis pigmentosa.She was diagnosed as carrying an expanded CAG/CTG tract (92 repeats) before a molecular diagnosis of SCA2 was made in her father. Facial dysmorphism associated with developmental delay and retinitis pigmentosa in early childhood should prompt a careful family investigation for ataxia and study of ATX2.
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Affiliation(s)
- Roberto Di Fabio
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Via Francesco Faggiana 34, Latina, Italy.
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23
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Seidel K, Siswanto S, Brunt ERP, den Dunnen W, Korf HW, Rüb U. Brain pathology of spinocerebellar ataxias. Acta Neuropathol 2012; 124:1-21. [PMID: 22684686 DOI: 10.1007/s00401-012-1000-x] [Citation(s) in RCA: 283] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 05/25/2012] [Accepted: 05/25/2012] [Indexed: 12/22/2022]
Abstract
The autosomal dominant cerebellar ataxias (ADCAs) represent a heterogeneous group of neurodegenerative diseases with progressive ataxia and cerebellar degeneration. The current classification of this disease group is based on the underlying genetic defects and their typical disease courses. According to this categorization, ADCAs are divided into the spinocerebellar ataxias (SCAs) with a progressive disease course, and the episodic ataxias (EA) with episodic occurrences of ataxia. The prominent disease symptoms of the currently known and genetically defined 31 SCA types result from damage to the cerebellum and interconnected brain grays and are often accompanied by more specific extra-cerebellar symptoms. In the present review, we report the genetic and clinical background of the known SCAs and present the state of neuropathological investigations of brain tissue from SCA patients in the final disease stages. Recent findings show that the brain is commonly seriously affected in the polyglutamine SCAs (i.e. SCA1, SCA2, SCA3, SCA6, SCA7, and SCA17) and that the patterns of brain damage in these diseases overlap considerably in patients suffering from advanced disease stages. In the more rarely occurring non-polyglutamine SCAs, post-mortem neuropathological data currently are scanty and investigations have been primarily performed in vivo by means of MRI brain imaging. Only a minority of SCAs exhibit symptoms and degenerative patterns allowing for a clear and unambiguous diagnosis of the disease, e.g. retinal degeneration in SCA7, tau aggregation in SCA11, dentate calcification in SCA20, protein depositions in the Purkinje cell layer in SCA31, azoospermia in SCA32, and neurocutaneous phenotype in SCA34. The disease proteins of polyglutamine ataxias and some non-polyglutamine ataxias aggregate as cytoplasmic or intranuclear inclusions and serve as morphological markers. Although inclusions may impair axonal transport, bind transcription factors, and block protein quality control, detailed molecular and pathogenetic consequences remain to be determined.
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Affiliation(s)
- Kay Seidel
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe University, Theodor-Stern-Kai 7, 60950, Frankfurt/Main, Germany
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24
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Sequeiros J, Martins S, Silveira I. Epidemiology and population genetics of degenerative ataxias. HANDBOOK OF CLINICAL NEUROLOGY 2012; 103:227-51. [PMID: 21827892 DOI: 10.1016/b978-0-444-51892-7.00014-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jorge Sequeiros
- Institute of Molecular and Cell Biology, University of Porto, Portugal.
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25
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Yu Z, Zhu Y, Chen-Plotkin AS, Clay-Falcone D, McCluskey L, Elman L, Kalb RG, Trojanowski JQ, Lee VMY, Van Deerlin VM, Gitler AD, Bonini NM. PolyQ repeat expansions in ATXN2 associated with ALS are CAA interrupted repeats. PLoS One 2011; 6:e17951. [PMID: 21479228 PMCID: PMC3066214 DOI: 10.1371/journal.pone.0017951] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Accepted: 02/16/2011] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating, rapidly progressive disease leading to paralysis and death. Recently, intermediate length polyglutamine (polyQ) repeats of 27-33 in ATAXIN-2 (ATXN2), encoding the ATXN2 protein, were found to increase risk for ALS. In ATXN2, polyQ expansions of ≥ 34, which are pure CAG repeat expansions, cause spinocerebellar ataxia type 2. However, similar length expansions that are interrupted with other codons, can present atypically with parkinsonism, suggesting that configuration of the repeat sequence plays an important role in disease manifestation in ATXN2 polyQ expansion diseases. Here we determined whether the expansions in ATXN2 associated with ALS were pure or interrupted CAG repeats, and defined single nucleotide polymorphisms (SNPs) rs695871 and rs695872 in exon 1 of the gene, to assess haplotype association. We found that the expanded repeat alleles of 40 ALS patients and 9 long-repeat length controls were all interrupted, bearing 1-3 CAA codons within the CAG repeat. 21/21 expanded ALS chromosomes with 3CAA interruptions arose from one haplotype (GT), while 18/19 expanded ALS chromosomes with <3CAA interruptions arose from a different haplotype (CC). Moreover, age of disease onset was significantly earlier in patients bearing 3 interruptions vs fewer, and was distinct between haplotypes. These results indicate that CAG repeat expansions in ATXN2 associated with ALS are uniformly interrupted repeats and that the nature of the repeat sequence and haplotype, as well as length of polyQ repeat, may play a role in the neurological effect conferred by expansions in ATXN2.
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Affiliation(s)
- Zhenming Yu
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Yongqing Zhu
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alice S. Chen-Plotkin
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Dana Clay-Falcone
- Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Leo McCluskey
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Lauren Elman
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Robert G. Kalb
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - John Q. Trojanowski
- Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Virginia M.-Y. Lee
- Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Vivianna M. Van Deerlin
- Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Aaron D. Gitler
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Nancy M. Bonini
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Howard Hughes Medical Institute, Philadelphia, Pennsylvania, United States of America
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