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Sbragia E, Assini A, Calzavara S, Carrera P, Solaro CM, Di Maria E. A novel SPAST gene splicing variant (c.1617-2A>C) in a heterozygous carrier with hereditary spastic paraplegia. eNeurologicalSci 2024; 35:100506. [PMID: 38883204 PMCID: PMC11179584 DOI: 10.1016/j.ensci.2024.100506] [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: 03/05/2024] [Revised: 05/20/2024] [Accepted: 05/24/2024] [Indexed: 06/18/2024] Open
Abstract
Hereditary spastic paraplegia (HSP) is a group of genetically heterogenous neurodegenerative disorders characterized by progressive spasticity and weakness of lower limbs. We report a novel splicing variant (c.1617-2A>C) of the SPAST gene in a heterozygous carrier from an Italian family with autosomal dominant HSP. The case study describes a pure form of spastic paraparesis with the cardinal clinical features of SPG4. The novel variant affects a canonical splice site and is likely to disrupt RNA splicing. We conclude that the c.1617-2A>C substitution is a null variant, which could be classified as pathogenic; its penetrance should be further investigated.
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Affiliation(s)
- Elvira Sbragia
- Unit of Neurology, Galliera Hospital, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal-Child Health, University of Genoa, Genoa, Italy
| | | | - Silvia Calzavara
- Laboratory of Clinical Molecular Genetics, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Paola Carrera
- Laboratory of Clinical Molecular Genetics, IRCCS Ospedale San Raffaele, Milan, Italy
- Unit of Genomics for Diagnosis of Genetic Diseases, IRCCS Ospedale San Raffaele, Milan, Italy
| | | | - Emilio Di Maria
- Department of Health Sciences, University of Genoa, Genoa, Italy
- University Unit of Medical Genetics, Galliera Hospital, Genoa, Italy
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Ferese R, Scala S, Suppa A, Campopiano R, Asci F, Zampogna A, Chiaravalloti MA, Griguoli A, Storto M, Pardo AD, Giardina E, Zampatti S, Fornai F, Novelli G, Fanelli M, Zecca C, Logroscino G, Centonze D, Gambardella S. Cohort analysis of novel SPAST variants in SPG4 patients and implementation of in vitro and in vivo studies to identify the pathogenic mechanism caused by splicing mutations. Front Neurol 2023; 14:1296924. [PMID: 38145127 PMCID: PMC10748595 DOI: 10.3389/fneur.2023.1296924] [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: 09/19/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023] Open
Abstract
Introduction Pure hereditary spastic paraplegia (SPG) type 4 (SPG4) is caused by mutations of SPAST gene. This study aimed to analyze SPAST variants in SPG4 patients to highlight the occurrence of splicing mutations and combine functional studies to assess the relevance of these variants in the molecular mechanisms of the disease. Methods We performed an NGS panel in 105 patients, in silico analysis for splicing mutations, and in vitro minigene assay. Results and discussion The NGS panel was applied to screen 105 patients carrying a clinical phenotype corresponding to upper motor neuron syndrome (UMNS), selectively affecting motor control of lower limbs. Pathogenic mutations in SPAST were identified in 12 patients (11.42%), 5 missense, 3 frameshift, and 4 splicing variants. Then, we focused on the patients carrying splicing variants using a combined approach of in silico and in vitro analysis through minigene assay and RNA, if available. For two splicing variants (i.e., c.1245+1G>A and c.1414-2A>T), functional assays confirm the types of molecular alterations suggested by the in silico analysis (loss of exon 9 and exon 12). In contrast, the splicing variant c.1005-1delG differed from what was predicted (skipping exon 7), and the functional study indicates the loss of frame and formation of a premature stop codon. The present study evidenced the high splice variants in SPG4 patients and indicated the relevance of functional assays added to in silico analysis to decipher the pathogenic mechanism.
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Affiliation(s)
| | | | - Antonio Suppa
- IRCCS Neuromed, Pozzilli, Italy
- Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy
| | | | | | | | | | | | | | | | - Emiliano Giardina
- Genomic Medicine Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Stefania Zampatti
- Genomic Medicine Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesco Fornai
- IRCCS Neuromed, Pozzilli, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Giuseppe Novelli
- IRCCS Neuromed, Pozzilli, Italy
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
| | - Mirco Fanelli
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
| | - Chiara Zecca
- Center for Neurodegenerative Diseases and the Aging Brain, Department of Clinical Research in Neurology of the University of Bari “Aldo Moro” at “Pia Fondazione Card G. Panico” Hospital Tricase, Lecce, Italy
| | - Giancarlo Logroscino
- Center for Neurodegenerative Diseases and the Aging Brain, Department of Clinical Research in Neurology of the University of Bari “Aldo Moro” at “Pia Fondazione Card G. Panico” Hospital Tricase, Lecce, Italy
| | - Diego Centonze
- IRCCS Neuromed, Pozzilli, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Stefano Gambardella
- IRCCS Neuromed, Pozzilli, Italy
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
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Genetic and Epidemiological Study of Adult Ataxia and Spastic Paraplegia in Eastern Quebec. Can J Neurol Sci 2021; 48:655-665. [PMID: 33397523 DOI: 10.1017/cjn.2020.277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To estimate the minimum prevalence of adult hereditary ataxias (HA) and spastic paraplegias (HSP) in Eastern Quebec and to evaluate the proportion of associated mutations in identified genes. METHODS We conducted a descriptive cross-sectional study of patients who met clinical criteria for the diagnosis of HA (n = 241) and HSP (n = 115) in the East of the Quebec province between January 2007 and July 2019. The primary outcome was the prevalence per 100,000 persons with a 95% confidence interval (CI). The secondary outcome was the frequency of mutations identified by targeted next-generation sequencing (NGS) approach. Minimum carrier frequency for identified variants was calculated based on allele frequency values and the Hardy-Weinberg (HW) equation. RESULTS The minimum prevalence of HA in Eastern Quebec was estimated at 6.47/100 000 [95% CI; 6.44-6.51]; divided into 3.73/100 000 for autosomal recessive (AR) ataxias and 2.67/100 000 for autosomal dominant (AD) ataxias. The minimum prevalence of HSP was 4.17/100 000 [95% CI; 4.14-4.2]; with 2.05/100 000 for AD-HSP and 2.12/100 000 for AR-HSP. In total, 52.4% of patients had a confirmed genetic diagnosis. AR cerebellar ataxia type 1 (2.67/100 000) and AD spastic paraplegia SPG4 (1.18/100 000) were the most prevalent disorders identified. Mutations were identified in 23 genes and molecular alterations in 7 trinucleotides repeats expansion; the most common mutations were c.15705-12 A > G in SYNE1 and c.1529C > T (p.A510V) in SPG7. CONCLUSIONS We described the minimum prevalence of genetically defined adult HA and HSP in Eastern Quebec. This study provides a framework for international comparisons and service planning.
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Erfanian Omidvar M, Torkamandi S, Rezaei S, Alipoor B, Omrani MD, Darvish H, Ghaedi H. Genotype-phenotype associations in hereditary spastic paraplegia: a systematic review and meta-analysis on 13,570 patients. J Neurol 2019; 268:2065-2082. [PMID: 31745725 DOI: 10.1007/s00415-019-09633-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/07/2019] [Accepted: 11/09/2019] [Indexed: 12/13/2022]
Abstract
AIMS The hereditary spastic paraplegias (HSPs) are a heterogeneous group of inherited neurodegenerative disorders. Although, several genotype-phenotype studies have carried out on HSPs, the association between genotypes and clinical phenotypes remain incomplete since most studies are small in size or restricted to a few genes. Accordingly, this study provides the systematic meta-analysis of genotype-phenotype associations in HSP. METHODS AND RESULTS We retrieved literature on genotype-phenotype associations in patients with HSP and mutated SPAST, REEP1, ATL1, SPG11, SPG15, SPG7, SPG35, SPG54, SPG5. In total, 147 studies with 13,570 HSP patients were included in our meta-analysis. The frequency of mutations in SPAST (25%) was higher than REEP1 (3%), as well as ATL1 (5%) in AD-HSP patients. As for AR-HSP patients, the rates of mutations in SPG11 (18%), SPG15 (7%) and SPG7 (13%) were higher than SPG5 (5%), as well as SPG35 (8%) and SPG54 (7%). The mean age of AD-HSP onset for ATL1 mutation-positive patients was earlier than patients with SPAST, REEP1 mutations. Also, the tendency toward younger age at AR-HSP onset for SPG35 was higher than other mutated genes. It is noteworthy that the mean age at HSP onset ranged from infancy to adulthood. As for the gender distribution, the male proportion in SPG7-HSP (90%) and REEP1-HSP (78%) was markedly high. The frequency of symptoms was varied among patients with different mutated genes. The rates of LL weakness, superficial sensory abnormalities, neuropathy, and deep sensory impairment were noticeably high in REEP1 mutations carriers. Also, in AR-HSP patients with SPG11 mutations, the presentation of symptoms including pes cavus, Neuropathy, and UL spasticity was higher. CONCLUSION Our comprehensive genotype-phenotype assessment of available data displays that the mean age at disease onset and particular sub-phenotypes are associated with specific mutated genes which might be beneficial for a diagnostic procedure and differentiation of the specific mutated genes phenotype among diverse forms of HSP.
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Affiliation(s)
- Maryam Erfanian Omidvar
- Department of Medical Laboratory Technology, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahram Torkamandi
- Department of Medical Genetics and Immunology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Somaye Rezaei
- Department of Neurology, Imam Khomeini Hospital, Urmia University of Medical Sciences, Urmia, Iran
| | - Behnam Alipoor
- Department of Laboratory Sciences, Faculty of Parmedicine, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Mir Davood Omrani
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Velenjak St., Shahid Chamran Highway, Tehran, IR, Iran
| | - Hossein Darvish
- Department of Medical Genetics, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Hamid Ghaedi
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Velenjak St., Shahid Chamran Highway, Tehran, IR, Iran.
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Rudenskaya GE, Kadnikova VA, Ryzhkova OP. [Common forms of hereditary spastic paraplegias]. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:94-104. [PMID: 30874534 DOI: 10.17116/jnevro201911902194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A group of hereditary spastic paraplegias includes about 80 spastic paraplegia genes (SPG): forms with identified (almost 70) or only mapped (about 10) genes. Methods of next generation sequencing (NGS), along with new SPG discovering, modify knowledge about earlier delineated SPG. Clinical and genetic characteristics of common autosomal dominant (SPG4, SPG3, SPG31) and autosomal recessive (SPG11, SPG7, SPG15) forms are presented.
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Affiliation(s)
| | - V A Kadnikova
- Research Centre for Medical Genetics, Moscow, Russia
| | - O P Ryzhkova
- Research Centre for Medical Genetics, Moscow, Russia
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Franker MAM, Hoogenraad CC. Microtubule-based transport - basic mechanisms, traffic rules and role in neurological pathogenesis. J Cell Sci 2013; 126:2319-29. [PMID: 23729742 DOI: 10.1242/jcs.115030] [Citation(s) in RCA: 156] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Microtubule-based transport is essential for neuronal function because of the large distances that must be traveled by various building blocks and cellular materials. Recent studies in various model systems have unraveled several regulatory mechanisms and traffic rules that control the specificity, directionality and delivery of neuronal cargos. Local microtubule cues, opposing motor activity and cargo-adaptors that regulate motor activity control microtubule-based transport in neurons. Impairment of intracellular transport is detrimental to neurons and has emerged as a common factor in several neurological disorders. Genetic approaches have revealed strong links between intracellular transport processes and the pathogenesis of neurological diseases in both the central and peripheral nervous system. This Commentary highlights recent advances in these areas and discusses the transport defects that are associated with the development of neurological diseases.
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Affiliation(s)
- Mariella A M Franker
- Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
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