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Ferrari Aggradi CR, Rimoldi M, Romagnoli G, Velardo D, Meneri M, Iacobucci D, Ripolone M, Napoli L, Ciscato P, Moggio M, Comi GP, Ronchi D, Corti S, Abati E. Lafora Disease: A Case Report and Evolving Treatment Advancements. Brain Sci 2023; 13:1679. [PMID: 38137127 PMCID: PMC10742041 DOI: 10.3390/brainsci13121679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/20/2023] [Accepted: 12/03/2023] [Indexed: 12/24/2023] Open
Abstract
Lafora disease is a rare genetic disorder characterized by a disruption in glycogen metabolism. It manifests as progressive myoclonus epilepsy and cognitive decline during adolescence. Pathognomonic is the presence of abnormal glycogen aggregates that, over time, produce large inclusions (Lafora bodies) in various tissues. This study aims to describe the clinical and histopathological aspects of a novel Lafora disease patient, and to provide an update on the therapeutical advancements for this disorder. A 20-year-old Libyan boy presented with generalized tonic-clonic seizures, sporadic muscular jerks, eyelid spasms, and mental impairment. Electroencephalography showed multiple discharges across both brain hemispheres. Brain magnetic resonance imaging was unremarkable. Muscle biopsy showed increased lipid content and a very mild increase of intermyofibrillar glycogen, without the polyglucosan accumulation typically observed in Lafora bodies. Despite undergoing three lines of antiepileptic treatment, the patient's condition showed minimal to no improvement. We identified the homozygous variant c.137G>A, p.(Cys46Tyr), in the EPM2B/NHLRC1 gene, confirming the diagnosis of Lafora disease. To our knowledge, the presence of lipid aggregates without Lafora bodies is atypical. Lafora disease should be considered during the differential diagnosis of progressive, myoclonic, and refractory epilepsies in both children and young adults, especially when accompanied by cognitive decline. Although there are no effective therapies yet, the development of promising new strategies prompts the need for an early and accurate diagnosis.
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Affiliation(s)
- Carola Rita Ferrari Aggradi
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy; (C.R.F.A.); (G.R.); (M.M.); (G.P.C.); (D.R.)
| | - Martina Rimoldi
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (M.R.); (D.V.); (M.R.); (P.C.); (M.M.)
- Medical Genetics Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Gloria Romagnoli
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy; (C.R.F.A.); (G.R.); (M.M.); (G.P.C.); (D.R.)
| | - Daniele Velardo
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (M.R.); (D.V.); (M.R.); (P.C.); (M.M.)
| | - Megi Meneri
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy; (C.R.F.A.); (G.R.); (M.M.); (G.P.C.); (D.R.)
- Stroke Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Davide Iacobucci
- Neurology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Michela Ripolone
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (M.R.); (D.V.); (M.R.); (P.C.); (M.M.)
| | - Laura Napoli
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (M.R.); (D.V.); (M.R.); (P.C.); (M.M.)
| | - Patrizia Ciscato
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (M.R.); (D.V.); (M.R.); (P.C.); (M.M.)
| | - Maurizio Moggio
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (M.R.); (D.V.); (M.R.); (P.C.); (M.M.)
| | - Giacomo Pietro Comi
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy; (C.R.F.A.); (G.R.); (M.M.); (G.P.C.); (D.R.)
- Neurology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Dario Ronchi
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy; (C.R.F.A.); (G.R.); (M.M.); (G.P.C.); (D.R.)
- Neurology Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Stefania Corti
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy; (C.R.F.A.); (G.R.); (M.M.); (G.P.C.); (D.R.)
- Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (M.R.); (D.V.); (M.R.); (P.C.); (M.M.)
| | - Elena Abati
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy; (C.R.F.A.); (G.R.); (M.M.); (G.P.C.); (D.R.)
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Sun Y, Zhou Z, Wang Q, Yan J, Zhang Z, Cui T. MRI characteristics due to gene mutations in a Chinese pedigree with Lafora disease. Mol Genet Genomic Med 2023; 11:e2228. [PMID: 37455597 PMCID: PMC10568394 DOI: 10.1002/mgg3.2228] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/20/2023] [Accepted: 06/03/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND AND PURPOSE Lafora disease (LD) is a very rare autosomal recessive disorder manifesting primarily as fatal, congenital, and neurodegenerative epilepsies. We aimed to describe the MRI characteristics due to gene mutations in a Chinese pedigree with LD. METHODS Whole-exome sequencing, muscle biopsy, pedigree analysis, and MRI analysis were conducted. Five family members (two of whom were affected by LD) were whole-genome sequenced. Longitudinal changes in brain MRI volumes were analyzed by Freesurfer. RESULTS We identified a new intron heterozygous mutation in the EMP2A gene c.71 (exon 1) G>A in a Chinese LD pedigree that was characterized by refractory seizures, progressive vision impairment, and declines in motor and cognitive functions. The patient suffered generalized tonic-clonic seizures since the age of 15 years and had severe forms of progressive myoclonic seizure. She eventually died after being admitted to the intensive care unit due to status epilepticus at the age of 24 years. Period acid Schiff staining showed positive polyglucosan particles in muscle biopsy specimens. Regions of atrophy in the whole brain, and especially in the hippocampus, were detected. CONCLUSIONS We identified a new heterozygous mutation (c.71+1G>A) in a Chinese LD pedigree, which broadens the mutation spectrum of LD genes. We found that the patient exhibited brain volumetric atrophy along with rapidly worsening symptoms. These results contribute to our understanding of LD.
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Affiliation(s)
- Yueqian Sun
- Department of Neurology, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
| | - Ziqi Zhou
- Department of Neurology, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
| | - Qun Wang
- Department of Neurology, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
- China National Clinical Research Center for Neurological DiseasesBeijingChina
- Beijing Institute for Brain Disorders, Collaborative Innovation Center for Brain DisordersCapital Medical UniversityBeijingChina
- Beijing Key Laboratory of NeuromodulationBeijingChina
| | - Jing Yan
- Department of Neurology, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
- China National Clinical Research Center for Neurological DiseasesBeijingChina
| | - Zaiqiang Zhang
- Department of Neurology, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
- China National Clinical Research Center for Neurological DiseasesBeijingChina
| | - Tao Cui
- Department of Neurology, Beijing Tiantan HospitalCapital Medical UniversityBeijingChina
- China National Clinical Research Center for Neurological DiseasesBeijingChina
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d'Orsi G, Farolfi A, Muccioli L, Palumbo O, Palumbo P, Modoni S, Allegri V, Garibotto V, Di Claudio MT, Di Muro E, Benvenuto M, Bisulli F, Carella M. Association of CSF and PET markers of neurodegeneration with electroclinical progression in Lafora disease. Front Neurol 2023; 14:1202971. [PMID: 37448753 PMCID: PMC10337130 DOI: 10.3389/fneur.2023.1202971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 06/05/2023] [Indexed: 07/15/2023] Open
Abstract
Purpose To evaluate the electro-clinical features in association with laboratory and instrumental correlates of neurodegeneration to detect the progression of Lafora disease (LD). Methods We investigated the electro-clinical longitudinal data and CSF Aβ42, p-tau181 and t-tauAg, amyloid, and 18F-FDG PET of five unrelated LD families. Results Three progressive electro-clinical stages were identified. The early phase was characterized by rare, generalized tonic-clonic and focal visual seizures, followed by the occurrence of myoclonus after a period ranging from 2 to 12 months. The intermediate stage, usually occurring 2 years after the onset of epilepsy, is characterized by a worsening of epilepsy and myoclonus associated with progressive dementia and cerebellar signs. Finally, the late stage, evolving after a mean period of 7 ± 1.41 years from the onset of the disease, was characterized by gait ataxia resulting in bedriddenness, severe dementia, daily/pluri-daily myoclonus, drug-resistant epilepsy, clusters of seizures or status epilepticus, and medical complications. Amyloid (CSF Aβ42, amyloid PET) and neurodegenerative (CSF p-tau181 and t-tauAg, FDG-PET) biomarkers indicate a pattern of cognitive impairment of the non-Alzheimer's disease type. A total of 80% of the LD patients showed more severe hypometabolism in the second FDG-PET scan compared to the first scan performed in a lower phase; the lateral temporal lobe and the thalamus hypometabolism were associated with the presence of intermediate or late phase. Conclusions Three electroclinical and 18F-FDG PET evolutive stages are useful biomarkers for the progression of LD and could help to evaluate the efficacy of new disease-modifying treatments. The combination of traditional CSF biomarkers improves the diagnostic accuracy of cognitive decline in LD patients, indicating a cognitive impairment of the non-Alzheimer's disease type.
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Affiliation(s)
- Giuseppe d'Orsi
- Neurology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Andrea Farolfi
- Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Lorenzo Muccioli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Orazio Palumbo
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Pietro Palumbo
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Sergio Modoni
- Nuclear Medicine Department, Policlinico Riuniti, Foggia, Italy
| | - Vincenzo Allegri
- Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Valentina Garibotto
- Diagnostic Department, University Hospitals of Geneva, CIBM Center of Biomedical Imaging and NIMTLab, University of Geneva, Geneva, Switzerland
| | - Maria Teresa Di Claudio
- Neurology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Ester Di Muro
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Mario Benvenuto
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Francesca Bisulli
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Full Member of the European Reference Network EpiCARE), Bologna, Italy
| | - Massimo Carella
- Division of Medical Genetics, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
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Degenerative dementias: a question of syndrome or disease? NEUROLOGÍA (ENGLISH EDITION) 2022; 37:480-491. [DOI: 10.1016/j.nrleng.2019.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/07/2019] [Indexed: 11/20/2022] Open
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Robles Bayón A. Degenerative dementias: A question of syndrome or disease? Neurologia 2022; 37:480-491. [PMID: 31331676 DOI: 10.1016/j.nrl.2019.03.016] [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: 01/04/2019] [Accepted: 03/07/2019] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Neurologists refer to numerous "syndromes,‿ consisting of specific combinations of clinical manifestations, following a specific progression pattern, and with the support of blood analysis (without genomic-proteomic parameters) and neuroimaging findings (MRI, CT, perfusion SPECT, or 18F-FDG-PET scans). Neurodegenerative "diseases,‿ on the other hand, are defined by specific combinations of clinical signs and histopathological findings; these must be confirmed by a clinical examination and a histology study or evidence of markers of a specific disorder for the diagnosis to be made. However, we currently know that most genetic and histopathological alterations can result in diverse syndromes. The genetic or histopathological aetiology of each syndrome is also heterogeneous, and we may encounter situations with pathophysiological alterations characterising more than one neurodegenerative disease. Sometimes, specific biomarkers are detected in the preclinical stage. DEVELOPMENT We performed a literature review to identify patients whose histopathological or genetic disorder was discordant with that expected for the clinical syndrome observed, as well as patients presenting multiple neurodegenerative diseases, confirming the heterogeneity and overlap between syndromes and diseases. We also observed that the treatments currently prescribed to patients with neurodegenerative diseases are symptomatic. CONCLUSIONS Our findings show that the search for disease biomarkers should be restricted to research centres, given the lack of disease-modifying drugs or treatments improving survival. Moreover, syndromes and specific molecular or histopathological alterations should be managed independently of one another, and new "diseases‿ should be defined and adapted to current knowledge and practice.
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Affiliation(s)
- A Robles Bayón
- Unidad de Neurología Cognitiva, Hospital HM Rosaleda, Santiago de Compostela, La Coruña, España.
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Liang T, Wu J, Chen H, Qian J, Xu Z. Novel mutation of EPM2A causes progressive myoclonic epilepsy: a case report. Neurol Sci 2022; 43:3467-3471. [DOI: 10.1007/s10072-022-05986-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/25/2022] [Indexed: 11/29/2022]
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Xingxua T, Xinjuan L, Yuncan C, Dongyan W. Compound heterozygosity for novel variations of the NHLRC1 Gene in a family with Lafora Disease. Clin Neurol Neurosurg 2022; 218:107255. [DOI: 10.1016/j.clineuro.2022.107255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 11/28/2022]
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Pondrelli F, Muccioli L, Licchetta L, Mostacci B, Zenesini C, Tinuper P, Vignatelli L, Bisulli F. Natural history of Lafora disease: a prognostic systematic review and individual participant data meta-analysis. Orphanet J Rare Dis 2021; 16:362. [PMID: 34399803 PMCID: PMC8365996 DOI: 10.1186/s13023-021-01989-w] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 07/29/2021] [Indexed: 12/29/2022] Open
Abstract
Background Lafora disease (LD) is a rare fatal autosomal recessive form of progressive myoclonus epilepsy. It affects previously healthy children or adolescents, causing pharmacoresistant epilepsy, myoclonus and severe psychomotor deterioration. This work aims to describe the clinical course of LD and identify predictors of outcome by means of a prognostic systematic review with individual participant data meta-analysis. Methods A search was conducted on MEDLINE and Embase with no restrictions on publication date. Only studies reporting genetically confirmed LD cases were included. Kaplan–Meier estimate was used to assess probability of death and loss of autonomy. Univariable and multivariable Cox regression models with mixed effects (clustered survival data) were performed to evaluate prognostic factors. Results Seventy-three papers describing 298 genetically confirmed LD cases were selected. Mean age at disease onset was 13.4 years (SD 3.7), with 9.1% aged ≥ 18 years. Overall survival rates in 272 cases were 93% [95% CI 89–96] at 5 years, 62% [95% CI 54–69] at 10 years and 57% [95% CI 49–65] at 15 years. Median survival time was 11 years. The probability of loss of autonomy in 110 cases was 45% [95% CI 36–55] at 5 years, 75% [95% CI 66–84] at 10 years, and 83% [95% CI 74–90] at 15 years. Median loss of autonomy time was 6 years. Asian origin and age at onset < 18 years emerged as negative prognostic factors, while type of mutated gene and symptoms at onset were not related to survival or disability. Conclusions This study documented that half of patients survived at least 11 years. The notion of actual survival rate and prognostic factors is crucial to design studies on the effectiveness of upcoming new disease-modifying therapies.
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Affiliation(s)
- Federica Pondrelli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - Lorenzo Muccioli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - Laura Licchetta
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Full Member of the ERN EpiCARE, Bologna, Italy
| | - Barbara Mostacci
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Full Member of the ERN EpiCARE, Bologna, Italy
| | - Corrado Zenesini
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Full Member of the ERN EpiCARE, Bologna, Italy
| | - Paolo Tinuper
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Full Member of the ERN EpiCARE, Bologna, Italy
| | - Luca Vignatelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Full Member of the ERN EpiCARE, Bologna, Italy
| | - Francesca Bisulli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy. .,IRCCS Istituto delle Scienze Neurologiche di Bologna, Full Member of the ERN EpiCARE, Bologna, Italy.
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Farajzadeh Valilou S, Karimzad Hagh J, Salimi Asl M, Abdi Rad I, Edizadeh M, Pooladi A. A novel biallelic LMNB2 variant in a patient with progressive myoclonus epilepsy and ataxia: A case of laminopathy. Clin Case Rep 2021; 9:e04520. [PMID: 34466237 PMCID: PMC8381754 DOI: 10.1002/ccr3.4520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/20/2021] [Accepted: 05/30/2021] [Indexed: 12/26/2022] Open
Abstract
The report of LMNB2-related progressive myoclonus epilepsy and ataxia due to missense homozygous c.473G>T variant.
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Affiliation(s)
- Saeed Farajzadeh Valilou
- Department of Medical Genetics and Sarem Cell Research Center (SCRC)Sarem Womens' HospitalTehranIran
- Medical Genetics Network (MeGeNe)Universal Scientific Education and Research Network (USERN)TehranIran
| | - Javad Karimzad Hagh
- Department of Medical Genetics and Sarem Cell Research Center (SCRC)Sarem Womens' HospitalTehranIran
- IVF CenterCuypers & Cuypers Fertility Center Heinsberger HöfeHeinsbergGermany
| | - Mohammad Salimi Asl
- Department of Medical Genetics and Sarem Cell Research Center (SCRC)Sarem Womens' HospitalTehranIran
| | - Isa Abdi Rad
- Departament of Medical GeneticsSchool of MedicineUrmia University of Medical SciencesUrmiaIran
| | - Masoud Edizadeh
- Biotechnology DepartmentSchool of MedicineLorestan University of Medical SciencesKhorramabadLorestanIran
| | - Arash Pooladi
- Cancer and Immunology Research CenterResearch Institute for Health DevelopmentKurdistan University of Medical SciencesSanandajIran
- Department of Medical GeneticsFaculty of MedicineKurdistan University of Medical SciencesSanandajIran
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Riva A, Orsini A, Scala M, Taramasso V, Canafoglia L, d'Orsi G, Di Claudio MT, Avolio C, D'Aniello A, Elia M, Franceschetti S, Di Gennaro G, Bisulli F, Tinuper P, Tappatà M, Romeo A, Freri E, Marini C, Costa C, Sofia V, Ferlazzo E, Magaudda A, Veggiotti P, Gennaro E, Pistorio A, Minetti C, Bianchi A, Striano S, Michelucci R, Zara F, Minassian BA, Striano P. Italian cohort of Lafora disease: Clinical features, disease evolution, and genotype-phenotype correlations. J Neurol Sci 2021; 424:117409. [PMID: 33773408 DOI: 10.1016/j.jns.2021.117409] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/22/2021] [Accepted: 03/17/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Lafora disease (LD) is characterized by progressive myoclonus, refractory epilepsy, and cognitive deterioration. This complex neurodegenerative condition is caused by pathogenic variants in EPM2A/EPM2B genes, encoding two essential glycogen metabolism enzymes known as laforin and malin. Long-term follow-up data are lacking. We describe the clinical features and genetic findings of a cohort of 26 Italian patients with a long clinical follow-up. METHODS Patients with EPM2A/EPM2B pathogenic variants were identified by direct gene sequencing or gene panels with targeted re-sequencing. Disease progression, motor functions, and mental performance were assessed by a simplified disability scale. Spontaneous/action myoclonus severity was scored by the Magaudda Scale. RESULTS Age range was 12.2-46.2 years (mean:25.53 ± 9.14). Age at disease onset ranged from 10 to 22 years (mean:14.04 ± 2.62). The mean follow-up period was 11.48 ± 7.8 years. Twelve out of the 26 (46%) patients preserved walking ability and 13 (50%) maintained speech. A slower disease progression with preserved ambulation and speech after ≥4 years of follow-up was observed in 1 (11%) out of the 9 (35%) EPM2A patients and in 6 (35%) out of the 17 (65%) EPM2B patients. Follow-up was >10 years in 7 (41.2%) EPM2B individuals, including two harbouring the homozygous p.(D146N) pathogenic variant. CONCLUSIONS This study supports an overall worse disease outcome with severe deterioration of ambulation and speech in patients carrying EPM2A mutations. However, the delayed onset of disabling symptoms observed in the EPM2B subjects harbouring the p.(D146N) pathogenic variant suggests that the underlying causative variant may still influence LD severity.
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Affiliation(s)
- Antonella Riva
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Genova, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova, Genova, Italy.
| | - Alessandro Orsini
- Pediatric Clinic, Department of Clinical and Experimental Medicine, Università di Pisa, Pisa, Italy
| | - Marcello Scala
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova, Genova, Italy; Pediatric Neurology and Muscular Disease Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Vittoria Taramasso
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova, Genova, Italy
| | | | - Giuseppe d'Orsi
- Epilepsy Centre-S.C. Neurologia Universitaria, Policlinico Riuniti, Foggia, Italy
| | | | - Carlo Avolio
- Epilepsy Centre-S.C. Neurologia Universitaria, Policlinico Riuniti, Foggia, Italy
| | | | - Maurizio Elia
- Unit of Neurology and Clinical Neurophysiopathology, Oasi Research Institute, IRCCS, Troina, Italy
| | | | | | - Francesca Bisulli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Reference Center for Rare and Complex Epilepsies - EpiCARE), Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Paolo Tinuper
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Reference Center for Rare and Complex Epilepsies - EpiCARE), Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Maria Tappatà
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Reference Center for Rare and Complex Epilepsies - EpiCARE), Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Antonino Romeo
- Pediatric Neurology Unit and Epilepsy Center, Department of Neuroscience, "Fatebenefratelli e Oftalmico" Hospital, Milano, Italy
| | - Elena Freri
- Department of Pediatric Neuroscience, IRCCS Foundation, Carlo Besta Neurological Institute, Milan, Italy
| | - Carla Marini
- Child Neurology and Psychiatric Unit, Salesi Pediatric Hospital, United Hospitals of Ancona, Ancona, Italy
| | - Cinzia Costa
- Neurology Clinic, S.M. Misericordia Hospital, Departement of Medicine, University of Perugia, Perugia, Italy
| | - Vito Sofia
- Dipartimento "G.F Ingrassia", Università degli Studi di Catania, Catania, Italy
| | - Edoardo Ferlazzo
- Department of Medical and Surgical Sciences, "Magna Graecia" University of Catanzaro, Germaneto, Catanzaro, Italy
| | - Adriana Magaudda
- Epilepsy Center, Department of Clinical and Experimental Medicine, AOU Policlinico "G. Martino", Messina, Italy
| | - Pierangelo Veggiotti
- Department of the Mother and Child Health, Pediatric Unit, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Elena Gennaro
- UOC Laboratorio di Genetica Umana, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Angela Pistorio
- Pediatric Neurology and Muscular Disease Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Carlo Minetti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova, Genova, Italy; Pediatric Neurology and Muscular Disease Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy
| | - Amedeo Bianchi
- Department of Neurology and Epilepsy Centre, San Donato Hospital, Arezzo, Italy
| | - Salvatore Striano
- Department of Neuroscience, Reproductive and Odontostomatological Sciences, Federico II University, Napoli, Italy
| | - Roberto Michelucci
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Epilepsy Center (Reference Center for Rare and Complex Epilepsies - EpiCARE), Bologna, Italy; Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Federico Zara
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Genova, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova, Genova, Italy
| | - Berge Arakel Minassian
- Pediatric Neurology, University of Texas Southwestern and Dallas Children's Medical Centre, Dallas, TX, USA
| | - Pasquale Striano
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova, Genova, Italy; Pediatric Neurology and Muscular Disease Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy.
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Goyani S, Roy M, Singh R. TRIM-NHL as RNA Binding Ubiquitin E3 Ligase (RBUL): Implication in development and disease pathogenesis. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166066. [PMID: 33418035 DOI: 10.1016/j.bbadis.2020.166066] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/14/2020] [Accepted: 12/27/2020] [Indexed: 12/20/2022]
Abstract
TRIM proteins are RING domain-containing modular ubiquitin ligases, unique due to their stimuli specific expression, localization, and turnover. The TRIM family consists of more than 76 proteins, including the TRIM-NHL sub-family which possesses RNA binding ability along with the inherent E3 Ligase activity, hence can be classified as a unique class of RNA Binding Ubiquitin Ligases (RBULs). Having these two abilities, TRIM-NHL proteins can play important role in a wide variety of cellular processes and their dysregulation can lead to complex and systemic pathological conditions. Increasing evidence suggests that TRIM-NHL proteins regulate RNA at the transcriptional and post-transcriptional level having implications in differentiation, development, and many pathological conditions. This review explores the evolving role of TRIM-NHL proteins as TRIM-RBULs, their ubiquitin ligase and RNA binding ability regulating cellular processes, and their possible role in different pathophysiological conditions.
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Affiliation(s)
- Shanikumar Goyani
- Department of Biochemistry, Faculty of Science, The M.S. University of Baroda, Vadodara 390 002, Gujarat, India
| | - Milton Roy
- Department of Biochemistry, Faculty of Science, The M.S. University of Baroda, Vadodara 390 002, Gujarat, India
| | - Rajesh Singh
- Department of Biochemistry, Faculty of Science, The M.S. University of Baroda, Vadodara 390 002, Gujarat, India.
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12
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Rossi M, van der Veen S, Merello M, Tijssen MAJ, van de Warrenburg B. Myoclonus-Ataxia Syndromes: A Diagnostic Approach. Mov Disord Clin Pract 2020; 8:9-24. [PMID: 33426154 DOI: 10.1002/mdc3.13106] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/30/2020] [Accepted: 10/14/2020] [Indexed: 12/30/2022] Open
Abstract
Background A myriad of disorders combine myoclonus and ataxia. Most causes are genetic and an increasing number of genes are being associated with myoclonus-ataxia syndromes (MAS), due to recent advances in genetic techniques. A proper etiologic diagnosis of MAS is clinically relevant, given the consequences for genetic counseling, treatment, and prognosis. Objectives To review the causes of MAS and to propose a diagnostic algorithm. Methods A comprehensive and structured literature search following PRISMA criteria was conducted to identify those disorders that may combine myoclonus with ataxia. Results A total of 135 causes of combined myoclonus and ataxia were identified, of which 30 were charted as the main causes of MAS. These include four acquired entities: opsoclonus-myoclonus-ataxia syndrome, celiac disease, multiple system atrophy, and sporadic prion diseases. The distinction between progressive myoclonus epilepsy and progressive myoclonus ataxia poses one of the main diagnostic dilemmas. Conclusions Diagnostic algorithms for pediatric and adult patients, based on clinical manifestations including epilepsy, are proposed to guide the differential diagnosis and corresponding work-up of the most important and frequent causes of MAS. A list of genes associated with MAS to guide genetic testing strategies is provided. Priority should be given to diagnose or exclude acquired or treatable disorders.
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Affiliation(s)
- Malco Rossi
- Movement Disorders Section Neuroscience Department Buenos Aires Argentina.,Argentine National Scientific and Technological Research Council (CONICET) Buenos Aires Argentina
| | - Sterre van der Veen
- Pontificia Universidad Católica Argentina (UCA) Buenos Aires Argentina.,Department of Neurology University of Groningen, University Medical Center Groningen Groningen The Netherlands
| | - Marcelo Merello
- Movement Disorders Section Neuroscience Department Buenos Aires Argentina.,Argentine National Scientific and Technological Research Council (CONICET) Buenos Aires Argentina.,Pontificia Universidad Católica Argentina (UCA) Buenos Aires Argentina
| | - Marina A J Tijssen
- Department of Neurology University of Groningen, University Medical Center Groningen Groningen The Netherlands.,Expertise Center Movement Disorders Groningen University Medical Center Groningen (UMCG) Groningen The Netherlands
| | - Bart van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition & Behaviour Radboud University Medical Center Nijmegen The Netherlands
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Abstract
Lafora disease is a severe, autosomal recessive, progressive myoclonus epilepsy. The disease usually manifests in previously healthy adolescents, and death commonly occurs within 10 years of symptom onset. Lafora disease is caused by loss-of-function mutations in EPM2A or NHLRC1, which encode laforin and malin, respectively. The absence of either protein results in poorly branched, hyperphosphorylated glycogen, which precipitates, aggregates and accumulates into Lafora bodies. Evidence from Lafora disease genetic mouse models indicates that these intracellular inclusions are a principal driver of neurodegeneration and neurological disease. The integration of current knowledge on the function of laforin-malin as an interacting complex suggests that laforin recruits malin to parts of glycogen molecules where overly long glucose chains are forming, so as to counteract further chain extension. In the absence of either laforin or malin function, long glucose chains in specific glycogen molecules extrude water, form double helices and drive precipitation of those molecules, which over time accumulate into Lafora bodies. In this article, we review the genetic, clinical, pathological and molecular aspects of Lafora disease. We also discuss traditional antiseizure treatments for this condition, as well as exciting therapeutic advances based on the downregulation of brain glycogen synthesis and disease gene replacement.
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Seeing the developments of epileptology from inside the stream. Epilepsy Behav 2018; 86:214-218. [PMID: 30017835 DOI: 10.1016/j.yebeh.2018.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 06/04/2018] [Indexed: 11/21/2022]
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Parihar R, Rai A, Ganesh S. Lafora disease: from genotype to phenotype. J Genet 2018; 97:611-624. [PMID: 30027899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The progressive myoclonic epilepsy of Lafora or Lafora disease (LD) is a neurodegenerative disorder characterized by recurrent seizures and cognitive deficits. With typical onset in the late childhood or early adolescence, the patients show progressive worsening of the disease symptoms, leading to death in about 10 years. It is an autosomal recessive disorder caused by the loss-of-function mutations in the EPM2A gene, coding for a protein phosphatase (laforin) or the NHLRC1 gene coding for an E3 ubiquitin ligase (malin). LD is characterized by the presence of abnormally branched water insoluble glycogen inclusions known as Lafora bodies in the neurons and other tissues, suggesting a role for laforin and malin in glycogen metabolic pathways. Mouse models of LD, developed by targeted disruption of the Epm2a or Nhlrc1 gene, recapitulated most of the symptoms and pathological features as seen in humans, and have offered insight into the pathomechanisms. Besides the formation of Lafora bodies in the neurons in the presymptomatic stage, the animal models have also demonstrated perturbations in the proteolytic pathways, such as ubiquitin proteasome system and autophagy, and inflammatory response. This review attempts to provide a comprehensive coverage on the genetic defects leading to the LD in humans, on the functional properties of the laforin and malin proteins, and on how defects in any one of these two proteins result in a clinically similar phenotype. We also discuss the disease pathologies as revealed by the studies on the animal models and, finally, on the progress with therapeutic attempts albeit in the animal models.
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Affiliation(s)
- Rashmi Parihar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur 208 016, India.
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17
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Nicolescu RC, Al-Khawaga S, Minassian BA, Hussain K. Diabetes Mellitus in a Patient With Lafora Disease: Possible Links With Pancreatic β-Cell Dysfunction and Insulin Resistance. Front Pediatr 2018; 6:424. [PMID: 30701169 PMCID: PMC6343460 DOI: 10.3389/fped.2018.00424] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/21/2018] [Indexed: 12/12/2022] Open
Abstract
Lafora disease (LD) is a rare autosomal recessive disorder characterized by progressive myoclonic epilepsy followed by continuous neurological decline, culminating in death within 10 years. LD leads to accumulation of insoluble, abnormal, glycogen-like structures called Lafora bodies (LBs). It is caused by mutations in the gene encoding glycogen phosphatase (EPM2A) or the E3 ubiquitin ligase malin (EPM2B/NHLRC1). These two proteins are involved in an intricate, however, incompletely elucidated pathway governing glycogen metabolism. The formation of EPM2A and malin signaling complex promotes the ubiquitination of proteins participating in glycogen metabolism, where dysfunctional mutations lead to the formation of LBs. Herein, we describe a 13-years-old child with LD due to a NHLRC1 (c.386C > A, p.Pro129His) mutation, who has developed diabetes mellitus and was treated with metformin. We discuss how basic mechanisms of LD could be linked to β-cell dysfunction and insulin resistance.
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Affiliation(s)
- Ramona C Nicolescu
- Division of Endocrinology and Diabetes, Department of Pediatrics, University of Liège, Centre Hospitalier Régional de la Citadelle, Liège, Belgium
| | - Sara Al-Khawaga
- Division of Endocrinology, Department of Pediatrics, Sidra Medicine Outpatient Clinic, Doha, Qatar
| | - Berge A Minassian
- Division of Neurology, Department of Pediatrics, University of Texas Southwestern, Dallas, TX, United States
| | - Khalid Hussain
- Division of Endocrinology, Department of Pediatrics, Sidra Medicine Outpatient Clinic, Doha, Qatar
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Casciato S, Gambardella S, Mascia A, Quarato PP, D'Aniello A, Ackurina Y, Albano V, Fornai F, Scala S, Di Gennaro G. Severe and rapidly-progressive Lafora disease associated with NHLRC1 mutation: a case report. Int J Neurosci 2017; 127:1150-1153. [DOI: 10.1080/00207454.2017.1337012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | | | | | | | | | - Yana Ackurina
- Functional Diagnostic Department, Kazakh-Russian Medical National University, Almaty, Kazakhstan
| | | | - Francesco Fornai
- IRCCS “NEUROMED”, Pozzilli (IS), Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
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Abstract
Lafora disease (LD) is an autosomal recessive progressive myoclonus epilepsy due to mutations in the EPM2A (laforin) and EPM2B (malin) genes, with no substantial genotype-phenotype differences between the two. Founder effects and recurrent mutations are common, and mostly isolated to specific ethnic groups and/or geographical locations. Pathologically, LD is characterized by distinctive polyglucosans, which are formations of abnormal glycogen. Polyglucosans, or Lafora bodies (LB) are typically found in the brain, periportal hepatocytes of the liver, skeletal and cardiac myocytes, and in the eccrine duct and apocrine myoepithelial cells of sweat glands. Mouse models of the disease and other naturally occurring animal models have similar pathology and phenotype. Hypotheses of LB formation remain controversial, with compelling evidence and caveats for each hypothesis. However, it is clear that the laforin and malin functions regulating glycogen structure are key. With the exception of a few missense mutations LD is clinically homogeneous, with onset in adolescence. Symptoms begin with seizures, and neurological decline follows soon after. The disease course is progressive and fatal, with death occurring within 10 years of onset. Antiepileptic drugs are mostly non-effective, with none having a major influence on the progression of cognitive and behavioral symptoms. Diagnosis and genetic counseling are important aspects of LD, and social support is essential in disease management. Future therapeutics for LD will revolve around the pathogenesics of the disease. Currently, efforts at identifying compounds or approaches to reduce brain glycogen synthesis appear to be highly promising.
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Clinical and genetic studies in patients with Lafora disease from Pakistan. J Neurol Sci 2017; 373:263-267. [PMID: 28131202 DOI: 10.1016/j.jns.2017.01.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 12/29/2016] [Accepted: 01/03/2017] [Indexed: 11/20/2022]
Abstract
Lafora disease (LD) is progressive myoclonic epilepsy with late childhood- to teenage-onset. Mutations in two genes, EPM2A and NHLRC1, are responsible for this autosomal recessive disease in many patients Worldwide. In present study, we reported two unrelated consanguineous Pakistani families with Lafora disease (Families A and B). Affected individuals in both families presented with generalized tonic clonic seizures, intellectual disability, ataxia and cognitive decline. Diagnosis of Lafora disease was made on histo-pathological analysis of the skin biopsy, found positive for lafora bodies in periodic acid schiff stain and frequent generalized epileptiform discharges on electroencephalogram (EEG). Bi-directional sequencing in family A was performed for EPM2A and NHLRC1 genes but no mutation was found. In family B, Illumina TruSight One Sequencing Panel covering 4813 OMIM genes was carried out and we identified a novel homozygous mutation c.95G>T; p.32Trp>Leu of EPM2A gene which was found co-segregated in this family through Sanger sequencing. Structural analysis of this mutation, through different in silico approaches, predicted loss of stability and conformation in Laforin protein.
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Interdependence of laforin and malin proteins for their stability and functions could underlie the molecular basis of locus heterogeneity in Lafora disease. J Biosci 2016; 40:863-71. [PMID: 26648032 DOI: 10.1007/s12038-015-9570-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lafora disease (LD), an autosomal recessive and fatal form of neurodegenerative disorder, is characterized by the presence of polyglucosan inclusions in the affected tissues including the brain. LD can be caused by defects either in the EPM2A gene coding for the laforin protein phosphatase or the NHLRC1 gene coding for the malin ubiquitin ligase. Since the clinical symptoms of LD patients representing the two genetic groups are very similar and since malin is known to interact with laforin, we were curious to examine the possibility that the two proteins regulate each other's function. Using cell biological assays we demonstrate here that (i) malin promotes its own degradation via autoubiquitination, (ii) laforin prevents the auto-degradation of malin by presenting itself as a substrate and (iii) malin preferentially degrades the phosphatase-inactive laforin monomer. Our results that laforin and malin regulate each other's stability and activity offers a novel and attractive model to explain the molecular basis of locus heterogeneity observed in LD.
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Kecmanović M, Keckarević-Marković M, Keckarević D, Stevanović G, Jović N, Romac S. Genetics of Lafora progressive myoclonic epilepsy: current perspectives. APPLICATION OF CLINICAL GENETICS 2016; 9:49-53. [PMID: 27194917 PMCID: PMC4859416 DOI: 10.2147/tacg.s57890] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Lafora disease (LD) is a fatal neurodegenerative disorder caused by loss-of-function mutations in either laforin glycogen phosphatase gene (EPM2A) or malin E3 ubiquitin ligase gene (NHLRC1). LD is associated with gradual accumulation of Lafora bodies (LBs). LBs are aggregates of polyglucosan, a long, linear, poorly branched, hyperphosphorylated, insoluble form of glycogen. Loss-of-function mutations either in the EPM2A or in the NHLRC1 gene lead to polyglucosan formation. One hypothesis on LB formation is based on findings that laforin–malin complex downregulates glycogen synthase (GS) through malin-mediated ubiquitination, and the other one is based on findings that laforin dephosphorylates glycogen. According to the first hypothesis, polyglucosan formation is a result of increased GS activity, and according to the second, an increased glycogen phosphate leads to glycogen conformational change, unfolding, precipitation, and conversion to polyglucosan, while GS remains bound to the precipitating glycogen. In this review, we summarize all the recent findings that have important implications for the treatment of LD, all of them showing that partial inhibition of GS activity may be sufficient to prevent the progression of the disease. The current perspective in LD is high-throughput screening for small molecules that act on the disease pathway, that is, partial inhibitors of GS, which opens a therapeutic window for potential treatment of this fatal disease.
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Affiliation(s)
- Miljana Kecmanović
- Faculty of Biology, Center for Human Molecular Genetics, University of Belgrade, Belgrade, Serbia
| | | | - Dušan Keckarević
- Faculty of Biology, Center for Human Molecular Genetics, University of Belgrade, Belgrade, Serbia
| | - Galina Stevanović
- Clinic of Neurology and Psychiatry for Children and Youth, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Nebojša Jović
- Clinic of Neurology and Psychiatry for Children and Youth, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Stanka Romac
- Faculty of Biology, Center for Human Molecular Genetics, University of Belgrade, Belgrade, Serbia
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García-Cabrero AM, Sánchez-Elexpuru G, Serratosa JM, Sánchez MP. Enhanced sensitivity of laforin- and malin-deficient mice to the convulsant agent pentylenetetrazole. Front Neurosci 2014; 8:291. [PMID: 25309313 PMCID: PMC4162417 DOI: 10.3389/fnins.2014.00291] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Accepted: 08/27/2014] [Indexed: 12/04/2022] Open
Abstract
Lafora disease is a rare form of inherited progressive myoclonus epilepsy caused by mutations in the EPM2A gene encoding laforin, or in the EPM2B gene, which encodes malin. It is characterized by the presence of polyglucosan inclusion bodies (Lafora bodies) in brain and other tissues. Genetically engineered mice lacking expression of either the laforin (Epm2a(-/-) ) or malin (Epm2b(-/-) ) genes display a number of neurological and behavioral abnormalities that resemble those found in patients suffering from Lafora disease; of these, both Epm2a(-/-) and Epm2b(-/-) mice have shown altered motor activity, impaired motor coordination, episodic memory deficits, and different degrees of spontaneous epileptic activity. In this study, we analyze the sensitivity of Epm2a(-/-) and Epm2b(-/-) mice to the convulsant drug pentylenetetrazol (PTZ), an antagonist of the γ-aminobutyric acid type A (GABAA) receptor, commonly used to induce epileptic tonic-clonic seizures in laboratory animals. PTZ-induced epileptic activity, including myoclonic jerks and tonic-clonic seizures, was analyzed in 2 age groups of mice comprising representative samples of young adult and aged mice, after administration of PTZ at sub-convulsive and convulsive doses. Epm2a(-/-) and Epm2b(-/-) mice showed a lower convulsive threshold after PTZ injections at sub-convulsive doses. A lower convulsive threshold and shorter latencies to develop epileptic seizures were observed after PTZ injections at convulsive doses. Different patterns of generalized seizures and of discharges were observed in Epm2a(-/-) and Epm2b(-/-) mice. Epm2a(-/-) and Epm2b(-/-) mice present an increased sensitivity to the convulsant agent PTZ that may reflect different degrees of increased GABAA receptor-mediated hyperexcitability.
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Affiliation(s)
- Ana M. García-Cabrero
- Laboratory of Neurology, IIS-Fundación Jiménez Díaz, Universidad Autónoma de MadridMadrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades RarasMadrid, Spain
| | - Gentzane Sánchez-Elexpuru
- Laboratory of Neurology, IIS-Fundación Jiménez Díaz, Universidad Autónoma de MadridMadrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades RarasMadrid, Spain
| | - José M. Serratosa
- Laboratory of Neurology, IIS-Fundación Jiménez Díaz, Universidad Autónoma de MadridMadrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades RarasMadrid, Spain
| | - Marina P. Sánchez
- Laboratory of Neurology, IIS-Fundación Jiménez Díaz, Universidad Autónoma de MadridMadrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades RarasMadrid, Spain
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Late onset Lafora disease and novel EPM2A mutations: breaking paradigms. Epilepsy Res 2014; 108:1501-10. [PMID: 25246353 DOI: 10.1016/j.eplepsyres.2014.08.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/28/2014] [Accepted: 08/21/2014] [Indexed: 11/21/2022]
Abstract
Lafora disease (LD) is an autosomal recessive progressive myoclonus epilepsy with classic adolescent onset of stimuli sensitive seizures. Patients typically deteriorate rapidly with dementia, ataxia, vegetative failure and death by 25 years of age. LD is caused by homozygous mutations in EPM2A or EPM2B genes. We found four novel mutations in EPM2A - three in exon 4 (Q247X, H265R G279C) and one in exon 1 (Y86D) - and a previously described mutation in exon 4 (R241X). These five EPM2A mutations were found in four index cases and affected relatives. Patient 1 with classic LD was doubly heterozygous for H265R and R241X in exon 4; while Patient 2, who also had classic LD, was homozygous for Q247X in exon 4. Patient 3 with classic LD was homozygous for Y86D in exon 1, but the same mutation in his affected brother manifested an atypical earlier childhood onset. For the first time, we describe a later onset and slower progression of EPM2A-deficient LD seen in Patient 4 and her three sisters who were doubly heterozygous for R241X and G279C in exon 4. In these sisters, seizures started later at 21 to 28 years of age and progressed slowly with patients living beyond 30 years of age. Our observations suggest that variations in phenotypes of EPM2A-deficient LD, like an earlier childhood or adolescent or later adult onset with a rapid or slower course, depend on a second modifying factor separate from pathogenicity or exon location of EPM2A mutations. A modifying gene amongst the patient's genetic background or environmental factors may condition age of onset and rapid or slow progression of LD.
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Increased Oxidative Stress and Impaired Antioxidant Response in Lafora Disease. Mol Neurobiol 2014; 51:932-46. [DOI: 10.1007/s12035-014-8747-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 05/07/2014] [Indexed: 10/25/2022]
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Strnad P, Nuraldeen R, Guldiken N, Hartmann D, Mahajan V, Denk H, Haybaeck J. Broad Spectrum of Hepatocyte Inclusions in Humans, Animals, and Experimental Models. Compr Physiol 2013; 3:1393-436. [DOI: 10.1002/cphy.c120032] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Sharma J, Mukherjee D, Rao SNR, Iyengar S, Shankar SK, Satishchandra P, Jana NR. Neuronatin-mediated aberrant calcium signaling and endoplasmic reticulum stress underlie neuropathology in Lafora disease. J Biol Chem 2013; 288:9482-90. [PMID: 23408434 DOI: 10.1074/jbc.m112.416180] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Lafora disease (LD) is a teenage-onset inherited progressive myoclonus epilepsy characterized by the accumulations of intracellular inclusions called Lafora bodies and caused by mutations in protein phosphatase laforin or ubiquitin ligase malin. But how the loss of function of either laforin or malin causes disease pathogenesis is poorly understood. Recently, neuronatin was identified as a novel substrate of malin that regulates glycogen synthesis. Here we demonstrate that the level of neuronatin is significantly up-regulated in the skin biopsy sample of LD patients having mutations in both malin and laforin. Neuronatin is highly expressed in human fetal brain with gradual decrease in expression in developing and adult brain. However, in adult brain, neuronatin is predominantly expressed in parvalbumin-positive GABAergic interneurons and localized in their processes. The level of neuronatin is increased and accumulated as insoluble aggregates in the cortical area of LD brain biopsy samples, and there is also a dramatic loss of parvalbumin-positive GABAergic interneurons. Ectopic expression of neuronatin in cultured neuronal cells results in increased intracellular Ca(2+), endoplasmic reticulum stress, proteasomal dysfunction, and cell death that can be partially rescued by malin. These findings suggest that the neuronatin-induced aberrant Ca(2+) signaling and endoplasmic reticulum stress might underlie LD pathogenesis.
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Affiliation(s)
- Jaiprakash Sharma
- Cellular and Molecular Neuroscience, National Brain Research Centre, Manesar, Gurgaon 122 050, India
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Kecmanović M, Jović N, Cukić M, Keckarević-Marković M, Keckarević D, Stevanović G, Romac S. Lafora disease: severe phenotype associated with homozygous deletion of the NHLRC1 gene. J Neurol Sci 2013; 325:170-3. [PMID: 23317923 DOI: 10.1016/j.jns.2012.12.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/04/2012] [Accepted: 12/04/2012] [Indexed: 10/27/2022]
Abstract
Lafora disease (LD) is a severe, autosomal recessive, latechildhood- to teenage-onset, progressive myoclonic epilepsy. It is due to either EPM2A or NHLRC1 mutations. We describe a patient with homozygous deletion encompassing the entire NHLRC1 gene, not previously reported, and with clinical course more progressive than in the most patients with NHLRC1 mutations. The diagnosis of LD in our patient was based on the typical clinic, neurophysiological presentation, as well as skin biopsy followed by molecular genetics findings. She developed normally until the age of 15, when she had her first occipital and generalized seizures. Four years after the first seizure the patient became bedridden, demented and presented with severe clinical condition. She died of pneumonia at age 20. This report is the first case of homozygosity for NHLRC1 deletion and thus adds to mutational heterogeneity of LD. Besides, it widens the spectrum of LD patients with severe phenotype and NHLRC1 mutations.
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Affiliation(s)
- Miljana Kecmanović
- Faculty of Biology, University of Belgrade, Studentski trg 16, P.O. Box 52, 11000 Belgrade, Serbia.
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Laforin and malin deletions in mice produce similar neurologic impairments. J Neuropathol Exp Neurol 2012; 71:413-21. [PMID: 22487859 DOI: 10.1097/nen.0b013e318253350f] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Lafora disease is a progressive myoclonus epilepsy caused by mutations in the EPM2A gene encoding laforin or in the EPM2B gene encoding malin. It is characterized by the presence of polyglucosan intracellular inclusion bodies (Lafora bodies) in brain and other tissues. Targeted disruption of Epm2a or Epm2b genes in mice produced widespread neuronal degeneration and accumulation of Lafora bodies in neuronal and nonneuronal tissues. Here we analyzed the neurologic alterations produced by disruption of the laforin gene in Epm2a mice and compared them to those in malin-deficient mice. Both Epm2a and Epm2b mice showed altered motor activity, impaired motor coordination, abnormal hind limb clasping, and episodic memory deficits. Epm2a mice also had tonic-clonic seizures, whereas both Epm2a and Epm2b mice had spontaneous single spikes, spike-wave, polyspikes, and polyspike-wave complexes with correlated myoclonic jerks. Neurologic alterations observed in the mutants were comparable and correlated with the accumulation of abundant Lafora bodies in the cerebral cortex, the hippocampus, the basal ganglia, the cerebellum, and the brainstem, suggesting that these inclusions could cause cognitive and behavioral deterioration. Thus, both Epm2a and Epm2b mice exhibit many pathologic aspects seen in patients with Lafora disease and may be valuable for the study of this disorder.
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Phenotype variations in Lafora progressive myoclonus epilepsy: possible involvement of genetic modifiers? J Hum Genet 2012; 57:283-5. [PMID: 22456482 DOI: 10.1038/jhg.2012.29] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Lafora progressive myoclonus epilepsy, also known as Lafora disease (LD), is the most severe and fatal form of progressive myoclonus epilepsy with its typical onset during the late childhood or early adolescence. LD is characterized by recurrent epileptic seizures and progressive decline in intellectual function. LD can be caused by defects in any of the two known genes and the clinical features of these two genetic groups are almost identical. The past one decade has witnessed considerable success in identifying the LD genes, their mutations, the cellular functions of gene products and on molecular basis of LD. Here, we briefly review the current literature on the phenotype variations, on possible presence of genetic modifiers, and candidate modifiers as targets for therapeutic interventions in LD.
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Sharma J, Mulherkar S, Mukherjee D, Jana NR. Malin regulates Wnt signaling pathway through degradation of dishevelled2. J Biol Chem 2012; 287:6830-9. [PMID: 22223637 DOI: 10.1074/jbc.m111.315135] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Using yeast-two hybrid screening followed by co-immunoprecipitation assay, we have found that the Lafora disease ubiquitin ligase malin interacts with dishevelled2, a key mediator of Wnt signaling pathway. Overexpression of malin enhances the degradation of dishevelled2 and inhibits Wnt signaling, which is evident from the down-regulation of β-catenin target genes and the decrease in β-catenin-mediated transcriptional activity. Partial knockdown of malin significantly increases the level of dishevelled2 and up-regulates Wnt signaling. Several malin mutants are found to be ineffective in degrading dishevelled2 and regulating the Wnt pathway. We have also found that malin enhances K48- and K63-linked ubiquitination of dishevelled2 that could lead to its degradation through both proteasome and autophagy. Altogether, our results indicate that malin regulates Wnt signaling pathway through the degradation of dishevelled2 and suggest possible deregulation of Wnt signaling in Lafora disease.
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Affiliation(s)
- Jaiprakash Sharma
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon 122 050, India
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Guerrero R, Vernia S, Sanz R, Abreu-Rodríguez I, Almaraz C, García-Hoyos M, Michelucci R, Tassinari CA, Riguzzi P, Nobile C, Sanz P, Serratosa JM, Gómez-Garre P. A PTG variant contributes to a milder phenotype in Lafora disease. PLoS One 2011; 6:e21294. [PMID: 21738631 PMCID: PMC3127956 DOI: 10.1371/journal.pone.0021294] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 05/25/2011] [Indexed: 11/18/2022] Open
Abstract
Lafora disease is an autosomal recessive form of progressive myoclonus epilepsy with no effective therapy. Although the outcome is always unfavorable, onset of symptoms and progression of the disease may vary. We aimed to identify modifier genes that may contribute to the clinical course of Lafora disease patients with EPM2A or EPM2B mutations. We established a list of 43 genes coding for proteins related to laforin/malin function and/or glycogen metabolism and tested common polymorphisms for possible associations with phenotypic differences using a collection of Lafora disease families. Genotype and haplotype analysis showed that PPP1R3C may be associated with a slow progression of the disease. The PPP1R3C gene encodes protein targeting to glycogen (PTG). Glycogen targeting subunits play a major role in recruiting type 1 protein phosphatase (PP1) to glycogen-enriched cell compartments and in increasing the specific activity of PP1 toward specific glycogenic substrates (glycogen synthase and glycogen phosphorylase). Here, we report a new mutation (c.746A>G, N249S) in the PPP1R3C gene that results in a decreased capacity to induce glycogen synthesis and a reduced interaction with glycogen phosphorylase and laforin, supporting a key role of this mutation in the glycogenic activity of PTG. This variant was found in one of two affected siblings of a Lafora disease family characterized by a remarkable mild course. Our findings suggest that variations in PTG may condition the course of Lafora disease and establish PTG as a potential target for pharmacogenetic and therapeutic approaches.
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Affiliation(s)
- Rosa Guerrero
- Laboratorio de Neurología-Unidad de Epilepsia, Servicio de Neurología, Instituto Investigación Sanitaria Fundación Jiménez Díaz, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Santiago Vernia
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (CSIC), and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Raúl Sanz
- Laboratorio de Neurología-Unidad de Epilepsia, Servicio de Neurología, Instituto Investigación Sanitaria Fundación Jiménez Díaz, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Irene Abreu-Rodríguez
- Laboratorio de Investigaciones Biomédicas, Instituto de Biomedicina de Sevilla (IBiS), Sevilla, Spain
| | - Carmen Almaraz
- Laboratorio de Neurología-Unidad de Epilepsia, Servicio de Neurología, Instituto Investigación Sanitaria Fundación Jiménez Díaz, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - María García-Hoyos
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (CSIC), and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Roberto Michelucci
- Unit of Neurology, Department of Neurosciences, Bellaria Hospital, Bologna, Italy
| | | | - Patrizia Riguzzi
- Unit of Neurology, Department of Neurosciences, Bellaria Hospital, Bologna, Italy
| | - Carlo Nobile
- Section of Padua, CNR-Institute of Neurosciences, Padua, Italy
| | - Pascual Sanz
- Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas (CSIC), and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - José M. Serratosa
- Laboratorio de Neurología-Unidad de Epilepsia, Servicio de Neurología, Instituto Investigación Sanitaria Fundación Jiménez Díaz, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- * E-mail: (JMS); (PG-G)
| | - Pilar Gómez-Garre
- Laboratorio de Neurología-Unidad de Epilepsia, Servicio de Neurología, Instituto Investigación Sanitaria Fundación Jiménez Díaz, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
- Unidad de Trastornos del Movimiento, Servicio de Neurología y Neurofisiología Clínica, Instituto de Biomedicina de Sevilla (IBiS), Sevilla, Spain
- * E-mail: (JMS); (PG-G)
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Sharma J, Rao SNR, Shankar SK, Satishchandra P, Jana NR. Lafora disease ubiquitin ligase malin promotes proteasomal degradation of neuronatin and regulates glycogen synthesis. Neurobiol Dis 2011; 44:133-41. [PMID: 21742036 DOI: 10.1016/j.nbd.2011.06.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 05/27/2011] [Accepted: 06/16/2011] [Indexed: 01/01/2023] Open
Abstract
Lafora disease (LD) is the inherited progressive myoclonus epilepsy caused by mutations in either EPM2A gene, encoding the protein phosphatase laforin or the NHLRC1 gene, encoding the ubiquitin ligase malin. Since malin is an ubiquitin ligase and its mutations cause LD, it is hypothesized that improper clearance of its substrates might lead to LD pathogenesis. Here, we demonstrate for the first time that neuronatin is a novel substrate of malin. Malin interacts with neuronatin and enhances its degradation through proteasome. Interestingly, neuronatin is an aggregate prone protein, forms aggresome upon inhibition of cellular proteasome function and malin recruited to those aggresomes. Neuronatin is found to stimulate the glycogen synthesis through the activation of glycogen synthase and malin prevents neuronatin-induced glycogen synthesis. Several LD-associated mutants of malin are ineffective in the degradation of neuronatin and suppression of neuronatin-induced glycogen synthesis. Finally, we demonstrate the increased levels of neuronatin in the skin biopsy sample of LD patients. Overall, our results indicate that malin negatively regulates neuronatin and its loss of function in LD results in increased accumulation of neuronatin, which might be implicated in the formation of Lafora body or other aspect of disease pathogenesis.
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Affiliation(s)
- Jaiprakash Sharma
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon-122 050, India
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Brackmann FA, Kiefer A, Agaimy A, Gencik M, Trollmann R. Rapidly progressive phenotype of Lafora disease associated with a novel NHLRC1 mutation. Pediatr Neurol 2011; 44:475-7. [PMID: 21555062 DOI: 10.1016/j.pediatrneurol.2011.01.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 12/16/2010] [Accepted: 01/17/2011] [Indexed: 10/18/2022]
Abstract
Lafora disease is a fatal, autosomal recessive form of progressive myoclonus epilepsy. Patients characteristically exhibit myoclonic and tonic-clonic seizures and cognitive impairment, beginning in their second decade. Alterations in two genes were identified as the cause of the disease. Mutations in the NHL repeat containing 1 (NHLRC1) gene were described in association with a more benign clinical course and later age of death, compared with epilepsy progressive myoclonus type 2A (EPM2A) mutations. We describe a rapidly progressive phenotype of Lafora disease in an adolescent patient with a novel NHLRC1 mutation. He developed severe disability and dementia less than 2 years after the onset of signs.
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Affiliation(s)
- Florian A Brackmann
- Department of Pediatrics, Friedrich-Alexander-University of Erlangen-Nuremberg, Loschgestrasse 15, 91054 Erlangen, Germany.
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Turnbull J, Wang P, Girard JM, Ruggieri A, Wang TJ, Draginov AG, Kameka AP, Pencea N, Zhao X, Ackerley CA, Minassian BA. Glycogen hyperphosphorylation underlies lafora body formation. Ann Neurol 2011; 68:925-33. [PMID: 21077101 DOI: 10.1002/ana.22156] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Glycogen, the largest cytosolic macromolecule, acquires solubility, essential to its function, through extreme branching. Lafora bodies are aggregates of polyglucosan, a long, linear, poorly branched, and insoluble form of glycogen. Lafora bodies occupy vast numbers of neuronal dendrites and perikarya in Lafora disease in time-dependent fashion, leading to intractable and fatal progressive myoclonus epilepsy. Lafora disease is caused by deficiency of either the laforin glycogen phosphatase or the malin E3 ubiquitin ligase. The 2 leading hypotheses of Lafora body formation are: (1) increased glycogen synthase activity extends glycogen strands too rapidly to allow adequate branching, resulting in polyglucosans; and (2) increased glycogen phosphate leads to glycogen conformational change, unfolding, precipitation, and conversion to polyglucosan. Recently, it was shown that in the laforin phosphatase-deficient form of Lafora disease, there is no increase in glycogen synthase, but there is a dramatic increase in glycogen phosphate, with subsequent conversion of glycogen to polyglucosan. Here, we determine whether Lafora bodies in the malin ubiquitin ligase-deficient form of the disease are due to increased glycogen synthase or increased glycogen phosphate. METHODS We generated malin-deficient mice and tested the 2 hypotheses. RESULTS Malin-deficient mice precisely replicate the pathology of Lafora disease with Lafora body formation in skeletal muscle, liver, and brain, and in the latter in the pathognomonic perikaryal and dendritic locations. Glycogen synthase quantity and activity are unchanged. There is a highly significant increase in glycogen phosphate. INTERPRETATION We identify a single common modification, glycogen hyperphosphorylation, as the root cause of Lafora body pathogenesis.
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Affiliation(s)
- Julie Turnbull
- Department of Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada
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Rao SN, Maity R, Sharma J, Dey P, Shankar SK, Satishchandra P, Jana NR. Sequestration of chaperones and proteasome into Lafora bodies and proteasomal dysfunction induced by Lafora disease-associated mutations of malin. Hum Mol Genet 2010; 19:4726-34. [DOI: 10.1093/hmg/ddq407] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Abstract
Lafora disease is a rare, fatal, autosomal recessive, progressive myoclonic epilepsy. It may also be considered as a disorder of carbohydrate metabolism because of the formation of polyglucosan inclusion bodies in neural and other tissues due to abnormalities of the proteins laforin or malin. The condition is characterized by epilepsy, myoclonus and dementia. Diagnostic findings on MRI and neurophysiological testing are not definitive and biopsy or genetic studies may be required. Therapy in Lafora disease is currently limited to symptomatic management of the epilepsy, myoclonus and intercurrent complications. With a greater understanding of the pathophysiological processes involved, there is justified hope for future therapies.
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Affiliation(s)
- Thomas S Monaghan
- Department of Neurology and Neuroscience, Beaumont Hospital and Royal College of Surgeons in Ireland, Dublin 9, Ireland
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Rao SNR, Sharma J, Maity R, Jana NR. Co-chaperone CHIP stabilizes aggregate-prone malin, a ubiquitin ligase mutated in Lafora disease. J Biol Chem 2010; 285:1404-13. [PMID: 19892702 PMCID: PMC2801266 DOI: 10.1074/jbc.m109.006312] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 11/04/2009] [Indexed: 01/21/2023] Open
Abstract
Lafora disease (LD) is an autosomal recessive neurodegenerative disorder caused by mutation in either the dual specificity phosphatase laforin or ubiquitin ligase malin. A pathological hallmark of LD is the accumulation of cytoplasmic polyglucosan inclusions commonly known as Lafora bodies in both neuronal and non-neuronal tissues. How mutations in these two proteins cause disease pathogenesis is not well understood. Malin interacts with laforin and recruits to aggresomes upon proteasome inhibition and was shown to degrade misfolded proteins. Here we report that malin is spontaneously misfolded and tends to be aggregated, degraded by proteasomes, and forms not only aggresomes but also other cytoplasmic and nuclear aggregates in all transfected cells upon proteasomal inhibition. Malin also interacts with Hsp70. Several disease-causing mutants of malin are comparatively more unstable than wild type and form aggregates in most transfected cells even without the inhibition of proteasome function. These cytoplasmic and nuclear aggregates are immunoreactive to ubiquitin and 20 S proteasome. Interestingly, progressive proteasomal dysfunction and cell death is also most frequently observed in the mutant malin-overexpressed cells compared with the wild-type counterpart. Finally, we demonstrate that the co-chaperone carboxyl terminus of the Hsc70-interacting protein (CHIP) stabilizes malin by modulating the activity of Hsp70. All together, our results suggest that malin is unstable, and the aggregate-prone protein and co-chaperone CHIP can modulate its stability.
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Affiliation(s)
- Sudheendra N. R. Rao
- From the Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon-122 050, India
| | - Jaiprakash Sharma
- From the Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon-122 050, India
| | - Ranjan Maity
- From the Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon-122 050, India
| | - Nihar Ranjan Jana
- From the Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon-122 050, India
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Singh S, Ganesh S. Lafora progressive myoclonus epilepsy: A meta-analysis of reported mutations in the first decade following the discovery of theEPM2AandNHLRC1genes. Hum Mutat 2009; 30:715-23. [DOI: 10.1002/humu.20954] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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40
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Novel mutation in the NHLRC1 gene in a Malian family with a severe phenotype of Lafora disease. Neurogenetics 2009; 10:319-23. [PMID: 19322595 PMCID: PMC2758214 DOI: 10.1007/s10048-009-0190-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Accepted: 03/18/2009] [Indexed: 11/24/2022]
Abstract
We studied a Malian family with parental consanguinity and two of eight siblings affected with late-childhood-onset progressive myoclonus epilepsy and cognitive decline, consistent with the diagnosis of Lafora disease. Genetic analysis showed a novel homozygous single-nucleotide variant in the NHLRC1 gene, c.560A>C, producing the missense change H187P. The changed amino acid is highly conserved, and the mutation impairs malin's ability to degrade laforin in vitro. Pathological evaluation showed manifestations of Lafora disease in the entire brain, with particularly severe involvement of the pallidum, thalamus, and cerebellum. Our findings document Lafora disease with severe manifestations in the West African population.
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Abstract
Abstract Lafora progressive myoclonus epilepsy is an autosomal recessive, fatal, generalized polyglucosan storage disorder that occurs in childhood or adolescence with stimulus sensitive epilepsy (resting and action myoclonias, grand mal, and absence), dementia, ataxia and rapid neurologic deterioration. Mutations in EPM2A/laforin cause 58% of cases and mutations in EPM2B/malin cause 35% of cases. Accumulating evidence points to Lafora disease as primarily a disorder of cell death with impaired clearance of misfolded proteins, as shown by ubiquitin-positive aggresomes in HeLa cells transfected with mutated laforin, ubiquitin-positive polyglucosan inclusion bodies, and malin/E3 ubiquitin ligase polyubiquitination of laforin. How polyglucosan inclusion bodies accumulate is still a mystery. Polyglucosan accumulates hypothetically because of an overactive polyglucosan biosynthetic pathway or a breakdown in polyglucosan degradation. Five separate laboratories are looking for the biochemical pathways that connect laforin and malin to polyglucosan synthesis or degradation. A curative therapy for human Lafora disease with laforin replacement therapy using neutral pegylated immunoliposomes is being investigated.
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Affiliation(s)
- Antonio V Delgado-Escueta
- Comprehensive Epilepsy Program, Epilepsy Genetics/Genomics Laboratories, VA Greater Los Angeles Healthcare System, 11301 Wilshire Boulevard, West Los Angeles, CA 90073, USA.
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Mittal S, Dubey D, Yamakawa K, Ganesh S. Lafora disease proteins malin and laforin are recruited to aggresomes in response to proteasomal impairment. Hum Mol Genet 2007; 16:753-62. [PMID: 17337485 DOI: 10.1093/hmg/ddm006] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Lafora disease (LD), an autosomal recessive neurodegenerative disorder, is characterized by the presence of cytoplasmic polyglucosan inclusions known as Lafora bodies in several tissues including the brain. Laforin, a protein phosphatase, and malin, an ubiquitin ligase, are two of the proteins that are known to be defective in LD. Malin interacts with laforin and promotes its polyubiquitination and degradation. Here we show that malin and laforin co-localize in endoplasmic reticulum (ER) and that they form centrosomal aggregates when treated with proteasomal inhibitors in both neuronal and non-neuronal cells. Laforin/malin aggregates co-localize with gamma-tubulin and cause redistribution of alpha-tubulin. These aggregates are also immunoreactive to ubiquitin, ubiquitin-conjugating enzyme, ER chaperone and proteasome subunits, demonstrating their aggresome-like properties. Furthermore, we show that the centrosomal aggregation of laforin and malin is dependent on the functional microtubule network. Laforin and malin form aggresome when expressed together or otherwise, suggesting that the two proteins are recruited to the centrosome independent of each other. Taken together, our results suggest that the centrosomal accumulation of malin, possibly with the help of laforin, may enhance the ubiquitination of its substrates and facilitate their efficient degradation by proteasome. Defects in malin or laforin may thus lead to increased levels of misfolded and/or target proteins, which may eventually affect the physiological processes of the neuron. Thus, defects in protein degradation and clearance are likely to be the primary trigger in the physiopathology of LD.
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Affiliation(s)
- Shuchi Mittal
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, 208016, India
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