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Michell-Robinson MA, Watt KEN, Grouza V, Macintosh J, Pinard M, Tuznik M, Chen X, Darbelli L, Wu CL, Perrier S, Chitsaz D, Uccelli NA, Liu H, Cox TC, Müller CW, Kennedy TE, Coulombe B, Rudko DA, Trainor PA, Bernard G. Hypomyelination, hypodontia and craniofacial abnormalities in a Polr3b mouse model of leukodystrophy. Brain 2023; 146:5070-5085. [PMID: 37635302 PMCID: PMC10690025 DOI: 10.1093/brain/awad249] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 06/23/2023] [Accepted: 07/06/2023] [Indexed: 08/29/2023] Open
Abstract
RNA polymerase III (Pol III)-related hypomyelinating leukodystrophy (POLR3-HLD), also known as 4H leukodystrophy, is a severe neurodegenerative disease characterized by the cardinal features of hypomyelination, hypodontia and hypogonadotropic hypogonadism. POLR3-HLD is caused by biallelic pathogenic variants in genes encoding Pol III subunits. While approximately half of all patients carry mutations in POLR3B encoding the RNA polymerase III subunit B, there is no in vivo model of leukodystrophy based on mutation of this Pol III subunit. Here, we determined the impact of POLR3BΔ10 (Δ10) on Pol III in human cells and developed and characterized an inducible/conditional mouse model of leukodystrophy using the orthologous Δ10 mutation in mice. The molecular mechanism of Pol III dysfunction was determined in human cells by affinity purification-mass spectrometry and western blot. Postnatal induction with tamoxifen induced expression of the orthologous Δ10 hypomorph in triple transgenic Pdgfrα-Cre/ERT; R26-Stopfl-EYFP; Polr3bfl mice. CNS and non-CNS features were characterized using a variety of techniques including microCT, ex vivo MRI, immunofluorescence, immunohistochemistry, spectral confocal reflectance microscopy and western blot. Lineage tracing and time series analysis of oligodendrocyte subpopulation dynamics based on co-labelling with lineage-specific and/or proliferation markers were performed. Proteomics suggested that Δ10 causes a Pol III assembly defect, while western blots demonstrated reduced POLR3BΔ10 expression in the cytoplasm and nucleus in human cells. In mice, postnatal Pdgfrα-dependent expression of the orthologous murine mutant protein resulted in recessive phenotypes including severe hypomyelination leading to ataxia, tremor, seizures and limited survival, as well as hypodontia and craniofacial abnormalities. Hypomyelination was confirmed and characterized using classic methods to quantify myelin components such as myelin basic protein and lipids, results which agreed with those produced using modern methods to quantify myelin based on the physical properties of myelin membranes. Lineage tracing uncovered the underlying mechanism for the hypomyelinating phenotype: defective oligodendrocyte precursor proliferation and differentiation resulted in a failure to produce an adequate number of mature oligodendrocytes during postnatal myelinogenesis. In summary, we characterized the Polr3bΔ10 mutation and developed an animal model that recapitulates features of POLR3-HLD caused by POLR3B mutations, shedding light on disease pathogenesis, and opening the door to the development of therapeutic interventions.
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Affiliation(s)
- Mackenzie A Michell-Robinson
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Kristin E N Watt
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Vladimir Grouza
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
| | - Julia Macintosh
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Maxime Pinard
- Translational Proteomics Research Unit, Montreal Clinical Research Institute, Montréal, QC H2W 1R7, Canada
| | - Marius Tuznik
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
| | - Xiaoru Chen
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Lama Darbelli
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Chia-Lun Wu
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Stefanie Perrier
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Daryan Chitsaz
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
| | - Nonthué A Uccelli
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
| | - Hanwen Liu
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
| | - Timothy C Cox
- Department of Oral and Craniofacial Sciences, School of Dentistry, and Pediatrics, School of Medicine, University of Missouri – Kansas City, Kansas City, MO 64108, USA
| | - Christoph W Müller
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Timothy E Kennedy
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
| | - Benoit Coulombe
- Translational Proteomics Research Unit, Montreal Clinical Research Institute, Montréal, QC H2W 1R7, Canada
- Department of Biochemistry and Molecular Medicine, University of Montréal, Montréal, QC H3C 3J7, Canada
| | - David A Rudko
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
- Department of Biomedical Engineering, McGill University, Montréal, QC H3A 2B4, Canada
| | - Paul A Trainor
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
- Department of Anatomy and Cell Biology, The University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
- Department of Pediatrics, McGill University, Montréal, QC H4A 3J1, Canada
- Department of Human Genetics, McGill University, Montréal, QC H4A 0C7, Canada
- Department of Specialized Medicine, Division of Medical Genetics, Montreal Children’s Hospital and McGill University Health Centre, Montréal, QC H4A 3J1, Canada
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2
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Macintosh J, Perrier S, Pinard M, Tran LT, Guerrero K, Prasad C, Prasad AN, Pastinen T, Thiffault I, Coulombe B, Bernard G. Biallelic pathogenic variants in POLR3D alter tRNA transcription and cause a hypomyelinating leukodystrophy: A case report. Front Neurol 2023; 14:1254140. [PMID: 37915380 PMCID: PMC10616956 DOI: 10.3389/fneur.2023.1254140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023] Open
Abstract
RNA polymerase III-related leukodystrophy (POLR3-related leukodystrophy) is a rare, genetically determined hypomyelinating disease arising from biallelic pathogenic variants in genes encoding subunits of RNA polymerase III (Pol III). Here, we describe the first reported case of POLR3-related leukodystrophy caused by biallelic pathogenic variants in POLR3D, encoding the RPC4 subunit of Pol III. The individual, a female, demonstrated delays in walking and expressive and receptive language as a child and later cognitively plateaued. Additional neurological features included cerebellar signs (e.g., dysarthria, ataxia, and intention tremor) and dysphagia, while non-neurological features included hypodontia, hypogonadotropic hypogonadism, and dysmorphic facial features. Her MRI was notable for diffuse hypomyelination with myelin preservation of early myelinating structures, characteristic of POLR3-related leukodystrophy. Exome sequencing revealed the biallelic variants in POLR3D, a missense variant (c.541C > T, p.P181S) and an intronic splice site variant (c.656-6G > A, p.?). Functional studies of the patient's fibroblasts demonstrated significantly decreased RNA-level expression of POLR3D, along with reduced expression of other Pol III subunit genes. Notably, Pol III transcription was also shown to be aberrant, with a significant decrease in 7SK RNA and several distinct tRNA genes analyzed. Affinity purification coupled to mass spectrometry of the POLR3D p.P181S variant showed normal assembly of Pol III subunits yet altered interaction of Pol III with the PAQosome chaperone complex, indicating the missense variant is likely to alter complex maturation. This work identifies biallelic pathogenic variants in POLR3D as a novel genetic cause of POLR3-related leukodystrophy, expanding the molecular spectrum associated with this disease, and proposes altered tRNA homeostasis as a factor in the underlying biology of this hypomyelinating disorder.
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Affiliation(s)
- Julia Macintosh
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Stefanie Perrier
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Maxime Pinard
- Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
| | - Luan T. Tran
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Kether Guerrero
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Chitra Prasad
- Department of Pediatrics, London Health Sciences Center and Western University, London, ON, Canada
- Medical Genetics Program of Southwestern Ontario, London Health Sciences Center, London, ON, Canada
- Children’s Health Research Institute, London, ON, Canada
| | - Asuri N. Prasad
- Department of Pediatrics, London Health Sciences Center and Western University, London, ON, Canada
- Children’s Health Research Institute, London, ON, Canada
| | - Tomi Pastinen
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, United States
- University of Missouri Kansas City School of Medicine, Kansas City, MO, United States
- Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO, United States
| | - Isabelle Thiffault
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, United States
- University of Missouri Kansas City School of Medicine, Kansas City, MO, United States
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, United States
| | - Benoit Coulombe
- Institut de Recherches Cliniques de Montréal, Montreal, QC, Canada
- Département de Biochimie et Médecine Moléculaire, Faculté de Médecine, Université de Montréal, Montreal, QC, Canada
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Department of Pediatrics, McGill University, Montreal, QC, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Centre, Montreal, QC, Canada
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3
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Mirchi A, Guay SP, Tran LT, Wolf NI, Vanderver A, Brais B, Sylvain M, Pohl D, Rossignol E, Saito M, Moutton S, González-Gutiérrez-Solana L, Thiffault I, Kruer MC, Moron DG, Kauffman M, Goizet C, Sztriha L, Glamuzina E, Melançon SB, Naidu S, Retrouvey JM, Lacombe S, Bernardino-Cuesta B, De Bie I, Bernard G. Craniofacial features of POLR3-related leukodystrophy caused by biallelic variants in POLR3A, POLR3B and POLR1C. J Med Genet 2023; 60:1026-1034. [PMID: 37197783 PMCID: PMC10579516 DOI: 10.1136/jmg-2023-109223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 04/16/2023] [Indexed: 05/19/2023]
Abstract
BACKGROUND RNA polymerase III-related or 4H leukodystrophy (POLR3-HLD) is an autosomal recessive hypomyelinating leukodystrophy characterized by neurological dysfunction, hypodontia and hypogonadotropic hypogonadism. The disease is caused by biallelic pathogenic variants in POLR3A, POLR3B, POLR1C or POLR3K. Craniofacial abnormalities reminiscent of Treacher Collins syndrome have been originally described in patients with POLR3-HLD caused by biallelic pathogenic variants in POLR1C. To date, no published studies have appraised in detail the craniofacial features of patients with POLR3-HLD. In this work, the specific craniofacial characteristics of patients with POLR3-HLD associated with biallelic pathogenic variants in POLR3A, POLR3B and POLR1C are described. METHODS The craniofacial features of 31 patients with POLR3-HLD were evaluated, and potential genotype-phenotype associations were evaluated. RESULTS Various craniofacial abnormalities were recognized in this patient cohort, with each individual presenting at least one craniofacial abnormality. The most frequently identified features included a flat midface (61.3%), a smooth philtrum (58.0%) and a pointed chin (51.6%). In patients with POLR3B biallelic variants, a thin upper lip was frequent. Craniofacial anomalies involving the forehead were most commonly associated with biallelic variants in POLR3A and POLR3B while a higher proportion of patients with POLR1C biallelic variants demonstrated bitemporal narrowing. CONCLUSION Through this study, we demonstrated that craniofacial abnormalities are common in patients with POLR3-HLD. This report describes in detail the dysmorphic features of POLR3-HLD associated with biallelic variants in POLR3A, POLR3B and POLR1C.
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Affiliation(s)
- Amytice Mirchi
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Department of Pediatrics, McGill University, Montreal, Quebec, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Simon-Pierre Guay
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Quebec, Canada
| | - Luan T Tran
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Nicole I Wolf
- Department of Child Neurology, Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers, and Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Vrije Universiteit, Amsterdam, Netherlands
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bernard Brais
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Michel Sylvain
- Centre Mère Enfant, CHU de Québec, Québec City, Quebec, Canada
| | - Daniela Pohl
- Division of Neurology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - Elsa Rossignol
- Departments of Neurosciences and Pediatrics, CHU-Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada
| | - Michael Saito
- Department of Pediatrics, University of California Riverside School of Medicine, Riverside Medical Clinic, Riverside, California, USA
| | - Sebastien Moutton
- Centre Pluridisciplinaire de Diagnostic PréNatal, MSPBordeaux Bagatelle, Talence, France
| | - Luis González-Gutiérrez-Solana
- Sección de Neuropediatría, Hospital Infantil Universitario Niño Jesús, Madrid, España; Grupo Clínico Vinculado al Centro de Investigación Biomédica en Red para Enfermedades Raras (CIBERER) GCV14/ER/6, Hospital Infantil Universitario Nino Jesus, Madrid, Spain
| | - Isabelle Thiffault
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, Missouri, USA
- University of Missouri Kansas City School of Medicine, Kansas City, Missouri, USA
| | - Michael C Kruer
- Departments of Child Health, Neurology, and Cellular & Molecular Medicine and Program in Genetics, University of Arizona College of Medicine, Phoenix, Arizona, USA
- Programs in Neuroscience and Molecular & Cellular Biology, School of Life Sciences, Arizona State University, Tempe, Arizona, USA
- Pediatric Movement Disorders Program, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, Arizona, USA
| | - Dolores Gonzales Moron
- Neurogenetics Unit, Department of Neurology, Hospital JM Ramos Mejia, ADC, Buenos Aires, Argentina
| | - Marcelo Kauffman
- Neurogenetics Unit, Department of Neurology, Hospital JM Ramos Mejia and CONICET-Universidad Austral, Buenos Aires, Argentina
| | - Cyril Goizet
- Centre de Référence Neurogénétique, Service de Génétique Médicale, Bordeaux University Hospital, CHU Bordeaux, Bordeaux, France
- NRGEN team, INCIA, CNRS UMR 5287, University of Bordeaux, Bordeaux, France
| | - László Sztriha
- Department of Paediatrics, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
| | - Emma Glamuzina
- Adult and Paediatric National Metabolic Service, Starship Children's Hospital, Auckland, Te Whatu Ora, New Zealand
| | - Serge B Melançon
- Department of Medical Genetics, McGill University Health Centre, Montreal Children's Hospital, Montreal, Quebec, Canada
| | - Sakkubai Naidu
- Department of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
| | - Jean-Marc Retrouvey
- Department of Orthodontics, University of Missouri, Kansas City, Missouri, USA
| | - Suzanne Lacombe
- Department of Orthodontics, University of Missouri, Kansas City, Missouri, USA
| | | | - Isabelle De Bie
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Quebec, Canada
- Department of Laboratory Medicine, McGill University Health Centre, Montreal, Quebec, Canada
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
- Department of Pediatrics, McGill University, Montreal, Quebec, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Quebec, Canada
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4
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Schoenmakers DH, Leferink PS, Vanderver A, Bonkowsky JL, Krägeloh-Mann I, Bernard G, Bertini E, Fatemi A, Fogel BL, Wolf NI, Skwirut D, Buck A, Holberg B, Saunier-Vivar EF, Rauner R, Dekker H, van Bokhoven P, Stellingwerff MD, Berkhof J, van der Knaap MS. Core protocol development for phase 2/3 clinical trials in the leukodystrophy vanishing white matter: a consensus statement by the VWM consortium and patient advocates. BMC Neurol 2023; 23:305. [PMID: 37592248 PMCID: PMC10433679 DOI: 10.1186/s12883-023-03354-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 08/02/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND The leukodystrophy "Vanishing White Matter" (VWM) is an orphan disease with neurological decline and high mortality. Currently, VWM has no approved treatments, but advances in understanding pathophysiology have led to identification of promising therapies. Several investigational medicinal products are either in or about to enter clinical trial phase. Clinical trials in VWM pose serious challenges, as VWM has an episodic disease course; disease phenotype is highly heterogeneous and predictable only for early onset; and study power is limited by the small patient numbers. To address these challenges and accelerate therapy delivery, the VWM Consortium, a group of academic clinicians with expertise in VWM, decided to develop a core protocol to function as a template for trials, to improve trial design and facilitate sharing of control data, while permitting flexibility regarding other trial details. Overall aims of the core protocol are to collect safety, tolerability, and efficacy data for treatment assessment and marketing authorization. METHODS To develop the core protocol, the VWM Consortium designated a committee, including clinician members of the VWM Consortium, family and patient group advocates, and experts in statistics, clinical trial design and alliancing with industries. We drafted three age-specific protocols, to stratify into more homogeneous patient groups, of ages ≥ 18 years, ≥ 6 to < 18 years and < 6 years. We chose double-blind, randomized, placebo-controlled design for patients aged ≥ 6 years; and open-label non-randomized natural-history-controlled design for patients < 6 years. The protocol describes study populations, age-specific endpoints, inclusion and exclusion criteria, study schedules, sample size determinations, and statistical considerations. DISCUSSION The core protocol provides a shared uniformity across trials, enables a pool of shared controls, and reduces the total number of patients necessary per trial, limiting the number of patients on placebo. All VWM clinical trials are suggested to adhere to the core protocol. Other trial components such as choice of primary outcome, pharmacokinetics, pharmacodynamics, and biomarkers are flexible and unconstrained by the core protocol. Each sponsor is responsible for their trial execution, while the control data are handled by a shared research organization. This core protocol benefits the efficiency of parallel and consecutive trials in VWM, and we hope accelerates time to availability of treatments for VWM. TRIAL REGISTRATION NA. From a scientific and ethical perspective, it is strongly recommended that all interventional trials using this core protocol are registered in a clinical trial register.
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Affiliation(s)
- Daphne H Schoenmakers
- Department of Child Neurology, Emma's Children's Hospital, Amsterdam UMC Location Vrije Universiteit, Amsterdam, The Netherlands
- Amsterdam Leukodystrophy Center, Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Platform "Medicine for Society", Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands
| | - Prisca S Leferink
- IXA Neuroscience, Amsterdam Neuroscience, Amsterdam UMC Location Vrije Universiteit, Amsterdam, The Netherlands
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Joshua L Bonkowsky
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA
- Primary Children's Hospital, Intermountain Healthcare, Salt Lake City, Utah, USA
| | - Ingeborg Krägeloh-Mann
- Department of Developmental and Child Neurology, Social Pediatrics, University Children's Hospital Tübingen, Tübingen, Germany
| | - Geneviève Bernard
- Departments of Neurology and Neurosurgery, Pediatrics and Human Genetics, McGill University; Department Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, Canada
| | - Enrico Bertini
- Research Unit of Neuromuscular and Neurodegenerative Diseases, Translational Pediatrics and Clinical Genetics Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Ali Fatemi
- Kennedy Krieger Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Brent L Fogel
- Los Angeles David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Nicole I Wolf
- Department of Child Neurology, Emma's Children's Hospital, Amsterdam UMC Location Vrije Universiteit, Amsterdam, The Netherlands
- Amsterdam Leukodystrophy Center, Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Amsterdam, The Netherlands
| | - Donna Skwirut
- United Leukodystrophy Foundation, DeKalb Illinois, USA
- VWM Families Foundation, Greenwhich, CT, USA
| | | | | | - Elise F Saunier-Vivar
- Research Department, European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France
| | - Robert Rauner
- United Leukodystrophy Foundation, DeKalb Illinois, USA
| | - Hanka Dekker
- Vereniging Volwassenen, Kinderen en Stofwisselingsziekten, Zwolle, The Netherlands
| | - Pieter van Bokhoven
- IXA Neuroscience, Amsterdam Neuroscience, Amsterdam UMC Location Vrije Universiteit, Amsterdam, The Netherlands
| | - Menno D Stellingwerff
- Department of Child Neurology, Emma's Children's Hospital, Amsterdam UMC Location Vrije Universiteit, Amsterdam, The Netherlands
- Amsterdam Leukodystrophy Center, Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Amsterdam, The Netherlands
| | - Johannes Berkhof
- Department of Epidemiology and Data Science, Amsterdam UMC Location Vrije Universiteit, Amsterdam, The Netherlands
| | - Marjo S van der Knaap
- Department of Child Neurology, Emma's Children's Hospital, Amsterdam UMC Location Vrije Universiteit, Amsterdam, The Netherlands.
- Amsterdam Leukodystrophy Center, Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Amsterdam, The Netherlands.
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, The Netherlands.
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5
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Modesti NB, Evans SH, Jaffe N, Vanderver A, Gavazzi F. Early recognition of patients with leukodystrophies. Curr Probl Pediatr Adolesc Health Care 2022; 52:101311. [PMID: 36470810 DOI: 10.1016/j.cppeds.2022.101311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Leukodystrophies are defined as differences in normal myelin development and maintenance in the central nervous system. They typically present as white matter imaging abnormalities in young children with delayed developmental milestones. As the scientific community begins to better understand and research the mechanisms underlying leukodystrophies, clinical trials and approved therapies for specific disorders are becoming available. These interventions, ranging from repurposing of existing small molecules to recently approved gene therapies, are highly dependent on early diagnosis. It is essential for pediatricians to identify affected individuals promptly, but they face challenges including lack of awareness of the disorders and nonspecific symptom presentation (e.g., cognitive or motor developmental delay). This review provides five hypothetical clinical presentations and describes the disease mechanisms, typical symptoms, and treatments currently available for common leukodystrophies: Krabbe Disease, Aicardi Goutières Syndrome (AGS), Metachromatic leukodystrophy (MLD), Alexander Disease (AxD), Pelizaeus-Merzbacher Disease (PMD), and X-Linked Adrenoleukodystrophy (X-ALD.) This review educates pediatricians to recognize the presentation of leukodystrophies in affected children. These clinical vignettes can serve as a framework for pediatricians to identify potentially treatable rare disorders among their patients.
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Affiliation(s)
- Nicholson B Modesti
- Neurology Department, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sarah Helen Evans
- Neurology Department, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Nicole Jaffe
- Neurology Department, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Adeline Vanderver
- Neurology Department, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Francesco Gavazzi
- Neurology Department, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
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6
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Amanat M, Nemeth CL, Fine AS, Leung DG, Fatemi A. Antisense Oligonucleotide Therapy for the Nervous System: From Bench to Bedside with Emphasis on Pediatric Neurology. Pharmaceutics 2022; 14:2389. [PMID: 36365206 PMCID: PMC9695718 DOI: 10.3390/pharmaceutics14112389] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/26/2022] [Accepted: 11/02/2022] [Indexed: 09/05/2023] Open
Abstract
Antisense oligonucleotides (ASOs) are disease-modifying agents affecting protein-coding and noncoding ribonucleic acids. Depending on the chemical modification and the location of hybridization, ASOs are able to reduce the level of toxic proteins, increase the level of functional protein, or modify the structure of impaired protein to improve function. There are multiple challenges in delivering ASOs to their site of action. Chemical modifications in the phosphodiester bond, nucleotide sugar, and nucleobase can increase structural thermodynamic stability and prevent ASO degradation. Furthermore, different particles, including viral vectors, conjugated peptides, conjugated antibodies, and nanocarriers, may improve ASO delivery. To date, six ASOs have been approved by the US Food and Drug Administration (FDA) in three neurological disorders: spinal muscular atrophy, Duchenne muscular dystrophy, and polyneuropathy caused by hereditary transthyretin amyloidosis. Ongoing preclinical and clinical studies are assessing the safety and efficacy of ASOs in multiple genetic and acquired neurological conditions. The current review provides an update on underlying mechanisms, design, chemical modifications, and delivery of ASOs. The administration of FDA-approved ASOs in neurological disorders is described, and current evidence on the safety and efficacy of ASOs in other neurological conditions, including pediatric neurological disorders, is reviewed.
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Affiliation(s)
- Man Amanat
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christina L. Nemeth
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Amena Smith Fine
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Doris G. Leung
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Center for Genetic Muscle Disorders, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Ali Fatemi
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Incidence of Aicardi-Goutières syndrome and KCNT1-related epilepsy in Denmark. Mol Genet Metab Rep 2022; 33:100924. [PMID: 36262748 PMCID: PMC9574483 DOI: 10.1016/j.ymgmr.2022.100924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/07/2022] [Accepted: 10/08/2022] [Indexed: 11/06/2022] Open
Abstract
Objective To estimate the incidence of Aicardi-Goutières syndrome (AGS) and potassium sodium-activated channel subfamily T member 1 (KCNT1)-related epilepsy in Denmark and to characterize the patients diagnosed with AGS and KCNT1-related epilepsy. Background AGS and KCNT1-related epilepsy are 2 distinct rare genetic disorders. Due to the rarity of AGS and KCNT1-related epilepsy, the epidemiology remains unclear. The incidences for these diseases or the carriers with disease-related genetic variants remain unknown. Materials and methods This is a retrospective, non-interventional, population-based study using aggregate data from the Danish population register and hospital-based patient-level data in Denmark to identify persons with genetically confirmed AGS between January 2010 to December 2020 and KCNT1-related epilepsies between January 2012 to December 2020. Cases of these disorders were identified from in-hospital databases, and pathogenic variants were identified and confirmed by Sanger and/or whole exome (panel-based) sequencing. The incidence of AGS and KCNT1-related epilepsy were estimated in separate statistical analyses. Results A total of 7 AGS patients were identified. The mean age at AGS diagnosis was 19.4 months (median age 14 months). TREX1 (n < 5) and RNASEH2B (n ≥ 5) genes were reported with confirmed pathogenic variants. The birth incidence of AGS was <0.7600 per 100,000 live births. The average annual incidence rate was calculated as 0.0539 (95% CI: 0.0217–0.1111) per 100,000 persons per year in the total population < 18 years (n = 7); the average annual incidence rate was <0.7538 per 100,000 persons per year (n < 5) in the population < 12 months, and the average annual incidence rate in the population ≥ 12 months and < 18 years was <0.0406 per 100,000 persons per year (n < 5). A total of 14 KCNT1-related epilepsy cases were identified during the study period (n = 5 in 2016, remaining 9 cases in 2013 and 2015). The mean age at diagnosis was 20.6 years (median 19 years) for KCNT1 cases. A total of 8 cases (57.1%) were ≥ 18 years, and 6 (42.9%) were < 18 years at diagnosis. The phenotype autosomal dominant or sporadic sleep-related hypermotor epilepsy (ADSHE) (n = 10, 71.4%) was most reported; the remaining 4 cases had either epilepsy of infancy with migrating focal seizures (EIMFS) or an unclassifiable developmental and epileptic encephalopathy (DEE). The birth incidence of KCNT1-related epilepsy was ≤1.1205 per 100,000 live births. The average annual incidence rates per 100,000 persons per year during the study period were 0.0431 (95% confidence interval [CI]: 0.0236–0.0723; n = 14) in the overall population ≤ 50 years, 0.0568 (95% CI: 0.0209–0.1237; n = 6) in the population < 18 years, and 0.0365 (95% CI: 0.0157–0.0718; n = 8) in the population ≥ 18 and ≤ 50 years. There were 3 families with at least 2 cases diagnosed with KCNT1-related epilepsies (on average 3.3 cases per family), indicating 10 cases in total within the 3 families. All KCNT1 cases of ADSHE phenotype came from the 3 families. The higher incidence of older ages and ADSHE cases compared with previous KCNT1 studies is likely due to the capture of prevalent and familial previously undiagnosed cases. Excluding these family cases, the average annual incidence was 0.0123 (95% CI: 0.0034–0.0315, n = 4) per 100,000 persons per year in the population ≤ 50 years during 2012–2020. Conclusions AGS and KCNT1-related epilepsy are particularly rare diseases. The annual average incidence rate of AGS was 0.0539 per 100,000 persons per year in the population < 18 years and birth incidence was <0.7600 per 100,000 live births during 2010–2020. The average annual incidence rate of KCNT1-related epilepsy was 0.0431 per 100,000 persons per year in the population ≤ 50 years and the birth incidence was ≤1.1205 per 100,000 live births during 2012–2020. Given similar healthcare systems and genetic pools, these findings may provide insight on the incidence of these rare diseases in the Nordics.
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Huang YT, Giacomini PS, Massie R, Venkateswaran S, Trudelle AM, Fadda G, Sharifian-Dorche M, Boudjani H, Poliquin-Lasnier L, Airas L, Saveriano AW, Ziller MG, Miller E, Martinez-Rios C, Wilson N, Davila J, Rush C, Longbrake EE, Longoni G, Macaron G, Bernard G, Tampieri D, Antel J, Brais B, La Piana R. The White Matter Rounds experience: The importance of a multidisciplinary network to accelerate the diagnostic process for adult patients with rare white matter disorders. Front Neurol 2022; 13:928493. [PMID: 35959404 PMCID: PMC9359417 DOI: 10.3389/fneur.2022.928493] [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: 04/25/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Introduction Adult genetic leukoencephalopathies are rare neurological disorders that present unique diagnostic challenges due to their clinical and radiological overlap with more common white matter diseases, notably multiple sclerosis (MS). In this context, a strong collaborative multidisciplinary network is beneficial for shortening the diagnostic odyssey of these patients and preventing misdiagnosis. The White Matter Rounds (WM Rounds) are multidisciplinary international online meetings attended by more than 30 physicians and scientists from 15 participating sites that gather every month to discuss patients with atypical white matter disorders. We aim to present the experience of the WM Rounds Network and demonstrate the value of collaborative multidisciplinary international case discussion meetings in differentiating and preventing misdiagnoses between genetic white matter diseases and atypical MS. Methods We retrospectively reviewed the demographic, clinical and radiological data of all the subjects presented at the WM Rounds since their creation in 2013. Results Seventy-four patients (mean age 44.3) have been referred and discussed at the WM Rounds since 2013. Twenty-five (33.8%) of these patients were referred by an MS specialist for having an atypical presentation of MS, while in most of the remaining cases, the referring physician was a geneticist (23; 31.1%). Based on the WM Rounds recommendations, a definite diagnosis was made in 36/69 (52.2%) patients for which information was available for retrospective review. Of these diagnosed patients, 20 (55.6%) had a genetic disease, 8 (22.2%) had MS, 3 (8.3%) had both MS and a genetic disorder and 5 (13.9%) had other non-genetic conditions. Interestingly, among the patients initially referred by an MS specialist, 7/25 were definitively diagnosed with MS, 5/25 had a genetic condition (e.g., X-linked adrenoleukodystrophy and hereditary small vessel diseases like Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) and COL4A1-related disorder), and one had both MS and a genetic demyelinating neuropathy. Thanks to the WM Rounds collaborative efforts, the subjects who currently remain without a definite diagnosis, despite extensive investigations performed in the clinical setting, have been recruited in research studies aimed at identifying novel forms of genetic MS mimickers. Conclusions The experience of the WM Rounds Network demonstrates the benefit of collective discussions on complex cases to increase the diagnostic rate and decrease misdiagnosis in patients with rare or atypical white matter diseases. Networks of this nature allow physicians and scientists to compare and share information on challenging cases from across the world, provide a basis for future multicenter research studies, and serve as model for other rare diseases.
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Affiliation(s)
- Yu Tong Huang
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Paul S. Giacomini
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Rami Massie
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Sunita Venkateswaran
- Department of Pediatrics, Division of Neurology, CHEO, University of Ottawa, Ottawa, ON, Canada
| | | | - Giulia Fadda
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Maryam Sharifian-Dorche
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Hayet Boudjani
- Department of Neurology, Maisonneuve-Rosemont Hospital, Université de Montréal, Montreal, QC, Canada
| | | | - Laura Airas
- Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland
| | - Alexander W. Saveriano
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Matthias Georg Ziller
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada,Department of Neurology, St. Mary's Hospital, Montreal, QC, Canada
| | - Elka Miller
- Department of Medical Imaging, CHEO, University of Ottawa, Ottawa, ON, Canada
| | | | - Nagwa Wilson
- Department of Medical Imaging, CHEO, University of Ottawa, Ottawa, ON, Canada
| | - Jorge Davila
- Department of Medical Imaging, CHEO, University of Ottawa, Ottawa, ON, Canada
| | - Carolina Rush
- Division of Neurology, Neuroscience Department, University of Ottawa, Ottawa, ON, Canada
| | - Erin E. Longbrake
- Department of Neurology, Yale MS Center, Yale School of Medicine, North Haven, CT, United States
| | - Giulia Longoni
- Department of Pediatrics, Division of Neurology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Gabrielle Macaron
- Department of Neurology, Hotel Dieu de France Hospital, Saint Joseph University, Beirut, Lebanon
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada,Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, QC, Canada,Child Health and Human Development Program, Research Institute of the McGill University Health Center, Montreal, QC, Canada,Departments of Pediatrics and Human Genetics, McGill University, Montreal, QC, Canada
| | - Donatella Tampieri
- Department of Diagnostic Radiology, Kingston Health Science Centre, Queen's University, Kingston, ON, Canada
| | - Jack Antel
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Roberta La Piana
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada,Department of Diagnostic Radiology, McGill University, Montreal, QC, Canada,*Correspondence: Roberta La Piana
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Wongkittichote P, Mar SS, McKinstry RC, Nguyen H. Case Report: A Novel EIF2B3 Pathogenic Variant in Central Nervous System Hypomyelination/Vanishing White Matter. Front Genet 2022; 13:893057. [PMID: 35783294 PMCID: PMC9247212 DOI: 10.3389/fgene.2022.893057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/11/2022] [Indexed: 11/23/2022] Open
Abstract
Leukodystrophies are a group of heterogeneous disorders affecting brain myelin. Among those, childhood ataxia with central nervous system hypomyelination/vanishing white matter (CACH/VWM) is one of the more common inherited leukodystrophies. Pathogenic variants in one of the genes encoding five subunits of EIF2B are associated with CACH/VWM. Herein, we presented a case of CACH/VWM who developed ataxia following a minor head injury. Brain magnetic resonance imaging showed extensive white matter signal abnormality. Diagnosis of CACH/VWM was confirmed by the presence of compound heterozygous variants in EIF2B3: the previously known pathogenic variant c c.260C>T (p.Ala87Val) and the novel variant c.673C>T (p.Arg225Trp). Based on the American College of Medical Genetics (ACMG) recommendations, we classified p.Arg225Trp as likely pathogenic. We report a novel variant in a patient with CACH/VWM and highlight the importance of genetic testing in patients with leukodystrophies.
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Affiliation(s)
- Parith Wongkittichote
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St Louis, MO, United States
| | - Soe Soe Mar
- Division of Pediatric Neurology, Department of Neurology, Washington University School of Medicine, St Louis, MO, United States
| | - Robert C. McKinstry
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO, United States
| | - Hoanh Nguyen
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St Louis, MO, United States
- *Correspondence: Hoanh Nguyen,
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10
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[Research advances in the clinical genetics of leukodystrophy in children]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2022; 24:711-716. [PMID: 35762440 PMCID: PMC9250391 DOI: 10.7499/j.issn.1008-8830.2202020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Leukodystrophy (LD) is a group of genetic heterogeneous diseases characterized by primary abnormalities in glial cells and myelin sheath, and it is a common nervous system disease in children and has significant genotype-phenotype correlation. In recent years, the improvement in high-throughput sequencing has changed the diagnostic and therapeutic mode of LD, and elaborative phenotype analysis, such as the collection of natural history and multimodal neuroimaging evaluation during development, also provides important information for subsequent genetic diagnosis. This article reviews LD from the perspective of clinical genetics, in order to improve the awareness of this disease among pediatricians in China.
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11
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van der Knaap MS, Bonkowsky JL, Vanderver A, Schiffmann R, Krägeloh-Mann I, Bertini E, Bernard G, Fatemi SA, Wolf NI, Saunier-Vivar E, Rauner R, Dekker H, van Bokhoven P, van de Ven P, Leferink PS. Therapy Trial Design in Vanishing White Matter: An Expert Consortium Opinion. Neurol Genet 2022; 8:e657. [PMID: 35128050 PMCID: PMC8811717 DOI: 10.1212/nxg.0000000000000657] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/21/2021] [Indexed: 01/04/2023]
Abstract
Vanishing white matter (VWM) is a leukodystrophy caused by recessive variants in the genes EIF2B1-EIF2B5. It is characterized by chronic neurologic deterioration with superimposed stress-provoked episodes of rapid decline. Disease onset spans from the antenatal period through senescence. Age at onset predicts disease evolution for patients with early onset, whereas disease evolution is unpredictable for later onset; patients with infantile and early childhood onset consistently have severe disease with rapid neurologic decline and often early death, whereas patients with later onset have highly variable disease. VWM is rare, but likely underdiagnosed, particularly in adults. Apart from measures to prevent stressors that could provoke acute deteriorations, only symptomatic care is currently offered. With increased insight into VWM disease mechanisms, opportunities for treatment have emerged. EIF2B1-EIF2B5 encode the 5-subunit eukaryotic initiation factor 2B complex, which is essential for translation of mRNAs into proteins and is a principal regulator of the integrated stress response (ISR). ISR deregulation is central to VWM pathology. Targeting components of the ISR has proven beneficial in mutant VWM mouse models, and several drugs are now in clinical development. However, clinical trials in VWM pose considerable challenges: low numbers of known patients with VWM, unpredictable disease course for patients with onset after early childhood, absence of intermediate biomarkers, and novel first-in-human molecular targets. Given these challenges and considering the critical need to offer therapies, we have formulated recommendations for enhanced diagnosis, drug trial setup, and patient selection, based on our expert evaluation of molecular, laboratory, and clinical data.
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Affiliation(s)
- Marjo S van der Knaap
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Joshua L Bonkowsky
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Adeline Vanderver
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Raphael Schiffmann
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Ingeborg Krägeloh-Mann
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Enrico Bertini
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Genevieve Bernard
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Seyed Ali Fatemi
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Nicole I Wolf
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Elise Saunier-Vivar
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Robert Rauner
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Hanka Dekker
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Pieter van Bokhoven
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Peter van de Ven
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
| | - Prisca S Leferink
- Department of Pediatric Neurology (M.S.v.d.K., N.I.W.), Amsterdam Leukodystrophy Center, Emma Children's Hospital, Amsterdam University Medical Centers; Amsterdam Neuroscience (M.S.v.d.K., N.I.W.); Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, Vrije Universiteit, Amsterdam, the Netherlands; Division of Pediatric Neurology (J.L.B.), Department of Pediatrics, University of Utah School of Medicine; Primary Children's Hospital (J.L.B.), Intermountain Healthcare, Salt Lake City, UT; Division of Neurology (A.V.), Children's Hospital of Philadelphia; Department of Neurology (A.V.), Perelman School of Medicine, University of Pennsylvania, PA; 4D Molecular Therapeutics (R.S.), Emeryville, CA; Department of Developmental and Child Neurology (I.K.-M.), Social Pediatrics, University Children's Hospital Tübingen, Germany; Department of Neuroscience (E.B.), Unit of Neuromuscular and Neurodegenerative Diseases, Laboratory of Molecular Medicine, Genetics and Rare Diseases Research Division, IRCCS Ospedale Pediatrico Bambino Gesù, Rome 00146, Italy; Departments of Neurology and Neurosurgery (G.B.), Pediatrics and Human Genetics, McGill University; Department Specialized Medicine (G.B.), Division of Medical Genetics, McGill University Health Center; Child Health and Human Development Program (G.B.), Research Institute of the McGill University Health Center, Montreal, Canada; Kennedy Krieger Institute (S.A.F.), Johns Hopkins University, Baltimore, MD; Research Department (E.S.-V.), European Leukodystrophies Association International and European Leukodystrophies Association France, Paris, France; United Leukodystrophy Foundation (R.R.), DeKalb, IL; Vereniging Volwassenen, Kinderen en Stofwisselingsziekten (H.D.), Zwolle, the Netherlands; Industry Alliance Office (P.v.B., P.S.L.), Amsterdam Neuroscience, Amsterdam University Medical Centers; and Department of Epidemiology and Data Science (P.v.d.V.), Amsterdam University Medical Centers, Vrije Universiteit, Amsterdam, the Netherlands
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12
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Bonkowsky JL. New insights into genetic white matter disorders. Dev Med Child Neurol 2021; 63:1010. [PMID: 33834484 DOI: 10.1111/dmcn.14891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/11/2021] [Indexed: 11/29/2022]
Abstract
This commentary is on the original article by Knuutinen et al. on pages 1066–1074 of this issue.
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Affiliation(s)
- Joshua L Bonkowsky
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA
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13
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Knuutinen OA, Oikarainen JH, Suo-Palosaari MH, Kangas SM, Rahikkala EJ, Pokka TML, Moilanen JS, Hinttala RML, Vieira PM, Uusimaa JM. Epidemiological, clinical, and genetic characteristics of paediatric genetic white matter disorders in Northern Finland. Dev Med Child Neurol 2021; 63:1066-1074. [PMID: 33948933 DOI: 10.1111/dmcn.14884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/01/2021] [Indexed: 12/21/2022]
Abstract
AIM To examine the epidemiological, clinical, and genetic characteristics of paediatric patients with genetic white matter disorders (GWMDs) in Northern Finland. METHOD A longitudinal population-based cohort study was conducted in the tertiary catchment area of Oulu University Hospital from 1990 to 2019. Patients were identified retrospectively by International Statistical Classification of Diseases and Related Health Problems codes in hospital records and prospectively by attending physicians. Inclusion criteria were children younger than 18 years with defined GWMDs or genetic disorders associated with white matter abnormalities (WMAs) on brain magnetic resonance imaging. RESULTS Eighty patients (mean age [SD] at the end of the study 11y [8y 6mo], range 0-35y; 45 males, 35 females) were diagnosed with a defined GWMD. The cumulative childhood incidence was 30 per 100 000 live births. Regarding those patients with 49 distinct GWMDs, 20% had classic leukodystrophies and 80% had genetic leukoencephalopathies. The most common leukodystrophies were cerebral adrenoleukodystrophy, Krabbe disease, and Salla disease. Additionally, 29 patients (36%) had genetic aetiologies not previously associated with brain WMAs or they had recently characterised GWMDs, including SAMD9L- and NHLRC2-related neurological disorders. Aetiology was mitochondrial in 21% of patients. The most common clinical findings were motor developmental delay, intellectual disability, hypotonia, and spasticity. INTERPRETATION The cumulative childhood incidence of childhood-onset GWMDs was higher than previously described. Comprehensive epidemiological and natural history data are needed before future clinical trials are undertaken. What this paper adds Forty-nine distinct genetic white matter disorders (GWMDs) were identified, with 20% of cases being classic leukodystrophies. The cumulative childhood incidence of GWMDs was higher than described previously. A considerable proportion (36%) of GWMDs were previously undefined or recently characterised GWMDs. Mitochondrial aetiology was more common (21%) than previously reported.
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Affiliation(s)
- Oula A Knuutinen
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Jaakko H Oikarainen
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
| | - Maria H Suo-Palosaari
- Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland.,Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland
| | - Salla M Kangas
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Elisa J Rahikkala
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | - Tytti M-L Pokka
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Clinic for Children and Adolescents, Oulu University Hospital, Oulu, Finland
| | - Jukka S Moilanen
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Department of Clinical Genetics, Oulu University Hospital, Oulu, Finland
| | - Reetta M L Hinttala
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Päivi M Vieira
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Clinic for Children and Adolescents, Oulu University Hospital, Oulu, Finland
| | - Johanna M Uusimaa
- PEDEGO Research Unit, University of Oulu, Oulu, Finland.,Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.,Clinic for Children and Adolescents, Oulu University Hospital, Oulu, Finland
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Abstract
Leukodystrophies are a group of genetically determined disorders that affect development or maintenance of central nervous system myelin. Leukodystrophies have an incidence of at least 1 in 4700 live births and significant morbidity and elevated risk of early death. This report includes a discussion of the types of leukodystrophies; their prevalence, clinical presentation, symptoms, and diagnosis; and current and future treatments. Leukodystrophies can present at any age from infancy to adulthood, with variability in disease progression and clinical presentation, ranging from developmental delay to seizures to spasticity. Diagnosis is based on a combination of history, examination, and radiologic and laboratory findings, including genetic testing. Although there are few cures, there are significant opportunities for care and improvements in patient well-being. Rapid advances in imaging and diagnosis, the emergence of and requirement for timely treatments, and the addition of leukodystrophy screening to newborn screening, make an understanding of the leukodystrophies necessary for pediatricians and other care providers for children.
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Affiliation(s)
- Joshua L Bonkowsky
- Division of Pediatric Neurology, Department of Pediatrics, School of Medicine, University of Utah and Brain and Spine Center, Primary Children's Hospital, Salt Lake City, Utah
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15
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Bradbury AM, Ream MA. Recent Advancements in the Diagnosis and Treatment of Leukodystrophies. Semin Pediatr Neurol 2021; 37:100876. [PMID: 33892849 DOI: 10.1016/j.spen.2021.100876] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/08/2021] [Accepted: 01/17/2021] [Indexed: 11/26/2022]
Abstract
Leukodystrophies and genetic leukoencephalopathies comprise a growing group of inherited white matter disorders. Diagnostic rates have improved with increased utilization of next generation sequencing. As treatment options continue to advance for leukodystrophies, so will candidacy for inclusion in the United States' newborn Recommended Universal Screening Panel as was achieved for X-linked adrenoleukodystrophy. Stem cell therapies have become standard of care for selected leukodystrophies. However, transplantation-related risks remain high and outcomes are not fully satisfactory. Transduction of autologous hematopoietic stem cells with lentiviral vectors, referred to as ex vivo gene therapy, circumvents some, but not all, of the risks of traditional transplantation and has recently been demonstrated to be safe and efficective in clinical studies of X-linked adrenoleukodystrophy and metachromatic leukodystrophy. Gene therapy, through direct infusion of adeno-associated virus vectors, has emerged as a safer alternative for many monogenetic pediatric neurological disorders. Numerous preclinical studies have shown safety and efficacy of adeno-associated virus gene therapy in leukodystrophies allowing expanded access treatment for Canavan disease prior to initiation of a clinical trial. For inherited white matter disorders resulting from overexpression of a protein, such as Pelizaeus-Merzbacher disease, emerging RNA therapies have shown success in preclinical studies and promise for rapid translation to the clinic. Lastly, small molecule and protein therapies remain a long-term treatment option for a number of leukodystrophies, including intrathecal enzyme replacement therapy for metachromatic leukodystrophy. Herein we review recent advances in diagnosis and treatment of inherited white matter disorders.
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Affiliation(s)
| | - Margie A Ream
- Division of Neurology, Nationwide Children's Hospital, Columbus, OH.
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