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Hsiao C, Tsai T, Shen T, Tsai Y, Liao Y, Lee Y, Tsai P. Characterization of a novel TFG variant causing autosomal recessive pure hereditary spastic paraplegia. Ann Clin Transl Neurol 2024; 11:1909-1920. [PMID: 38837630 PMCID: PMC11251477 DOI: 10.1002/acn3.52113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/03/2024] [Accepted: 05/15/2024] [Indexed: 06/07/2024] Open
Abstract
OBJECTIVE TFG mutations have previously been implicated in autosomal recessive hereditary spastic paraplegia (HSP), also known as SPG57. This study aimed to investigate the clinical and molecular features of TFG mutations in a Taiwanese HSP cohort. METHODS Genetic analysis of TFG was conducted in 242 unrelated Taiwanese HSP patients using a targeted resequencing panel covering the entire coding regions of TFG. Functional assays were performed using an in vitro cell model to assess the impact of TFG variants on protein function. Additionally, other representative TFG mutant proteins were examined to understand the broader implications of TFG mutations in HSP. RESULTS The study identified a novel homozygous TFG c.177A>C (p.(Lys59Asn)) variant in a family with adolescent-onset, pure form HSP. Functional analysis revealed that the Lys59Asn TFG variant, similar to other HSP-associated TFG mutants, exhibited a low affinity between TFG monomers and abnormal assembly of TFG homo-oligomers. These structural alterations led to aberrant intracellular distribution, compromising TFG's protein secretion function and resulting in decreased cellular viability. INTERPRETATION These findings confirm that the homozygous TFG c.177A>C (p.(Lys59Asn)) variant is a novel cause of SPG57. The study expands our understanding of the clinical and mutational spectrum of TFG-associated diseases, highlighting the functional defects associated with this specific TFG variant. Overall, this research contributes to the broader comprehension of the genetic and molecular mechanisms underlying HSP.
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Affiliation(s)
- Cheng‐Tsung Hsiao
- Department of NeurologyTaipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang Ming Chiao Tung University School of MedicineTaipeiTaiwan
| | - Tzu‐Yun Tsai
- Department of Life SciencesNational Chung Hsing UniversityTaichungTaiwan
| | - Ting‐Yi Shen
- Department of Life SciencesNational Chung Hsing UniversityTaichungTaiwan
| | - Yu‐Shuen Tsai
- Cancer and Immunology Research CenterNational Yang Ming Chiao Tung UniversityTaipeiTaiwan
| | - Yi‐Chu Liao
- Department of NeurologyTaipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang Ming Chiao Tung University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang Ming Chiao Tung UniversityTaipeiTaiwan
| | - Yi‐Chung Lee
- Department of NeurologyTaipei Veterans General HospitalTaipeiTaiwan
- Department of NeurologyNational Yang Ming Chiao Tung University School of MedicineTaipeiTaiwan
- Brain Research CenterNational Yang Ming Chiao Tung UniversityTaipeiTaiwan
- Center for Intelligent Drug Systems and Smart Bio‐devices (IDS2B)National Yang Ming Chiao Tung UniversityHsinchuTaiwan
| | - Pei‐Chien Tsai
- Department of Life SciencesNational Chung Hsing UniversityTaichungTaiwan
- The iEGG and Animal Biotechnology Research CenterNational Chung Hsing UniversityTaichungTaiwan
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2
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Elhadi YAM, Alrawa SS, Alfadul ESA, Mahgoub EAA, El-Osta A, Belal SA, Lucero-Prisno DE, El Dabbah NA, Yahia A. Consanguinity and willingness to perform premarital genetic screening in Sudan. Eur J Hum Genet 2023:10.1038/s41431-023-01438-1. [PMID: 37528188 DOI: 10.1038/s41431-023-01438-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 07/03/2023] [Accepted: 07/18/2023] [Indexed: 08/03/2023] Open
Abstract
Consanguineous marriage is prevalent in certain world regions due to cultural, economic, and social reasons. However, it can lead to negative consequences including an increased risk of genetic disorders in offspring. Premarital genetic screening (PMGS) is an important tool to identify and manage these risks before marriage. This study aimed to assess the magnitude of consanguineous marriage, knowledge of genetic diseases and PMGS, and attitudes and willingness to perform PMGS in Sudan. A national household survey was conducted using a multistage sampling technique, with a sample size of 2272 participants. Data were collected from December 2022 to March 2023 using an interviewer-administered questionnaire. A significant proportion of respondents (364/850, 42.8%) were married to consanguineal partners, with various types of relatedness. Moreover, 32.1% (242/755) of single respondents were planning to marry a close relative, signifying the likely persistence of consanguineous marriages in Sudan. The level of knowledge regarding genetic diseases and PMGS was relatively low in many states of Sudan, indicating the need for increased awareness interventions. A significant number of participants (85.2%) agreed that premarital screening is effective in reducing genetic diseases, whereas 71.2% supported the introduction of a mandatory PMGS program. Excluding married participants, 82.3% (1265/1537) of respondents were willing to perform PMGS, if implemented. These findings reflect the public positive attitude towards introducing the PMGS program and policies in Sudan and underscore the importance of addressing the knowledge gap of PMGS before such a potential implementation.
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Affiliation(s)
| | - Salma S Alrawa
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | | | - Austen El-Osta
- Self-Care Academic Research Unit (SCARU), School of Public Health, Imperial College London, London, UK
| | | | - Don Eliseo Lucero-Prisno
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Noha Ahmed El Dabbah
- Department of Health Administration and Behavioural Sciences, High Institute of Public Health, Alexandria University, Alexandria, Egypt
| | - Ashraf Yahia
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.
- Astrid Lindgren Children's Hospital, Karolinska University Hospital, Solna, Sweden.
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3
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Galatolo D, Trovato R, Scarlatti A, Rossi S, Natale G, De Michele G, Barghigiani M, Cioffi E, Filla A, Bilancieri G, Casali C, Santorelli FM, Silvestri G, Tessa A. Power of NGS-based tests in HSP diagnosis: analysis of massively parallel sequencing in clinical practice. Neurogenetics 2023; 24:147-160. [PMID: 37131039 DOI: 10.1007/s10048-023-00717-9] [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: 10/13/2022] [Accepted: 04/24/2023] [Indexed: 05/04/2023]
Abstract
Hereditary spastic paraplegia (HSP) refers to a group of heterogeneous neurological disorders mainly characterized by corticospinal degeneration (pure forms), but sometimes associated with additional neurological and extrapyramidal features (complex HSP). The advent of next-generation sequencing (NGS) has led to huge improvements in knowledge of HSP genetics and made it possible to clarify the genetic etiology of hundreds of "cold cases," accelerating the process of reaching a molecular diagnosis. The different NGS-based strategies currently employed as first-tier approaches most commonly involve the use of targeted resequencing panels and exome sequencing, whereas genome sequencing remains a second-tier approach because of its high costs. The question of which approach is the best is still widely debated, and many factors affect the choice. Here, we aim to analyze the diagnostic power of different NGS techniques applied in HSP, by reviewing 38 selected studies in which different strategies were applied in different-sized cohorts of patients with genetically uncharacterized HSP.
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Affiliation(s)
| | - Rosanna Trovato
- Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Arianna Scarlatti
- Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
- Laboratory of Biology, BIO@SNS, Scuola Normale Superiore, Pisa, Italy
| | - Salvatore Rossi
- UOC Neurologia, Fondazione Policlinico Universitario 'A. Gemelli' IRCCS, Rome, Italy
| | - Gemma Natale
- Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Giovanna De Michele
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University, Naples, Italy
| | | | - Ettore Cioffi
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | - Alessandro Filla
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, Federico II University, Naples, Italy
| | | | - Carlo Casali
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy
| | | | - Gabriella Silvestri
- UOC Neurologia, Fondazione Policlinico Universitario 'A. Gemelli' IRCCS, Rome, Italy
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4
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Yahia A, Hamed AAA, Mohamed IN, Elseed MA, Salih MA, El-Sadig SM, Siddig HE, Nasreldien AEM, Abdullah MA, Elzubair M, Omer FY, Bakhiet AM, Abubaker R, Abozar F, Adil R, Emad S, Musallam MA, Eltazi IZM, Omer Z, Malik H, Mohamed MOE, Elhassan AA, Mohamed EOE, Ahmed AKMA, Ahmed EAA, Eltaraifee E, Hussein BK, Abd Allah ASI, Salah L, Nimir M, Tag Elseed OM, Elhassan TEA, Elbashier A, Alfadul ESA, Fadul M, Ali KF, Taha SOMA, Bushara EE, Amin M, Koko M, Ibrahim ME, Ahmed AE, Elsayed LEO, Stevanin G. Clinical phenotyping and genetic diagnosis of a large cohort of Sudanese families with hereditary spinocerebellar degenerations. Eur J Hum Genet 2023:10.1038/s41431-023-01344-6. [PMID: 37012327 DOI: 10.1038/s41431-023-01344-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 02/12/2023] [Accepted: 03/13/2023] [Indexed: 04/05/2023] Open
Abstract
Hereditary spinocerebellar degenerations (SCDs) is an umbrella term that covers a group of monogenic conditions that share common pathogenic mechanisms and include hereditary spastic paraplegia (HSP), cerebellar ataxia, and spinocerebellar ataxia. They are often complicated with axonal neuropathy and/or intellectual impairment and overlap with many neurological conditions, including neurodevelopmental disorders. More than 200 genes and loci inherited through all modes of Mendelian inheritance are known. Autosomal recessive inheritance predominates in consanguineous communities; however, autosomal dominant and X-linked inheritance can also occur. Sudan is inhabited by genetically diverse populations, yet it has high consanguinity rates. We used next-generation sequencing, genotyping, bioinformatics analysis, and candidate gene approaches to study 90 affected patients from 38 unrelated Sudanese families segregating multiple forms of SCDs. The age-at-onset in our cohort ranged from birth to 35 years; however, most patients manifested childhood-onset diseases (the mean and median ages at onset were 7.5 and 3 years, respectively). We reached the genetic diagnosis in 63% and possibly up to 73% of the studied families when considering variants of unknown significance. Combining the present data with our previous analysis of 25 Sudanese HSP families, the success rate reached 52-59% (31-35/59 families). In this article we report candidate variants in genes previously known to be associated with SCDs or other phenotypically related monogenic disorders. We also highlight the genetic and clinical heterogeneity of SCDs in Sudan, as we did not identify a major causative gene in our cohort, and the potential for discovering novel SCD genes in this population.
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Affiliation(s)
- Ashraf Yahia
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.
- Paris Brain Institute - ICM, CNRS UMR7225, INSERM 1127, Sorbonne University, F-75000, Paris, France.
- Center of Neurodevelopmental Disorders (KIND), Centre for Psychiatry Research, Department of Women's and Children's Health, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.
- Astrid Lindgren Children's Hospital, Karolinska University Hospital, Solna, Sweden.
| | - Ahlam A A Hamed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Inaam N Mohamed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Maha A Elseed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Mustafa A Salih
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
- College of Medicine, AlMughtaribeen University, Khartoum, Sudan
| | | | | | - Ali Elsir Musa Nasreldien
- Pediatric Neurology Department, Red Cross Memorial Children Hospital (RCWMCH), University of Cape Town (UCT), Cape Town, South Africa
| | | | - Maha Elzubair
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | | | - Rayan Abubaker
- Sudanese Neurogenetics Research group, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
- National University Biomedical Research Institute, National University, Khartoum, Sudan
| | - Fatima Abozar
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Rawaa Adil
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Sara Emad
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Isra Z M Eltazi
- Neurology Department, Hamad Medical Corporation, Doha, Qatar
| | - Zulfa Omer
- Department of Hematology and Medical Oncology, University of Cincinnati Medical Center, Ohio, USA
| | - Hiba Malik
- Department of Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ, UK
| | - Mayada O E Mohamed
- Division of Emergency Medicine, Sudan Medical Specialization Board, Khartoum, Sudan
| | - Ali A Elhassan
- Sudan Neuroscience Projects, University of Khartoum, Khartoum, Sudan
| | | | - Ahmed K M A Ahmed
- Department of Molecular Neuroscience, Graduate school of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka, 565-0871, Japan
- WPI Immunology Frontier Research Center, Osaka University, 3-1, Yamadaoka, Suita, Osaka, 565-0871, Japan
| | | | | | - Bidour K Hussein
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | | | - Lina Salah
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Mohamed Nimir
- Department of Pathology, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
- Warwick Medical School, University of Warwick, Coventry, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | | | | | | | | | - Moneeb Fadul
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Khalil F Ali
- Department of Cardiology, Royal Derby Hospital, Derby, UK
| | | | | | - Mutaz Amin
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Al-Neelain University, Khartoum, Sudan
| | - Mahmoud Koko
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | | | - Ammar E Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Liena E O Elsayed
- Department of Basic Sciences, College of Medicine, Princess Nourah bint Abdulrahman University, Riyadh, P.O.Box 84428, Riyadh, 11671, Saudi Arabia
| | - Giovanni Stevanin
- Paris Brain Institute - ICM, CNRS UMR7225, INSERM 1127, Sorbonne University, F-75000, Paris, France.
- Univ. Bordeaux, CNRS, INCIA, UMR 5287, F-33000, Bordeaux, France.
- EPHE, PSL Research university, CNRS, INCIA, UMR 5287, F-75000, Paris, France.
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5
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Peotter JL, Pustova I, Lettman MM, Shatadal S, Bradberry MM, Winter-Reed AD, Charan M, Sharkey EE, Alvin JR, Bren AM, Oie AK, Chapman ER, Salamat MS, Audhya A. TFG regulates secretory and endosomal sorting pathways in neurons to promote their activity and maintenance. Proc Natl Acad Sci U S A 2022; 119:e2210649119. [PMID: 36161950 PMCID: PMC9546632 DOI: 10.1073/pnas.2210649119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/18/2022] [Indexed: 02/01/2023] Open
Abstract
Molecular pathways that intrinsically regulate neuronal maintenance are poorly understood, but rare pathogenic mutations that underlie neurodegenerative disease can offer important insights into the mechanisms that facilitate lifelong neuronal function. Here, we leverage a rat model to demonstrate directly that the TFG p.R106C variant implicated previously in complicated forms of hereditary spastic paraplegia (HSP) underlies progressive spastic paraparesis with accompanying ventriculomegaly and thinning of the corpus callosum, consistent with disease phenotypes identified in adolescent patients. Analyses of primary cortical neurons obtained from CRISPR-Cas9-edited animals reveal a kinetic delay in biosynthetic secretory protein transport from the endoplasmic reticulum (ER), in agreement with prior induced pluripotent stem cell-based studies. Moreover, we identify an unexpected role for TFG in the trafficking of Rab4A-positive recycling endosomes specifically within axons and dendrites. Impaired TFG function compromises the transport of at least a subset of endosomal cargoes, which we show results in down-regulated inhibitory receptor signaling that may contribute to excitation-inhibition imbalances. In contrast, the morphology and trafficking of other organelles, including mitochondria and lysosomes, are unaffected by the TFG p.R106C mutation. Our findings demonstrate a multifaceted role for TFG in secretory and endosomal protein sorting that is unique to cells of the central nervous system and highlight the importance of these pathways to maintenance of corticospinal tract motor neurons.
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Affiliation(s)
- Jennifer L. Peotter
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Iryna Pustova
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Molly M. Lettman
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Shalini Shatadal
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Mazdak M. Bradberry
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Allison D. Winter-Reed
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Maya Charan
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Erin E. Sharkey
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - James R. Alvin
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Alyssa M. Bren
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Annika K. Oie
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Edwin R. Chapman
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
- HHMI, University of Wisconsin-Madison, Madison, WI 53705
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705
| | - M. Shahriar Salamat
- Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
- Department of Neurological Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705
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Li C, Lin J, Gu X, Hou Y, Liu K, Jiang Q, Ou R, Wei Q, Chen X, Song W, Zhao B, Wu Y, Chen Y, Shang H. Mutation Screening of TFG in α-Synucleinopathy and Amyotrophic Lateral Sclerosis. Mov Disord 2022; 37:1756-1761. [PMID: 35642252 DOI: 10.1002/mds.29079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/05/2022] [Accepted: 05/09/2022] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Recently, p.R383H in TFG was identified as the disease cause in a family with α-synucleinopathy and amyotrophic lateral sclerosis (ALS). However, no further replication has been conducted in larger cohorts. OBJECTIVE The aim was to explore the genetic role of TFG in α-synucleinopathy and ALS. METHODS We analyzed the rare protein-coding variants in patients with Parkinson's disease (PD), ALS, multiple system atrophy (MSA), spastic paraplegia (N = 2709), and 7536 controls with whole-exome sequencing. RESULTS Nine rare variants were identified in PD and two in MSA. One PD patient carried the same variant p.R383H. Similarly, this patient developed early-onset PD with bradykinesia and rigidity on the left side as the initial symptoms. However, at the gene level, rare variants of TFG were not enriched in patients. CONCLUSIONS Rare variants of TFG were not enriched in α-synucleinopathy and ALS. However, we could not deny the potential pathogenicity of specific variants such as p.R383H. Further exploration is still necessary. © 2022 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Chunyu Li
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Junyu Lin
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaojing Gu
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Yanbing Hou
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Kuncheng Liu
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Qirui Jiang
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Ruwei Ou
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Qianqian Wei
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Xueping Chen
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Wei Song
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Bi Zhao
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Ying Wu
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Yongping Chen
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Huifang Shang
- Department of Neurology, Laboratory of Neurodegenerative Disorders, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
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7
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Mahungu AC, Monnakgotla N, Nel M, Heckmann JM. A review of the genetic spectrum of hereditary spastic paraplegias, inherited neuropathies and spinal muscular atrophies in Africans. Orphanet J Rare Dis 2022; 17:133. [PMID: 35331287 PMCID: PMC8944057 DOI: 10.1186/s13023-022-02280-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 03/07/2022] [Indexed: 11/10/2022] Open
Abstract
Background Genetic investigations of inherited neuromuscular disorders in Africans, have been neglected. We aimed to summarise the published data and comment on the genetic evidence related to inherited neuropathies (Charcot-Marie-Tooth disease (CMT)), hereditary spastic paraplegias (HSP) and spinal muscular atrophy (SMA) in Africans. Methods PubMed was searched for relevant articles and manual checking of references and review publications were performed for African-ancestry participants with relevant phenotypes and identified genetic variants. For each case report we extracted phenotype information, inheritance pattern, variant segregation and variant frequency in population controls (including up to date frequencies from the gnomAD database). Results For HSP, 23 reports were found spanning the years 2000–2019 of which 19 related to North Africans, with high consanguinity, and six included sub-Saharan Africans. For CMT, 19 reports spanning years 2002–2021, of which 16 related to North Africans and 3 to sub-Saharan Africans. Most genetic variants had not been previously reported. There were 12 reports spanning years 1999–2020 related to SMN1-SMA caused by homozygous exon 7 ± 8 deletion. Interestingly, the population frequency of heterozygous SMN1-exon 7 deletion mutations appeared 2 × lower in Africans compared to Europeans, in addition to differences in the architecture of the SMN2 locus which may impact SMN1-SMA prognosis. Conclusions Overall, genetic data on inherited neuromuscular diseases in sub-Saharan Africa, are sparse. If African patients with rare neuromuscular diseases are to benefit from the expansion in genomics capabilities and therapeutic advancements, then it is critical to document the mutational spectrum of inherited neuromuscular disease in Africa. Highlights Review of genetic variants reported in hereditary spastic paraplegia in Africans Review of genetic variants reported in genetic neuropathies in Africans Review of genetic underpinnings of spinal muscular atrophies in Africans Assessment of pathogenic evidence for candidate variants
Supplementary Information The online version contains supplementary material available at 10.1186/s13023-022-02280-2.
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Affiliation(s)
- Amokelani C Mahungu
- Neurology Research Group, University of Cape Town Neuroscience Institute, Cape Town, South Africa
| | | | - Melissa Nel
- Neurology Research Group, University of Cape Town Neuroscience Institute, Cape Town, South Africa
| | - Jeannine M Heckmann
- E8-74 Neurology, Department of Medicine, Groote Schuur Hospital and the University of Cape Town Neuroscience Institute, University of Cape Town, Cape Town, South Africa.
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8
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Elsayed LEO, Eltazi IZ, Ahmed AE, Stevanin G. Insights into Clinical, Genetic, and Pathological Aspects of Hereditary Spastic Paraplegias: A Comprehensive Overview. Front Mol Biosci 2021; 8:690899. [PMID: 34901147 PMCID: PMC8662366 DOI: 10.3389/fmolb.2021.690899] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 10/19/2021] [Indexed: 12/31/2022] Open
Abstract
Hereditary spastic paraplegias (HSP) are a heterogeneous group of motor neurodegenerative disorders that have the core clinical presentation of pyramidal syndrome which starts typically in the lower limbs. They can present as pure or complex forms with all classical modes of monogenic inheritance reported. To date, there are more than 100 loci/88 spastic paraplegia genes (SPG) involved in the pathogenesis of HSP. New patterns of inheritance are being increasingly identified in this era of huge advances in genetic and functional studies. A wide range of clinical symptoms and signs are now reported to complicate HSP with increasing overall complexity of the clinical presentations considered as HSP. This is especially true with the emergence of multiple HSP phenotypes that are situated in the borderline zone with other neurogenetic disorders. The genetic diagnostic approaches and the utilized techniques leave a diagnostic gap of 25% in the best studies. In this review, we summarize the known types of HSP with special focus on those in which spasticity is the principal clinical phenotype ("SPGn" designation). We discuss their modes of inheritance, clinical phenotypes, underlying genetics, and molecular pathways, providing some observations about therapeutic opportunities gained from animal models and functional studies. This review may pave the way for more analytic approaches that take into consideration the overall picture of HSP. It will shed light on subtle associations that can explain the occurrence of the disease and allow a better understanding of its observed variations. This should help in the identification of future biomarkers, predictors of disease onset and progression, and treatments for both better functional outcomes and quality of life.
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Affiliation(s)
- Liena E. O. Elsayed
- Department of Basic Sciences, College of Medicine, Princess Nourah bint Abdulrahman University [PNU], Riyadh, Saudi Arabia
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Ammar E. Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Giovanni Stevanin
- Institut du Cerveau – Paris Brain Institute - ICM, Sorbonne Université, INSERM, CNRS, APHP, Paris, France
- CNRS, INCIA, Université de Bordeaux, Bordeaux, France
- Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
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9
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Yoo D, Lee W, Lee SJ, Sung JJ, Jeon GS, Ban JJ, Shin C, Kim J, Kim HS, Ahn TB. A Novel TFG Mutation in a Korean Family with α-Synucleinopathy and Amyotrophic Lateral Sclerosis. Mov Disord 2021; 37:384-391. [PMID: 34779525 DOI: 10.1002/mds.28857] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/24/2021] [Accepted: 10/28/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Tropomyosin-receptor kinase fused gene (TFG) functions as a regulator of intracellular protein packaging and trafficking at the endoplasmic reticulum exit sites. TFG has recently been proposed as a cause of multisystem proteinopathy. OBJECTIVES Here, we describe a Korean family presenting with Parkinson's disease or amyotrophic lateral sclerosis caused by a novel variant of TFG (c.1148 G > A, p.Arg383His). METHODS We collected clinical, genetic, dopamine transporter imaging, nerve conduction, and electromyography data from the seven subjects. To verify the pathogenicity of the R383H variant, we studied cell viability and the abnormal aggregation of α-synuclein and TAR DNA-binding protein 43 (TDP-43) in HeLa cells expressing R383H-TFG. RESULTS The clinical phenotypes of the R383H-TFG mutation varied; of the five family members, one had Parkinson's disease, three had subclinical parkinsonism, and one (the proband) had amyotrophic lateral sclerosis. The individual with multiple system atrophy was the proband's paternal cousin, but the TFG genotype was not confirmed due to unavailability of samples. Our in vitro studies showed that R383H-TFG overexpression impaired cell viability. In cells co-expressing R383H-TFG and α-synuclein, insoluble α-synuclein aggregates increased in concentration and were secreted from the cells and co-localized with R383H-TFG. The levels of cytoplasmic insoluble aggregates of TDP-43 increased in HeLa cells expressing R383H-TFG and co-localized with R383H-TFG. CONCLUSIONS Clinical and in vitro studies have supported the pathogenic role of the novel TFG mutation in α-synucleinopathy and TDP-43 proteinopathy. These findings expand the phenotypic spectrum of TFG and suggest a pivotal role of endoplasmic reticulum dysfunction during neurodegeneration. © 2021 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Dallah Yoo
- Department of Neurology, Kyung Hee University Hospital, Kyung Hee University College of Medicine, Seoul, Republic of Korea
| | - Wonjae Lee
- Department of Biomedical Sciences, Neuroscience Research Institute, and Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.,Neuramedy Co., Ltd, Seoul, Republic of Korea
| | - Seung-Jae Lee
- Department of Biomedical Sciences, Neuroscience Research Institute, and Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jung-Joon Sung
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Gye Sun Jeon
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jae-Jun Ban
- Department of Neurology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Chaewon Shin
- Department of Neurology, Neuroscience Center, Chungnam National University Sejong Hospital, Chungnam National University College of Medicine, Sejong-si, Republic of Korea
| | - Jungho Kim
- Laboratory of Molecular and Cellular Biology, Department of Life Science, Sogang University, Seoul, Republic of Korea
| | - Hyo Sun Kim
- Laboratory of Molecular and Cellular Biology, Department of Life Science, Sogang University, Seoul, Republic of Korea
| | - Tae-Beom Ahn
- Department of Neurology, Kyung Hee University Hospital, Kyung Hee University College of Medicine, Seoul, Republic of Korea
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10
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Yahia A, Elsayed LEO, Valter R, Hamed AAA, Mohammed IN, Elseed MA, Salih MA, Esteves T, Auger N, Abubaker R, Koko M, Abozar F, Malik H, Adil R, Emad S, Musallam MA, Idris R, Eltazi IZM, Babai A, Ahmed EAA, Abd Allah ASI, Mairey M, Ahmed AKMA, Elbashir MI, Brice A, Ibrahim ME, Ahmed AE, Lamari F, Stevanin G. Pathogenic Variants in ABHD16A Cause a Novel Psychomotor Developmental Disorder With Spastic Paraplegia. Front Neurol 2021; 12:720201. [PMID: 34489854 PMCID: PMC8417901 DOI: 10.3389/fneur.2021.720201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 07/28/2021] [Indexed: 12/20/2022] Open
Abstract
Introduction: Hereditary spastic paraplegia is a clinically and genetically heterogeneous neurological entity that includes more than 80 disorders which share lower limb spasticity as a common feature. Abnormalities in multiple cellular processes are implicated in their pathogenesis, including lipid metabolism; but still 40% of the patients are undiagnosed. Our goal was to identify the disease-causing variants in Sudanese families excluded for known genetic causes and describe a novel clinico-genetic entity. Methods: We studied four patients from two unrelated consanguineous Sudanese families who manifested a neurological phenotype characterized by spasticity, psychomotor developmental delay and/or regression, and intellectual impairment. We applied next-generation sequencing, bioinformatics analysis, and Sanger sequencing to identify the genetic culprit. We then explored the consequences of the identified variants in patients-derived fibroblasts using targeted-lipidomics strategies. Results and Discussion: Two homozygous variants in ABHD16A segregated with the disease in the two studied families. ABHD16A encodes the main brain phosphatidylserine hydrolase. In vitro, we confirmed that ABHD16A loss of function reduces the levels of certain long-chain lysophosphatidylserine species while increases the levels of multiple phosphatidylserine species in patient's fibroblasts. Conclusion:ABHD16A loss of function is implicated in the pathogenesis of a novel form of complex hereditary spastic paraplegia.
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Affiliation(s)
- Ashraf Yahia
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,Department of Biochemistry, Faculty of Medicine, National University, Khartoum, Sudan.,Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Liena E O Elsayed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,College of Medicine, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Remi Valter
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Ahlam A A Hamed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Maha A Elseed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Mustafa A Salih
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Typhaine Esteves
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Nicolas Auger
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Rayan Abubaker
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Mahmoud Koko
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tubingen, Germany
| | - Fatima Abozar
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Hiba Malik
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Rawaa Adil
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Sara Emad
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Razaz Idris
- Letterkenny University Hospital, Letterkenny, Ireland
| | - Isra Z M Eltazi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Arwa Babai
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Elhami A A Ahmed
- UNESCO Chair on Bioethics, University of Khartoum, Khartoum, Sudan
| | | | - Mathilde Mairey
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Ahmed K M A Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan.,Immunology Frontier Research Center, Osaka University, Suita, Japan
| | | | - Alexis Brice
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France
| | - Muntaser E Ibrahim
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Ammar E Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Foudil Lamari
- APHP, Pitié-Salpêtrière Hospital, Metabolic Biochemistry unit, Department of Biochemistry of Neurometabolic Diseases, Paris, France
| | - Giovanni Stevanin
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute, INSERM, CNRS, Hôpital Pitié-Salpêtrière, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
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11
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Sánchez Marco SB, Peña Segura JL, López Lafuente A, López Pisón J, Lafuente Hidalgo M, Pérez Delgado R. Spastic Paraplegia Type 57: A Cerebral Palsy Mimic. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1732483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | | | | | | | | | - Raquel Pérez Delgado
- Department of Paediatric Neurology, Hospital Infantil Universitario Miguel Servet, Zaragoza, Spain
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12
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Gumeni S, Vantaggiato C, Montopoli M, Orso G. Hereditary Spastic Paraplegia and Future Therapeutic Directions: Beneficial Effects of Small Compounds Acting on Cellular Stress. Front Neurosci 2021; 15:660714. [PMID: 34025345 PMCID: PMC8134669 DOI: 10.3389/fnins.2021.660714] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 03/29/2021] [Indexed: 12/29/2022] Open
Abstract
Hereditary spastic paraplegia (HSP) is a group of inherited neurodegenerative conditions that share a characteristic feature of degeneration of the longest axons within the corticospinal tract, which leads to progressive spasticity and weakness of the lower limbs. Mutations of over 70 genes produce defects in various biological pathways: axonal transport, lipid metabolism, endoplasmic reticulum (ER) shaping, mitochondrial function, and endosomal trafficking. HSPs suffer from an adequate therapeutic plan. Currently the treatments foreseen for patients affected by this pathology are physiotherapy, to maintain the outgoing tone, and muscle relaxant therapies for spasticity. Very few clinical studies have been conducted, and it's urgent to implement preclinical animal studies devoted to pharmacological test and screening, to expand the rose of compounds potentially attractive for clinical trials. Small animal models, such as Drosophila melanogaster and zebrafish, have been generated, analyzed, and used as preclinical model for screening of compounds and their effects. In this work, we briefly described the role of HSP-linked proteins in the organization of ER endomembrane system and in the regulation of ER homeostasis and stress as a common pathological mechanism for these HSP forms. We then focused our attention on the pharmacodynamic and pharmacokinetic features of some recently identified molecules with antioxidant property, such as salubrinal, guanabenz, N-acetyl cysteine, methylene blue, rapamycin, and naringenin, and on their potential use in future clinical studies. Expanding the models and the pharmacological screening for HSP disease is necessary to give an opportunity to patients and clinicians to test new molecules.
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Affiliation(s)
- Sentiljana Gumeni
- Department of Cell Biology and Biophysics, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Chiara Vantaggiato
- Laboratory of Molecular Biology, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - Monica Montopoli
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padua, Italy
| | - Genny Orso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padua, Italy
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13
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Ibrahim ME. Genetic diversity of the Sudanese: insights on origin and implications for health. Hum Mol Genet 2021; 30:R37-R41. [PMID: 33864377 PMCID: PMC8223596 DOI: 10.1093/hmg/ddab028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 11/21/2022] Open
Abstract
By virtue of their cultural, linguistic and genetic legacies, many populations from Sudan have deep histories in the region and retain high genetic diversities. Sudan’s location in north east Africa, a unique spot believed to act as a climatic refuge during periods of climate extremes, might have dictated that fate. Among the marked consequences of this diversity is the potential to provide information on the origin and structure of human populations within and outside the continent, as well as migration patterns towards various parts of the African continent, and out of Africa. The diverse Sudanese gene pool further has the potential to inform on genetic adaptations driven by culture and the environment resulting in unique and interesting traits, some of which are yet to be investigated. In addition, these genomes could offer clues to complex issues of causation amidst the challenge of new paradigms in biology underpinned by the genomic revolution.
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14
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Khorrami M, Tabatabaiefar MA, Khorram E, Yaghini O, Rezaei M, Hejazifar A, Riahinezhad M, Kheirollahi M. Homozygous TFG gene variants expanding the mutational and clinical spectrum of hereditary spastic paraplegia 57 and a review of literature. J Hum Genet 2021; 66:973-981. [PMID: 33767317 DOI: 10.1038/s10038-021-00919-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/20/2021] [Accepted: 03/04/2021] [Indexed: 01/17/2023]
Abstract
In recent years, the tropomyosin-receptor kinase fused gene (TFG) has been linked to diverse hereditary neurodegenerative disorders, including a very rare complex hereditary spastic paraplegia, named spastic paraplegia type 57 (SPG57). Until now, four pathogenic homozygous variants of the TFG gene have been reported associated with SPG57. Two consanguineous Iranian families (1 and 2), the first one with two affected members and the second one with one, all with an early-onset progressive muscle weakness, spasticity, and several neurological symptoms were examined via the whole-exome sequencing. Two homozygous missense variants including c.41A>G (p.Lys14Arg) and c.316C>T (p.Arg106Cys) have been found in the related families. The candidate variants were confirmed by Sanger sequencing and found to co-segregate with the disease in families. The bioinformatics analysis showed the deleterious effects of these nucleotide changes and the variants were classified as pathogenic according to ACMG guidelines. A comparison of the clinical presentation of the patients harboring c.41A>G (p.Lys14Arg) with previously reported SPG57 revealed variability in the severity state and unreported clinical presentation, including, facial atrophy, nystagmus, hyperelastic skin, cryptorchidism, hirsutism, kyphoscoliosis, and pectus excavatum. The affected member of the second family carried a previously reported homozygous c.316C>T (p.Arg106Cys) variant and displayed a complex HSP including optic atrophy. Remarkable clinical differences were observed between the family 1 and 2 harboring the c.41A>G (p.Lys14Arg) and c.316C>T (p.Arg106Cys) variants, which could be attributed to the distinct affected domains (PB1 domains and coiled-coil domains), and therefore, SPG57 might have been representing phenotype vs. variant position correlation.
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Affiliation(s)
- Mehdi Khorrami
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Erfan Khorram
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Omid Yaghini
- Department of Pediatrics, School of Medicine, Growth and Development Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mojgan Rezaei
- Department of Biology, Faculty of Science, Yazd University, Yazd, Iran
| | - Arash Hejazifar
- Department of Biology, School of Sciences, The University of Isfahan, Isfahan, Iran
| | - Maryam Riahinezhad
- Department of Radiology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Majid Kheirollahi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
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15
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Yahia A, Stevanin G. The History of Gene Hunting in Hereditary Spinocerebellar Degeneration: Lessons From the Past and Future Perspectives. Front Genet 2021; 12:638730. [PMID: 33833777 PMCID: PMC8021710 DOI: 10.3389/fgene.2021.638730] [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: 12/07/2020] [Accepted: 03/02/2021] [Indexed: 01/02/2023] Open
Abstract
Hereditary spinocerebellar degeneration (SCD) encompasses an expanding list of rare diseases with a broad clinical and genetic heterogeneity, complicating their diagnosis and management in daily clinical practice. Correct diagnosis is a pillar for precision medicine, a branch of medicine that promises to flourish with the progressive improvements in studying the human genome. Discovering the genes causing novel Mendelian phenotypes contributes to precision medicine by diagnosing subsets of patients with previously undiagnosed conditions, guiding the management of these patients and their families, and enabling the discovery of more causes of Mendelian diseases. This new knowledge provides insight into the biological processes involved in health and disease, including the more common complex disorders. This review discusses the evolution of the clinical and genetic approaches used to diagnose hereditary SCD and the potential of new tools for future discoveries.
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Affiliation(s)
- Ashraf Yahia
- Department of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
- Department of Biochemistry, Faculty of Medicine, National University, Khartoum, Sudan
- Institut du Cerveau, INSERM U1127, CNRS UMR7225, Sorbonne Université, Paris, France
- Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Giovanni Stevanin
- Institut du Cerveau, INSERM U1127, CNRS UMR7225, Sorbonne Université, Paris, France
- Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
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16
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Elsayed LEO, Mohammed IN, Hamed AAA, Elseed MA, Salih MAM, Yahia A, Abubaker R, Koko M, Abd Allah ASI, Elbashir MI, Ibrahim ME, Brice A, Ahmed AE, Stevanin G. Novel Homozygous Missense Mutation in the ARG1 Gene in a Large Sudanese Family. Front Neurol 2020; 11:569996. [PMID: 33193012 PMCID: PMC7658625 DOI: 10.3389/fneur.2020.569996] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/25/2020] [Indexed: 12/16/2022] Open
Abstract
Background: Arginases catalyze the last step in the urea cycle. Hyperargininemia, a rare autosomal-recessive disorder of the urea cycle, presents after the first year of age with regression of milestones and evolves gradually into progressive spastic quadriplegia and cognitive dysfunction. Genetic studies reported various mutations in the ARG1 gene that resulted in hyperargininemia due to a complete or partial loss of arginase activity. Case Presentation: Five patients from an extended highly consanguineous Sudanese family presented with regression of the acquired milestones, spastic quadriplegia, and mental retardation. The disease onset ranged from 1 to 3 years of age. Two patients had epileptic seizures and one patient had stereotypic clapping. Genetic testing using whole-exome sequencing, done for the patients and a healthy parent, confirmed the presence of a homozygous novel missense variant in the ARG1 gene [GRCh37 (NM_001244438.1): exon 4: g.131902487T>A, c.458T>A, p.(Val153Glu)]. The variant was predicted pathogenic by five algorithms and affected a highly conserved amino acid located in the protein domain ureohydrolase, arginase subgroup. Sanger sequencing of 13 sampled family members revealed complete co-segregation between the variant and the disease distribution in the family in line with an autosomal-recessive mode of inheritance. Biochemical analysis confirmed hyperargininemia in five patients. Conclusion: This study reports the first Sudanese family with ARG1 mutation. The reported variant is a loss-of-function missense mutation. Its pathogenicity is strongly supported by the clinical phenotype, the computational functional impact prediction, the complete co-segregation with the disease, and the biochemical assessment.
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Affiliation(s)
- Liena E O Elsayed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,College of Medicine, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia.,Institut du Cerveau, INSERM, CNRS, Sorbonne Université, Paris, France
| | | | - Ahlam A A Hamed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Maha A Elseed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Mustafa A M Salih
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ashraf Yahia
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan.,Institut du Cerveau, INSERM, CNRS, Sorbonne Université, Paris, France.,Department of Biochemistry, Faculty of Medicine, National University, Khartoum, Sudan.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Rayan Abubaker
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Mahmoud Koko
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tuebingen, Germany
| | | | | | - Muntaser E Ibrahim
- Department of Molecular Biology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Alexis Brice
- Institut du Cerveau, INSERM, CNRS, Sorbonne Université, Paris, France.,APHP, Pitié-Salpêtrière Hospital, Department of genetics, Paris, France
| | - Ammar E Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Giovanni Stevanin
- Institut du Cerveau, INSERM, CNRS, Sorbonne Université, Paris, France.,Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France.,APHP, Pitié-Salpêtrière Hospital, Department of genetics, Paris, France
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17
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Slosarek EL, Schuh AL, Pustova I, Johnson A, Bird J, Johnson M, Frankel EB, Bhattacharya N, Hanna MG, Burke JE, Ruhl DA, Quinney K, Block S, Peotter JL, Chapman ER, Sheets MD, Butcher SE, Stagg SM, Audhya A. Pathogenic TFG Mutations Underlying Hereditary Spastic Paraplegia Impair Secretory Protein Trafficking and Axon Fasciculation. Cell Rep 2020; 24:2248-2260. [PMID: 30157421 PMCID: PMC6152936 DOI: 10.1016/j.celrep.2018.07.081] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/30/2018] [Accepted: 07/25/2018] [Indexed: 02/07/2023] Open
Abstract
Length-dependent axonopathy of the corticospinal tract causes lower limb spasticity and is characteristic of several neurological disorders, including hereditary spastic paraplegia (HSP) and amyotrophic lateral sclerosis. Mutations in Trk-fused gene (TFG) have been implicated in both diseases, but the pathomechanisms by which these alterations cause neuropathy remain unclear. Here, we biochemically and genetically define the impact of a mutation within the TFG coiled-coil domain, which underlies earlyonset forms of HSP. We find that the TFG (p.R106C) mutation alters compaction of TFG ring complexes, which play a critical role in the export of cargoes from the endoplasmic reticulum (ER). Using CRISPR-mediated genome editing, we engineered human stem cells that express the mutant form of TFG at endogenous levels and identified specific defects in secretion from the ER and axon fasciculation following neuronal differentiation. Together, our data highlight a key role for TFG-mediated protein transport in the pathogenesis of HSP. Slosarek et al. demonstrate that pathological mutations in TFG, which underlie various forms of neurodegenerative disease, impair secretory protein transport from the endoplasmic reticulum and compromise the ability of axons to self-associate. These findings highlight a critical function for the early secretory pathway in neuronal maintenance.
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Affiliation(s)
- Erin L Slosarek
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Amber L Schuh
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Iryna Pustova
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Adam Johnson
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Jennifer Bird
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Matthew Johnson
- Department of Chemistry and Biochemistry, Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
| | - E B Frankel
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Nilakshee Bhattacharya
- Department of Chemistry and Biochemistry, Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
| | - Michael G Hanna
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Jordan E Burke
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - David A Ruhl
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Kyle Quinney
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Samuel Block
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Jennifer L Peotter
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Edwin R Chapman
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Michael D Sheets
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA
| | - Samuel E Butcher
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Scott M Stagg
- Department of Chemistry and Biochemistry, Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health, 440 Henry Mall, Madison, WI 53706, USA.
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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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19
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Khani M, Taheri H, Shamshiri H, Houlden H, Efthymiou S, Alavi A, Nafissi S, Elahi E. Continuum of phenotypes in hereditary motor and sensory neuropathy with proximal predominance and Charcot-Marie-Tooth patients with TFG
mutation. Am J Med Genet A 2019; 179:1507-1515. [DOI: 10.1002/ajmg.a.61184] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/12/2019] [Accepted: 04/23/2019] [Indexed: 02/03/2023]
Affiliation(s)
- Marzieh Khani
- School of Biology; College of Science, University of Tehran; Tehran Iran
| | - Hanieh Taheri
- School of Biology; College of Science, University of Tehran; Tehran Iran
| | - Hosein Shamshiri
- Department of Neurology; Tehran University of Medical Sciences; Tehran Iran
| | - Henry Houlden
- Department of Molecular Neuroscience; UCL Institute of Neurology; London United Kingdom
| | - Stephanie Efthymiou
- Department of Molecular Neuroscience; UCL Institute of Neurology; London United Kingdom
| | - Afagh Alavi
- Genetics Research Center; University of Social Welfare and Rehabilitation Sciences; Tehran Iran
| | - Shahriar Nafissi
- Department of Neurology; Tehran University of Medical Sciences; Tehran Iran
| | - Elahe Elahi
- School of Biology; College of Science, University of Tehran; Tehran Iran
- Department of Biotechnology; College of Science, University of Tehran; Tehran Iran
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20
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Boutry M, Morais S, Stevanin G. Update on the Genetics of Spastic Paraplegias. Curr Neurol Neurosci Rep 2019; 19:18. [DOI: 10.1007/s11910-019-0930-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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21
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Miyabayashi T, Ochiai T, Suzuki N, Aoki M, Inui T, Okubo Y, Sato R, Togashi N, Takashima H, Ishiura H, Tsuji S, Koh K, Takiyama Y, Haginoya K. A novel homozygous mutation of the TFG gene in a patient with early onset spastic paraplegia and later onset sensorimotor polyneuropathy. J Hum Genet 2018; 64:171-176. [DOI: 10.1038/s10038-018-0538-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 11/01/2018] [Accepted: 11/02/2018] [Indexed: 01/14/2023]
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22
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R106C TFG variant causes infantile neuroaxonal dystrophy "plus" syndrome. Neurogenetics 2018; 19:179-187. [PMID: 29971521 DOI: 10.1007/s10048-018-0552-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 06/15/2018] [Indexed: 12/15/2022]
Abstract
TFG (tropomyosin-receptor kinase fused gene) encodes an essential protein in the regulation of vesicular trafficking between endoplasmic reticulum and Golgi apparatus. The homozygous variant c.316C > T within TFG has been previously associated with a complicated hereditary spastic paraplegia (HSP) phenotype in two unrelated Indian families. Here, we describe the first Italian family with two affected siblings harboring the same variant, who in childhood were classified as infantile neuroaxonal dystrophy (INAD) based on clinical and neuropathological findings. Twenty years after the first diagnosis, exome sequencing was instrumental to identify the genetic cause of this disorder and clinical follow-up of patients allowed us to reconstruct the natural history of this clinical entity. Investigations on patient's fibroblasts demonstrate the presence of altered mitochondrial network and inner membrane potential, associated with metabolic impairment. Our study highlights phenotypic heterogeneity characterizing individuals carrying the same pathogenic variant in TFG and provides an insight on tight connection linking mitochondrial efficiency and neuronal health to vesicular trafficking.
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23
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Cox NJ, Unlu G, Bisnett BJ, Meister TR, Condon BM, Luo PM, Smith TJ, Hanna M, Chhetri A, Soderblom EJ, Audhya A, Knapik EW, Boyce M. Dynamic Glycosylation Governs the Vertebrate COPII Protein Trafficking Pathway. Biochemistry 2017; 57:91-107. [PMID: 29161034 DOI: 10.1021/acs.biochem.7b00870] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The COPII coat complex, which mediates secretory cargo trafficking from the endoplasmic reticulum, is a key control point for subcellular protein targeting. Because misdirected proteins cannot function, protein sorting by COPII is critical for establishing and maintaining normal cell and tissue homeostasis. Indeed, mutations in COPII genes cause a range of human pathologies, including cranio-lenticulo-sutural dysplasia (CLSD), which is characterized by collagen trafficking defects, craniofacial abnormalities, and skeletal dysmorphology. Detailed knowledge of the COPII pathway is required to understand its role in normal cell physiology and to devise new treatments for disorders in which it is disrupted. However, little is known about how vertebrates dynamically regulate COPII activity in response to developmental, metabolic, or pathological cues. Several COPII proteins are modified by O-linked β-N-acetylglucosamine (O-GlcNAc), a dynamic form of intracellular protein glycosylation, but the biochemical and functional effects of these modifications remain unclear. Here, we use a combination of chemical, biochemical, cellular, and genetic approaches to demonstrate that site-specific O-GlcNAcylation of COPII proteins mediates their protein-protein interactions and modulates cargo secretion. In particular, we show that individual O-GlcNAcylation sites of SEC23A, an essential COPII component, are required for its function in human cells and vertebrate development, because mutation of these sites impairs SEC23A-dependent in vivo collagen trafficking and skeletogenesis in a zebrafish model of CLSD. Our results indicate that O-GlcNAc is a conserved and critical regulatory modification in the vertebrate COPII-dependent trafficking pathway.
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Affiliation(s)
| | - Gokhan Unlu
- Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center , Nashville, Tennessee 37232, United States
| | | | | | | | | | | | - Michael Hanna
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health , Madison, Wisconsin 53706, United States
| | | | - Erik J Soderblom
- Duke Proteomics and Metabolomics Core Facility, Center for Genomic and Computational Biology, Duke University , Durham, North Carolina 27710, United States
| | - Anjon Audhya
- Department of Biomolecular Chemistry, University of Wisconsin-Madison School of Medicine and Public Health , Madison, Wisconsin 53706, United States
| | - Ela W Knapik
- Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center , Nashville, Tennessee 37232, United States
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Trk-fused gene (TFG) regulates pancreatic β cell mass and insulin secretory activity. Sci Rep 2017; 7:13026. [PMID: 29026155 PMCID: PMC5638802 DOI: 10.1038/s41598-017-13432-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/25/2017] [Indexed: 12/19/2022] Open
Abstract
The Trk-fused gene (TFG) is reportedly involved in the process of COPII-mediated vesicle transport and missense mutations in TFG cause several neurodegenerative diseases including hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P). The high coincidence ratio between HMSN-P and diabetes mellitus suggests TFG to have an important role(s) in glucose homeostasis. To examine this possibility, β-cell specific TFG knockout mice (βTFG KO) were generated. Interestingly, βTFG KO displayed marked glucose intolerance with reduced insulin secretion. Immunohistochemical analysis revealed smaller β-cell masses in βTFG KO than in controls, likely attributable to diminished β-cell proliferation. Consistently, β-cell expansion in response to a high-fat, high-sucrose (HFHS) diet was significantly impaired in βTFG KO. Furthermore, glucose-induced insulin secretion was also markedly impaired in islets isolated from βTFG KO. Electron microscopic observation revealed endoplasmic reticulum (ER) dilatation, suggestive of ER stress, and smaller insulin crystal diameters in β-cells of βTFG KO. Microarray gene expression analysis indicated downregulation of NF-E2 related factor 2 (Nrf2) and its downstream genes in TFG depleted islets. Collectively, TFG in pancreatic β-cells plays a vital role in maintaining both the mass and function of β-cells, and its dysfunction increases the tendency to develop glucose intolerance.
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25
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Tariq H, Naz S. TFG associated hereditary spastic paraplegia: an addition to the phenotypic spectrum. Neurogenetics 2017; 18:105-109. [DOI: 10.1007/s10048-017-0508-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 01/14/2017] [Indexed: 01/15/2023]
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