1
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Cornejo-Olivas M, Solis-Ponce L, Araujo-Aliaga I, Milla-Neyra K, Ortega O, Illanes-Manrique M, Mazzetti P, Manrique-Enciso C, Cubas-Montecino D, Saraiva-Pereira ML, Jardim LB, Sarapura-Castro E. Machado Joseph-Disease Is Rare in the Peruvian Population. CEREBELLUM (LONDON, ENGLAND) 2023; 22:1192-1199. [PMID: 36323979 DOI: 10.1007/s12311-022-01491-4] [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: 10/21/2022] [Indexed: 11/06/2022]
Abstract
Spinocerebellar ataxia type 3 or Machado-Joseph disease (MJD/SCA3) is the most prevalent autosomal dominant cerebellar ataxia worldwide, but its frequency varies by geographic region. We describe MJD/SCA3 patients diagnosed in a tertiary healthcare institution in Peru. In a cohort of 341 individuals (253 probands) with clinical ataxia diagnosis, seven MJD/SCA3 probands were identified and their pedigrees extended, detecting a total of 18 MJD/SCA3 cases. Out of 506 alleles from all probands from this cohort, the 23-CAG repeat was the most common ATXN3 allele (31.8%), followed by the 14-CAG repeat allele (26.1%). Normal alleles ranged from 12 to 38 repeats while pathogenic alleles ranged from 64 to 75 repeats. We identified 80 large normal (LN) alleles (15.8%). Five out of seven families declared an affected family member traced back to foreign countries (England, Japan, China, and Trinidad and Tobago). MJD/SCA3 patients showed ataxia, accompanied by pyramidal signs, dysarthria, and dysphagia as well as abnormal oculomotor movements. In conclusion, ATXN3 allelic distribution in non-MJD/SCA3 patients with ataxia is similar to the distribution in normal individuals around the world, whereas LN allele frequency reinforces no correlation with the frequency of MJD/SCA3. Evidence of any atypical MJD/SCA3 phenotype was not found. Furthermore, haplotypes are required to confirm the foreign origin of MJD/SCA3 in the Peruvian population.
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Affiliation(s)
- Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru.
- Carrera de Medicina Humana, Universidad Científica del Sur, Lima, Peru.
| | - Lesly Solis-Ponce
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
- Instituto Nacional de Salud, Lima, Peru
| | - Ismael Araujo-Aliaga
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Karina Milla-Neyra
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Olimpio Ortega
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Maryenela Illanes-Manrique
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
- Global Brain Health Institute, University of California, San Francisco, CA, USA
| | - Pilar Mazzetti
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
- Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Carla Manrique-Enciso
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Diana Cubas-Montecino
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, Lima, Peru
| | - Maria Luiza Saraiva-Pereira
- Serviço de Genética Médica e Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
- Deptos. de Bioquímica e Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Laura B Jardim
- Serviço de Genética Médica e Centros de Pesquisa Clínica e Experimental, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
- Deptos. de Bioquímica e Medicina Interna, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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2
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Kurosaki T, Ashizawa T. The genetic and molecular features of the intronic pentanucleotide repeat expansion in spinocerebellar ataxia type 10. Front Genet 2022; 13:936869. [PMID: 36199580 PMCID: PMC9528567 DOI: 10.3389/fgene.2022.936869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/25/2022] [Indexed: 11/13/2022] Open
Abstract
Spinocerebellar ataxia type 10 (SCA10) is characterized by progressive cerebellar neurodegeneration and, in many patients, epilepsy. This disease mainly occurs in individuals with Indigenous American or East Asian ancestry, with strong evidence supporting a founder effect. The mutation causing SCA10 is a large expansion in an ATTCT pentanucleotide repeat in intron 9 of the ATXN10 gene. The ATTCT repeat is highly unstable, expanding to 280–4,500 repeats in affected patients compared with the 9–32 repeats in normal individuals, one of the largest repeat expansions causing neurological disorders identified to date. However, the underlying molecular basis of how this huge repeat expansion evolves and contributes to the SCA10 phenotype remains largely unknown. Recent progress in next-generation DNA sequencing technologies has established that the SCA10 repeat sequence has a highly heterogeneous structure. Here we summarize what is known about the structure and origin of SCA10 repeats, discuss the potential contribution of variant repeats to the SCA10 disease phenotype, and explore how this information can be exploited for therapeutic benefit.
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Affiliation(s)
- Tatsuaki Kurosaki
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY, United States
- Center for RNA Biology, University of Rochester, Rochester, NY, United States
- *Correspondence: Tatsuaki Kurosaki, ; Tetsuo Ashizawa,
| | - Tetsuo Ashizawa
- Stanley H. Appel Department of Neurology, Houston Methodist Research Institute and Weil Cornell Medical College at Houston Methodist Houston, TX, United States
- *Correspondence: Tatsuaki Kurosaki, ; Tetsuo Ashizawa,
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3
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Velázquez-Pérez L, Rodríguez-Labrada R, González-Garcés Y, Vázquez-Mojena Y, Pérez-Rodríguez R, Ziemann U. Neurophysiological features in spinocerebellar ataxia type 2: Prospects for novel biomarkers. Clin Neurophysiol 2021; 135:1-12. [PMID: 34998091 DOI: 10.1016/j.clinph.2021.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/05/2021] [Accepted: 12/13/2021] [Indexed: 12/12/2022]
Abstract
Electrophysiological biomarkers are useful to assess the degeneration and progression of the nervous system in pre-ataxic and ataxic stages of the Spinocerebellar Ataxia Type 2 (SCA2). These biomarkers are essentially defined by their clinical significance, discriminating patients and/or preclinical subjects from healthy controls in cross-sectional studies, their significant changes over time in longitudinal studies, and their correlation with the cytosine-guanine-adenine (CAG) repeat expansion and/or clinical ataxia scores, time of evolution and time to ataxia onset. We classified electrophysiological biomarkers into three main types: (1) preclinical, (2) disease progression and (3) genetic damage. We review the data that identify sural nerve potential amplitude, maximum saccadic velocity, sleep efficiency, rapid eye movement (REM) sleep percentage, K-complex density, REM sleep without atonia percentage, corticomuscular coherence, central motor conduction time, visual P300 latency, and antisaccadic error correction latency as reliable preclinical, progression and/or genetic damage biomarkers of SCA2. These electrophysiological biomarkers will facilitate the conduction of clinical trials that test the efficacy of emerging treatments in SCA2.
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Affiliation(s)
- Luis Velázquez-Pérez
- Cuban Academy of Sciences, Cuba st 460, Between Amargura and Teniente Rey, La Habana Vieja, La Habana, Cuba; Centre for the Research and Rehabilitation of Hereditary Ataxias, Libertad st 26, Between 12th and 16th Streets, Holguín, Cuba.
| | | | - Yasmany González-Garcés
- Centre for the Research and Rehabilitation of Hereditary Ataxias, Libertad st 26, Between 12th and 16th Streets, Holguín, Cuba
| | | | - Roberto Pérez-Rodríguez
- Machine Learning Department, Holguin University, Ave Celia Sánchez Between Ave de los Internacionalistas y Final, Hilda Torres, Holguín, Cuba
| | - Ulf Ziemann
- Department of Neurology & Stroke, University of Tübingen, Tübingen, Germany; Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
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4
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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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5
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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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6
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Nitschke L, Tewari A, Coffin SL, Xhako E, Pang K, Gennarino VA, Johnson JL, Blanco FA, Liu Z, Zoghbi HY. miR760 regulates ATXN1 levels via interaction with its 5' untranslated region. Genes Dev 2020; 34:1147-1160. [PMID: 32763910 PMCID: PMC7462065 DOI: 10.1101/gad.339317.120] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/07/2020] [Indexed: 01/24/2023]
Abstract
Identifying modifiers of dosage-sensitive genes involved in neurodegenerative disorders is imperative to discover novel genetic risk factors and potential therapeutic entry points. In this study, we focus on Ataxin-1 (ATXN1), a dosage-sensitive gene involved in the neurodegenerative disease spinocerebellar ataxia type 1 (SCA1). While the precise maintenance of ATXN1 levels is essential to prevent disease, the mechanisms that regulate ATXN1 expression remain largely unknown. We demonstrate that ATXN1's unusually long 5' untranslated region (5' UTR) negatively regulates its expression via posttranscriptional mechanisms. Based on recent reports that microRNAs (miRNAs) can interact with both 3' and 5' UTRs to regulate their target genes, we identify miR760 as a negative regulator that binds to a conserved site in ATXN1's 5' UTR to induce RNA degradation and translational inhibition. We found that delivery of Adeno-associated virus (AAV)-expressing miR760 in the cerebellum reduces ATXN1 levels in vivo and mitigates motor coordination deficits in a mouse model of SCA1. These findings provide new insights into the regulation of ATXN1 levels, present additional evidence for miRNA-mediated gene regulation via 5' UTR binding, and raise the possibility that noncoding mutations in the ATXN1 locus may act as risk factors for yet to be discovered progressive ataxias.
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Affiliation(s)
- Larissa Nitschke
- Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Ambika Tewari
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Stephanie L Coffin
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Program in Genetics and Genomics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Eder Xhako
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Program in Genetics and Genomics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Kaifang Pang
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Vincenzo A Gennarino
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Jennifer L Johnson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
| | - Francisco A Blanco
- Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Zhandong Liu
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Huda Y Zoghbi
- Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030, USA
- Program in Genetics and Genomics, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA
- Howard Hughes Medical Institute, Houston, Texas 77030, USA
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7
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Novis LE, Spitz M, Jardim M, Raskin S, Teive HAG. Evidence and practices of the use of next generation sequencing in patients with undiagnosed autosomal dominant cerebellar ataxias: a review. ARQUIVOS DE NEURO-PSIQUIATRIA 2020; 78:576-585. [PMID: 32725052 DOI: 10.1590/0004-282x20200017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 01/28/2020] [Indexed: 11/22/2022]
Abstract
Autosomal dominant cerebellar ataxias (ADCA) are heterogeneous diseases with a highly variable phenotype and genotype. They can be divided into episodic ataxia and spinocerebellar ataxia (SCA); the latter is considered the prototype of the ADCA. Most of the ADCA are caused by polyglutamine expansions, mainly SCA 1, 2, 3, 6, 7, 17 and Dentatorubral-pallidoluysian atrophy (DRPLA). However, 30% of patients remain undiagnosed after testing for these most common SCA. Recently, several studies have demonstrated that the new generation of sequencing methods are useful for the diagnose of these patients. This review focus on searching evidence on the literature, its usefulness in clinical practice and future perspectives.
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Affiliation(s)
- Luiz Eduardo Novis
- Universidade do Estado do Rio de Janeiro, Hospital Universitário Pedro Ernesto, Serviço de Neurologia, Rio de Janeiro RJ, Brazil
| | - Mariana Spitz
- Universidade do Estado do Rio de Janeiro, Hospital Universitário Pedro Ernesto, Serviço de Neurologia, Rio de Janeiro RJ, Brazil
| | - Marcia Jardim
- Universidade do Estado do Rio de Janeiro, Hospital Universitário Pedro Ernesto, Serviço de Neurologia, Rio de Janeiro RJ, Brazil
| | | | - Hélio A G Teive
- Universidade Federal do Paraná, Departamento de Clínica Médica, Serviço de Neurologia, Setor de Distúrbios do Movimento, Hospital das Clínicas, Curitiba PR, Brazil
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8
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Cornejo-Olivas M, Inca-Martinez M, Castilhos RM, Furtado GV, Mattos EP, Bampi GB, Leistner-Segal S, Marca V, Mazzetti P, Saraiva-Pereira ML, Jardim LB. Genetic Analysis of Hereditary Ataxias in Peru Identifies SCA10 Families with Incomplete Penetrance. THE CEREBELLUM 2020; 19:208-215. [PMID: 31900855 DOI: 10.1007/s12311-019-01098-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Relative frequency of hereditary ataxias remains unknown in many regions of Latin America. We described the relative frequency in spinocerebellar ataxias (SCA) due to (CAG)n and to (ATTCT)n expansions, as well as Friedreich ataxia (FRDA), among cases series of ataxic individuals from Peru. Among ataxic index cases from 104 families (38 of them with and 66 without autosomal dominant pattern of inheritance), we identified 22 SCA10, 8 SCA2, 3 SCA6, 2 SCA3, 2 SCA7, 1 SCA1, and 9 FRDA cases (or families). SCA10 was by far the most frequent one. Findings in SCA10 and FRDA families were of note. Affected genitors were not detected in 7 out of 22 SCA10 nuclear families; then overall maximal penetrance of SCA10 was estimated as 85%; in multiplex families, penetrance was 94%. Two out of nine FRDA cases carried only one allele with a GAA expansion. SCA10 was the most frequent hereditary ataxia in Peru. Our data suggested that ATTCT expansions at ATXN10 might not be fully penetrant and/or instability between generations might frequently cross the limits between non-penetrant and penetrant lengths. A unique distribution of inherited ataxias in Peru requires specific screening panels, considering SCA10 as first line of local diagnosis guidelines.
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Affiliation(s)
- Mario Cornejo-Olivas
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, 1271 Ancash St, Barrios Altos, 15003, Lima, Peru. .,Center for Global Health, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Miguel Inca-Martinez
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, 1271 Ancash St, Barrios Altos, 15003, Lima, Peru.,Lerner Research Institute, Genomic Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Raphael Machado Castilhos
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Serviço de Neurologia, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Gabriel Vasata Furtado
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Eduardo Preusser Mattos
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Giovana Bavia Bampi
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Sandra Leistner-Segal
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Victoria Marca
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, 1271 Ancash St, Barrios Altos, 15003, Lima, Peru
| | - Pilar Mazzetti
- Neurogenetics Research Center, Instituto Nacional de Ciencias Neurológicas, 1271 Ancash St, Barrios Altos, 15003, Lima, Peru
| | - Maria Luiza Saraiva-Pereira
- Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Laboratório de Identificação Genética, 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.,Instituto de Genética Médica Populacional (INAGEMP), 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.,Laboratório de Identificação Genética, 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.,Instituto de Genética Médica Populacional (INAGEMP), Porto Alegre, Brazil
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9
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Teive HAG, Meira AT, Camargo CHF, Munhoz RP. The Geographic Diversity of Spinocerebellar Ataxias (SCAs) in the Americas: A Systematic Review. Mov Disord Clin Pract 2019; 6:531-540. [PMID: 31538086 DOI: 10.1002/mdc3.12822] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/20/2019] [Accepted: 07/25/2019] [Indexed: 12/26/2022] Open
Abstract
Background The frequency and presentation of each of the most common forms of spinocerebellar ataxias (SCAs) varies widely. In the case of the Americas, this diversity is particularly dynamic given additional social, demographic, and cultural characteristics. Objective To describe the regional prevalence and clinical phenotypes of SCAs throughout the continent. Methods A literature search was performed in both MEDLINE and LILACS databases. The research was broadened to include the screening of reference lists of systematic review articles for additional studies. Investigations dating from the earliest available through 2019. Only studies in English, Portuguese, and Spanish were included. We analyzed publications with genetically confirmed cases only, ranging from robust samples with epidemiological data to case reports and case series from each country or regions. Results Overall, SCA3 is the most common form in the continent. Region-specific prevalence and ranking of the common forms vary. On the other hand, region-specific phenotypic variations were not consistently found based on the available literature analyzed, with the exception of the absence of epilepsy in SCA10 consistently described in a particular cluster of cases in South Brazil. Conclusion Systematic, multinational studies analyzing in detail the true frequencies of SCAs across the Americas as well as distinct clinical signs and clues of each form would be ideal to look for these potential variations.
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Affiliation(s)
- Hélio A G Teive
- Movement Disorders Unit, Neurology Service, Internal Medicine Department Hospital de Clínicas, Federal University of Parana Curitiba Parana Brazil.,Neurological Diseases Group Graduate Program of Internal Medicine, Hospital de Clínicas, Federal University of Parana Curitiba Parana Brazil
| | - Alex T Meira
- Movement Disorders Unit, Neurology Service, Internal Medicine Department Hospital de Clínicas, Federal University of Parana Curitiba Parana Brazil
| | - Carlos Henrique F Camargo
- Neurological Diseases Group Graduate Program of Internal Medicine, Hospital de Clínicas, Federal University of Parana Curitiba Parana Brazil
| | - Renato P Munhoz
- Movement Disorders Centre Toronto Western Hospital, University of Toronto Toronto Ontario Canada
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10
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Abstract
The spinocerebellar ataxias (SCAs) are a genetically heterogeneous group of autosomal dominantly inherited progressive disorders, the clinical hallmark of which is loss of balance and coordination accompanied by slurred speech; onset is most often in adult life. Genetically, SCAs are grouped as repeat expansion SCAs, such as SCA3/Machado-Joseph disease (MJD), and rare SCAs that are caused by non-repeat mutations, such as SCA5. Most SCA mutations cause prominent damage to cerebellar Purkinje neurons with consecutive cerebellar atrophy, although Purkinje neurons are only mildly affected in some SCAs. Furthermore, other parts of the nervous system, such as the spinal cord, basal ganglia and pontine nuclei in the brainstem, can be involved. As there is currently no treatment to slow or halt SCAs (many SCAs lead to premature death), the clinical care of patients with SCA focuses on managing the symptoms through physiotherapy, occupational therapy and speech therapy. Intense research has greatly expanded our understanding of the pathobiology of many SCAs, revealing that they occur via interrelated mechanisms (including proteotoxicity, RNA toxicity and ion channel dysfunction), and has led to the identification of new targets for treatment development. However, the development of effective therapies is hampered by the heterogeneity of the SCAs; specific therapeutic approaches may be required for each disease.
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11
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Abstract
Machado-Joseph disease (MJD) also known as Spinocerebellar ataxia type 3, is a hereditary neurodegenerative disease associated with severe clinical manifestations and premature death. Although rare, it is the most common autosomal dominant spinocerebellar ataxia worldwide and has a distinct geographic distribution, reaching peak prevalence in certain regions of Brazil, Portugal and China. Due to its clinical heterogeneity, it was initially described as several different entities and as had many designations over the last decades. An accurate diagnosis become possible in 1994, after the identification of the MJD1 gene. Among its wide clinical spectrum, progressive cerebellar ataxia is normally present. Other symptoms include pyramidal syndrome, peripheral neuropathy, oculomotor abnormalities, extrapyramidal signs and sleep disorders. On the basis of the presence/absence of important extra-pyramidal signs, and the presence/absence of peripheral signs, five clinical types have been defined. Neuroimaging studies like MRI, DTI and MRS, can be useful as they can characterize structural and functional differences in specific subgroups of patients with MJD. There is no effective treatment for MJD. Symptomatic therapies are used to relieve some of the clinical symptoms and physiotherapy is also helpful in improving quality of live. Several clinical trials have been carried out using different molecules like sulfamethoxazole-trimethoprim, varenicline and lithium carbonate, but the results of these trials were negative or showed little benefit. Future studies sufficiently powered and adequately designed are warranted.
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12
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Atadzhanov M, Smith DC, Mwaba MH, Siddiqi OK, Bryer A, Greenberg LJ. Clinical and genetic analysis of spinocerebellar ataxia type 7 (SCA7) in Zambian families. CEREBELLUM & ATAXIAS 2017; 4:17. [PMID: 29214039 PMCID: PMC5706398 DOI: 10.1186/s40673-017-0075-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/03/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND To date, 43 types of Spinocerebellar Ataxias (SCAs) have been identified. A subset of the SCAs are caused by the pathogenic expansion of a CAG repeat tract within the corresponding gene. Ethnic and geographic differences are evident in the prevalence of the autosomal dominant SCAs. Few descriptions of the clinical phenotype and molecular genetics of the SCAs are available from the African continent. Established studies mostly concern the South African populations, where there is a high frequency of SCA1, SCA2 and SCA7. The SCA7 mutation in South Africa (SA) has been found almost exclusively in families of indigenous Black African ethnic origin. OBJECTIVE To present the results of the first clinical description of seven Zambian families presenting with autosomal dominant SCA, as well as the downstream molecular genetic analysis of a subset of these families. METHODS The study was undertaken at the University Teaching Hospital in Lusaka, Zambia. Ataxia was quantified with the Brief Ataxia Rating Scale derived from the modified international ataxia rating scale. Molecular genetic testing for 5 types of SCA (SCA1, SCA2, SCA3, SCA6 and SCA7) was performed at the National Health Laboratory Service at Groote Schuur Hospital and the Division of Human Genetics, University of Cape Town, SA. The clinical and radiological features were evaluated in seven families with autosomal dominant cerebellar ataxia. Molecular genetic analysis was completed on individuals representing three of the seven families. RESULTS All affected families were ethnic Zambians from various tribes, originating from three different regions of the country (Eastern, Western and Central province). Thirty-four individuals from four families had phenotypic features of SCA7. SCA7 was confirmed by molecular testing in 10 individuals from 3 of these families. The age of onset of the disease varied from 12 to 59 years. The most prominent phenotypic features in these families were gait and limb ataxia, dysarthria, visual loss, ptosis, ophthalmoparesis/ophthalmoplegia, pyramidal tract signs, and dementia. Affected members of the SCA7 families had progressive macular degeneration and cerebellar atrophy. All families displayed marked anticipation of age at onset and rate of symptom progression. The pathogenic SCA7 CAG repeat ranges varied from 47 to 56 repeats. Three additional families were found to have clinical phenotypes associated with autosomal dominant SCA, however, DNA was not available for molecular confirmation. The age of onset of the disease in these families varied from 19 to 53 years. The most common clinical picture in these families included a combination of cerebellar symptoms with slow saccadic eye movements, peripheral neuropathy, dementia and tremor. CONCLUSION SCA is prevalent in ethnic Zambian families. The SCA7 families in this report had similar clinical presentations to families described in other African countries. In all families, the disease had an autosomal dominant pattern of inheritance across multiple generations. All families displayed anticipation of both age of onset and the rate of disease progression. Further clinical and molecular investigations of the inherited ataxias in a larger cohort of patients is important to understand the natural history and origin of SCAs in the Zambian population.
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Affiliation(s)
- Masharip Atadzhanov
- Department of Internal Medicine, University of Zambia School of Medicine, Lusaka, Zambia
| | - Danielle C. Smith
- Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Division of Neurology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa
| | - Mwila H. Mwaba
- Department of Internal Medicine, University of Zambia School of Medicine, Lusaka, Zambia
| | - Omar K. Siddiqi
- Department of Internal Medicine, University of Zambia School of Medicine, Lusaka, Zambia
- Global Neurology Program, Division of Neuro-Immunology, Center for Virology and Vaccine Research, Department of Neurology, Beth Deaconess Medical Center, Harvard Medical School, Boston, MA USA
| | - Alan Bryer
- Division of Neurology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa
| | - L. Jacquie Greenberg
- Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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13
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Velázquez-Pérez LC, Rodríguez-Labrada R, Fernandez-Ruiz J. Spinocerebellar Ataxia Type 2: Clinicogenetic Aspects, Mechanistic Insights, and Management Approaches. Front Neurol 2017; 8:472. [PMID: 28955296 PMCID: PMC5601978 DOI: 10.3389/fneur.2017.00472] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/25/2017] [Indexed: 12/14/2022] Open
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant cerebellar ataxia that occurs as a consequence of abnormal CAG expansions in the ATXN2 gene. Progressive clinical features result from the neurodegeneration of cerebellum and extra-cerebellar structures including the pons, the basal ganglia, and the cerebral cortex. Clinical, electrophysiological, and imaging approaches have been used to characterize the natural history of the disease, allowing its classification into four distinct stages, with special emphasis on the prodromal stage, which is characterized by a plethora of motor and non-motor features. Neuropathological investigations of brain tissue from SCA2 patients reveal a widespread involvement of multiple brain systems, mainly cerebellar and brainstem systems. Recent findings linking ataxin-2 intermediate expansions to other neurodegenerative diseases such as amyotrophic lateral sclerosis have provided insights into the ataxin-2-related toxicity mechanism in neurodegenerative diseases and have raised new ethical challenges to molecular predictive diagnosis of SCA2. No effective neuroprotective therapies are currently available for SCA2 patients, but some therapeutic options such as neurorehabilitation and some emerging neuroprotective drugs have shown palliative benefits.
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Affiliation(s)
- Luis C Velázquez-Pérez
- Centre for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba.,Medical University of Holguín "Mariana Grajales", Holguín, Cuba
| | - Roberto Rodríguez-Labrada
- Centre for the Research and Rehabilitation of Hereditary Ataxias, Holguín, Cuba.,Physical Culture School, University of Holguin "Oscar Lucero", Holguín, Cuba
| | - Juan Fernandez-Ruiz
- Department of Physiology, Medicine School, UNAM, Cuernavaca, Mexico.,Psychology School, Universidad Veracruzana, Xalapa, Mexico
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14
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Velázquez-Pérez L, Rodríguez-Labrada R, Laffita-Mesa JM. Prodromal spinocerebellar ataxia type 2: Prospects for early interventions and ethical challenges. Mov Disord 2017; 32:708-718. [DOI: 10.1002/mds.26969] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 01/24/2017] [Accepted: 01/30/2017] [Indexed: 12/29/2022] Open
Affiliation(s)
| | | | - José Miguel Laffita-Mesa
- Centre for the Research and Rehabilitation of Hereditary Ataxias; Holguín Cuba
- Department of Clinical Neuroscience; Karolinska Universitetssjukhuset; Stockholm Sweden
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15
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Alves-Cruzeiro JMDC, Mendonça L, Pereira de Almeida L, Nóbrega C. Motor Dysfunctions and Neuropathology in Mouse Models of Spinocerebellar Ataxia Type 2: A Comprehensive Review. Front Neurosci 2016; 10:572. [PMID: 28018166 PMCID: PMC5156697 DOI: 10.3389/fnins.2016.00572] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/28/2016] [Indexed: 12/16/2022] Open
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant ataxia caused by an expansion of CAG repeats in the exon 1 of the gene ATXN2, conferring a gain of toxic function that triggers the appearance of the disease phenotype. SCA2 is characterized by several symptoms including progressive gait ataxia and dysarthria, slow saccadic eye movements, sleep disturbances, cognitive impairments, and psychological dysfunctions such as insomnia and depression, among others. The available treatments rely on palliative care, which mitigate some of the major symptoms but ultimately fail to block the disease progression. This persistent lack of effective therapies led to the development of several models in yeast, C. elegans, D. melanogaster, and mice to serve as platforms for testing new therapeutic strategies and to accelerate the research on the complex disease mechanisms. In this work, we review 4 transgenic and 1 knock-in mouse that exhibit a SCA2-related phenotype and discuss their usefulness in addressing different scientific problems. The knock-in mice are extremely faithful to the human disease, with late onset of symptoms and physiological levels of mutant ataxin-2, while the other transgenic possess robust and well-characterized motor impairments and neuropathological features. Furthermore, a new BAC model of SCA2 shows promise to study the recently explored role of non-coding RNAs as a major pathogenic mechanism in this devastating disorder. Focusing on specific aspects of the behavior and neuropathology, as well as technical aspects, we provide a highly practical description and comparison of all the models with the purpose of creating a useful resource for SCA2 researchers worldwide.
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Affiliation(s)
| | - Liliana Mendonça
- Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal
| | - Luís Pereira de Almeida
- Center for Neuroscience and Cell Biology, University of CoimbraCoimbra, Portugal; Faculty of Pharmacy, University of CoimbraCoimbra, Portugal
| | - Clévio Nóbrega
- Department of Biomedical Sciences and Medicine and Center for Biomedical Research, University of Algarve Faro, Portugal
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16
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Neurogenetics in Peru: clinical, scientific and ethical perspectives. J Community Genet 2015; 6:251-7. [PMID: 26013639 DOI: 10.1007/s12687-015-0239-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 05/18/2015] [Indexed: 10/23/2022] Open
Abstract
Neurogenetics, the science that studies the genetic basis of the development and function of the nervous system, is a discipline of recent development in Peru, an emerging Latin American country. Herein, we review the clinical, scientific and ethical aspects regarding the development of this discipline, starting with the first molecular diagnosis of neurogenetic diseases, to family and population-based genetic association studies. Neurogenetics in Peru aims to better explain the epidemiology of monogenic and complex neurodegenerative disorders that will help in implementing public health policies for these disorders. The characterization of Peru and its health system, legal issues regarding rare diseases and the historical milestones in neurogenetics are also discussed.
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17
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Salas-Vargas J, Mancera-Gervacio J, Velázquez-Pérez L, Rodrígez-Labrada R, Martínez-Cruz E, Magaña JJ, Durand-Rivera A, Hernández-Hernández O, Cisneros B, Gonzalez-Piña R. Spinocerebellar ataxia type 7: a neurodegenerative disorder with peripheral neuropathy. Eur Neurol 2015; 73:173-8. [PMID: 25614072 DOI: 10.1159/000370239] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 11/30/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND Autosomal dominant spinocerebellar ataxias (SCA) are a group of inherited neurodegenerative disorders that typically show peripheral neuropathy. SCA7 is one of the rarest forms of SCA (<1/100,000 individuals). However, the disease shows a prevalence of ∼800/100,000 inhabitants in certain regions of Mexico. This low global prevalence may explain, at least in part, the isolated anecdotal and limited clinical data regarding peripheral neuropathy in SCA7 patients. AIM To assess sensory and motor peripheral nerve action potentials in an SCA7 patients group and in healthy volunteers, and subsequently correlate the electrophysiological findings with clinical and genetic features. MATERIALS AND METHODS We enrolled in our study, 13 symptomatic SCA7 patients with a confirmed molecular and clinical diagnosis, and 19 healthy volunteers as the control group. Nerve conduction studies were carried out using standard electromyography recording methods. The sensory and motor latency, amplitude and conduction velocity were recorded in both experimental groups and analyzed using the Student's t-test. RESULTS SCA7 patients showed a significant prolongation of sensory nerve conduction latencies, as well as a decrease in sensory amplitudes. Decreases in motor amplitudes and peroneal conduction velocity were also observed. Finally, we found an association between CAG repeats and the severity of cerebellar and non-cerebellar symptoms with electrophysiological signs of demyelinization. DISCUSSION Our results reveal the existence of a critical sensorimotor peripheral neuropathy in SCA7 patients. Moreover, we show that using sensitive electrophysiological tools to evaluate nerve conduction can improve the diagnosis and design of therapeutic options based on pharmacological and rehabilitative strategies. CONCLUSION These findings demonstrate that SCA7 is a disease that globally affects the peripheral nervous system.
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Affiliation(s)
- José Salas-Vargas
- Centro de Rehabilitación e Inclusión Social de Veracruz, Xalapa, Mexico
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18
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Mercadillo RE, Galvez V, Díaz R, Paredes L, Velázquez-Moctezuma J, Hernandez-Castillo CR, Fernandez-Ruiz J. Social and Cultural Elements Associated with Neurocognitive Dysfunctions in Spinocerebellar Ataxia Type 2 Patients. Front Psychiatry 2015; 6:90. [PMID: 26113822 PMCID: PMC4462049 DOI: 10.3389/fpsyt.2015.00090] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 05/27/2015] [Indexed: 11/30/2022] Open
Abstract
Spinocerebellar Ataxia Type 2 (SCA2) is a rare genetic disorder producing cerebellar degeneration and affecting motor abilities. Neuroimaging studies also show neurodegeneration in subcortical and cortical regions related to emotional and social processes. From social neuroscience, it is suggested that motor and social abilities can be influenced by particular cultural dynamics so, culture is fundamental to understand the effect of brain-related alterations. Here, we present the first analysis about the cultural elements related to the SCA2 disorder in 15 patients previously evaluated with neuroimaging and psychometric instruments, and their nuclear relationships distributed in six geographical and cultural regions in Mexico. Ethnographic records and photographic and video archives about the quotidian participant's routine were obtained from the patients, their relatives and their caregivers. The information was categorized and interpreted taking into consideration cultural issues and patients' medical files. Our analyses suggest that most of the participants do not understand the nature of the disease and this misunderstanding favors magic and non-medical explanations. Patients' testimonies suggest a decrease in pain perception as well as motor alterations that may be related to interoceptive dysfunctions. Relatives' testimonies indicate patients' lack of social and emotional interests that may be related to frontal, temporal, and cerebellar degeneration. In general, participants use their religious beliefs to deal with the disease and only a few of them trust the health system. Patients and their families are either openly rejected and ignored, tolerated or even helped by their community accordingly to different regional traits. We propose that ethnography can provide social representations to understand the patients' alterations, to formulate neurobiological hypotheses, to develop neurocognitive interventions, and to improve the medical approach to the disease.
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Affiliation(s)
- Roberto Emmanuele Mercadillo
- Laboratorio de Neuropsicología, Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México , Mexico City , Mexico ; Consejo Nacional de Ciencia y Tecnología-Cátedras , Mexico City , Mexico ; Área de Neurociencias, Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana, Unidad Iztapalapa , Mexico City , Mexico
| | - Víctor Galvez
- Posgrado en Neuroetología, Universidad Veracruzana , Xalapa , Mexico
| | - Rosalinda Díaz
- Laboratorio de Neuropsicología, Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México , Mexico City , Mexico
| | - Lorena Paredes
- Facultad de Psicología, Universidad Nacional Autónoma de México , Mexico City , Mexico
| | - Javier Velázquez-Moctezuma
- Área de Neurociencias, Departamento de Biología de la Reproducción, Universidad Autónoma Metropolitana, Unidad Iztapalapa , Mexico City , Mexico
| | - Carlos R Hernandez-Castillo
- Consejo Nacional de Ciencia y Tecnología-Cátedras , Mexico City , Mexico ; Instituto de Neuroetología, Universidad Veracruzana , Xalapa , Mexico
| | - Juan Fernandez-Ruiz
- Laboratorio de Neuropsicología, Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México , Mexico City , Mexico ; Posgrado en Neuroetología, Universidad Veracruzana , Xalapa , Mexico ; Facultad de Psicología, Universidad Veracruzana , Xalapa , Mexico
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Cintra VP, Lourenço CM, Marques SE, de Oliveira LM, Tumas V, Marques W. Mutational screening of 320 Brazilian patients with autosomal dominant spinocerebellar ataxia. J Neurol Sci 2014; 347:375-9. [DOI: 10.1016/j.jns.2014.10.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/23/2014] [Accepted: 10/27/2014] [Indexed: 11/26/2022]
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20
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de Castilhos RM, Furtado GV, Gheno TC, Schaeffer P, Russo A, Barsottini O, Pedroso JL, Salarini DZ, Vargas FR, de Lima MADFD, Godeiro C, Santana-da-Silva LC, Toralles MBP, Santos S, van der Linden H, Wanderley HY, de Medeiros PFV, Pereira ET, Ribeiro E, Saraiva-Pereira ML, Jardim LB. Spinocerebellar ataxias in Brazil--frequencies and modulating effects of related genes. THE CEREBELLUM 2014; 13:17-28. [PMID: 23943520 DOI: 10.1007/s12311-013-0510-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
This study describes the frequency of spinocerebellar ataxias and of CAG repeats range in different geographical regions of Brazil, and explores the hypothetical role of normal CAG repeats at ATXN1, ATXN2, ATXN3, CACNA1A, and ATXN7 genes on age at onset and on neurological findings. Patients with symptoms and family history compatible with a SCA were recruited in 11 cities of the country; clinical data and DNA samples were collected. Capillary electrophoresis was performed to detect CAG lengths at SCA1, SCA2, SCA3/MJD, SCA6, SCA7, SCA12, SCA17, and DRPLA associated genes, and a repeat primed PCR was used to detect ATTCT expansions at SCA10 gene. Five hundred forty-four patients (359 families) were included. There were 214 SCA3/MJD families (59.6 %), 28 SCA2 (7.8 %), 20 SCA7 (5.6 %), 15 SCA1 (4.2 %), 12 SCA10 (3.3 %), 5 SCA6 (1.4 %), and 65 families without a molecular diagnosis (18.1 %). Divergent rates of SCA3/MJD, SCA2, and SCA7 were seen in regions with different ethnic backgrounds. 64.7 % of our SCA10 patients presented seizures. Among SCA2 patients, longer ATXN3 CAG alleles were associated with earlier ages at onset (p < 0.036, linear regression). A portrait of SCAs in Brazil was obtained, where variation in frequencies seemed to parallel ethnic differences. New potential interactions between some SCA-related genes were presented.
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Affiliation(s)
- Raphael Machado de Castilhos
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90.035-903, Porto Alegre, Rio Grande do Sul, Brazil
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21
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García-Velázquez LE, Canizales-Quinteros S, Romero-Hidalgo S, Ochoa-Morales A, Martínez-Ruano L, Márquez-Luna C, Acuña-Alonzo V, Villarreal-Molina MT, Alonso-Vilatela ME, Yescas-Gómez P. Founder effect and ancestral origin of the spinocerebellar ataxia type 7 (SCA7) mutation in Mexican families. Neurogenetics 2013; 15:13-7. [DOI: 10.1007/s10048-013-0387-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 12/04/2013] [Indexed: 11/28/2022]
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22
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Hernandez-Castillo CR, Alcauter S, Galvez V, Barrios FA, Yescas P, Ochoa A, Garcia L, Diaz R, Gao W, Fernandez-Ruiz J. Disruption of visual and motor connectivity in spinocerebellar ataxia type 7. Mov Disord 2013; 28:1708-16. [DOI: 10.1002/mds.25618] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/28/2013] [Accepted: 07/01/2013] [Indexed: 11/06/2022] Open
Affiliation(s)
- Carlos R. Hernandez-Castillo
- Instituto de Neuroetologia; Universidad Veracruzana; Xalapa Mexico
- Department of Radiology and BRIC; University of North Carolina; Chapel Hill North Carolina USA
| | - Sarael Alcauter
- Department of Radiology and BRIC; University of North Carolina; Chapel Hill North Carolina USA
| | - Victor Galvez
- Instituto de Neuroetologia; Universidad Veracruzana; Xalapa Mexico
| | - Fernando A. Barrios
- Instituto de Neurobiología; Universidad Nacional Autónoma de México; Mexico City Mexico
| | - Petra Yescas
- Departamento de Neurogenetica y Biologia Molecular; Instituto Nacional de Neurologia y Neurocirugia. Manuel Velasco Suarez; Mexico City Mexico
| | - Adriana Ochoa
- Departamento de Neurogenetica y Biologia Molecular; Instituto Nacional de Neurologia y Neurocirugia. Manuel Velasco Suarez; Mexico City Mexico
| | - Lizbeth Garcia
- Departamento de Neurogenetica y Biologia Molecular; Instituto Nacional de Neurologia y Neurocirugia. Manuel Velasco Suarez; Mexico City Mexico
| | - Rosalinda Diaz
- Departamento de Fisiologia, Facultad de Medicina; Universidad Nacional Autonoma de Mexico; Mexico City Mexico
| | - Wei Gao
- Department of Radiology and BRIC; University of North Carolina; Chapel Hill North Carolina USA
| | - Juan Fernandez-Ruiz
- Instituto de Neuroetologia; Universidad Veracruzana; Xalapa Mexico
- Departamento de Fisiologia, Facultad de Medicina; Universidad Nacional Autonoma de Mexico; Mexico City Mexico
- Facultad de Psicologia; Universidad Veracruzana; Xalapa Mexico
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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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Cruz-Mariño T, Laffita-Mesa JM, Gonzalez-Zaldivar Y, Velazquez-Santos M, Aguilera-Rodriguez R, Estupinan-Rodriguez A, Vazquez-Mojena Y, Macleod P, Paneque M, Velazquez-Perez L. Large normal and intermediate alleles in the context of SCA2 prenatal diagnosis. J Genet Couns 2013; 23:89-96. [PMID: 23813298 DOI: 10.1007/s10897-013-9615-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 05/22/2013] [Indexed: 12/22/2022]
Abstract
In 2001 a program for predictive testing of Spinocerebellar Ataxia type 2 was developed in Cuba, based on the detection of an abnormal CAG trinucleotide repeat expansion in the ATXN2 gene. A descriptive study was designed to assess the implications of ATXN2 large normal and intermediate alleles in the context of the SCA2 Prenatal Diagnosis Program. Four clinical scenarios were selected based upon the behaviour of large normal and intermediate alleles when passing from one generation to the next, showing expansions, contractions, or stability in the CAG repeat size. In some populations, traditional Mendelian risk figures of 0 % or 50 % may not be applicable due to the high frequency of unstable large normal alleles. Couples with no family history of SCA2 may have a >0 % risk of having an affected offspring. Similarly, couples in which there is both an expanded and a large normal allele may have a recurrence risk >50 %. It is imperative that these issues be addressed with these couples during genetic counseling. These recurrence risks have to be carefully estimated in the presence of such alleles (particularly alleles ≥27 CAG repeats), carriers need to be aware of the potential risk for their descendants, and programs for prenatal diagnosis must be available for them.
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Affiliation(s)
- Tania Cruz-Mariño
- Predictive Genetics Department, Center for the Research and Rehabilitation of Hereditary Ataxias, Reparto Edecio Pérez, Carretera Vía Habana, Holguín, Cuba, 80100,
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25
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Magaña J, Tapia-Guerrero Y, Velázquez-Pérez L, Cerecedo-Zapata C, Maldonado-Rodríguez M, Jano-Ito J, Leyva-García N, González-Piña R, Martínez-Cruz E, Hernández-Hernández O, Cisneros B. Analysis of CAG repeats in five SCA loci in Mexican population: epidemiological evidence of a SCA7 founder effect. Clin Genet 2013; 85:159-65. [DOI: 10.1111/cge.12114] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 01/25/2013] [Accepted: 01/25/2013] [Indexed: 12/14/2022]
Affiliation(s)
- J.J. Magaña
- Laboratory of Genomic Medicine, Department of Genetics; National Rehabilitation Institute (INR); Mexico City Mexico
| | - Y.S. Tapia-Guerrero
- Laboratory of Genomic Medicine, Department of Genetics; National Rehabilitation Institute (INR); Mexico City Mexico
- Superior Medicine School; National Polytechnic Institute (IPN); Mexico City Mexico
| | - L. Velázquez-Pérez
- General Direction, Center for Research and Rehabilitation of the Hereditary Ataxias (CIRAH); Holguín Cuba
| | - C.M. Cerecedo-Zapata
- Laboratory of Genomic Medicine, Department of Genetics; National Rehabilitation Institute (INR); Mexico City Mexico
| | - M. Maldonado-Rodríguez
- Laboratory of Genomic Medicine, Department of Genetics; National Rehabilitation Institute (INR); Mexico City Mexico
- Faculty of Chemistry; National Autonomous University of Mexico (UNAM); Mexico City Mexico
| | - J.S. Jano-Ito
- Laboratory of Genomic Medicine, Department of Genetics; National Rehabilitation Institute (INR); Mexico City Mexico
| | - N. Leyva-García
- Laboratory of Genomic Medicine, Department of Genetics; National Rehabilitation Institute (INR); Mexico City Mexico
| | | | - E. Martínez-Cruz
- Rehabilitation Sub Direction, Rehabilitation and Special Education Center of Veracruz (CREEVER-DIF); Xalapa Veracruz Mexico
| | - O. Hernández-Hernández
- Laboratory of Genomic Medicine, Department of Genetics; National Rehabilitation Institute (INR); Mexico City Mexico
| | - B. Cisneros
- Department of Genetics and Molecular Biology; Center of Research and Advanced Studies (CINVESTAV)-IPN; Mexico City Mexico
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Magaña JJ, Velázquez-Pérez L, Cisneros B. Spinocerebellar ataxia type 2: clinical presentation, molecular mechanisms, and therapeutic perspectives. Mol Neurobiol 2012; 47:90-104. [PMID: 22996397 DOI: 10.1007/s12035-012-8348-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 09/05/2012] [Indexed: 12/13/2022]
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant genetic disease characterized by cerebellar dysfunction associated with slow saccades, early hyporeflexia, severe tremor of postural or action type, peripheral neuropathy, cognitive disorders, and other multisystemic features. SCA2, one of the most common ataxias worldwide, is caused by the expansion of a CAG triplet repeat located in the N-terminal coding region of the ATXN2 gene, which results in the incorporation of a segment of polyglutamines in the mutant protein, being longer expansions associated with earlier onset and more sever disease in subsequent generations. In this review, we offer a detailed description of the clinical manifestations of SCA2 and compile the experimental evidence showing the participation of ataxin-2 in crucial cellular processes, including messenger RNA maturation and translation, and endocytosis. In addition, we discuss in the light of present data the potential molecular mechanisms underlying SCA2 pathogenesis. The mutant protein exhibits a toxic gain of function that is mainly attributed to the generation of neuronal inclusions of phosphorylated and/or proteolytic cleaved mutant ataxin-2, which might alter normal ataxin-2 function, leading to cell dysfunction and death of target cells. In the final part of this review, we discuss the perspectives of development of therapeutic strategies for SCA2. Based on previous experience with other polyglutamine disorders and considering the molecular basis of SCA2 pathogenesis, a nuclei-acid-based strategy focused on the specific silencing of the dominant disease allele that preserves the expression of the wild-type allele is highly desirable and might prevent toxic neurodegenerative sequelae.
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Affiliation(s)
- J J Magaña
- Department of Genetics, National Rehabilitation Institute (INR), Mexico City, Mexico
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Transgenic models of spinocerebellar ataxia type 10: modeling a repeat expansion disorder. Genes (Basel) 2012; 3:481-491. [PMID: 24533179 PMCID: PMC3899997 DOI: 10.3390/genes3030481] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 07/24/2012] [Accepted: 07/26/2012] [Indexed: 01/01/2023] Open
Abstract
Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurodegenerative disease with a spectrum of phenotypes. SCA10 is caused by a pentanucleotide repeat expansion of the ATTCT motif within intron 9 of ATAXIN 10 (ATXN10). Patients present with cerebellar ataxia; however, a subset also develops epileptic seizures which significantly contribute to the morbidity and mortality of the disease. Past research from our lab has demonstrated that epileptic SCA10 patients predominantly originate from or have ancestral ties to Mexico. In addition, a large proportion of epileptic SCA10 patients carry repeat interruptions within their SCA10 expansion. This paper outlines the variability in SCA10 phenotypes and our attempts to model these phenotypes using transgenic mouse models and highlights the benefits of using a transgenic model organism to understand the pathological mechanisms of a human disease.
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Velázquez-Pérez L, Rodríguez-Labrada R, García-Rodríguez JC, Almaguer-Mederos LE, Cruz-Mariño T, Laffita-Mesa JM. A comprehensive review of spinocerebellar ataxia type 2 in Cuba. THE CEREBELLUM 2011; 10:184-98. [PMID: 21399888 DOI: 10.1007/s12311-011-0265-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant cerebellar ataxia characterized by a progressive cerebellar syndrome associated to saccadic slowing, peripheral neuropathy, cognitive disorders, and other multisystem features. SCA2 is caused by the abnormal expansion of cytosine-adenine-guanine triplet repeats in the encoding region of the ATXN2 gene and therefore the expression of toxic polyglutamine expansions in the ataxin 2 protein, which cause progressive neuronal death of Purkinje cells in the cerebellum and several pontine, mesencephalic, and thalamic neurons among other cells. Worldwide, SCA2 is the second most frequent type of spinocerebellar ataxia, only surpassed by SCA3. Nevertheless, in Holguin, Cuba, the disease reaches the highest prevalence, resulting from a putative foundational effect. This review discusses the most important advances in the genotypical and phenotypical studies of SCA2, highlighting the comprehensive characterization reached in Cuba through clinical, neuroepidemiological, neurochemical, and neurophysiological evaluation of SCA2 patients and pre-symptomatic subjects, which has allowed the identification of new disease biomarkers and therapeutical opportunities. These findings provide guidelines, from a Cuban viewpoint, for the clinical management of the disease, its diagnosis, genetic counseling, and therapeutical options through rehabilitative therapy and/or pharmacological options.
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Affiliation(s)
- Luis Velázquez-Pérez
- Centro para la Investigación y Rehabilitación de Ataxias Hereditarias, 80100, Holguín, Cuba.
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Bettencourt C, Lima M. Machado-Joseph Disease: from first descriptions to new perspectives. Orphanet J Rare Dis 2011; 6:35. [PMID: 21635785 PMCID: PMC3123549 DOI: 10.1186/1750-1172-6-35] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 06/02/2011] [Indexed: 11/23/2022] Open
Abstract
Machado-Joseph Disease (MJD), also known as spinocerebellar ataxia type 3 (SCA3), represents the most common form of SCA worldwide. MJD is an autosomal dominant neurodegenerative disorder of late onset, involving predominantly the cerebellar, pyramidal, extrapyramidal, motor neuron and oculomotor systems; although sharing features with other SCAs, the identification of minor, but more specific signs, facilitates its differential diagnosis. MJD presents strong phenotypic heterogeneity, which has justified the classification of patients into three main clinical types. Main pathological lesions are observed in the spinocerebellar system, as well as in the cerebellar dentate nucleus. MJD's causative mutation consists in an expansion of an unstable CAG tract in exon 10 of the ATXN3 gene, located at 14q32.1. Haplotype-based studies have suggested that two main founder mutations may explain the present global distribution of the disease; the ancestral haplotype is of Asian origin, and has an estimated age of around 5,800 years, while the second mutational event has occurred about 1,400 years ago. The ATXN3 gene encodes for ataxin-3, which is ubiquitously expressed in neuronal and non-neuronal tissues, and, among other functions, is thought to participate in cellular protein quality control pathways. Mutated ATXN3 alleles consensually present about 61 to 87 CAG repeats, resulting in an expanded polyglutamine tract in ataxin-3. This altered protein gains a neurotoxic function, through yet unclear mechanisms. Clinical variability of MJD is only partially explained by the size of the CAG tract, which leaves a residual variance that should be explained by still unknown additional factors. Several genetic tests are available for MJD, and Genetic Counseling Programs have been created to better assist the affected families, namely on what concerns the possibility of pre-symptomatic testing. The main goal of this review was to bring together updated knowledge on MJD, covering several aspects from its initial descriptions and clinical presentation, through the discovery of the causative mutation, its origin and dispersion, as well as molecular genetics aspects considered essential for a better understanding of its neuropathology. Issues related with molecular testing and Genetic Counseling, as well as recent progresses and perspectives on genetic therapy, are also addressed.
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Affiliation(s)
- Conceição Bettencourt
- Center of Research in Natural Resources (CIRN) and Department of Biology, University of the Azores, Ponta Delgada, Portugal
- Institute for Molecular and Cellular Biology (IBMC), University of Porto, Porto, Portugal
- Laboratorio de Biología Molecular, Instituto de Enfermedades Neurológicas de Guadalajara, Fundación Socio-Sanitaria de Castilla-La Mancha, Guadalajara, Spain
| | - Manuela Lima
- Center of Research in Natural Resources (CIRN) and Department of Biology, University of the Azores, Ponta Delgada, Portugal
- Institute for Molecular and Cellular Biology (IBMC), University of Porto, Porto, Portugal
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Quet F, Preux PM, Huerta M, Ramirez R, Abad T, Fragoso G, Morales J, Sciutto E, Fleury A. Determining the burden of neurological disorders in populations living in tropical areas: who would be questioned? Lessons from a Mexican rural community. Neuroepidemiology 2011; 36:194-203. [PMID: 21606653 DOI: 10.1159/000327496] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 03/07/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The best approach to determine the burden of neurological disorders in developing countries is to perform population-based studies. Our objectives were to determine the prevalence of neurological disorders in a Mexican rural community and assess the usefulness of a household screening questionnaire. METHODS The survey took place in a Mexican rural community of Puebla State in Mexico. This was a cross-sectional, population-based, 2-phase study including a comparison of the usefulness levels of the individual (IQ) and household (HQ) questionnaires. RESULTS A total of 4,008 individuals participated in the prevalence study using the IQ; of these, 280 neurological examinations allowed to identify 127 individuals suffering from at least 1 neurological disease. The most frequent ailments were headache (22.4/1,000, 95% confidence interval, CI: 17.7-28.2), neuropathy (7.1/1,000, CI 95%: 4.4-11.3) and epilepsy (3.9/1,000, CI 95%: 2.3-6.5). The HQ, used in parallel with the IQ, detected significantly fewer neurological cases. This result was mainly due to the low capacity of the HQ to detect headache. CONCLUSIONS Results of the prevalence study are discussed emphasizing their relevance in adequately allocating resources. The usefulness of the HQ for screening neurological disorders in general was low, but could be adequate for specific neurological disorders.
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Affiliation(s)
- Fabrice Quet
- IFR 145 GEIST, Institut d'Epidémiologie Neurologique et de Neurologie Tropicale, EA 3174 Neuroepidémiologie Tropicale et Comparée, Université de Limoges, Limoges, France
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Gan SR, Shi SS, Wu JJ, Wang N, Zhao GX, Weng ST, Murong SX, Lu CZ, Wu ZY. High frequency of Machado-Joseph disease identified in southeastern Chinese kindreds with spinocerebellar ataxia. BMC MEDICAL GENETICS 2010; 11:47. [PMID: 20334689 PMCID: PMC2861663 DOI: 10.1186/1471-2350-11-47] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 03/25/2010] [Indexed: 12/23/2022]
Abstract
Background Machado-Joseph disease (MJD), caused by a CAG repeat expansion located in exon10 of the ATXN3 gene, is now regarded as one of the most common spinocerebellar ataxia (SCA) in the world. The relative frequency of MJD among SCA has previously been estimated at about 50% in the Chinese population and has been reported to be related to the frequency of large normal alleles in some populations. Taq polymerase has been used for PCR in nearly all studies reported previously. Methods Normal and expanded alleles of ATXN3 were detected via PCR using LA Taq DNA polymerase (better for GC-rich sequences) and denaturing polyacrylamide gel electrophoresis in 150 normal individuals and 138 unrelated probands from autosomal dominant SCA families. To compare reaction efficiency, 12 MJD patients' expanded alleles were amplified with La Taq and Taq polymerase respectively in the same amplifying systems and reaction conditions. Results Normal alleles ranged from 12 to 42 CAG repeats. The most common allele contained 14 repeats with a frequency of 23.3%, which corroborates previous reports. The frequency of large normal alleles (>27 repeats) was 0.28, which was very high relative to previous reports. The frequency of MJD in SCA patients was 72.5%, which was significantly higher than those in previous reports about the Chinese and other Asian populations. This frequency was one of the highest reported worldwide, with only Portuguese and Brazilian populations exhibiting higher proportions. All 12 expanded alleles were amplified in PCR with La Taq polymerase, whereas only 2 expanded alleles were amplified with Taq polymerase. Conclusion We have first reported the highest relative frequency of MJD in Asia, and we attribute this high frequency to a more efficient PCR using LA Taq polymerase and hypothesized that large ANs may act as a reservoir for expanded alleles in the Southeastern Chinese population.
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Affiliation(s)
- Shi-Rui Gan
- Department of Neurology and Institute of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai 200040, China
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32
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Velázquez Pérez L, Cruz GS, Santos Falcón N, Enrique Almaguer Mederos L, Escalona Batallan K, Rodríguez Labrada R, Paneque Herrera M, Laffita Mesa JM, Rodríguez Díaz JC, Rodríguez RA, González Zaldivar Y, Coello Almarales D, Almaguer Gotay D, Jorge Cedeño H. Molecular epidemiology of spinocerebellar ataxias in Cuba: Insights into SCA2 founder effect in Holguin. Neurosci Lett 2009; 454:157-60. [DOI: 10.1016/j.neulet.2009.03.015] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 03/04/2009] [Accepted: 03/05/2009] [Indexed: 11/25/2022]
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