scholarly journals A polyalanine antibody for the diagnosis of oculopharyngeal muscular dystrophy and polyalanine-related diseases

2017 ◽  
Vol 1 ◽  
pp. 1
Author(s):  
Shawn J. Stochmanski ◽  
François Blondeau ◽  
Martine Girard ◽  
Pascale Hince ◽  
Daniel Rochefort ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Trinucleotide Repeat ◽  
Late Onset ◽  
Cag Repeat ◽  
Spinocerebellar Ataxia Type ◽  
Causative Mutation ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Spinocerebellar Ataxia Type 3 ◽  
Repeat Tract ◽  
Repeat Expansions

Eighteen severe human diseases have so far been associated with trinucleotide repeat expansions coding for either polyalanine (encoded by a GCN repeat tract) or polyglutamine (encoded by a CAG repeat tract).  Among them, oculopharyngeal muscular dystrophy (OPMD), spinocerebellar ataxia type-3 (SCA3), and Huntington’s disease (HD) are late-onset autosomal-dominant disorders characterized by the presence of intranuclear inclusions (INIs).  We have previously identified the OPMD causative mutation as a small expansion (from 2 in normal to 7 in disease) of a GCG repeat tract in the PABPN1 gene.  In addition, -1 ribosomal frameshifting has been reported to occur in expanded CAG repeat tracts in the ATXN3 (SCA3) and HTT (HD) genes, resulting in the translation of a hybrid CAG/GCA repeat tract and the production of a polyalanine-containing peptide.  Previous studies on OPMD suggest that polyalanine-induced toxicity is very sensitive to the dosage and length of the alanine stretch.  Here we report the characterization of a polyclonal antibody that selectively recognizes pathological expansions of polyalanine in PABPN1.  Furthermore, our antibody also detects the presence of alanine proteins in INIs of SCA3 and HD patient samples.

scholarly journals A Japanese case of oculopharyngeal muscular dystrophy (OPMD) with PABPN1 c.35G > C; p.Gly12Ala point mutation

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yo-suke Nishii ◽  
Yu-ichi Noto ◽  
Rei Yasuda ◽  
Takamasa Kitaoji ◽  
Shinji Ashida ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Point Mutation ◽  
Trinucleotide Repeat ◽  
Late Onset ◽  
Lower Limbs ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Muscle Involvement ◽  
Case Presentation ◽  
Japanese Case ◽  
Expansion Mutation

Abstract Background Oculopharyngeal muscular dystrophy (OPMD) is a late-onset muscular dystrophy characterised by slowly progressive ptosis, dysphagia, and proximal limb muscle weakness. A common cause of OPMD is the short expansion of a GCG or GCA trinucleotide repeat in PABPN1 gene. Case presentation A 78-year-old woman presented with ptosis and gradually progressive dysphagia. Her son had the same symptoms. A physical examination and muscle imaging (MRI and ultrasound) showed impairment of the tongue, proximal muscles of the upper limbs, and flexor muscles of the lower limbs. Needle-electromyography (EMG) of bulbar and facial muscles revealed a myopathic pattern. Based on the characteristic muscle involvement pattern and needle-EMG findings, we suspected that the patient had OPMD. Gene analysis revealed PABPN1 c.35G > C point mutation, which mimicked the effect of a common causative repeat expansion mutation of OPMD. Conclusion We herein describe the first reported Japanese case of OPMD with PABPN1 point mutation, suggesting that this mutation is causative in Asians as well as in Europeans, in whom it was originally reported.

An insight into advances in the pathogenesis and therapeutic strategies of spinocerebellar ataxia type 3

2015 ◽  
Vol 26 (1) ◽  
Author(s):  
Yan Wu ◽  
Ying Peng ◽  
Yidong Wang
Keyword(s):  
Spinocerebellar Ataxia ◽  
Symptom Relief ◽  
Cellular Protein ◽  
Cag Repeat ◽  
Spinocerebellar Ataxia Type ◽  
Spinocerebellar Ataxia Type 3 ◽  
Repeat Expansions ◽  
Type 3 ◽  
Neural Signaling ◽  
And Oxidative Stress

AbstractSpinocerebellar ataxia type 3 (SCA3) is the most common type of spinocerebellar ataxia, which are inherited neurodegenerative diseases. CAG repeat expansions that translate into an abnormal length of glutamine residues are considered to be the disease-causing mutation. The pathological mechanisms of SCA3 are not fully elucidated but may include aggregate or inclusion formation, imbalance of cellular protein homeostasis, axonal transportation dysfunction, translation dysregulation, mitochondrial damage and oxidative stress, abnormal neural signaling pathways, etc. Currently, symptom relief is the only available therapeutic route; however, promising therapeutic targets have been discovered, such as decreasing the mutant protein through RNA interference (RNAi) and antisense oligonucleotides (AONs) and replacement therapy using stem cell transplantation. Other potential targets can inhibit the previously mentioned pathological mechanisms. However, additional efforts are necessary before these strategies can be used clinically.

scholarly journals Recent Progress in Oculopharyngeal Muscular Dystrophy

2021 ◽  
Vol 10 (7) ◽  
pp. 1375
Author(s):  
Satoshi Yamashita
Keyword(s):  
Muscular Dystrophy ◽  
Recent Progress ◽  
Trinucleotide Repeat ◽  
Late Onset ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Limb Weakness ◽  
Medical Needs ◽  
Therapeutic Benefits ◽  
Initial Symptoms ◽  
Swallowing Problems

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset intractable myopathy, characterized by slowly progressive ptosis, dysphagia, and proximal limb weakness. It is caused by the abnormal expansion of the alanine-encoding (GCN)n trinucleotide repeat in the exon 1 of the polyadenosine (poly[A]) binding protein nuclear 1 gene (11–18 repeats in OPMD instead of the normal 10 repeats). As the disease progresses, the patients gradually develop a feeling of suffocation, regurgitation of food, and aspiration pneumonia, although the initial symptoms and the progression patterns vary among the patients. Autologous myoblast transplantation may provide therapeutic benefits by reducing swallowing problems in these patients. Therefore, it is important to assemble information on such patients for the introduction of effective treatments in nonendemic areas. Herein, we present a concise review of recent progress in clinical and pathological studies of OPMD and introduce an idea for setting up a nation-wide OPMD disease registry in Japan. Since it is important to understand patients’ unmet medical needs, realize therapeutically targetable symptoms, and identify indices of therapeutic efficacy, our attempt to establish a unique patient registry of OPMD will be a helpful tool to address these urgent issues.

scholarly journals Frequency of the different mutations causing spinocerebellar ataxia (SCA1, SCA2, MJD/SCA3 and DRPLA) in a large group of Brazilian patients

1997 ◽  
Vol 55 (3B) ◽  
pp. 519-529 ◽  
Author(s):  
Iscia Lopes-Cendesi ◽  
Hélio G.A. Teive ◽  
Maria E Calcagnotto ◽  
Jaderson C. da Costa ◽  
Francisco Cardoso ◽  
...  
Keyword(s):  
Spinocerebellar Ataxia ◽  
Autosomal Dominant ◽  
Late Onset ◽  
Geographic Origin ◽  
Autosomal Dominant Inheritance ◽  
Cag Repeat ◽  
Spinocerebellar Ataxia Type ◽  
Dominant Inheritance ◽  
Coding Region ◽  
Spinocerebellar Ataxia Type 3

Spinocerebellar ataxia type 1 (SCA1), spinocerebellar ataxia type 2 (SCA2) and Machado-Joseph disease or spinocerebellar ataxia type 3 (MJD/SCA3) are three distinctive forms of autosomal dominant spinocerebellar ataxia (SCA) caused by expansions of an unstable CAG repeat localized in the coding region of the causative genes. Another related disease, dentatorubropallidoluysian atrophy (DRPLA) is also caused by an unstable triplet repeat and can present as SCA in late onset patients. We investigated the frequency of the SCA1, SCA2, MJD/SCA3 and DRPLA mutations in 328 Brazilian patients with SCA, belonging to 90 unrelated families with various patterns of inheritance and originating in different geographic regions of Brazil. We found mutations in 35 families (39%), 32 of them with a clear autosomal dominant inheritance. The frequency of the SCA1 mutation was 3% of all patients; and 6 % in the dominantly inherited SCAs. We identified the SCA2 mutation in 6% of all families and in 9% of the families with autosomal dominant inheritance. The MJD/SCA3 mutation was detected in 30 % of all patients; and in the 44% of the dominantly inherited cases. We found no DRPLA mutation. In addition, we observed variability in the frequency of the different mutations according to geographic origin of the patients, which is probably related to the distinct colonization of different parts of Brazil. These results suggest that SCA may be occasionally caused by the SCA1 and SCA2 mutations in the Brazilian population, and that the MJD/SCA3 mutation is the most common cause of dominantly inherited SCA in Brazil.

scholarly journals Homozygous spinocerebellar ataxia type 3 in China: a case report

2021 ◽  
Vol 49 (6) ◽  
pp. 030006052110213
Author(s):  
Yuchao Chen ◽  
Dan Li ◽  
Minger Wei ◽  
Menglu Zhou ◽  
Linan Zhang ◽  
...  
Keyword(s):  
Spinocerebellar Ataxia ◽  
Clinical Phenotype ◽  
Gene Dosage ◽  
Cag Repeat ◽  
Cag Repeats ◽  
Spinocerebellar Ataxia Type ◽  
Contraction Pattern ◽  
Spinocerebellar Ataxia Type 3 ◽  
Type 3 ◽  
Stable Transmission

Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disease caused by a heterozygous CAG repeat expansion in the ataxin 3 gene ( ATXN3). However, patients with homozygous SCA3 carrying expanded CAG repeats in both alleles of ATXN3 are extremely rare. Herein, we present a case of a 50-year-old female who had homozygous SCA3 with expansion of 62/62 repeats. Segregation analysis of the patient’s family showed both a contraction pattern of CAG repeat length and stable transmission. The present case demonstrated an earlier onset and more severe clinical phenotype than that seen in heterozygous individuals, suggesting that the gene dosage enhances disease severity.

scholarly journals Dystonia in Patients with Spinocerebellar Ataxia 3 - Machado-Joseph disease: An Underestimated Diagnosis?

2018 ◽  
Vol 12 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Ligia Maria Perrucci Catai ◽  
Carlos Henrique Ferreira Camargo ◽  
Adriana Moro ◽  
Gustavo Ribas ◽  
Salmo Raskin ◽  
...  
Keyword(s):  
Spinocerebellar Ataxia ◽  
Movement Disorders ◽  
Disease Onset ◽  
Cag Repeat ◽  
Spinocerebellar Ataxia Type ◽  
Spinocerebellar Ataxia Type 3 ◽  
Generalized Dystonia ◽  
Machado Joseph Disease ◽  
Sca3 Patient ◽  
Type 3

Background:Spinocerebellar Ataxia type 3 (SCA3) or Machado-Joseph Disease (MJD) is characterized by cerebellar, central and peripheral symptoms, including movement disorders. Dystonia can be classified as hereditary and neurodegenerative when present in SCA3.Objective:The objective of this study was to evaluate the dystonia characteristics in patients with MJD.Method:We identified all SCA3 patients with dystonia from the SCA3 HC-UFPR database, between December 2015 and December 2016.Their medical records were reviewed to verify the diagnosis of dystonia and obtain demographic and clinical data. Standardized evaluation was carried out through the classification of Movement Disorders Society of 2013 and Burke Fahn-Marsden scale (BFM).Results:Amongst the presenting some common characteristics, 381 patients with SCA3, 14 (3.7%) subjects presented dystonia: 5 blepharospasm, 1 cervical dystonia, 3 oromandibular, 3 multifocal and 2 generalized dystonia. Regarding dystonia's subtypes, 71.4% had SCA3 subtype I and 28.6% SCA3 subtype II. The average age of the disease onset was 40±10.7 years; the SCA3 disease duration was 11.86± 6.13 years; the CAG repeat lengths ranged from 75 to 78, and the BFM scores ranged from 1.0 to 40. There was no correlation between the dystonia severity and CAG repeat lengths or the SCA3 clinical evolution.Conclusion:Dystonia in SCA3 is frequent and displays highly variable clinical profiles and severity grades. Dystonia is therefore a present symptom in SCA3, which may precede the SCA3 classic symptoms. Dystonia diagnosis is yet to be properly recognized within SCA3 patient.

scholarly journals Spinocerebellar ataxia type 6 in Brazil

2008 ◽  
Vol 66 (3b) ◽  
pp. 691-694 ◽  
Author(s):  
Hélio A.G. Teive ◽  
Renato Puppi Munhoz ◽  
Salmo Raskin ◽  
Lineu César Werneck
Keyword(s):  
Cerebellar Ataxia ◽  
Spinocerebellar Ataxia ◽  
Late Onset ◽  
Cag Repeat ◽  
Autosomal Dominant Cerebellar Ataxia ◽  
Spinocerebellar Ataxia Type ◽  
Spinocerebellar Ataxia Type 6 ◽  
Voltage Dependent ◽  
Pure Cerebellar Ataxia ◽  
Japanese Ancestry

Spinocerebellar ataxia type 6 (SCA 6) is an autosomal dominant cerebellar ataxia caused by CAG repeat expansion in the SCA6 gene, a alpha 1A voltage-dependent calcium channel subunit gene on chromosome 19p13. SCA-6 is characterized predominantly by slowly progressive pure cerebellar ataxia with late onset. We report three index patients, with pure, late onset, cerebellar ataxia, belonging to three different Brazilian families, all of them with Japanese ancestry, from Hokkaido island of Japan.

scholarly journals Activation of the ubiquitin-proteasome system contributes to oculopharyngeal muscular dystrophy through muscle atrophy

PLoS Genetics ◽  
2022 ◽  
Vol 18 (1) ◽  
pp. e1010015
Author(s):  
Cécile Ribot ◽  
Cédric Soler ◽  
Aymeric Chartier ◽  
Sandy Al Hayek ◽  
Rima Naït-Saïdi ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Muscle Atrophy ◽  
Late Onset ◽  
Oral Treatment ◽  
Ubiquitin Proteasome System ◽  
Proteasome Activity ◽  
Functional Study ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Ubiquitin Proteasome ◽  
And Function

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset disorder characterized by progressive weakness and degeneration of specific muscles. OPMD is due to extension of a polyalanine tract in poly(A) binding protein nuclear 1 (PABPN1). Aggregation of the mutant protein in muscle nuclei is a hallmark of the disease. Previous transcriptomic analyses revealed the consistent deregulation of the ubiquitin-proteasome system (UPS) in OPMD animal models and patients, suggesting a role of this deregulation in OPMD pathogenesis. Subsequent studies proposed that UPS contribution to OPMD involved PABPN1 aggregation. Here, we use a Drosophila model of OPMD to address the functional importance of UPS deregulation in OPMD. Through genome-wide and targeted genetic screens we identify a large number of UPS components that are involved in OPMD. Half dosage of UPS genes reduces OPMD muscle defects suggesting a pathological increase of UPS activity in the disease. Quantification of proteasome activity confirms stronger activity in OPMD muscles, associated with degradation of myofibrillar proteins. Importantly, improvement of muscle structure and function in the presence of UPS mutants does not correlate with the levels of PABPN1 aggregation, but is linked to decreased degradation of muscle proteins. Oral treatment with the proteasome inhibitor MG132 is beneficial to the OPMD Drosophila model, improving muscle function although PABPN1 aggregation is enhanced. This functional study reveals the importance of increased UPS activity that underlies muscle atrophy in OPMD. It also provides a proof-of-concept that inhibitors of proteasome activity might be an attractive pharmacological approach for OPMD.

scholarly journals A Novel SCA3 Knock-in Mouse Model Mimics the Human SCA3 Disease Phenotype Including Neuropathological, Behavioral, and Transcriptional Abnormalities Especially in Oligodendrocytes

2021 ◽  
Author(s):  
Eva Haas ◽  
Rana D. Incebacak ◽  
Thomas Hentrich ◽  
Chrisovalantou Huridou ◽  
Thorsten Schmidt ◽  
...  
Keyword(s):  
Mouse Model ◽  
Brain Regions ◽  
Cag Repeat ◽  
Spinocerebellar Ataxia Type ◽  
The Novel ◽  
Spinocerebellar Ataxia Type 3 ◽  
Transcriptional Changes ◽  
Cerebellar Tissue ◽  
Type 3 ◽  
Polyq Expansion

AbstractSpinocerebellar ataxia type 3 is the most common autosomal dominant inherited ataxia worldwide, caused by a CAG repeat expansion in the Ataxin-3 gene resulting in a polyglutamine (polyQ)-expansion in the corresponding protein. The disease is characterized by neuropathological, phenotypical, and specific transcriptional changes in affected brain regions. So far, there is no mouse model available representing all the different aspects of the disease, yet highly needed for a better understanding of the disease pathomechanisms. Here, we characterized a novel Ataxin-3 knock-in mouse model, expressing a heterozygous or homozygous expansion of 304 CAACAGs in the murine Ataxin-3 locus using biochemical, behavioral, and transcriptomic approaches. We compared neuropathological, and behavioral features of the new knock-in model with the in SCA3 research mostly used YAC84Q mouse model. Further, we compared transcriptional changes found in cerebellar samples of the SCA3 knock-in mice and post-mortem human SCA3 patients. The novel knock-in mouse is characterized by the expression of a polyQ-expansion in the murine Ataxin-3 protein, leading to aggregate formation, especially in brain regions known to be vulnerable in SCA3 patients, and impairment of Purkinje cells. Along these neuropathological changes, the mice showed a reduction in body weight accompanied by gait and balance instability. Transcriptomic analysis of cerebellar tissue revealed age-dependent differential expression, enriched for genes attributed to myelinating oligodendrocytes. Comparing these changes with those found in cerebellar tissue of SCA3 patients, we discovered an overlap of differentially expressed genes pointing towards similar gene expression perturbances in several genes linked to myelin sheaths and myelinating oligodendrocytes.

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