1
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Baille G, Geoffre N, Wissocq A, Planté-Bordeneuve P, Mutez E, Huin V. Early-onset phenotype in a patient with an intermediate allele and a large SCA1 expansion: a case report. BMC Neurol 2024; 24:348. [PMID: 39289638 PMCID: PMC11406724 DOI: 10.1186/s12883-024-03846-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 09/03/2024] [Indexed: 09/19/2024] Open
Abstract
BACKGROUND Spinocerebellar ataxia type 1, is a rare neurodegenerative disorder with autosomal dominant inheritance belonging to the polyglutamine diseases. The diagnosis of this disease requires genetic testing that may also include the search for CAT interruption of the CAG repeat tract. CASE PRESENTATION One 23-years-old patient suffers from a severe ataxia, with early-onset and rapid progression of the disease. His father might have been affected, but no molecular confirmation has been performed. The genetic results were negative for the Friedreich's ataxia, spinocerebellar ataxia type 2, 3, 6, 7 and 17. The numbers of CAG repeats in the ATXN1 gene was assessed by fluorescent PCR, tripled-primed PCR and enzymatic digestion for the search of sequence interruption in the CAG repeats. The patient carried one pathogenic allele of 61 CAG and one intermediate allele of 37 CAG in the ATXN1 gene. Both alleles were uninterrupted. CONCLUSIONS We report a rare case of spinocerebellar ataxia type 1 with an intermediate allele and a large SCA1 expansion. The determination of the absence of CAT interruption brought crucial information concerning this molecular diagnosis, the prediction of the disease and had practical consequences for genetic counseling.
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Affiliation(s)
- Guillaume Baille
- Delafontaine Hospital Center, Department of Neurology, Saint-Denis, F93200, France
| | - Nicolas Geoffre
- Department of Toxicology and Genopathies, UF Neurobiology, CHU Lille, Lille, F-59000, France
| | - Anna Wissocq
- Department of Toxicology and Genopathies, UF Neurobiology, CHU Lille, Lille, F-59000, France
| | | | - Eugénie Mutez
- Department of Neurology and Movement disorders, CHU Lille, Lille, F-59000, France
- Univ. Lille, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Inserm, Lille, F-59000, France
| | - Vincent Huin
- Department of Toxicology and Genopathies, UF Neurobiology, CHU Lille, Lille, F-59000, France.
- Univ. Lille, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Inserm, Lille, F-59000, France.
- Inserm UMRS1172, 'Alzheimer & Tauopathies', Bâtiment Biserte, Place de Verdun, Lille Cedex, 59045, France.
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2
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Sharafi S, Rezvani Z. Investigation of Spinocerebellar Ataxia (SCA) Disease in Iranian Patients and Accurate Trinucleotide Repeat Detection in the SCA3 by TP-PCR Method. Mol Neurobiol 2024:10.1007/s12035-024-04434-8. [PMID: 39155322 DOI: 10.1007/s12035-024-04434-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 08/09/2024] [Indexed: 08/20/2024]
Abstract
SCA (spinocerebellar ataxia) which is autosomal dominantly transferred is a subset of inherited cerebellar ataxia. These progressive neurological diseases have clinical features of ataxia and are derived from the destruction of the cerebellum. These diseases can also affect other areas, including the brainstem. Frequent proliferation of CAG nucleotides can encode polyglutamine and, as a result, produce the toxic polyglutamine (poly Q) protein that leads to many types of SCAs. They are categorized based on specific genetic mutations. The main symptoms of SCA, gait ataxia and incoordination, nystagmus, vision problems, and dysarthria, can be mentioned. In this study, 31 Iranians who were suspected of SCA disease were clinically diagnosed from November 2019 to September 2021. For these 31 patients suspected of spinocerebellar ataxia, PCR was performed, and the analysis was based on vertical electrophoresis. For SCA3 patients, the TP-PCR technique was carried out and evaluated by capillary electrophoresis. For all 31 patients, PCR function was successful according to the results attained by conventional PCR. The number of three nucleotide replications was within the normal range for 22 people, and nine patients were reported. Studies showed that three people suspected of SCA were infected with SCA3 according to the TP-PCR technique, and this was while seven people were diagnosed with SCA3 using the PCR method. As the purpose of this test is to provide a more accurate diagnostic method and prenatal diagnosis of this disease, the TP-PCR method proved to be more suitable when applied for the diagnosis of abnormal trinucleotides CAG in spinocerebellar ataxia type 3.
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Affiliation(s)
- Shafagh Sharafi
- Department of Cell and Molecular Biology, Faculty of Chemistry, University of Kashan, Qutb Rawandi Blvd, Kashan City, Isfahan Province, Iran
| | - Zahra Rezvani
- Department of Cell and Molecular Biology, Faculty of Chemistry, University of Kashan, Qutb Rawandi Blvd, Kashan City, Isfahan Province, Iran.
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3
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Buijsen RAM, Hu M, Sáez-González M, Notopoulou S, Mina E, Koning W, Gardiner SL, van der Graaf LM, Daoutsali E, Pepers BA, Mei H, van Dis V, Frimat JP, van den Maagdenberg AMJM, Petrakis S, van Roon-Mom WMC. Spinocerebellar Ataxia Type 1 Characteristics in Patient-Derived Fibroblast and iPSC-Derived Neuronal Cultures. Mov Disord 2023; 38:1428-1442. [PMID: 37278528 DOI: 10.1002/mds.29446] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/23/2023] [Accepted: 04/20/2023] [Indexed: 06/07/2023] Open
Abstract
BACKGROUND Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disease caused by a polyglutamine expansion in the ataxin-1 protein resulting in neuropathology including mutant ataxin-1 protein aggregation, aberrant neurodevelopment, and mitochondrial dysfunction. OBJECTIVES Identify SCA1-relevant phenotypes in patient-specific fibroblasts and SCA1 induced pluripotent stem cells (iPSCs) neuronal cultures. METHODS SCA1 iPSCs were generated and differentiated into neuronal cultures. Protein aggregation and neuronal morphology were evaluated using fluorescent microscopy. Mitochondrial respiration was measured using the Seahorse Analyzer. The multi-electrode array (MEA) was used to identify network activity. Finally, gene expression changes were studied using RNA-seq to identify disease-specific mechanisms. RESULTS Bioenergetics deficits in patient-derived fibroblasts and SCA1 neuronal cultures showed altered oxygen consumption rate, suggesting involvement of mitochondrial dysfunction in SCA1. In SCA1 hiPSC-derived neuronal cells, nuclear and cytoplasmic aggregates were identified similar in localization as aggregates in SCA1 postmortem brain tissue. SCA1 hiPSC-derived neuronal cells showed reduced dendrite length and number of branching points while MEA recordings identified delayed development in network activity in SCA1 hiPSC-derived neuronal cells. Transcriptome analysis identified 1050 differentially expressed genes in SCA1 hiPSC-derived neuronal cells associated with synapse organization and neuron projection guidance, where a subgroup of 151 genes was highly associated with SCA1 phenotypes and linked to SCA1 relevant signaling pathways. CONCLUSIONS Patient-derived cells recapitulate key pathological features of SCA1 pathogenesis providing a valuable tool for the identification of novel disease-specific processes. This model can be used for high throughput screenings to identify compounds, which may prevent or rescue neurodegeneration in this devastating disease. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Ronald A M Buijsen
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Michel Hu
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Maria Sáez-González
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Sofia Notopoulou
- Institute of Applied Biosciences, Centre for Research and Technology Hellas, Thessaloniki, Greece
| | - Eleni Mina
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Winette Koning
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Sarah L Gardiner
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Linda M van der Graaf
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Elena Daoutsali
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Barry A Pepers
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Hailiang Mei
- Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Vera van Dis
- Department of Pathology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
- Department of Pathology, Erasmus Medical Center, Rotterdam, Zuid-Holland, The Netherlands
| | - Jean-Philippe Frimat
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Arn M J M van den Maagdenberg
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
| | - Spyros Petrakis
- Institute of Applied Biosciences, Centre for Research and Technology Hellas, Thessaloniki, Greece
| | - Willeke M C van Roon-Mom
- Department of Human Genetics, Leiden University Medical Center, Leiden, Zuid-Holland, The Netherlands
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4
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Biswas DD, El Haddad L, Sethi R, Huston ML, Lai E, Abdelbarr MM, Mhandire DZ, ElMallah MK. Neuro-respiratory pathology in spinocerebellar ataxia. J Neurol Sci 2022; 443:120493. [PMID: 36410186 PMCID: PMC9808489 DOI: 10.1016/j.jns.2022.120493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 10/22/2022] [Accepted: 11/09/2022] [Indexed: 11/15/2022]
Abstract
The spinocerebellar ataxias (SCA) are a heterogeneous group of neurodegenerative disorders with an autosomal dominant inheritance. Symptoms include poor coordination and balance, peripheral neuropathy, impaired vision, incontinence, respiratory insufficiency, dysphagia, and dysarthria. Although many patients with SCA have respiratory-related complications, the exact mechanism and extent of this pathology remain unclear. This review aims to provide an update on the recent clinical and preclinical scientific findings on neuropathology causing respiratory insufficiency in SCA.
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Affiliation(s)
- Debolina D Biswas
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Léa El Haddad
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Ronit Sethi
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Meredith L Huston
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Elias Lai
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Mariam M Abdelbarr
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Doreen Z Mhandire
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA
| | - Mai K ElMallah
- Division of Pulmonary and Sleep Medicine, Department of Pediatrics, Duke University Medical Center, Box 2644, Durham, NC 27710, USA.
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5
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Olmos V, Gogia N, Luttik K, Haidery F, Lim J. The extra-cerebellar effects of spinocerebellar ataxia type 1 (SCA1): looking beyond the cerebellum. Cell Mol Life Sci 2022; 79:404. [PMID: 35802260 PMCID: PMC9993484 DOI: 10.1007/s00018-022-04419-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 12/28/2022]
Abstract
Spinocerebellar ataxia type 1 (SCA1) is one of nine polyglutamine (polyQ) diseases and is characterized as an adult late-onset, progressive, dominantly inherited genetic disease. SCA1 is caused by an increase in the number of CAG repeats in the ATXN1 gene leading to an expanded polyQ tract in the ATAXIN-1 protein. ATAXIN-1 is broadly expressed throughout the brain. However, until recently, SCA1 research has primarily centered on the cerebellum, given the characteristic cerebellar Purkinje cell loss observed in patients, as well as the progressive motor deficits, including gait and limb incoordination, that SCA1 patients present with. There are, however, also other symptoms such as respiratory problems, cognitive defects and memory impairment, anxiety, and depression observed in SCA1 patients and mouse models, which indicate that there are extra-cerebellar effects of SCA1 that cannot be explained solely through changes in the cerebellar region of the brain alone. The existing gap between human and mouse model studies of extra-cerebellar regions in SCA1 makes it difficult to answer many important questions in the field. This review will cover both the cerebellar and extra-cerebellar effects of SCA1 and highlight the need for further investigations into the impact of mutant ATXN1 expression in these regions. This review will also discuss implications of extra-cerebellar effects not only for SCA1 but other neurodegenerative diseases showing diverse pathology as well.
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Affiliation(s)
- Victor Olmos
- Department of Genetics, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA
| | - Neha Gogia
- Department of Genetics, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA
| | - Kimberly Luttik
- Interdepartmental Neuroscience Program, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA
- Department of Neuroscience, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA
| | | | - Janghoo Lim
- Department of Genetics, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA.
- Interdepartmental Neuroscience Program, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA.
- Department of Neuroscience, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA.
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA.
- Yale Stem Cell Center, Yale School of Medicine, 295 Congress Avenue, BCMM 154E, New Haven, CT, 06510, USA.
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6
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Barbé L, Finkbeiner S. Genetic and Epigenetic Interplay Define Disease Onset and Severity in Repeat Diseases. Front Aging Neurosci 2022; 14:750629. [PMID: 35592702 PMCID: PMC9110800 DOI: 10.3389/fnagi.2022.750629] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
Repeat diseases, such as fragile X syndrome, myotonic dystrophy, Friedreich ataxia, Huntington disease, spinocerebellar ataxias, and some forms of amyotrophic lateral sclerosis, are caused by repetitive DNA sequences that are expanded in affected individuals. The age at which an individual begins to experience symptoms, and the severity of disease, are partially determined by the size of the repeat. However, the epigenetic state of the area in and around the repeat also plays an important role in determining the age of disease onset and the rate of disease progression. Many repeat diseases share a common epigenetic pattern of increased methylation at CpG islands near the repeat region. CpG islands are CG-rich sequences that are tightly regulated by methylation and are often found at gene enhancer or insulator elements in the genome. Methylation of CpG islands can inhibit binding of the transcriptional regulator CTCF, resulting in a closed chromatin state and gene down regulation. The downregulation of these genes leads to some disease-specific symptoms. Additionally, a genetic and epigenetic interplay is suggested by an effect of methylation on repeat instability, a hallmark of large repeat expansions that leads to increasing disease severity in successive generations. In this review, we will discuss the common epigenetic patterns shared across repeat diseases, how the genetics and epigenetics interact, and how this could be involved in disease manifestation. We also discuss the currently available stem cell and mouse models, which frequently do not recapitulate epigenetic patterns observed in human disease, and propose alternative strategies to study the role of epigenetics in repeat diseases.
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Affiliation(s)
- Lise Barbé
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
| | - Steve Finkbeiner
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, CA, United States
- Department of Neurology, University of California, San Francisco, San Francisco, CA, United States
- Department of Physiology, University of California, San Francisco, San Francisco, CA, United States
- *Correspondence: Steve Finkbeiner,
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7
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Sharma P, Sonakar AK, Goel V, Garg A, Srivastava AK, Faruq M. A Novel co‐existence of
SCA1
and
SCA2
mutations in Indian patients. Mov Disord Clin Pract 2022; 9:688-692. [PMID: 35844270 PMCID: PMC9274345 DOI: 10.1002/mdc3.13464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/19/2022] [Accepted: 04/10/2022] [Indexed: 11/08/2022] Open
Abstract
Background Spinocerebellar ataxia 1 (SCA1) and SCA2 are dominantly inherited ataxias caused due to CAG expansion mutation in ATXN1 (CAG≥39) and ATXN2 (CAG≥32) genes located at 6p22.3 and 12q24.12 loci, respectively, with key manifestations of progressive limb and gait ataxia and with or without brain stem and pyramidal tract involvement. Both SCA1 and SCA2 are quite prevalent subtypes among the SCAs. There are very few reports that describe a combinatorial SCA subtype mutation in a single patient. Cases Here, we report a novel co-occurrence of SCA1 and SCA2 mutations in two unrelated patients. Case-1 was observed to carry ATXN1-CAG (30/40) and ATXN2-CAG (23/45), while case-2 harbored ATXN1-CAG (29/42) and ATXN2-CAG (23/41). Overall, the clinical outcome was complex with probable early onset than expected in Case-1 and in Case-2, we observed a significant delayed onset of the disease than expected. Conclusion These cases highlight the probabilistic interactive outcome of two unrelated genetic events towards a converging phenotype.
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Affiliation(s)
- Pooja Sharma
- Genomics and Molecular Medicine, CSIR‐Institute of Genomics and Integrative Biology (CSIR ‐IGIB), Mall Road Delhi 110007 India
- Academy for Scientific and Innovative Research Ghaziabad 201002 India
| | - Akhilesh K. Sonakar
- Neurology Department, Neuroscience Centre All India Institute of Medical Sciences New Delhi 110029 India
| | - Vinay Goel
- Neuroradiology Department, Neuroscience Centre All India Institute of Medical Sciences New Delhi 110029 India
| | - Ajay Garg
- Neuroradiology Department, Neuroscience Centre All India Institute of Medical Sciences New Delhi 110029 India
| | - Achal K. Srivastava
- Neurology Department, Neuroscience Centre All India Institute of Medical Sciences New Delhi 110029 India
| | - Mohammed Faruq
- Genomics and Molecular Medicine, CSIR‐Institute of Genomics and Integrative Biology (CSIR ‐IGIB), Mall Road Delhi 110007 India
- Academy for Scientific and Innovative Research Ghaziabad 201002 India
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8
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Sharma P, Sonakar AK, Tyagi N, Suroliya V, Kumar M, Kutum R, Asokchandran V, Ambawat S, Shamim U, Anand A, Ahmad I, Shakya S, Uppili B, Mathur A, Parveen S, Jain S, Singh J, Seth M, Zahra S, Joshi A, Goel D, Sahni S, Kamai A, Wadhwa S, Murali A, Saifi S, Chowdhury D, Pandey S, Anand KS, Narasimhan RL, Laskar S, Kushwaha S, Kumar M, Shaji CV, Srivastava MVP, Srivastava AK, Faruq M. Genetics of Ataxias in Indian Population: A Collative Insight from a Common Genetic Screening Tool. ADVANCED GENETICS (HOBOKEN, N.J.) 2022; 3:2100078. [PMID: 36618024 PMCID: PMC9744545 DOI: 10.1002/ggn2.202100078] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Indexed: 01/11/2023]
Abstract
Cerebellar ataxias (CAs) represent a group of autosomal dominant and recessive neurodegenerative disorders affecting cerebellum with or without spinal cord. Overall, CAs have preponderance for tandem nucleotide repeat expansions as an etiological factor (10 TREs explain nearly 30-40% of ataxia cohort globally). The experience of 10 years of common genetic ataxia subtypes for ≈5600 patients' referrals (Pan-India) received at a single center is shared herein. Frequencies (in %, n) of SCA types and FRDA in the sample cohort are observed as follows: SCA12 (8.6%, 490); SCA2 (8.5%, 482); SCA1 (4.8%, 272); SCA3 (2%, 113); SCA7 (0.5%, 28); SCA6 (0.1%, 05); SCA17 (0.1%, 05), and FRDA (2.2%, 127). A significant amount of variability in TRE lengths at each locus is observed, we noted presence of biallelic expansion, co-occurrence of SCA-subtypes, and the presence of premutable normal alleles. The frequency of mutated GAA-FRDA allele in healthy controls is 1/158 (0.63%), thus an expected FRDA prevalence of 1:100 000 persons. The data of this study are relevant not only for clinical decision making but also for guidance in direction of genetic investigations, transancestral comparison of genotypes, and lastly provide insight for policy decision for the consideration of SCAs under rare disease category.
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Affiliation(s)
- Pooja Sharma
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | | | - Nishu Tyagi
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | - Varun Suroliya
- Neurology DepartmentNeuroscience CentreNew Delhi110029India
| | - Manish Kumar
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | - Rintu Kutum
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Vivekananda Asokchandran
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | - Sakshi Ambawat
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Uzma Shamim
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Avni Anand
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Ishtaq Ahmad
- Neurology DepartmentNeuroscience CentreNew Delhi110029India
| | - Sunil Shakya
- Neurology DepartmentNeuroscience CentreNew Delhi110029India
| | - Bharathram Uppili
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | - Aradhana Mathur
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Shaista Parveen
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Shweta Jain
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Jyotsna Singh
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Neurology DepartmentNeuroscience CentreNew Delhi110029India
| | - Malika Seth
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Sana Zahra
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | - Aditi Joshi
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Divya Goel
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Shweta Sahni
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Asangla Kamai
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | - Saruchi Wadhwa
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
| | - Aparna Murali
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | - Sheeba Saifi
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India
| | | | - Sanjay Pandey
- Department of NeurologyGB Pant HospitalDelhi110002India
| | - Kuljeet Singh Anand
- Department of NeurologyPost Graduate Institute of Medical Education and ResearchDr. Ram Manohar Lohia HospitalNew Delhi110001India
| | | | | | - Suman Kushwaha
- Department of NeurologyInstitute of Human Behaviour and Allied SciencesDelhi110095India
| | | | | | | | | | - Mohammed Faruq
- Genomics and Molecular MedicineCSIR‐Institute of Genomics and Integrative Biology (CSIR‐IGIB)Mall RoadDelhi110007India,Academy for Scientific and Innovative ResearchGhaziabadUttar Pradesh201002India
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9
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Kononova S, Vinokurova D, Barashkov NA, Semenova A, Sofronova S, Oksana S, Tatiana D, Struchkov V, Burtseva T, Romanova A, Fedorova S. The attitude of young people in the city of Yakutsk to DNA-testing. Int J Circumpolar Health 2021; 80:1973697. [PMID: 34544327 PMCID: PMC8462860 DOI: 10.1080/22423982.2021.1973697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
This pilot research was one of the first sociological studies with general questions on genetic testing with 300 participants, 75% of which were representatives of one people - the Sakha. A quantitative method was used: a sociological survey with quota sampling (Δ ± 5%), held in February - March 2018 in the City of Yakutsk (n = 350).Analysis of the survey results have shown that the respondents have low levels of awareness about the DNA-testing method: 72.3% "do not know about the method". Only 18.7% of respondents knew that since 2000 the Medical-Genetic Centre of the Sakha Republic (Yakutia) conducts DNA diagnostics for hereditary diseases, with 81.0% replying that they didn't know that. The questionnaire has shown that 90.3% of participants would like to undergo DNA-testing to identify their susceptibility to genetic diseases. Our questionnaire has shown high levels of self-identity among the young Sakha and their desire to learn about their belonging to a specific ethnicity (49.3%) with the assistance of DNA-testing. Furthermore, based on the answers relating to motivations for undergoing DNA-testing, we can say that the respondents have confirmed the peculiarities of their national mindset, specifically, high value of children for a family: "concern for the health of my future children" was a great motivator for taking the test (50.3%).
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Affiliation(s)
- Sardana Kononova
- Department of Molecular Genetics, Yakut Scientific Centre of Complex Medical Problems, Yakutsk, Sakha Republic, Russian Federation
| | - Dekabrina Vinokurova
- Department of Psychology and Social Sciences, M.K. Ammosov North-Eastern Federal University, Yakutsk, Sakha Republic, Russian Federation
| | - Nikolay A Barashkov
- Department of Molecular Genetics, Yakut Scientific Centre of Complex Medical Problems, Yakutsk, Sakha Republic, Russian Federation
| | - Ariadna Semenova
- Department of Psychology and Social Sciences, M.K. Ammosov North-Eastern Federal University, Yakutsk, Sakha Republic, Russian Federation
| | - Sargylana Sofronova
- Department of Molecular Genetics, Yakut Scientific Centre of Complex Medical Problems, Yakutsk, Sakha Republic, Russian Federation
| | - Sidorova Oksana
- Department of Molecular Genetics, Yakut Scientific Centre of Complex Medical Problems, Yakutsk, Sakha Republic, Russian Federation
| | - Davydova Tatiana
- Department of Molecular Genetics, Yakut Scientific Centre of Complex Medical Problems, Yakutsk, Sakha Republic, Russian Federation
| | - Valentin Struchkov
- Department of Modern Languages and International Studies Translation, M.K. Ammosov North-Eastern Federal University, Yakutsk, Sakha Republic, Russian Federation
| | - Tatiana Burtseva
- Department of Pediatrics and pediatric surgery, M.K. Ammosov North-Eastern Federal University, Yakutsk, Sakha Republic, Russian Federation
| | - Anna Romanova
- Department of Molecular Genetics, Yakut Scientific Centre of Complex Medical Problems, Yakutsk, Sakha Republic, Russian Federation
| | - Sardana Fedorova
- Department of Molecular Biology, M.K. Ammosov North-Eastern Federal University, Yakutsk, Sakha Republic, Russian Federation
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10
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Nethisinghe S, Kesavan M, Ging H, Labrum R, Polke JM, Islam S, Garcia-Moreno H, Callaghan MF, Cavalcanti F, Pook MA, Giunti P. Interruptions of the FXN GAA Repeat Tract Delay the Age at Onset of Friedreich's Ataxia in a Location Dependent Manner. Int J Mol Sci 2021; 22:7507. [PMID: 34299126 PMCID: PMC8307455 DOI: 10.3390/ijms22147507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/12/2021] [Accepted: 06/18/2021] [Indexed: 12/03/2022] Open
Abstract
Friedreich's ataxia (FRDA) is a comparatively rare autosomal recessive neurological disorder primarily caused by the homozygous expansion of a GAA trinucleotide repeat in intron 1 of the FXN gene. The repeat expansion causes gene silencing that results in deficiency of the frataxin protein leading to mitochondrial dysfunction, oxidative stress and cell death. The GAA repeat tract in some cases may be impure with sequence variations called interruptions. It has previously been observed that large interruptions of the GAA repeat tract, determined by abnormal MboII digestion, are very rare. Here we have used triplet repeat primed PCR (TP PCR) assays to identify small interruptions at the 5' and 3' ends of the GAA repeat tract through alterations in the electropherogram trace signal. We found that contrary to large interruptions, small interruptions are more common, with 3' interruptions being most frequent. Based on detection of interruptions by TP PCR assay, the patient cohort (n = 101) was stratified into four groups: 5' interruption, 3' interruption, both 5' and 3' interruptions or lacking interruption. Those patients with 3' interruptions were associated with shorter GAA1 repeat tracts and later ages at disease onset. The age at disease onset was modelled by a group-specific exponential decay model. Based on this modelling, a 3' interruption is predicted to delay disease onset by approximately 9 years relative to those lacking 5' and 3' interruptions. This highlights the key role of interruptions at the 3' end of the GAA repeat tract in modulating the disease phenotype and its impact on prognosis for the patient.
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Affiliation(s)
- Suran Nethisinghe
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; (S.N.); (M.K.); (H.G.); (H.G.-M.)
| | - Maheswaran Kesavan
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; (S.N.); (M.K.); (H.G.); (H.G.-M.)
| | - Heather Ging
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; (S.N.); (M.K.); (H.G.); (H.G.-M.)
| | - Robyn Labrum
- Neurogenetics Service, Rare and Inherited Disease Laboratory, London North Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3BH, UK; (R.L.); (J.M.P.)
| | - James M. Polke
- Neurogenetics Service, Rare and Inherited Disease Laboratory, London North Genomic Laboratory Hub, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3BH, UK; (R.L.); (J.M.P.)
| | - Saiful Islam
- UCL Queen Square Institute of Neurology, London WC1N 3BG, UK;
| | - Hector Garcia-Moreno
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; (S.N.); (M.K.); (H.G.); (H.G.-M.)
| | - Martina F. Callaghan
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK;
| | - Francesca Cavalcanti
- Institute for Biomedical Research and Innovation (IRIB), Italian National Research Council (CNR), 87050 Mangone, Italy;
| | - Mark A. Pook
- Ataxia Research Group, Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge UB8 3PH, UK;
- Synthetic Biology Theme, Institute of Environment, Health and Societies, Brunel University London, Uxbridge UB8 3PH, UK
| | - Paola Giunti
- Ataxia Centre, Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK; (S.N.); (M.K.); (H.G.); (H.G.-M.)
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11
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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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12
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Tejwani L, Lim J. Pathogenic mechanisms underlying spinocerebellar ataxia type 1. Cell Mol Life Sci 2020; 77:4015-4029. [PMID: 32306062 PMCID: PMC7541529 DOI: 10.1007/s00018-020-03520-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/06/2020] [Accepted: 04/06/2020] [Indexed: 02/06/2023]
Abstract
The family of hereditary cerebellar ataxias is a large group of disorders with heterogenous clinical manifestations and genetic etiologies. Among these, over 30 autosomal dominantly inherited subtypes have been identified, collectively referred to as the spinocerebellar ataxias (SCAs). Generally, the SCAs are characterized by a progressive gait impairment with classical cerebellar features, and in a subset of SCAs, accompanied by extra-cerebellar features. Beyond the common gait impairment and cerebellar atrophy, the wide range of additional clinical features observed across the SCAs is likely explained by the diverse set of mutated genes that encode proteins with seemingly disparate functional roles in nervous system biology. By synthesizing knowledge obtained from studies of the various SCAs over the past several decades, convergence onto a few key cellular changes, namely ion channel dysfunction and transcriptional dysregulation, has become apparent and may represent central mechanisms of cerebellar disease pathogenesis. This review will detail our current understanding of the molecular pathogenesis of the SCAs, focusing primarily on the first described autosomal dominant spinocerebellar ataxia, SCA1, as well as the emerging common core mechanisms across the various SCAs.
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Affiliation(s)
- Leon Tejwani
- Interdepartmental Neuroscience Program, Yale School of Medicine, 295 Congress Avenue, New Haven, CT, 06510, USA
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, 06510, USA
| | - Janghoo Lim
- Interdepartmental Neuroscience Program, Yale School of Medicine, 295 Congress Avenue, New Haven, CT, 06510, USA.
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, 06510, USA.
- Department of Genetics, Yale School of Medicine, New Haven, CT, 06510, USA.
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale School of Medicine, New Haven, CT, 06510, USA.
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, 06510, USA.
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13
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Frequency and distribution of polyQ disease intermediate-length repeat alleles in healthy Italian population. Neurol Sci 2020; 41:1475-1482. [PMID: 31940111 DOI: 10.1007/s10072-019-04233-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/30/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Huntington disease (HD) and spinocerebellar ataxia type 1-2-17 (SCA1-2-17) are adult-onset autosomal dominant diseases, caused by triplet repeat expansions in the HTT, ATXN1, ATXN2, and TBP genes. Alleles with a repeat number just below the pathological threshold are associated with reduced penetrance and meiotic instability and are defined as intermediate alleles (IAs). OBJECTIVES We aimed to determine the frequencies of IAs in healthy Italian subjects and to compare the proportion of the IAs with the prevalence of the respective diseases. METHODS We analyzed the triplet repeat size in HTT, ATXN1, ATXN2, and TBP genes in the DNA samples from 729 consecutive adult healthy Italian subjects. RESULTS IAs associated with reduced penetrance were found in ATXN2 gene (1 subject, 0.1%) and TBP gene (0.82%). IAs at risk for meiotic instability were found in HTT (5.3%) and ATXN2 genes (2.7%). In ATXN1, we found a low percentage of IAs (0.4%). Alleles lacking the common CAT interruption within the CAG sequence were also rare (0.3%). CONCLUSIONS The high frequencies of IAs in HTT and ATXN2 genes suggest a correlation with the prevalence of the diseases in our population and support the hypothesis that IAs could represent a reservoir of new pathological expansions. On the opposite, ATXN1-IA were very rare in respect to the prevalence of SCA1 in our country, and TBP- IA were more frequent than expected, suggesting that other mechanisms could influence the occurrence of novel pathological expansions.
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14
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Hu YS, Do J, Edamakanti CR, Kini AR, Martina M, Stupp SI, Opal P. Self-assembling vascular endothelial growth factor nanoparticles improve function in spinocerebellar ataxia type 1. Brain 2019; 142:312-321. [PMID: 30649233 DOI: 10.1093/brain/awy328] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/21/2018] [Indexed: 12/17/2022] Open
Abstract
There is increasing appreciation for the role of the neurovascular unit in neurodegenerative diseases. We showed previously that the angiogenic and neurotrophic cytokine, vascular endothelial growth factor (VEGF), is suppressed to abnormally low levels in spinocerebellar ataxia type 1 (SCA1), and that replenishing VEGF reverses the cerebellar pathology in SCA1 mice. In that study, however, we used a recombinant VEGF, which is extremely costly to manufacture and biologically unstable as well as immunogenic. To develop a more viable therapy, here we test a synthetic VEGF peptide amphiphile that self-assembles into nanoparticles. We show that this nano-VEGF has potent neurotrophic and angiogenic properties, is well-tolerated, and leads to functional improvement in SCA1 mice even when administered at advanced stages of the disease. This approach can be generalized to other neurotrophic factors or molecules that act in a paracrine manner, offering a novel therapeutic strategy for neurodegenerative conditions.
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Affiliation(s)
- Yuan-Shih Hu
- Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Jeehaeh Do
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | | | - Ameet R Kini
- Department of Pathology, Loyola University Chicago Stritch School of Medicine, Maywood, Illinois, USA
| | - Marco Martina
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Samuel I Stupp
- Departments of Materials and Science and Engineering, Chemistry, Medicine, and Biomedical Engineering, Northwestern University, Evanston, IL USA.,Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, Illinois, USA
| | - Puneet Opal
- Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.,Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine Chicago, Illinois, USA
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15
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Szpisjak L, Zadori D, Klivenyi P, Vecsei L. Clinical Characteristics and Possible Drug Targets in Autosomal Dominant Spinocerebellar Ataxias. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2019; 18:279-293. [DOI: 10.2174/1871527318666190311155846] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/10/2018] [Accepted: 01/31/2019] [Indexed: 12/28/2022]
Abstract
Background & Objective:
The autosomal dominant spinocerebellar ataxias (SCAs) belong
to a large and expanding group of neurodegenerative disorders. SCAs comprise more than 40 subtypes
characterized by progressive ataxia as a common feature. The most prevalent diseases among SCAs
are caused by CAG repeat expansions in the coding-region of the causative gene resulting in polyglutamine
(polyQ) tract formation in the encoded protein. Unfortunately, there is no approved therapy to
treat cerebellar motor dysfunction in SCA patients. In recent years, several studies have been conducted
to recognize the clinical and pathophysiological aspects of the polyQ SCAs more accurately.
This scientific progress has provided new opportunities to develop promising gene therapies, including
RNA interference and antisense oligonucleotides.
Conclusion:
The aim of the current work is to give a brief summary of the clinical features of SCAs
and to review the cardinal points of pathomechanisms of the most common polyQ SCAs. In addition,
we review the last few year’s promising gene suppression therapies of the most frequent polyQ SCAs
in animal models, on the basis of which human trials may be initiated in the near future.
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Affiliation(s)
- Laszlo Szpisjak
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Denes Zadori
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Peter Klivenyi
- Department of Neurology, University of Szeged, Szeged, Hungary
| | - Laszlo Vecsei
- Department of Neurology, University of Szeged, Szeged, Hungary
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16
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Martins Junior CR, Borba FCD, Martinez ARM, Rezende TJRD, Cendes IL, Pedroso JL, Barsottini OGP, França Júnior MC. Twenty-five years since the identification of the first SCA gene: history, clinical features and perspectives for SCA1. ARQUIVOS DE NEURO-PSIQUIATRIA 2019; 76:555-562. [PMID: 30231129 DOI: 10.1590/0004-282x20180080] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2018] [Accepted: 06/04/2018] [Indexed: 11/21/2022]
Abstract
Spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of monogenic diseases that share ataxia and autosomal dominant inheritance as the core features. An important proportion of SCAs are caused by CAG trinucleotide repeat expansions in the coding region of different genes. In addition to genetic heterogeneity, clinical features transcend motor symptoms, including cognitive, electrophysiological and imaging aspects. Despite all the progress in the past 25 years, the mechanisms that determine how neuronal death is mediated by these unstable expansions are still unclear. The aim of this article is to review, from an historical point of view, the first CAG-related ataxia to be genetically described: SCA 1.
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Affiliation(s)
| | - Fabrício Castro de Borba
- Universidade de Campinas, Faculdade de Ciências Médicas, Departamento de Neurologia, Campinas SP, Brasil
| | | | | | - Iscia Lopes Cendes
- Universidade de Campinas, Faculdade de Ciências Médicas, Departamento de Genética Médica, Campinas SP, Brasil
| | - José Luiz Pedroso
- Universidade Federal de São Paulo, Unidade de Ataxia, Departamento de Neurologia, São Paulo SP, Brasil
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17
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Nethisinghe S, Pigazzini ML, Pemble S, Sweeney MG, Labrum R, Manso K, Moore D, Warner J, Davis MB, Giunti P. PolyQ Tract Toxicity in SCA1 is Length Dependent in the Absence of CAG Repeat Interruption. Front Cell Neurosci 2018; 12:200. [PMID: 30108484 PMCID: PMC6080413 DOI: 10.3389/fncel.2018.00200] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 06/19/2018] [Indexed: 11/20/2022] Open
Abstract
Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant neurodegenerative disorder caused by an expansion of a polyglutamine tract within the ATXN1 gene. Normal alleles have been reported to range from 6 to 35 repeats, intermediate alleles from 36 to 38 repeats and fully penetrant pathogenic alleles have at least 39 repeats. This distribution was based on relatively few samples and the narrow intermediate range makes the accuracy of the repeat sizing crucial for interpreting and reporting diagnostic tests, which can vary between laboratories. Here, we examine the distribution of 6378 SCA1 chromosomes and identify a very late onset SCA1 family with a fully penetrant uninterrupted pathogenic allele containing 38 repeats. This finding supports the theory that polyQ toxicity is related to the increase of the length of the inherited tracts and not as previously hypothesized to the structural transition occurring above a specific threshold. In addition, the threshold of toxicity shifts to a shorter polyQ length with the increase of the lifespan in SCA1. Furthermore, we show that SCA1 intermediate alleles have a different behavior compared to the other polyglutamine disorders as they do not show reduced penetrance when uninterrupted. Therefore, the pathogenic mechanism in SCA1 is distinct from other cytosine-adenine-guanine (CAG) repeat disorders. Accurately sizing repeats is paramount in precision medicine and can be challenging particularly with borderline alleles. We examined plasmids containing cloned CAG repeat tracts alongside a triplet repeat primed polymerase chain reaction (TP PCR) CAG repeat ladder to improve accuracy in repeat sizing by fragment analysis. This method accurately sizes the repeats irrespective of repeat composition or length. We also improved the model for calculating repeat length from fragment analysis sizing by fragment analyzing 100 cloned repeats of known size. Therefore, we recommend these methods for accurately sizing repeat lengths and restriction enzyme digestion to identify interruptions for interpretation of a given allele’s pathogenicity.
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Affiliation(s)
- Suran Nethisinghe
- Ataxia Centre, Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Maria Lucia Pigazzini
- Ataxia Centre, Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - Sally Pemble
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery (NHNN), London, United Kingdom
| | - Mary G Sweeney
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery (NHNN), London, United Kingdom
| | - Robyn Labrum
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery (NHNN), London, United Kingdom
| | - Katarina Manso
- Ataxia Centre, Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
| | - David Moore
- Molecular Genetics Laboratory, South East Scotland Genetics Service, Western General Hospital, Edinburgh, United Kingdom
| | - Jon Warner
- Molecular Genetics Laboratory, South East Scotland Genetics Service, Western General Hospital, Edinburgh, United Kingdom
| | - Mary B Davis
- Neurogenetics Unit, National Hospital for Neurology and Neurosurgery (NHNN), London, United Kingdom
| | - Paola Giunti
- Ataxia Centre, Department of Molecular Neuroscience, UCL Institute of Neurology, London, United Kingdom
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18
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Edamakanti CR, Do J, Didonna A, Martina M, Opal P. Mutant ataxin1 disrupts cerebellar development in spinocerebellar ataxia type 1. J Clin Invest 2018. [PMID: 29533923 DOI: 10.1172/jci96765] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Spinocerebellar ataxia type 1 (SCA1) is an adult-onset neurodegenerative disease caused by a polyglutamine expansion in the protein ATXN1, which is involved in transcriptional regulation. Although symptoms appear relatively late in life, primarily from cerebellar dysfunction, pathogenesis begins early, with transcriptional changes detectable as early as a week after birth in SCA1-knockin mice. Given the importance of this postnatal period for cerebellar development, we asked whether this region might be developmentally altered by mutant ATXN1. We found that expanded ATXN1 stimulates the proliferation of postnatal cerebellar stem cells in SCA1 mice. These hyperproliferating stem cells tended to differentiate into GABAergic inhibitory interneurons rather than astrocytes; this significantly increased the GABAergic inhibitory interneuron synaptic connections, disrupting cerebellar Purkinje cell function in a non-cell autonomous manner. We confirmed the increased basket cell-Purkinje cell connectivity in human SCA1 patients. Mutant ATXN1 thus alters the neural circuitry of the developing cerebellum, setting the stage for the later vulnerability of Purkinje cells to SCA1. We propose that other late-onset degenerative diseases may also be rooted in subtle developmental derailments.
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Affiliation(s)
| | - Jeehaeh Do
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | | | - Marco Martina
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Puneet Opal
- Davee Department of Neurology, and.,Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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19
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Shang XJ, Xu HL, Yang JS, Chen PP, Lin MT, Qian MZ, Lin HX, Chen XP, Chen YC, Jiang B, Chen YJ, Chen WJ, Wang N, Zhou ZM, Gan SR. Homozygote of spinocerebellar Ataxia type 3 correlating with severe phenotype based on analyses of clinical features. J Neurol Sci 2018; 390:111-114. [PMID: 29801869 DOI: 10.1016/j.jns.2018.04.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/22/2018] [Accepted: 04/16/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND Spinocerebellar ataxia type 3 (SCA3) is the most common subtype of SCAs worldwide. SCA3 homozygote is defined as expanded CAG repeats in both alleles that might exhibit severe phenotype due to gene dosage effect. However, a study on the systematic comparison of clinical phenotypes between homozygotes and heterozygotes to indicate these verity of phenotypes of homozygotes is still lacking. METHODS A total of 14 SCA3 homozygotes (3 Chinese participants and 11 participants from various ethnicity in different published studies) and 143 Chinese heterozygotes of SCA3 were recruited for this study. The 95% confidence intervals (CIs) of age at onset and disease severity expected from heterozygous patients were analyzed to detect the phenotypic differences between homozygotes and heterozygotes. RESULTS Almost all the homozygotes (13 of 14) were found to present a significant earlier age at onset compared with heterozygotes, because age at onset of most homozygotes was lower than the 95% CIs of age at onset of heterozygotes. Also, the clinical severity in most of the homozygotes (3 of 4) with identified clinical phenotypes was higher than the 95% CIs of severity in heterozygotes, indicating more severe clinical phenotypes in SCA3 homozygotes. CONCLUSIONS The homozygosity for SCA3 could lead to an earlier age of onset and putative severe clinical features. The findings of the present study suggested an influence of gene dosage on SCA3 phenotypes.
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Affiliation(s)
- Xian-Jin Shang
- Department of Neurology, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Hao-Ling Xu
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Jin-Shan Yang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Ping-Ping Chen
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Min-Ting Lin
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Mei-Zhen Qian
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China; Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University, Hangzhou, China
| | - Hui-Xia Lin
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Xiao-Ping Chen
- School of Mathematics and Computer Science & FJKLMAA, Fujian Normal University, Fuzhou, China
| | - Yu-Chao Chen
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Bin Jiang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China; Department of Neurology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Yi-Jun Chen
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Wan-Jin Chen
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Ning Wang
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China
| | - Zhi-Ming Zhou
- Department of Neurology, Yijishan Hospital of Wannan Medical College, Wuhu, China.
| | - Shi-Rui Gan
- Department of Neurology and Institute of Neurology, First Affiliated Hospital of Fujian Medical University, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China.
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Platonov FA, Tyryshkin K, Tikhonov DG, Neustroyeva TS, Sivtseva TM, Yakovleva NV, Nikolaev VP, Sidorova OG, Kononova SK, Goldfarb LG, Renwick NM. Genetic fitness and selection intensity in a population affected with high-incidence spinocerebellar ataxia type 1. Neurogenetics 2016; 17:179-85. [PMID: 27106293 DOI: 10.1007/s10048-016-0481-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/10/2016] [Indexed: 11/30/2022]
Abstract
Spinocerebellar ataxia type 1 (SCA1) is the major and likely the only type of autosomal dominant cerebellar ataxia in the Sakha (Yakut) people of Eastern Siberia. The prevalence rate of SCA1 has doubled over the past 21 years peaking at 46 cases per 100,000 rural population. The age at death correlates closely with the number of CAG triplet repeats in the mutant ATXN1 gene (r = -0.81); most patients with low-medium (39-55) repeat numbers survived until the end of reproductive age. The number of CAG repeats expands in meiosis, particularly in paternal transmissions; the average total increase in intergenerational transmissions in our cohort was estimated at 1.6 CAG repeats. The fertility rates of heterozygous carriers of 39-55 CAG repeats in women were no different from those of the general Sakha population. Overall, the survival of mutation carriers through reproductive age, unaltered fertility rates, low childhood mortality in SCA1-affected families, and intergenerational transmission of increasing numbers of CAG repeats in the ATXN1 gene indicate that SCA1 in the Sakha population will be maintained at high prevalence levels. The low (0.19) Crow's index of total selection intensity in our SCA1 cohort implies that this mutation is unlikely to be eliminated through natural selection alone.
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Affiliation(s)
- Fedor A Platonov
- Institute of Health, M.K. Ammosov North-Eastern Federal University, Yakutsk, 677010, The Russian Federation
| | - Kathrin Tyryshkin
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Dmitriy G Tikhonov
- Institute of Health, M.K. Ammosov North-Eastern Federal University, Yakutsk, 677010, The Russian Federation
| | - Tatyana S Neustroyeva
- Institute of Health, M.K. Ammosov North-Eastern Federal University, Yakutsk, 677010, The Russian Federation
| | - Tatyana M Sivtseva
- Institute of Health, M.K. Ammosov North-Eastern Federal University, Yakutsk, 677010, The Russian Federation
| | - Natalya V Yakovleva
- Institute of Health, M.K. Ammosov North-Eastern Federal University, Yakutsk, 677010, The Russian Federation
| | - Valerian P Nikolaev
- Institute of Health, M.K. Ammosov North-Eastern Federal University, Yakutsk, 677010, The Russian Federation
| | - Oksana G Sidorova
- Center for Integrated Medical Research, Academy of Medical Sciences, Yakutsk, 677010, The Russian Federation
| | - Sardana K Kononova
- Center for Integrated Medical Research, Academy of Medical Sciences, Yakutsk, 677010, The Russian Federation
| | - Lev G Goldfarb
- National Institute of Neurological Disorder and Stoke, NIH, Bethesda, MD, 20892, USA.
| | - Neil M Renwick
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, K7L 3N6, Canada
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Monin ML, Tezenas du Montcel S, Marelli C, Cazeneuve C, Charles P, Tallaksen C, Forlani S, Stevanin G, Brice A, Durr A. Survival and severity in dominant cerebellar ataxias. Ann Clin Transl Neurol 2015; 2:202-7. [PMID: 25750924 PMCID: PMC4338960 DOI: 10.1002/acn3.156] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 11/12/2014] [Accepted: 11/14/2014] [Indexed: 12/31/2022] Open
Abstract
Inherited spinocerebellar ataxias (SCAs) are known to be genetically and clinically heterogeneous. Whether severity and survival are variable, however, is not known. We, therefore, studied survival and severity in 446 cases and 509 relatives with known mutations. Survival was 68 years [95% CI: 65–70] in 223 patients with polyglutamine expansions versus 80 years [73–84] in 23 with other mutations (P < 0.0001). Disability was also more severe in the former: at age 60, 30% were wheelchair users versus 3% with other SCAs (P < 0.001). This has implications for genetic counseling and the design of therapeutic trials.
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Affiliation(s)
- Marie-Lorraine Monin
- AP-HP, Genetic Department, Pitié-Salpêtrière University Hospital F-75013, Paris, France ; Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06 UMR S 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital F-75013, Paris, France
| | - Sophie Tezenas du Montcel
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06, UMR S 1136, INSERM U 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique F-75013, Paris, France ; AP-HP, Biostatistics Unit, Groupe Hospitalier Pitié-Salpêtrière F-75013, Paris, France
| | - Cecilia Marelli
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06 UMR S 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital F-75013, Paris, France ; Department of Neurology, CHRU Guy de Chauliac Montpellier, France
| | - Cecile Cazeneuve
- AP-HP, Genetic Department, Pitié-Salpêtrière University Hospital F-75013, Paris, France
| | - Perrine Charles
- AP-HP, Genetic Department, Pitié-Salpêtrière University Hospital F-75013, Paris, France
| | - Chantal Tallaksen
- Department of Neurology, Oslo University Oslo, Norway ; Faculty of Medicine, Oslo University Oslo, Norway
| | - Sylvie Forlani
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06 UMR S 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital F-75013, Paris, France
| | - Giovanni Stevanin
- Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06 UMR S 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital F-75013, Paris, France ; Neurogenetics Team, Ecole Pratique des Hautes Etudes, Institut du Cerveau et de la Moelle épinière F-75013, Paris, France
| | - Alexis Brice
- AP-HP, Genetic Department, Pitié-Salpêtrière University Hospital F-75013, Paris, France ; Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06 UMR S 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital F-75013, Paris, France
| | - Alexandra Durr
- AP-HP, Genetic Department, Pitié-Salpêtrière University Hospital F-75013, Paris, France ; Sorbonne Universités, Université Pierre et Marie Curie (UPMC) Univ Paris 06 UMR S 1127, INSERM U 1127, CNRS UMR 7225, ICM (Brain and Spine Institute) Pitié-Salpêtrière Hospital F-75013, Paris, France
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Kumaran D, Balagopal K, Tharmaraj RGA, Aaron S, George K, Muliyil J, Sivadasan A, Danda S, Alexander M, Hasan G. Genetic characterization of Spinocerebellar ataxia 1 in a South Indian cohort. BMC MEDICAL GENETICS 2014; 15:114. [PMID: 25344417 PMCID: PMC4411758 DOI: 10.1186/s12881-014-0114-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/30/2014] [Indexed: 12/18/2022]
Abstract
Background Spinocerebellar ataxia type 1 (SCA1) is a late onset autosomal dominant cerebellar ataxia, caused by CAG triplet repeat expansion in the ATXN1 gene. The frequency of SCA1 occurrence is more in Southern India than in other regions as observed from hospital-based studies. However there are no reports on variability of CAG repeat expansion, phenotype-genotype association and founder mutations in a homogenous population from India. Methods Genomic DNA isolated from buccal mouthwash of the individuals in the cohort was used for PCR-based diagnosis of SCA1. Subsequently SNP’s found within the ATXN1 loci were identified by Taqman allelic discrimination assays. Significance testing of the genotype-phenotype associations was calculated by Kruskal-Wallis ANOVA test with post-hoc Dunnett’s test and Pearson’s correlation coefficient. Results By genetic analysis of an affected population in Southern India we identified 21 pre-symptomatic individuals including four that were well past the average age of disease onset of 44 years, 16 symptomatic and 63 normal individuals. All pre-symptomatic cases harbor “pure” expansions of greater than 40 CAGs. Genotyping to test for the presence of two previously identified SNPs showed a founder effect of the same repeat carrying allele as in the general Indian population. We show that SCA1 disease onset is significantly delayed when transmission of the disease is maternal. Conclusions Our finding of early disease onset in individuals with a paternally inherited allele could serve as valuable information for clinicians towards early detection of SCA1 in patients with affected fathers. Identification of older pre-symptomatic individuals (n = 4) in our cohort among individuals with a shared genetic and environmental background, suggests that second site genetic or epigenetic modifiers might significantly affect SCA1 disease progression. Moreover, such undetected SCA1 cases could underscore the true prevalence of SCA1 in India.
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Affiliation(s)
- Dhanya Kumaran
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka, India. .,Manipal University, Manipal, 576104, India.
| | - Krishnan Balagopal
- Department of Neurological Sciences, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
| | | | - Sanjith Aaron
- Department of Neurological Sciences, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
| | - Kuryan George
- Department of Community Health, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
| | - Jayaprakash Muliyil
- Department of Community Health, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
| | - Ajith Sivadasan
- Department of Neurological Sciences, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
| | - Sumita Danda
- Department of Clinical Genetics, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
| | - Mathew Alexander
- Department of Neurological Sciences, Christian Medical College and Hospital, Vellore, Tamil Nadu, India.
| | - Gaiti Hasan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka, India.
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Kononova SK, Sidorova OG, Fedorova SA, Platonov FA, Izhevskaya VL, Khusnutdinova EK. Bioethical issues of preventing hereditary diseases with late onset in the Sakha Republic (Yakutia). Int J Circumpolar Health 2014; 73:25062. [PMID: 25147769 PMCID: PMC4111875 DOI: 10.3402/ijch.v73.25062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Prenatal diagnosis of congenital and hereditary diseases is a priority for the development of medical technologies in Russia. However, there are not many published research results on bioethical issues of prenatal DNA testing. OBJECTIVE The main goal of the article is to describe some of the bioethical aspects of prenatal DNA diagnosis of hereditary diseases with late onset in genetic counselling practice in the Sakha Republic (Yakutia) - a far north-eastern region of Russia. METHODS The methods used in the research are genetic counselling, invasive chorionic villus biopsy procedures, molecular diagnosis, social and demographic characteristics of patients. RESULTS In 10 years, 48 (76%) pregnant women from families tainted with hereditary spinocerebellar ataxia type 1 and 15 pregnant women from families with myotonic dystrophy have applied for medical and genetic counselling in order to undergo prenatal DNA testing. The average number of applications is 7-8 per year. There are differences in prenatal genetic counselling approaches. CONCLUSION It is necessary to develop differentiated ethical approaches depending on the mode of inheritance, age of manifestation, and clinical polymorphism of hereditary disease.
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Affiliation(s)
- Sardana K. Kononova
- Yakutsk Scientific Center of Complex Medical Problems, Siberian Branch of the Russian Academy of Medical Sciences, Yakutsk, Russia
- Institute of Natural Sciences, M. K. Ammosov North-Eastern Federal University, Yakutsk, Russia
| | - Oksana G. Sidorova
- Yakutsk Scientific Center of Complex Medical Problems, Siberian Branch of the Russian Academy of Medical Sciences, Yakutsk, Russia
| | - Sardana A. Fedorova
- Yakutsk Scientific Center of Complex Medical Problems, Siberian Branch of the Russian Academy of Medical Sciences, Yakutsk, Russia
- Institute of Natural Sciences, M. K. Ammosov North-Eastern Federal University, Yakutsk, Russia
| | - Fedor A. Platonov
- Institute of Natural Sciences, M. K. Ammosov North-Eastern Federal University, Yakutsk, Russia
| | - Vera L. Izhevskaya
- Research Centre for Medical Genetics of the Russian Academy of Medical Sciences, Moscow, Russia
| | - Elza K. Khusnutdinova
- Institute for Biochemistry and Genetics, Ufa Scientific Centre of the Russian Academy of Sciences, Ufa, Russia
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A case of amyotrophic lateral sclerosis with intermediate ATXN-1 CAG repeat expansion in a large family with spinocerebellar ataxia type 1. J Neurol 2014; 261:1442-3. [DOI: 10.1007/s00415-014-7400-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 12/13/2022]
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Jhunjhunwala K, Prashanth DK, Netravathi M, Jain S, Purushottam M, Pal PK. Alterations in cortical excitability and central motor conduction time in spinocerebellar ataxias 1, 2 and 3: a comparative study. Parkinsonism Relat Disord 2012; 19:306-11. [PMID: 23219306 DOI: 10.1016/j.parkreldis.2012.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 09/25/2012] [Accepted: 11/07/2012] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Spinocerebellar ataxias 1, 2 and 3 (SCA1, SCA2 and SCA3) are CAG repeat disorders. The prevalence of changes in the cortical excitability and central motor conduction time (CMCT) in these disorders is largely unknown, and there are few studies which have compared these findings in the subtypes of SCA. The objectives of this study were to measure the cortical resting motor threshold (RMT) and CMCT using transcranial magnetic stimulation in patients with SCA1, SCA2, and SCA3. METHODS The subjects of this study were 32 genetically confirmed patients with SCA (SCA1 = 15, SCA2 = 11, SCA3 = 6). Transcranial magnetic stimulation (TMS) was performed using a figure-of-eight coil attached to Magstim 200 stimulator. Motor evoked potentials were recorded from first dorsal interosseous at rest. RMT was determined using standard techniques and the CMCT by 'F' wave method. Comparison was made with data from 32 healthy controls. RESULTS Compared to controls, the patients with SCA had significantly higher mean RMT as well as CMCT (RMT: 49.9 ± 9.1 vs. 41.5 ± 6.6, p < 0.0001; CMCT: 7.7 ± 2.3 ms vs. 4.8 ± 0.6 ms; p < 0.0001). When compared separately with the controls, while all the three subtypes of SCAs had significantly prolonged CMCT, only SCA1 and SCA3, but not SCA2 had significantly greater RMT. RMT and CMCT between patients with SCA2 and SCA3, and between SCA1 and SCA3 did not differ significantly, while SCA1 had significantly higher RMT and CMCT than SCA2. CONCLUSIONS Patients with SCA have reduced cortical excitability and prolonged central motor conduction time, which was most evident in SCA1 and least in SCA2.
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Affiliation(s)
- Ketan Jhunjhunwala
- Department of Neurology, National Institute of Mental Health & Neurosciences, Bangalore 560029, India
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Furtado S, Das S, Suchowersky O. A review of the inherited ataxias: recent advances in genetic, clinical and neuropathologic aspects. Parkinsonism Relat Disord 2012; 4:161-9. [PMID: 18591106 DOI: 10.1016/s1353-8020(98)00030-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/1998] [Accepted: 10/01/1998] [Indexed: 12/01/2022]
Abstract
Inherited ataxias are a heterogeneous group of disorders characterized by autosomal dominant and recessive inheritance. Recent advances in genetic research have resulted in an improved comprehension of their clinical presentation. Autosomal dominant cerebellar ataxias (ADCAs) include spinocerebellar ataxias (SCAs) and dentatorubral-pallidoluysian atrophy (DRPLA); six of these have been found to be trinucleotide repeat disorders. Episodic ataxia, types 1 and 2, are at present recognized to be channelopathies, caused by point mutations. Friedreich's ataxia (FA) which is an autosomal recessive disorder, resulting from a a unique trinucleotide repeat, is now recognized to have a wide age of onset and clinical spectrum. Ataxia-telangiectasia (AT), also an autosomal recessive cerebellar ataxia, is characterized by immunodeficiency. In this article, the genetic and clinical characteristics of these diseases are reviewed in detail.
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Affiliation(s)
- S Furtado
- Department of Clinical Neurosciences, University of Calgary, Area 3, UCMC, 3350 Hospital Drive, Calgary NW Alta, Canada T2N 4N1
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PROSPERI MATTIACF, PROSPERI LUCIANO, GRAY REBECCAR, SALEMI MARCO. ON COUNTING THE FREQUENCY DISTRIBUTION OF STRING MOTIFS IN MOLECULAR SEQUENCES. INT J BIOMATH 2012. [DOI: 10.1142/s1793524512500556] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This work investigates frequency distributions of strings within a text. The mathematical derivation accounts for variable alphabet size, character probabilities, and string/text lengths, under both the Bernoullian and the Markovian model for string generation. The analysis is limited to the set of non-clumpable strings, that cannot overlap with themselves. Two formulae (exact and approximated) are derived, calculating the frequency distribution of a string of length m found inside a text of length n (with m < n). The approximated formula has a constant complexity (in contrast to an exponential complexity of the exact) and makes it applicable to very long texts. The proposed formulae were applied to analyze string frequencies in a portion of the human genome, and to recalculate frequencies of known repeated motif within genes, associated to genetic diseases. A comparison with state-of-the-art methods was provided. The formulae presented here can be of use in the statistical evaluation of specific motif frequencies within very long texts (e.g. genes or genomes) and help in characterizing motifs in pathologic conditions.
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Affiliation(s)
- MATTIA C. F. PROSPERI
- Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, Emerging Pathogens Institute, University of Florida, P. O. Box 103633, 2055 Mowry Road, Gainesville, FL 32610-3633, USA
| | | | | | - MARCO SALEMI
- Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, Emerging Pathogens Institute, University of Florida, P. O. Box 103633, 2055 Mowry Road, Gainesville, FL 32610-3633, USA
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The ataxias. Neurogenetics 2012. [DOI: 10.1017/cbo9781139087711.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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The spinocerebellar ataxias: clinical aspects and molecular genetics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 724:351-74. [PMID: 22411256 DOI: 10.1007/978-1-4614-0653-2_27] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Spinocerebellar ataxias (SCAs) are a highly heterogeneous group of inherited neurological disorders, based on clinical characterization alone with variable degrees of cerebellar ataxia often accompanied by additional cerebellar and noncerebellar symptoms which in most cases defy differentiation. Molecular causative deficits in at least 31 genes underlie the clinical symptoms in the SCAs by triggering cerebellar and, very frequently, brain stem dysfunction. The identification of the causative molecular deficits enables the molecular diagnosis of the different SCA subtypes and facilitates genetic counselling. Recent scientific advances are shedding light into developing therapeutic strategies. The scope of this chapter is to provide updated details of the spinocerebellar ataxias with particular emphasis on those aspects aimed at facilitating the clinical and genetic diagnoses.
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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: 51] [Impact Index Per Article: 4.3] [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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Donato SD, Mariotti C, Taroni F. Spinocerebellar ataxia type 1. HANDBOOK OF CLINICAL NEUROLOGY 2012; 103:399-421. [PMID: 21827903 DOI: 10.1016/b978-0-444-51892-7.00025-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Spinocerebellar ataxia type 1 (SCA1) is one out of nine polyglutamine diseases, a group of late-onset neurodegenerative diseases present only in humans. SCA1, the first autosomal dominant cerebellar ataxia (ADCA) to be genetically characterized, is caused by the expansion of a CAG triplet repeat located in the N-terminal coding region of the disease-causing gene ATX1 located on chromosome 6p23: the mutation results in the production of a mutant protein, dubbed ataxin-1, with a longer-than-normal polyglutamine stretch. The predominant effect of the mutation is thought to be a toxic gain-of-function of the aberrant protein, and longer expansions are associated with earlier onset and more severe disease in subsequent generations. The most common presentation of SCA1 is dominant ataxia 'plus', characterized by cerebellar dysfunctions variably associated with slow saccades, ophthalmoplegia, pyramidal and extrapyramidal features, mild to moderate dementia, amyotrophy, and peripheral neuropathy. Its diagnostic pathological feature is olivopontocerebellar atrophy and degeneration predominantly affects the Purkinje cells and the dentate nuclei of the cerebellum. Pathogenesis is mainly attributed to the toxic effect of mutant ataxin-1, which localizes into the nucleus and, through restricted and aberrant protein-protein interactions, causes putative dysfunctional gene transcription in target cells which leads to late-onset cell dysfunction and death.
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Affiliation(s)
- Stefano Di Donato
- UO Biochimica e Genetics, IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
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Koefoed P, Nielsen JE, Hasholt L, Jensen PKA, Fenger K, Sørensen SA. The molecular diagnosis of spinocerebellar ataxia type 1 in patients with ataxia. Eur J Neurol 2011. [DOI: 10.1111/j.1468-1331.1997.tb00410.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
The spinocerebellar ataxias (SCA) are a large group of inherited disorders affecting the cerebellum and its afferent and efferent pathways. Their hallmark symptom is slowly progressive, symmetrical, midline, and appendicular ataxia. Some may also have associated hyperkinetic movements (chorea, dystonia, myoclonus, postural/action tremor, restless legs, rubral tremor, tics), which may aid in differential diagnosis and provide treatable targets to improve performance and quality of life in these progressive, incurable conditions. The typical dominant ataxias with associated hyperkinetic movements are SCA1-3, 6-8, 12, 14, 15, 17, 19-21, and 27. The common recessive ataxias with associated hyperkinetic movements are ataxia telangiectasia and Friedreich's ataxia. Fragile X tremor-ataxia syndrome (FXTAS) and multiple-system atrophy (a sporadic ataxia which is felt to have a genetic substrate) also have hyperkinetic features. A careful work-up should be done in all apparently sporadic cases, to rule out acquired causes of ataxia, some of which can cause hyperkinetic movements in addition to ataxia. Some testing should be done even in individuals with a confirmed genetic cause, as the presence of a secondary factor (nutritional deficiency, thyroid dysfunction) can contribute to the phenotype.
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Affiliation(s)
- Susan L Perlman
- David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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Koneva LA, Konev AV, Kucher AN. Simulation of the distribution of spinocerebellar ataxia type 1 in Yakut populations: Model parameters and results of simulation. RUSS J GENET+ 2010. [DOI: 10.1134/s1022795410070148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Koneva LA, Konev AV, Kucher AN. Simulation of the distribution of spinocerebellar ataxia type 1 in Yakut populations: Description of the model. RUSS J GENET+ 2010. [DOI: 10.1134/s1022795410030154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lin JX, Ishikawa K, Sakamoto M, Tsunemi T, Ishiguro T, Amino T, Toru S, Kondo I, Mizusawa H. Direct and accurate measurement of CAG repeat configuration in the ataxin-1 (ATXN-1) gene by "dual-fluorescence labeled PCR-restriction fragment length analysis". J Hum Genet 2008; 53:287-295. [PMID: 18301861 DOI: 10.1007/s10038-007-0242-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2007] [Accepted: 12/15/2007] [Indexed: 10/22/2022]
Abstract
Spinocerebellar ataxia type 1 (SCA1; OMIM: #164400) is an autosomal dominant cerebellar ataxia caused by an expansion of CAG repeat, which encodes polyglutamine, in the ataxin-1 (ATXN1) gene. Length of polyglutamine in the ATXN1 protein is the critical determinant of pathogenesis of this disease. Molecular diagnosis of SCA1 is usually undertaken by assessing the length of CAG repeat configuration using primers spanning this configuration. However, this conventional method may potentially lead to misdiagnosis in assessing polyglutamine-encoding CAG repeat length, since CAT interruptions may be present within the CAG repeat configuration, not only in normal controls but also in neurologically symptomatic subjects. We developed a new method for assessing actual CAG repeat numbers not interrupted by CAT sequences. Polymerase chain reaction using a primer pair labeled with two different fluorescences followed by restriction enzyme digestion with SfaNI which recognizes the sequence "GCATC(N)(5)", lengths of actual CAG repeats that encode polyglutamine were directly detected. We named this method "dual fluorescence labeled PCR-restriction fragment length analysis". We found that numbers of actual CAG repeat encoding polyglutamine do not overlap between our cohorts of normal chromosomes (n=385) and SCA1 chromosomes (n=5). We conclude that the present method is a useful way for molecular diagnosis of SCA1.
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Affiliation(s)
- Jiang X Lin
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Kinya Ishikawa
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan.
| | - Masaki Sakamoto
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Taiji Tsunemi
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Taro Ishiguro
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Takeshi Amino
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Shuta Toru
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan
| | - Ikuko Kondo
- Department of Medical Genetics, Ehime University, Onsen-gun, Ehime, Japan.,Ibaraki Prefectural Child Welfare Health Center, Yoshizawa-cho 3979-3, Mito, Ibaraki, 310-0845, Japan
| | - Hidehiro Mizusawa
- Department of Neurology and Neurological Science, Graduate School, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo, 113-8519, Japan
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39
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Dion V, Lin Y, Hubert L, Waterland RA, Wilson JH. Dnmt1 deficiency promotes CAG repeat expansion in the mouse germline. Hum Mol Genet 2008; 17:1306-17. [PMID: 18252747 DOI: 10.1093/hmg/ddn019] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Expanded CAG repeat tracts are the cause of at least a dozen neurodegenerative disorders. In humans, long CAG repeats tend to expand during transmissions from parent to offspring, leading to an earlier age of disease onset and more severe symptoms in subsequent generations. Here, we show that the maintenance DNA methyltransferase Dnmt1, which preserves the patterns of CpG methylation, plays a key role in CAG repeat instability in human cells and in the male and female mouse germlines. SiRNA knockdown of Dnmt1 in human cells destabilized CAG triplet repeats, and Dnmt1 deficiency in mice promoted intergenerational expansion of CAG repeats at the murine spinocerebellar ataxia type 1 (Sca1) locus. Importantly, Dnmt1(+/-) SCA1 mice, unlike their Dnmt1(+/+) SCA1 counterparts, closely reproduced the intergenerational instability patterns observed in human SCA1 patients. In addition, we found aberrant DNA and histone methylation at sites within the CpG island that abuts the expanded repeat tract in Dnmt1-deficient mice. These studies suggest that local chromatin structure may play a role in triplet repeat instability. These results are consistent with normal epigenetic changes during germline development contributing to intergenerational instability of CAG repeats in mice and in humans.
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Affiliation(s)
- Vincent Dion
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, USDA Children's Nutrition Research Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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40
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Abstract
Trinucleotide repeat expansions are an important cause of inherited neurodegenerative disease. The expanded repeats are unstable, changing in size when transmitted from parents to offspring (intergenerational instability, "meiotic instability") and often showing size variation within the tissues of an affected individual (somatic mosaicism, "mitotic instability"). Repeat instability is a clinically important phenomenon, as increasing repeat lengths correlate with an earlier age of onset and a more severe disease phenotype. The tendency of expanded trinucleotide repeats to increase in length during their transmission from parent to offspring in these diseases provides a molecular explanation for anticipation (increasing disease severity in successive affected generations). In this review, I explore the genetic and molecular basis of trinucleotide repeat instability. Studies of patients and families with trinucleotide repeat disorders have revealed a number of factors that determine the rate and magnitude of trinucleotide repeat change. Analysis of trinucleotide repeat instability in bacteria, yeast, and mice has yielded additional insights. Despite these advances, the pathways and mechanisms underlying trinucleotide repeat instability in humans remain largely unknown. There are many reasons to suspect that this uniquely human phenomenon will significantly impact upon our understanding of development, differentiation and neurobiology.
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Affiliation(s)
- A R La Spada
- Department of Laboratory Medicine and Pharmacology, University of Washington Medical Center, Seattle 98195, USA.
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41
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Zühlke C, Bürk K. Spinocerebellar ataxia type 17 is caused by mutations in the TATA-box binding protein. CEREBELLUM (LONDON, ENGLAND) 2007; 6:300-7. [PMID: 17853080 DOI: 10.1080/14734220601136177] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The spinocerebellar ataxia type 17 (SCA17) is characterized by cerebellar ataxia, dementia, and involuntary movements, including chorea and dystonia. In addition, psychiatric symptoms, pyramidal signs, and rigidity are common. MRI shows variable atrophy of the cerebrum, brainstem, and cerebellum. The autosomal dominantly inherited progressive neurodegenerative disorder is caused by an expanded CAA/CAG repeat coding for glutamine. Alleles of the normal range carry 25 to 42 glutamine residues, disease causing alleles 43 to 63. Alleles with 43 to 48 glutamine codons may be associated with incomplete penetrance. The mean age of onset is about 30 years for individuals with full-penetrance alleles, but ranges from three to 55 years.
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Affiliation(s)
- Christine Zühlke
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
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42
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Kurosaki T, Ninokata A, Wang L, Ueda S. Evolutionary scenario for acquisition of CAG repeats in human SCA1 gene. Gene 2006; 373:23-7. [PMID: 16497448 DOI: 10.1016/j.gene.2005.12.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 12/15/2005] [Accepted: 12/21/2005] [Indexed: 01/20/2023]
Abstract
We investigated the CAG repeat sequence of the spinocerebellar ataxia type 1 (SCA1) gene in various species of primates to reveal how human has acquired the repeat structure with interruptions. Our results demonstrate no repetitive structure in the region corresponding to the human CAG repeats in prosimians and New World monkeys like in rodents, perfect (uninterrupted) CAG repeats in Old World monkeys, and interrupted CAG repeats in hominoids. Comparative analysis on the secondary structures of the primate SCA1 transcripts suggests the human prototype was built in the common ancestor of simians. We show an evolutionary scenario for acquisition of CAG repeats with interruptions in the human SCA1 gene.
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Affiliation(s)
- Tatsuaki Kurosaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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43
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Sobczak K, Krzyzosiak WJ. Patterns of CAG repeat interruptions in SCA1 and SCA2 genes in relation to repeat instability. Hum Mutat 2005; 24:236-47. [PMID: 15300851 DOI: 10.1002/humu.20075] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
About 3% of the human genome is composed of simple sequence repeats and many of these sequences occur within genes. These repeats are often polymorphic in a normal population and their expansion in specific genes leads to a number of hereditary neurological diseases. Normal variants of disease-related genes contain either pure or interrupted repeats, and the postulated function of the interruptions is to prevent repeat expansions. Their structural role in the repeat tracts of genes and transcripts awaits detailed characterization. In this study, we have determined the SCA1 and SCA2 genotypes in a Polish population and found significant differences in allele spectra and frequencies from those reported for other populations. They are discussed in relation to the repeat expansion mechanism and disease incidence. We postulate that the dynamic mutation of the genes SCA1 (also ATX1 or ataxin 1) and SCA2 (also ATX2 or ataxin 2) may begin from the expansion of long pure repeat tracts without the prior loss of interruptions. A simple way of cost-effective allelotyping of CAG repeat regions in the SCA1 and SCA2genes is also shown. The reliable SSCP/duplex analysis presented here may be the method of choice for the systematic searching of genes for known and novel interrupted repeats.
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Affiliation(s)
- Krzysztof Sobczak
- Laboratory of Cancer Genetics, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.
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44
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Abstract
The autosomal dominant ataxias continue to bewilder us as the enormity of their genetic heterogeneity continues to unfold. The Human Genome Organization website now lists 22 such ataxias, not including dentatorubral-pallidoluysian atrophy. The early genetic discoveries in this field included several disorders caused by CAG repeat expansions within coding regions of the respective genes. More recent discoveries have included unstable expansions of nucleotide repeats in noncoding regions of genes as well as point mutations that have formed the basis of progressive dominant ataxias. This article summarizes the clinical and genetic features of the currently identified dominant ataxias.
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Affiliation(s)
- Christopher M Gomez
- Department of Neurology, University of Minnesota, Minneapolis, MN 55455, USA
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45
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Green AJE, Sivtseva TM, Danilova AP, Osakovsky VL, Vladimirtsev VA, Zeidler M, Knight RS, Platonov FA, Shatunov A, Alekseev VP, Krivoshapkin VG, Masters CL, Gajdusek DC, Goldfarb LG. Viliuisk encephalomyelitis: intrathecal synthesis of oligoclonal IgG. J Neurol Sci 2003; 212:69-73. [PMID: 12810001 DOI: 10.1016/s0022-510x(03)00107-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Viliuisk encephalomyelitis (VE) is a neurodegenerative disorder expressed as subacute meningo-encephalitis progressing to a more prolonged pan-encephalitic syndrome with a fatal outcome within 1 to 10 years. Some patients survive to a steady state of global dementia and severe spasticity that may last for over 20 years. Multiple micronecrotic foci surrounded by inflammatory infiltrates are observed throughout the cerebral cortex and other gray matter areas. Infectious etiology of VE is strongly suspected, but the causative agent has not been identified. We conducted a search for assays that might be helpful for VE diagnosis and established for the first time that the majority of patients with definite VE show evidence for intrathecal IgG synthesis correlating with the clinical manifestations of the disease. This indicates that the detection of oligoclonal IgG banding in the cerebrospinal fluid is a valuable diagnostic assay for VE. Implications of these findings for a possible etiology of VE are discussed.
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Affiliation(s)
- Alison J E Green
- The National CJD Surveillance Unit, Western General Hospital, Edinburgh EH4 2XU, UK
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46
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Fortune MT, Kennedy JL, Vincent JB. Anticipation and CAG*CTG repeat expansion in schizophrenia and bipolar affective disorder. Curr Psychiatry Rep 2003; 5:145-54. [PMID: 12685994 DOI: 10.1007/s11920-003-0031-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The genetic contribution to the etiologies of schizophrenia and bipolar affective disorder (BPAD) has been considered for many decades, with twin, family, and adoption studies indicating consistently that the familial clustering of affected individuals is accounted for mainly by genetic factors. Despite the strong evidence for a genetic component, very little is understood about the underlying genetic and molecular mechanisms for schizophrenia and BPAD. In the early 1990s, after the discovery of "dynamic mutation" or "unstable DNA" as a molecular basis for the genetic anticipation observed in Huntington's disease, myotonic dystrophy, and many others, and the recently rediscovered, albeit still controversial, evidence for genetic anticipation in major psychoses, the genetic epidemiology of schizophrenia and BPAD was re-evaluated to demonstrate strong endorsement for the unstable DNA model. Many of the non-Mendelian genetic features of schizophrenia and BPAD could be explained by the behaviour of unstable DNA, and several molecular genetic approaches became available for testing the unstable DNA hypothesis. However, despite promising findings in the mid-1990s, no trinucleotide repeat expansion has yet been identified as a cause of idiopathic schizophrenia or BPAD.
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MESH Headings
- Bipolar Disorder/genetics
- Carrier Proteins/genetics
- Chromosome Mapping/methods
- Chromosomes, Human, Pair 13/genetics
- Chromosomes, Human, Pair 19/genetics
- Chromosomes, Human, Pair 5/genetics
- DNA-Binding Proteins/genetics
- Exons
- Homeodomain Proteins/genetics
- Humans
- Huntington Disease/genetics
- Microfilament Proteins/genetics
- Nerve Tissue Proteins/genetics
- Polymorphism, Genetic/genetics
- RNA, Long Noncoding
- RNA, Messenger/genetics
- RNA, Untranslated
- Schizophrenia/genetics
- Schizophrenia/metabolism
- TCF Transcription Factors
- Transcription Factor 7-Like 2 Protein
- Transcription Factors/genetics
- Trinucleotide Repeat Expansion/genetics
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Affiliation(s)
- M Teresa Fortune
- Neurogenetics Section, Centre for Addiction and Mental Health, Clarke Division, 250 College Street, Toronto, ON M5T 1R8, Canada
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47
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Wiezel CEV, Canas MDCT, Simões AL. The SCA1 (Spinocerebellar ataxia type 1) and MJD (Machado-Joseph disease) CAG repeats in normal individuals: segregation analysis and allele frequencies. Genet Mol Biol 2003. [DOI: 10.1590/s1415-47572003000200002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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48
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Zühlke C, Dalski A, Hellenbroich Y, Bubel S, Schwinger E, Bürk K. Spinocerebellar ataxia type 1 (SCA1): phenotype-genotype correlation studies in intermediate alleles. Eur J Hum Genet 2002; 10:204-9. [PMID: 11973625 DOI: 10.1038/sj.ejhg.5200788] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2001] [Revised: 01/15/2002] [Accepted: 01/24/2002] [Indexed: 11/09/2022] Open
Abstract
CAG repeat expansions with loss of CAT interruptions in the coding region of the ataxin-1 gene are associated with spinocerebellar ataxia type 1 (SCA1). For molecular genetic diagnosis it is necessary to define the limits of normal and pathological size ranges. In most studies, normal alleles as measured by PCR range from 6-39 units with interruptions of 1-3 CAT trinucleotides that are thought to be involved in the stability of the trinucleotide stretch during DNA replication. Expanded alleles have been reported to carry 39-81 CAG trinucleotides without stabilising CAT interruptions. To evaluate the limits between normal and disease size ranges we analysed the repeat length and composition of the SCA1 gene in 15 individuals with alleles ranging from 36 and 41 triplets for genotype-phenotype correlation studies. We found the 39 trinucleotide-allele to be either interrupted by CAT repeats or formed by a pure CAG stretch. The clinical features of individuals carrying 39 uninterrupted CAG repeats did not differ from the SCA1 phenotype in general with dysphagia, pale discs, pyramidal signs and cerebellar tremor being more frequent as compared to other SCA genotypes. In contrast, the interrupted 39 trinucleotide-allele is not correlated with the SCA1 phenotype.
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Affiliation(s)
- Christine Zühlke
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
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49
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Gusella JF, MacDonald ME. Molecular genetics: unmasking polyglutamine triggers in neurodegenerative disease. Nat Rev Neurosci 2000; 1:109-15. [PMID: 11252773 DOI: 10.1038/35039051] [Citation(s) in RCA: 275] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Two decades ago, molecular genetic analysis provided a new approach for defining the roots of inherited disorders. This strategy has proved particularly powerful because, with only a description of the inheritance pattern, it can uncover previously unsuspected mechanisms of pathogenesis that are not implicated by known biological pathways or by the disease manifestations. Nowhere has the impact of molecular genetics been more evident than in the dominantly inherited neurodegenerative disorders, where eight unrelated diseases have been revealed to possess the same type of mutation--an expanded polyglutamine encoding sequence--affecting different genes.
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Affiliation(s)
- J F Gusella
- Molecular Neurogenetics Unit, Massachusetts General Hospital, Charlestown, Massachusetts 02129, USA.
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50
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Abstract
A growing number of neurodegenerative diseases have been found to result from the expansion of an unstable trinucleotide repeat. Over the past 6 years, researchers have focused on identifying the mechanism by which the expanded polyglutamine tract renders a protein toxic to a subset of vulnerable neurons. In this review, we summarize the clinicopathologic features of these disorders (spinobulbar muscular atrophy, Huntington disease, and the spinocerebellar ataxias, including dentatorubropallidoluysian atrophy), describe the genes involved and what is known about their products, and discuss the model systems that have lent insight into pathogenesis. The review concludes with a model for pathogenesis that illuminates the unifying features of these polyglutamine disorders. This model may prove relevant to other neurodegenerative disorders as well.
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Affiliation(s)
- H Y Zoghbi
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA.
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