1
|
Pan F, Zhang R, Liu X, Shi X, Xin Q, Qiao D, Li C, Zhang Y, Chen M, Guo W, Luan S, Shao L. Three exonic variants in the PHEX gene cause aberrant splicing in a minigene assay. Front Genet 2024; 15:1353674. [PMID: 38841723 PMCID: PMC11150636 DOI: 10.3389/fgene.2024.1353674] [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: 12/11/2023] [Accepted: 04/24/2024] [Indexed: 06/07/2024] Open
Abstract
Background: X-linked hypophosphatemia (XLH, OMIM 307800) is a rare phosphorus metabolism disorder caused by PHEX gene variants. Many variants simply classified as missense or nonsense variants were only analyzed at the DNA level. However, growing evidence indicates that some of these variants may alter pre-mRNA splicing, causing diseases. Therefore, this study aimed to use bioinformatics tools and a minigene assay to ascertain the effects of PHEX variations on pre-mRNA splicing. Methods: We analyzed 174 variants in the PHEX gene described as missense or nonsense variants. Finally, we selected eight candidate variants using bioinformatics tools to evaluate their effects on pre-mRNA splicing using a minigene assay system. The complementary DNA (cDNA) sequence for the PHEX gene (RefSeq NM_000444.6) serves as the basis for DNA variant numbering. Results: Of the eight candidate variants, three were found to cause abnormal splicing. Variants c.617T>G p.(Leu206Trp) and c.621T>A p.(Tyr207*) in exon 5 altered the splicing of pre-mRNA, owing to the activation of a cryptic splice site in exon 5, which produced an aberrant transcript lacking a part of exon 5, whereas variant c.1700G>C p.(Arg567Pro) in exon 16 led to the activation of a cryptic splice site in intron 16, resulting in a partial inclusion of intron 16. Conclusion: Our study employed a minigene system, which has a great degree of flexibility to assess abnormal splicing patterns under the circumstances of patient mRNA samples that are not available, to explore the impact of the exonic variants on pre-mRNA splicing. Based on the aforementioned experimental findings, we demonstrated the importance of analyzing exonic variants at the mRNA level.
Collapse
Affiliation(s)
- Fengjiao Pan
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Ruixiao Zhang
- Department of Emergency, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xuyan Liu
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xiaomeng Shi
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Qing Xin
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
- Department of Nephrology, The Key Laboratory for the Prevention and Treatment of Chronic Kidney Disease of Chongqing, Chongqing Clinical Research Center of Kidney and Urology Diseases, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Dan Qiao
- Department of Nephrology, Dalian Medical University, Dalian, China
| | - Changying Li
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Yan Zhang
- Department of Nephrology, Weifang Medical University, Weifang, China
| | - Mengke Chen
- Department of Nephrology, Liaocheng Third People’s Hospital, Liaocheng, China
| | - Wencong Guo
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
| | - Shufang Luan
- Department of Medical Insurance Administration, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Leping Shao
- Department of Nephrology, The Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
- Department of Nephrology, The First Affiliated Hospital of Xiamen University, Xiamen, China
| |
Collapse
|
2
|
Cameron JM, Ellis CA, Berkovic SF. ILAE Genetics Literacy series: Progressive myoclonus epilepsies. Epileptic Disord 2023; 25:670-680. [PMID: 37616028 PMCID: PMC10947580 DOI: 10.1002/epd2.20152] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/21/2023] [Accepted: 08/19/2023] [Indexed: 08/25/2023]
Abstract
Progressive Myoclonus Epilepsy (PME) is a rare epilepsy syndrome characterized by the development of progressively worsening myoclonus, ataxia, and seizures. A molecular diagnosis can now be established in approximately 80% of individuals with PME. Almost fifty genetic causes of PME have now been established, although some remain extremely rare. Herein, we provide a review of clinical phenotypes and genotypes of the more commonly encountered PMEs. Using an illustrative case example, we describe appropriate clinical investigation and therapeutic strategies to guide the management of this often relentlessly progressive and devastating epilepsy syndrome. This manuscript in the Genetic Literacy series maps to Learning Objective 1.2 of the ILAE Curriculum for Epileptology (Epileptic Disord. 2019;21:129).
Collapse
Affiliation(s)
- Jillian M. Cameron
- Epilepsy Research Centre, Department of MedicineUniversity of MelbourneAustin HealthMelbourneVictoriaAustralia
| | - Colin A. Ellis
- Department of NeurologyUniversity of Pennsylvania Perelman School of MedicinePhiladelphiaPennsylvaniaUSA
| | - Samuel F. Berkovic
- Epilepsy Research Centre, Department of MedicineUniversity of MelbourneAustin HealthMelbourneVictoriaAustralia
| | | |
Collapse
|
3
|
Abstract
In recent years, there has been a significant increase in preclinical studies to test genetic therapies for epilepsy. Some of these therapies have advanced to clinical trials and are being tested in patients with monogenetic or focal refractory epilepsy. This article provides an overview of the current state of preclinical studies that show potential for clinical translation. Specifically, we focus on genetic therapies that have demonstrated a clear effect on seizures in animal models and have the potential to be translated to clinical settings. Both therapies targeting the cause of the disease and those that treat symptoms are discussed. We believe that the next few years will be crucial in determining the potential of genetic therapies for treating patients with epilepsy.
Collapse
Affiliation(s)
- James S. Street
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Yichen Qiu
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, United Kingdom
| |
Collapse
|
4
|
Müller P, Lerche H. [Gene Therapy for Epilepsy: Clinical Studies are on the Road]. FORTSCHRITTE DER NEUROLOGIE-PSYCHIATRIE 2023; 91:135-140. [PMID: 36716773 DOI: 10.1055/a-1995-5405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
For more than 10 years, research has been conducted on gene therapies for the most severe forms of epilepsy, which until now have proven resistant to treatment. First gene therapies are now in clinical trials for pharmacoresistant focal epilepsies and Dravet syndrome. In this article, we describe how these and many more gene therapies work and what they target.
Collapse
Affiliation(s)
- Peter Müller
- Abteilung Neurologie mit Schwerpunkt Epileptologie, Hertie Institute für klinische Hirnforschung, Universität Tübingen
| | - Holger Lerche
- Abteilung Neurologie mit Schwerpunkt Epileptologie, Hertie Institute für klinische Hirnforschung, Universität Tübingen
| |
Collapse
|
5
|
Xin Q, Liu Q, Liu Z, Shi X, Liu X, Zhang R, Hong Y, Zhao X, Shao L. Twelve exonic variants in the SLC12A1 and CLCNKB genes alter RNA splicing in a minigene assay. Front Genet 2022; 13:961384. [PMID: 36092934 PMCID: PMC9452827 DOI: 10.3389/fgene.2022.961384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Bartter syndrome (BS) is a rare renal tubular disease caused by gene variants in SLC12A1, KCNJ1, CLCNKA, CLCNKB, BSND or MAGED2 genes. There is growing evidence that many exonic mutations can affect the pre-mRNA normal splicing and induce exon skipping by altering various splicing regulatory signals. Therefore, the aim of this study was to gain new insights into the consequences of exonic mutations associated with BS on pre-mRNA splicing.Methods: We analyzed all the missense, nonsense and synonymous variants described in six pathogenic genes by bioinformatics programs and identified candidate mutations that may promote exon skipping through a minigene system.Results: Results of the study showed that 12 of 14 candidate variants distributed in SLC12A1 (c.728G>A, C.735C>G, c.904C>T, c.905G>A, c.1304C>T, c.1493C>T, c.2221A>T) and CLCNKB (c.226C>T, c.228A>C, c.229G>A, c.229G>C, c.1979C>A) were identified to induce splicing alterations. These variants may not only disrupt exonic splicing enhancers (ESEs) but also generate new exonic splicing silencers (ESSs), or disturb the classic splicing sites.Conclusion: To our knowledge, this is a comprehensive study regarding alterations in pre-mRNA of exonic variants in BS pathogenic genes. Our results reinforce the necessity of assessing the consequences of exonic variants at the mRNA level.
Collapse
Affiliation(s)
- Qing Xin
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Qihua Liu
- Department of Material Supply Management, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Zhiying Liu
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xiaomeng Shi
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Xuyan Liu
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Ruixiao Zhang
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
| | - Yefeng Hong
- Department of Cardiology, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xiangzhong Zhao
- Medical Research Center, The Affiliated Hospital of Qingdao University, Qingdao, China
- *Correspondence: Xiangzhong Zhao, ; Leping Shao,
| | - Leping Shao
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao, China
- *Correspondence: Xiangzhong Zhao, ; Leping Shao,
| |
Collapse
|
6
|
Zimmern V, Minassian B, Korff C. A Review of Targeted Therapies for Monogenic Epilepsy Syndromes. Front Neurol 2022; 13:829116. [PMID: 35250833 PMCID: PMC8891748 DOI: 10.3389/fneur.2022.829116] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Accepted: 01/13/2022] [Indexed: 11/15/2022] Open
Abstract
Genetic sequencing technologies have led to an increase in the identification and characterization of monogenic epilepsy syndromes. This increase has, in turn, generated strong interest in developing “precision therapies” based on the unique molecular genetics of a given monogenic epilepsy syndrome. These therapies include diets, vitamins, cell-signaling regulators, ion channel modulators, repurposed medications, molecular chaperones, and gene therapies. In this review, we evaluate these therapies from the perspective of their clinical validity and discuss the future of these therapies for individual syndromes.
Collapse
Affiliation(s)
- Vincent Zimmern
- Division of Child Neurology, University of Texas Southwestern, Dallas, TX, United States
- *Correspondence: Vincent Zimmern
| | - Berge Minassian
- Division of Child Neurology, University of Texas Southwestern, Dallas, TX, United States
| | - Christian Korff
- Pediatric Neurology Unit, University Hospitals, Geneva, Switzerland
| |
Collapse
|
7
|
Riva A, Golda A, Balagura G, Amadori E, Vari MS, Piccolo G, Iacomino M, Lattanzi S, Salpietro V, Minetti C, Striano P. New Trends and Most Promising Therapeutic Strategies for Epilepsy Treatment. Front Neurol 2021; 12:753753. [PMID: 34950099 PMCID: PMC8690245 DOI: 10.3389/fneur.2021.753753] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 10/28/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Despite the wide availability of novel anti-seizure medications (ASMs), 30% of patients with epilepsy retain persistent seizures with a significant burden in comorbidity and an increased risk of premature death. This review aims to discuss the therapeutic strategies, both pharmacological and non-, which are currently in the pipeline. Methods: PubMed, Scopus, and EMBASE databases were screened for experimental and clinical studies, meta-analysis, and structured reviews published between January 2018 and September 2021. The terms “epilepsy,” “treatment” or “therapy,” and “novel” were used to filter the results. Conclusions: The common feature linking all the novel therapeutic approaches is the spasmodic rush toward precision medicine, aiming at holistically evaluating patients, and treating them accordingly as a whole. Toward this goal, different forms of intervention may be embraced, starting from the choice of the most suitable drug according to the type of epilepsy of an individual or expected adverse effects, to the outstanding field of gene therapy. Moreover, innovative insights come from in-vitro and in-vivo studies on the role of inflammation and stem cells in the brain. Further studies on both efficacy and safety are needed, with the challenge to mature evidence into reliable assets, ameliorating the symptoms of patients, and answering the challenges of this disease.
Collapse
Affiliation(s)
- Antonella Riva
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Alice Golda
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Ganna Balagura
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, Netherlands
| | - Elisabetta Amadori
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Maria Stella Vari
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Gianluca Piccolo
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Michele Iacomino
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Simona Lattanzi
- Department of Experimental and Clinical Medicine, Neurological Clinic, Marche Polytechnic University, Ancona, Italy
| | - Vincenzo Salpietro
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Carlo Minetti
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy
| |
Collapse
|
8
|
Alvarez MEV, Chivers M, Borovska I, Monger S, Giannoulatou E, Kralovicova J, Vorechovsky I. Transposon clusters as substrates for aberrant splice-site activation. RNA Biol 2020; 18:354-367. [PMID: 32965162 PMCID: PMC7951965 DOI: 10.1080/15476286.2020.1805909] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Transposed elements (TEs) have dramatically shaped evolution of the exon-intron structure and significantly contributed to morbidity, but how recent TE invasions into older TEs cooperate in generating new coding sequences is poorly understood. Employing an updated repository of new exon-intron boundaries induced by pathogenic mutations, termed DBASS, here we identify novel TE clusters that facilitated exon selection. To explore the extent to which such TE exons maintain RNA secondary structure of their progenitors, we carried out structural studies with a composite exon that was derived from a long terminal repeat (LTR78) and AluJ and was activated by a C > T mutation optimizing the 5ʹ splice site. Using a combination of SHAPE, DMS and enzymatic probing, we show that the disease-causing mutation disrupted a conserved AluJ stem that evolved from helix 3.3 (or 5b) of 7SL RNA, liberating a primordial GC 5ʹ splice site from the paired conformation for interactions with the spliceosome. The mutation also reduced flexibility of conserved residues in adjacent exon-derived loops of the central Alu hairpin, revealing a cross-talk between traditional and auxilliary splicing motifs that evolved from opposite termini of 7SL RNA and were approximated by Watson-Crick base-pairing already in organisms without spliceosomal introns. We also identify existing Alu exons activated by the same RNA rearrangement. Collectively, these results provide valuable TE exon models for studying formation and kinetics of pre-mRNA building blocks required for splice-site selection and will be useful for fine-tuning auxilliary splicing motifs and exon and intron size constraints that govern aberrant splice-site activation.
Collapse
Affiliation(s)
| | - Martin Chivers
- School of Medicine, University of Southampton, Southampton, UK
| | - Ivana Borovska
- Slovak Academy of Sciences, Institute of Molecular Physiology and Genetics, Bratislava, Slovak Republic
| | - Steven Monger
- Computational Genomics Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Eleni Giannoulatou
- Computational Genomics Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, Australia.,St. Vincent's Clinical School, University of New South Wales, Sydney, Australia
| | - Jana Kralovicova
- School of Medicine, University of Southampton, Southampton, UK.,Slovak Academy of Sciences, Institute of Molecular Physiology and Genetics, Bratislava, Slovak Republic
| | | |
Collapse
|
9
|
Neuroinflammation and progressive myoclonus epilepsies: from basic science to therapeutic opportunities. Expert Rev Mol Med 2020; 22:e4. [PMID: 32938505 PMCID: PMC7520540 DOI: 10.1017/erm.2020.5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Progressive myoclonus epilepsies (PMEs) are a group of genetic neurological disorders characterised by the occurrence of epileptic seizures, myoclonus and progressive neurological deterioration including cerebellar involvement and dementia. The primary cause of PMEs is variable and alterations in the corresponding mutated genes determine the progression and severity of the disease. In most cases, they lead to the death of the patient after a period of prolonged disability. PMEs also share poor information on the pathophysiological bases and the lack of a specific treatment. Recent reports suggest that neuroinflammation is a common trait under all these conditions. Here, we review similarities and differences in neuroinflammatory response in several PMEs and discuss the window of opportunity of using anti-inflammatory drugs in the treatment of several of these conditions.
Collapse
|
10
|
Coutinho MF, Santos JI, S. Mendonça L, Matos L, Prata MJ, S. Jurado A, Pedroso de Lima MC, Alves S. Lysosomal Storage Disease-Associated Neuropathy: Targeting Stable Nucleic Acid Lipid Particle (SNALP)-Formulated siRNAs to the Brain as a Therapeutic Approach. Int J Mol Sci 2020; 21:ijms21165732. [PMID: 32785133 PMCID: PMC7461213 DOI: 10.3390/ijms21165732] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/31/2020] [Accepted: 08/06/2020] [Indexed: 12/22/2022] Open
Abstract
More than two thirds of Lysosomal Storage Diseases (LSDs) present central nervous system involvement. Nevertheless, only one of the currently approved therapies has an impact on neuropathology. Therefore, alternative approaches are under development, either addressing the underlying enzymatic defect or its downstream consequences. Also under study is the possibility to block substrate accumulation upstream, by promoting a decrease of its synthesis. This concept is known as substrate reduction therapy and may be triggered by several molecules, such as small interfering RNAs (siRNAs). siRNAs promote RNA interference, a naturally occurring sequence-specific post-transcriptional gene-silencing mechanism, and may target virtually any gene of interest, inhibiting its expression. Still, naked siRNAs have limited cellular uptake, low biological stability, and unfavorable pharmacokinetics. Thus, their translation into clinics requires proper delivery methods. One promising platform is a special class of liposomes called stable nucleic acid lipid particles (SNALPs), which are characterized by high cargo encapsulation efficiency and may be engineered to promote targeted delivery to specific receptors. Here, we review the concept of SNALPs, presenting a series of examples on their efficacy as siRNA nanodelivery systems. By doing so, we hope to unveil the therapeutic potential of these nanosystems for targeted brain delivery of siRNAs in LSDs.
Collapse
Affiliation(s)
- Maria Francisca Coutinho
- Research and Development Unit, Department of Human Genetics, National Institute of Health Doutor Ricardo Jorge (INSA I.P), Rua Alexandre Herculano, 321, 4000-055 Porto, Portugal; (J.I.S.); (L.M.); (S.A.)
- Center for the Study of Animal Science, CECA-ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal
- Correspondence: ; Tel.: +351-(223)-401-113
| | - Juliana Inês Santos
- Research and Development Unit, Department of Human Genetics, National Institute of Health Doutor Ricardo Jorge (INSA I.P), Rua Alexandre Herculano, 321, 4000-055 Porto, Portugal; (J.I.S.); (L.M.); (S.A.)
- Biology Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal;
| | - Liliana S. Mendonça
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (L.S.M.); (M.C.P.d.L.)
- CIBB—Center for Innovative Biomedicine and Biotechnology, University of Coimbra, 3004-504 Coimbra, Portugal
| | - Liliana Matos
- Research and Development Unit, Department of Human Genetics, National Institute of Health Doutor Ricardo Jorge (INSA I.P), Rua Alexandre Herculano, 321, 4000-055 Porto, Portugal; (J.I.S.); (L.M.); (S.A.)
- Center for the Study of Animal Science, CECA-ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal
| | - Maria João Prata
- Biology Department, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal;
- i3S—Institute of Research and Innovation in Health/IPATIMUP—Institute of Molecular Pathology and Immunology of the University of Porto, Rua Alfredo Allen, 208 4200-135 Porto, Portugal
| | - Amália S. Jurado
- University of Coimbra, CNC—Center for Neuroscience and Cell Biology, Department of Life Sciences, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal;
| | - Maria C. Pedroso de Lima
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal; (L.S.M.); (M.C.P.d.L.)
| | - Sandra Alves
- Research and Development Unit, Department of Human Genetics, National Institute of Health Doutor Ricardo Jorge (INSA I.P), Rua Alexandre Herculano, 321, 4000-055 Porto, Portugal; (J.I.S.); (L.M.); (S.A.)
- Center for the Study of Animal Science, CECA-ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4051-401 Porto, Portugal
| |
Collapse
|
11
|
Riva A, Guglielmo A, Balagura G, Marchese F, Amadori E, Iacomino M, Minassian BA, Zara F, Striano P. Emerging treatments for progressive myoclonus epilepsies. Expert Rev Neurother 2020; 20:341-350. [PMID: 32153206 DOI: 10.1080/14737175.2020.1741350] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Introduction: Progressive myoclonus epilepsies (PMEs) are a group of neurodegenerative diseases, invariably leading to severe disability or fatal outcome in a few years or decades. Nowadays, PMEs treatment remains challenging with a significant burden of disability for patients. Pharmacotherapy is primarily used to treat seizures, which impact patients' quality of life. However, new approaches have emerged in the last few years, which try to curb the neurological deterioration of PMEs through a better knowledge of the pathogenetic process. This is a review on the newest therapeutic options for the treatment of PMEs.Areas covered: Experimental and clinical results on novel therapeutic approaches for the different forms of PME are reviewed and discussed. Special attention is primarily focused on the efficacy and tolerability outcomes, trying to infer the role novel approaches may have in the future.Expert opinion: The large heterogeneity of disease-causing mechanisms prevents researchers from identifying a single approach to treat PMEs. Understanding of pathophysiologic processes is leading the way to targeted therapies, which, through enzyme replacement or underlying gene defect correction have already proved to potentially strike on neurodegeneration.
Collapse
Affiliation(s)
- Antonella Riva
- Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G.Gaslini' Institute, Genoa, Italy
| | - Alberto Guglielmo
- Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G.Gaslini' Institute, Genoa, Italy
| | - Ganna Balagura
- Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G.Gaslini' Institute, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genoa, Italy
| | - Francesca Marchese
- Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G.Gaslini' Institute, Genoa, Italy
| | - Elisabetta Amadori
- Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G.Gaslini' Institute, Genoa, Italy
| | - Michele Iacomino
- Unit of Medical Genetics, IRCCS 'G.Gaslini' Institute, Genoa, Italy
| | - Berge Arakel Minassian
- Pediatric Neurology, University of Texas Southwestern and Dallas Children's Medical Center, Dallas, TX, USA
| | - Federico Zara
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genoa, Italy.,Unit of Medical Genetics, IRCCS 'G.Gaslini' Institute, Genoa, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, IRCCS 'G.Gaslini' Institute, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genoa, Italy
| |
Collapse
|
12
|
The best evidence for progressive myoclonic epilepsy: A pathway to precision therapy. Seizure 2019; 71:247-257. [PMID: 31476531 DOI: 10.1016/j.seizure.2019.08.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/21/2019] [Accepted: 08/23/2019] [Indexed: 12/13/2022] Open
Abstract
Progressive Myoclonus Epilepsies (PMEs) are a group of uncommon clinically and genetically heterogeneous disorders characterised by myoclonus, generalized epilepsy, and neurological deterioration, including dementia and ataxia. PMEs may have infancy, childhood, juvenile or adult onset, but usually present in late childhood or adolescence, at variance from epileptic encephalopathies, which start with polymorphic seizures in early infancy. Neurophysiologic recordings are suited to describe faithfully the time course of the shock-like muscle contractions which characterize myoclonus. A combination of positive and negative myoclonus is typical of PMEs. The gene defects for most PMEs (Unverricht-Lundborg disease, Lafora disease, several forms of neuronal ceroid lipofuscinoses, myoclonus epilepsy with ragged-red fibers [MERRF], and type 1 and 2 sialidoses) have been identified. PMEs are uncommon disorders, difficult to diagnose in the absence of extensive experience. Thus, aetiology is undetermined in many patients, despite the advance in molecular medicine. Treatment of PMEs remains essentially symptomaticof seizures and myoclonus, together with palliative, supportive, and rehabilitative measures. The response to therapy may initially be relatively favourable, afterwards however, seizures may become more frequent, and progressive neurologic decline occurs. The prognosis of a PME depends on the specific disease. The history of PMEs revealed that the international collaboration and sharing experience is the right way to proceed. This emerging picture and biological insights will allow us to find ways to provide the patients with meaningful treatment.
Collapse
|
13
|
In Silico Analysis of Missense Mutations as a First Step in Functional Studies: Examples from Two Sphingolipidoses. Int J Mol Sci 2018; 19:ijms19113409. [PMID: 30384423 PMCID: PMC6275066 DOI: 10.3390/ijms19113409] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 10/27/2018] [Accepted: 10/29/2018] [Indexed: 02/06/2023] Open
Abstract
In order to delineate a better approach to functional studies, we have selected 23 missense mutations distributed in different domains of two lysosomal enzymes, to be studied by in silico analysis. In silico analysis of mutations relies on computational modeling to predict their effects. Various computational platforms are currently available to check the probable causality of mutations encountered in patients at the protein and at the RNA levels. In this work we used four different platforms freely available online (Protein Variation Effect Analyzer- PROVEAN, PolyPhen-2, Swiss-model Expert Protein Analysis System—ExPASy, and SNAP2) to check amino acid substitutions and their effect at the protein level. The existence of functional studies, regarding the amino acid substitutions, led to the selection of the distinct protein mutants. Functional data were used to compare the results obtained with different bioinformatics tools. With the advent of next-generation sequencing, it is not feasible to carry out functional tests in all the variants detected. In silico analysis seems to be useful for the delineation of which mutants are worth studying through functional studies. Therefore, prediction of the mutation impact at the protein level, applying computational analysis, confers the means to rapidly provide a prognosis value to genotyping results, making it potentially valuable for patient care as well as research purposes. The present work points to the need to carry out functional studies in mutations that might look neutral. Moreover, it should be noted that single nucleotide polymorphisms (SNPs), occurring in coding and non-coding regions, may lead to RNA alterations and should be systematically verified. Functional studies can gain from a preliminary multi-step approach, such as the one proposed here.
Collapse
|