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Hosseinpour S, Razmara E, Heidari M, Rezaei Z, Ashrafi MR, Dehnavi AZ, Kameli R, Bereshneh AH, Vahidnezhad H, Azizimalamiri R, Zamani Z, Pak N, Rasulinezhad M, Mohammadi B, Ghabeli H, Ghafouri M, Mohammadi M, Zamani GR, Badv RS, Saket S, Rabbani B, Mahdieh N, Ahani A, Garshasbi M, Tavasoli AR. A comprehensive study of mutation and phenotypic heterogeneity of childhood mitochondrial leukodystrophies. Brain Dev 2024; 46:167-179. [PMID: 38129218 DOI: 10.1016/j.braindev.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 12/10/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023]
Abstract
OBJECTIVE Mitochondrial leukodystrophies (MLs) are mainly caused by impairments of the mitochondrial respiratory chains. This study reports the mutation and phenotypic spectrum of a cohort of 41 pediatric patients from 39 distinct families with MLs among 320 patients with a molecular diagnosis of leukodystrophies. METHODS This study summarizes the clinical, imaging, and molecular data of these patients for five years. RESULTS The three most common symptoms were neurologic regression (58.5%), pyramidal signs (58.5%), and extrapyramidal signs (43.9%). Because nuclear DNA mutations are responsible for a high percentage of pediatric MLs, whole exome sequencing was performed on all patients. In total, 39 homozygous variants were detected. Additionally, two previously reported mtDNA variants were identified with different levels of heteroplasmy in two patients. Among 41 mutant alleles, 33 (80.4%) were missense, 4 (9.8%) were frameshift (including 3 deletions and one duplication), and 4 (9.8%) were splicing mutations. Oxidative phosphorylation in 27 cases (65.8%) and mtDNA maintenance pathways in 8 patients (19.5%) were the most commonly affected mitochondrial pathways. In total, 5 novel variants in PDSS1, NDUFB9, FXBL4, SURF1, and NDUSF1 were also detected. In silico analyses showed how each novel variant may contribute to ML pathogenesis. CONCLUSIONS The findings of this study suggest whole-exome sequencing as a strong diagnostic genetic tool to identify the causative variants in pediatric MLs. In comparison between oxidative phosphorylation (OXPHOS) and mtDNA maintenance groups, brain stem and periaqueductal gray matter (PAGM) involvement were more commonly seen in OXPHOS group (P value of 0.002 and 0.009, respectively), and thinning of corpus callosum was observed more frequently in mtDNA maintenance group (P value of 0.042).
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Affiliation(s)
- Sareh Hosseinpour
- Department of Pediatric Neurology, Vali-e-Asr Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ehsan Razmara
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Morteza Heidari
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Rezaei
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Reza Ashrafi
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Zare Dehnavi
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
| | - Reyhaneh Kameli
- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
| | - Ali Hosseini Bereshneh
- Prenatal Diagnosis and Genetic Research Center, Dastgheib Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hassan Vahidnezhad
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, USA; Department of Pediatrics, The University of Pennsylvania School of Medicine, Philadelphia, USA
| | - Reza Azizimalamiri
- Department of Pediatric Neurology, Golestan Medical, Educational, and Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Zahra Zamani
- MD, MPH, Community Medicine Specialist, Tehran University of Medical Sciences, Tehran, Iran
| | - Neda Pak
- Department of Radiology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Rasulinezhad
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Bahram Mohammadi
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Homa Ghabeli
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Ghafouri
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Mohammadi
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Gholam Reza Zamani
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Sasan Saket
- Iranian Child Neurology Center of Excellence, Pediatric Neurology Research Center, Research Institute for Children Health, Mofid Children's and Shohada-e Tajrish Hospitals, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bahareh Rabbani
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nejat Mahdieh
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran; Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Ali Ahani
- Mendel Medical Genetics Laboratory, Iran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Jalal-Al Ahmad Hwy, Tarbiat Modares University, Tehran, Iran.
| | - Ali Reza Tavasoli
- Myelin Disorders Clinic, Division of Pediatric Neurology, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Neurology Division, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA.
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Nair LS, Nurul Jain JM, Dalal A, Ranganath P. Etiologic Spectrum of Pediatric-Onset Leukodystrophies and Genetic Leukoencephalopathies: The Five-Year Experience of a Tertiary Care Center in Southern India. Pediatr Neurol 2024; 152:130-152. [PMID: 38277958 DOI: 10.1016/j.pediatrneurol.2023.12.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/28/2023] [Accepted: 12/29/2023] [Indexed: 01/28/2024]
Abstract
BACKGROUND White matter (WM) disorders with a genetic etiology are classified as leukodystrophies (LDs) and genetic leukoencephalopathies (GLEs). There are very few studies pertaining to the etiologic spectrum of these disorders in the Asian Indian population. METHODS This study was conducted over a period of five years from January 2016 to December 2020, in the medical genetics department of a tertiary care hospital in southern India. A total of 107 patients up to age 18 years, with a diagnosis of a genetic WM disorder confirmed by molecular genetic testing and/or metabolic testing, were included in the study and categorized into LD or GLE group as per the classification suggested by the Global Leukodystrophy Initiative consortium in 2015. RESULTS Forty-one patients were diagnosed to have LDs, and 66 patients had GLEs. The two most common LDs were metachromatic LD (16 patients) and X-linked adrenoleukodystrophy (seven patients). In the GLE group, lysosomal storage disorders were the most common (40 patients) followed by mitochondrial disorders (nine patients), with other metabolic disorders and miscellaneous conditions making up the rest. The clinical presentations, neuroimaging findings, and mutation spectrum of the patients in our cohort are discussed. CONCLUSIONS This is one of the largest cohorts of genetic WM disorders reported till date from the Asian Indian population. The etiologies and clinical presentations identified in our study cohort are similar to those found in other Indian studies as well as in studies based on other populations from different parts of the world.
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Affiliation(s)
- Lekshmi S Nair
- Senior Resident, Department of Medical Genetics, Nizam's Institute of Medical Sciences, Hyderabad, Telangana, India
| | - Jamal Mohammed Nurul Jain
- Technical Officer, Diagnostics Division, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, India
| | - Ashwin Dalal
- Head, Diagnostics Division, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, India
| | - Prajnya Ranganath
- Additional Professor and Head, Department of Medical Genetics, Nizam's Institute of Medical Sciences, Hyderabad, Telangana, India; Adjunct Scientist, Diagnostics Division, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, Telangana, India.
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Ceravolo G, Zhelcheska K, Squadrito V, Pellerin D, Gitto E, Hartley L, Houlden H. Update on leukodystrophies and developing trials. J Neurol 2024; 271:593-605. [PMID: 37755460 PMCID: PMC10770198 DOI: 10.1007/s00415-023-11996-5] [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: 07/17/2023] [Revised: 09/08/2023] [Accepted: 09/10/2023] [Indexed: 09/28/2023]
Abstract
Leukodystrophies are a heterogeneous group of rare genetic disorders primarily affecting the white matter of the central nervous system. These conditions can present a diagnostic challenge, requiring a comprehensive approach that combines clinical evaluation, neuroimaging, metabolic testing, and genetic testing. While MRI is the main tool for diagnosis, advances in molecular diagnostics, particularly whole-exome sequencing, have significantly improved the diagnostic yield. Timely and accurate diagnosis is crucial to guide symptomatic treatment and assess eligibility to participate in clinical trials. Despite no specific cure being available for most leukodystrophies, gene therapy is emerging as a potential treatment avenue, rapidly advancing the therapeutic prospects in leukodystrophies. This review will explore diagnostic and therapeutic strategies for leukodystrophies, with particular emphasis on new trials.
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Affiliation(s)
- Giorgia Ceravolo
- Department of Neuromuscular Disorders, Institute of Neurology, University College London (UCL), London, UK.
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
| | - Kristina Zhelcheska
- Department of Neuromuscular Disorders, Institute of Neurology, University College London (UCL), London, UK
| | - Violetta Squadrito
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - David Pellerin
- Department of Neuromuscular Disorders, Institute of Neurology, University College London (UCL), London, UK
| | - Eloisa Gitto
- Neonatal and Paediatric Intensive Care Unit, Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | | | - Henry Houlden
- Department of Neuromuscular Disorders, Institute of Neurology, University College London (UCL), London, UK
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Cooper MS, Mackay MT, Shepherd DA, Dagia C, Fahey MC, Reddihough D, Reid SM, Harvey AS. Distinct manifestations and potential mechanisms of seizures due to cortical versus white matter injury in children. Epilepsy Res 2024; 199:107267. [PMID: 38113603 DOI: 10.1016/j.eplepsyres.2023.107267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 11/24/2023] [Accepted: 11/27/2023] [Indexed: 12/21/2023]
Abstract
PURPOSE To study seizure manifestations and outcomes in children with cortical versus white matter injury, differences potentially explaining variability of epilepsy in children with cerebral palsy. METHODS In this population-based retrospective cohort study, MRIs of children with cerebral palsy due to ischemia or haemorrhage were classified according to presence or absence of cortical injury. MRI findings were then correlated with history of neonatal seizures, seizures during childhood, epilepsy syndromes, and seizure outcomes. RESULTS Of 256 children studied, neonatal seizures occurred in 57 and seizures during childhood occurred in 93. Children with neonatal seizures were more likely to develop seizures during childhood, mostly those with cortical injury. Cortical injury was more strongly associated with (1) developing seizures during childhood, (2) more severe epilepsy syndromes (infantile spasms syndrome, focal epilepsy, Lennox-Gastaut syndrome), and (3) less likelihood of reaching > 2 years without seizures at last follow-up, compared to children without cortical injury. Children without cortical injury, mainly those with white matter injury, were less likely to develop neonatal seizures and seizures during childhood, and when they did, epilepsy syndromes were more commonly febrile seizures and self-limited focal epilepsies of childhood, with most achieving > 2 years without seizures at last follow-up. The presence of cortical injury also influenced seizure occurrence, severity, and outcome within the different predominant injury patterns of the MRI Classification System in cerebral palsy, most notably white matter injury. CONCLUSIONS Epileptogenesis is understood with cortical injury but not well with white matter injury, the latter potentially related to altered postnatal white matter development or myelination leading to apoptosis, abnormal synaptogenesis or altered thalamic connectivity of cortical neurons. These findings, and the potential mechanisms discussed, likely explain the variability of epilepsy in children with cerebral palsy and epilepsy following early-life brain injury in general.
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Affiliation(s)
- Monica S Cooper
- Department of Neurodevelopment & Disability, The Royal Children's Hospital, Melbourne, Victoria, Australia; Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia.
| | - Mark T Mackay
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia; Department of Neurology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Daisy A Shepherd
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia
| | - Charuta Dagia
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia; Department of Medical Imaging, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Michael C Fahey
- Department of Paediatrics, Monash University, Melbourne, Victoria, Australia
| | - Dinah Reddihough
- Department of Neurodevelopment & Disability, The Royal Children's Hospital, Melbourne, Victoria, Australia; Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia
| | - Susan M Reid
- Department of Neurodevelopment & Disability, The Royal Children's Hospital, Melbourne, Victoria, Australia; Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia
| | - A Simon Harvey
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Victoria, Australia; Department of Neurology, The Royal Children's Hospital, Melbourne, Victoria, Australia
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Kim HG, Han D, Kim J, Choi JS, Cho KO. 3D MR fingerprinting-derived myelin water fraction characterizing brain development and leukodystrophy. J Transl Med 2023; 21:914. [PMID: 38102606 PMCID: PMC10725020 DOI: 10.1186/s12967-023-04788-y] [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: 09/15/2023] [Accepted: 12/06/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Magnetic resonance fingerprinting (MRF) enables fast myelin quantification via the myelin water fraction (MWF), offering a noninvasive method to assess brain development and disease. However, MRF-derived MWF lacks histological evaluation and remains unexamined in relation to leukodystrophy. This study aimed to access MRF-derived MWF through histology in mice and establish links between myelin, development, and leukodystrophy in mice and children, demonstrating its potential applicability in animal and human studies. METHODS 3D MRF was performed on normal C57BL/6 mice with different ages, megalencephalic leukoencephalopathy with subcortical cyst 1 wild type (MLC1 WT, control) mice, and MLC 1 knock-out (MLC1 KO, leukodystrophy) mice using a 3 T MRI. MWF values were analyzed from 3D MRF data, and histological myelin quantification was carried out using immunohistochemistry to anti-proteolipid protein (PLP) in the corpus callosum and cortex. The associations between 'MWF and PLP' and 'MWF and age' were evaluated in C57BL/6 mice. MWF values were compared between MLC1 WT and MLC1 KO mice. MWF of normal developing children were retrospectively collected and the association between MWF and age was assessed. RESULTS In 35 C57BL/6 mice (age range; 3 weeks-48 weeks), MWF showed positive relations with PLP immunoreactivity in the corpus callosum (β = 0.0006, P = 0.04) and cortex (β = 0.0005, P = 0.006). In 12-week-old C57BL/6 mice MWF showed positive relations with PLP immunoreactivity (β = 0.0009, P = 0.003, R2 = 0.54). MWF in the corpus callosum (β = 0.0022, P < 0.001) and cortex (β = 0.0010, P < 0.001) showed positive relations with age. Seven MLC1 WT and 9 MLC1 KO mice showed different MWF values in the corpus callous (P < 0.001) and cortex (P < 0.001). A total of 81 children (median age, 126 months; range, 0-199 months) were evaluated and their MWF values according to age showed the best fit for the third-order regression model (adjusted R2 range, 0.44-0.94, P < 0.001). CONCLUSION MWF demonstrated associations with histologic myelin quantity, age, and the presence of leukodystrophy, underscoring the potential of 3D MRF-derived MWF as a rapid and noninvasive quantitative indicator of brain myelin content in both mice and humans.
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Affiliation(s)
- Hyun Gi Kim
- Department of Radiology, Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | | | - Jimin Kim
- Department of Radiology, Eunpyeong St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jeong-Sun Choi
- Department of Pharmacology, Department of Biomedicine & Health Sciences, Catholic Neuroscience Institute, Institute for Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-Gu, Seoul, 06591, South Korea
| | - Kyung-Ok Cho
- Department of Pharmacology, Department of Biomedicine & Health Sciences, Catholic Neuroscience Institute, Institute for Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-Gu, Seoul, 06591, South Korea.
- CMC Institute for Basic Medical Science, The Catholic Medical Center of The Catholic University of Korea, Seoul, Korea.
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Waung MW, Ma F, Wheeler AG, Zai CC, So J. The Diagnostic Landscape of Adult Neurogenetic Disorders. BIOLOGY 2023; 12:1459. [PMID: 38132285 PMCID: PMC10740572 DOI: 10.3390/biology12121459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/11/2023] [Accepted: 11/16/2023] [Indexed: 12/23/2023]
Abstract
Neurogenetic diseases affect individuals across the lifespan, but accurate diagnosis remains elusive for many patients. Adults with neurogenetic disorders often undergo a long diagnostic odyssey, with multiple specialist evaluations and countless investigations without a satisfactory diagnostic outcome. Reasons for these diagnostic challenges include: (1) clinical features of neurogenetic syndromes are diverse and under-recognized, particularly those of adult-onset, (2) neurogenetic syndromes may manifest with symptoms that span multiple neurological and medical subspecialties, and (3) a positive family history may not be present or readily apparent. Furthermore, there is a large gap in the understanding of how to apply genetic diagnostic tools in adult patients, as most of the published literature focuses on the pediatric population. Despite these challenges, accurate genetic diagnosis is imperative to provide affected individuals and their families guidance on prognosis, recurrence risk, and, for an increasing number of disorders, offer targeted treatment. Here, we provide a framework for recognizing adult neurogenetic syndromes, describe the current diagnostic approach, and highlight studies using next-generation sequencing in different neurological disease cohorts. We also discuss diagnostic pitfalls, barriers to achieving a definitive diagnosis, and emerging technology that may increase the diagnostic yield of testing.
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Affiliation(s)
- Maggie W. Waung
- Division of General Neurology, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
| | - Fion Ma
- Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, CA 94143, USA
| | - Allison G. Wheeler
- Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, CA 94143, USA
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Clement C. Zai
- Tanenbaum Centre for Pharmacogenetics, Molecular Brain Science, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada
- Department of Psychiatry, Institute of Medical Science, Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Joyce So
- Division of Medical Genetics, Department of Pediatrics, University of California, San Francisco, CA 94158, USA
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Gowda VK, Bylappa AY, Kinhal U, Srinivasan VM, Vamyanmane DK. Mitochondrial Complex I Deficiency Masquerading as Stroke-Like Episode Clinically and as Alexander Disease Radiologically Following Chicken Pox. Ann Indian Acad Neurol 2023; 26:977-979. [PMID: 38229652 PMCID: PMC10789425 DOI: 10.4103/aian.aian_339_23] [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: 04/19/2023] [Revised: 06/02/2023] [Accepted: 06/17/2023] [Indexed: 01/18/2024] Open
Abstract
Mitochondrial disorders are a group of metabolic disorders with variable presentation and usually affect organs with high energy requirements like the brain, eye, and heart. Seventeen-month-old girl child presented with right hemiparesis and regression of milestones following chicken pox. Investigations showed elevated lactate, white matter signal changes in both periventricular and subcortical white matter with frontal predominance in the MRI of the brain, cardiomyopathy in the echocardiography, with complex I deficiency in respiratory enzyme assay in the muscle biopsy. A homozygous missense variant c.304C>T (p. Arg102Cys) in exon 5 of NDUFS8 gene (chr11:67800682C>T; NM_002496.4) was detected on whole exome sequencing with positive parental Sanger for the same gene. The child was started on a mitochondrial cocktail, ramipril, and frusemide. Mitochondrial complex deficiency should be considered in cases with stroke-like episodes, and predominant white matter involvement on imaging mimicking classical genetic leukodystrophy like Alexander disease.
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Affiliation(s)
- Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bengaluru Karnataka, India
| | - Arun Y. Bylappa
- Department of Pediatrics, Indira Gandhi Institute of Child Health, Bengaluru Karnataka, India
| | - Uddhav Kinhal
- Department of Pediatrics, Indira Gandhi Institute of Child Health, Bengaluru Karnataka, India
| | | | - Dhananjaya K. Vamyanmane
- Department of Pediatric Radiology, Indira Gandhi Institute of Child Health, Bengaluru Karnataka, India
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Sun L, Lin W, Meng H, Zhang W, Hou S. A Chinese patient with POLR3A-related leukodystrophy: a case report and literature review. Front Neurol 2023; 14:1269237. [PMID: 37965164 PMCID: PMC10641775 DOI: 10.3389/fneur.2023.1269237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 10/10/2023] [Indexed: 11/16/2023] Open
Abstract
Background Leukodystrophies are hereditary white matter diseases characterized by genetic polymorphisms and considerable phenotypic variability. They can be classified into myelin and non-myelin malformations. These diseases are rare, affecting 1 out of 250,000-500,000 individuals and can manifest at any age. A subtype of leukodystrophy, associated with missense mutations in the RNA polymerase subunit III (POLR3A) gene, is inherited in an autosomal recessive manner. Case report We report and analyse a case of a 34-year-old female who presented with ataxia. Magnetic Resonance Imaging (MRI) of the brain revealed demyelinating lesions in the white matter. Genetic testing identified the c.4044C > G and c.1186-2A > G variants in the POLR3A gene. The patient was diagnosed with hypomyelinating leukodystrophy type 7 and received neurotrophic and symptomatic supportive therapy. However, after 1 month of follow-up, there was no improvement in her symptoms. Conclusion POLR3A-induced leukodystrophy is relatively rare and not well understood, making it challenging to diagnose and easy to overlook. The prognosis for this disease is generally poor, significantly impacting the quality of life of affected individuals. Currently, no cure is available for this condition, and treatment is limited to managing symptoms. Further research into new treatment methods for POLR3A-induced leukodystrophy is imperative to improve the quality of life and potentially extend the life expectancy of patients.
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Affiliation(s)
| | | | | | | | - Shuai Hou
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
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Ashrafi M, Kameli R, Hosseinpour S, Razmara E, Zamani Z, Rezaei Z, Mashayekhi R, Pak N, Barzegar M, Azizimalamiri R, Kashani MR, Khosroshahi N, Rasulinezhad M, Heidari M, Amanat M, Abdi A, Mohammadi B, Mohammadi M, Zamani GR, Badv RS, Omrani A, Nikbakht S, Bereshneh AH, Movahedinia M, Moghaddam HF, Ardakani HS, Akbari MG, Tousi MB, Shahi MV, Hosseini F, Amouzadeh MH, Hosseini SA, Nikkhah A, Khajeh A, Alizadeh H, Yarali B, Rohani M, Karimi P, Elahi HML, Hosseiny SMM, Sadeghzadeh MS, Mohebbi H, Moghadam MH, Aryan H, Vahidnezhad H, Soveizi M, Rabbani B, Rabbani A, Mahdieh N, Garshasbi M, Tavasoli AR. High genetic heterogeneity of leukodystrophies in Iranian children: the first report of Iranian Leukodystrophy Registry. Neurogenetics 2023; 24:279-289. [PMID: 37597066 DOI: 10.1007/s10048-023-00730-y] [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: 02/05/2023] [Accepted: 08/09/2023] [Indexed: 08/21/2023]
Abstract
Leukodystrophies (LDs) are a heterogeneous group of progressive neurological disorders and characterized by primary involvement of white matter of the central nervous system (CNS). This is the first report of the Iranian LD Registry database to describe the clinical, radiological, and genomic data of Persian patients with leukodystrophies. From 2016 to 2019, patients suspicious of LDs were examined followed by a brain magnetic resonance imaging (MRI). A single gene testing or whole-exome sequencing (WES) was used depending on the neuroradiologic phenotypes. In a few cases, the diagnosis was made by metabolic studies. Based on the MRI pattern, diagnosed patients were divided into cohorts A (hypomyelinating LDs) versus cohort B (Other LDs). The most recent LD classification was utilized for classification of diagnosed patients. For novel variants, in silico analyses were performed to verify their pathogenicity. Out of 680 registered patients, 342 completed the diagnostic evaluations. In total, 245 patients met a diagnosis which in turn 24.5% were categorized in cohort A and the remaining in cohort B. Genetic tests revealed causal variants in 228 patients consisting of 213 variants in 110 genes with 78 novel variants. WES and single gene testing identified a causal variant in 65.5% and 34.5% cases, respectively. The total diagnostic rate of WES was 60.7%. Lysosomal disorders (27.3%; GM2-gangliosidosis-9.8%, MLD-6.1%, KD-4.5%), amino and organic acid disorders (17.15%; Canavan disease-4.5%, L-2-HGA-3.6%), mitochondrial leukodystrophies (12.6%), ion and water homeostasis disorders (7.3%; MLC-4.5%), peroxisomal disorders (6.5%; X-ALD-3.6%), and myelin protein disorders (3.6%; PMLD-3.6%) were the most commonly diagnosed disorders. Thirty-seven percent of cases had a pathogenic variant in nine genes (ARSA, HEXA, ASPA, MLC1, GALC, GJC2, ABCD1, L2HGDH, GCDH). This study highlights the most common types as well as the genetic heterogeneity of LDs in Iranian children.
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Affiliation(s)
- Mahmoudreza Ashrafi
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Reyhaneh Kameli
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Sareh Hosseinpour
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Ehsan Razmara
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, 3800, Australia
| | - Zahra Zamani
- MD, MPH, Community Medicine Specialist, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Rezaei
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Raziyeh Mashayekhi
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Neda Pak
- Department of Radiology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Barzegar
- Pediatric Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Azizimalamiri
- Department of Pediatric Neurology, Golestan Medical, Educational, and Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | | | - Nahideh Khosroshahi
- Department of Pediatric Neurology, Bahrami Children Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Rasulinezhad
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Morteza Heidari
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Man Amanat
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Alireza Abdi
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Bahram Mohammadi
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Mahmoud Mohammadi
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Gholam Reza Zamani
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Abdolmajid Omrani
- Division of Clinical Studies, The Persian Gulf Nuclear Medicine Research Center, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Sedigheh Nikbakht
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Ali Hosseini Bereshneh
- Prenatal Diagnosis and Genetic Research Center, Dastgheib Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mojtaba Movahedinia
- Department of Pediatric, Growth Disorders of Children Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | | | | | - Masood Ghahvechi Akbari
- Department of Physical Medicine and Rehabilitation, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehran Beiraghi Tousi
- Pediatric Ward, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Vafaee Shahi
- Pediatric Growth and Development Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Firouzeh Hosseini
- Department of Pediatric Neurology, Hamedan University of Medical Sciences, Hamedan, Iran
| | | | - Seyed Ahmad Hosseini
- Department of Pediatric Neurology, Golestan University of Medical Sciences, Gorgan, Iran
| | - Ali Nikkhah
- Department of Pediatric Neurology, Mofid Children Hospital, Shahid Beheshti University of Medical, Tehran, Iran
| | - Ali Khajeh
- Children and Adolescence Research Center, Zahedan University of Medical Sciences, Zahedan, 000000321469345, Iran
| | - Hooman Alizadeh
- Department of Radiology, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Bahram Yarali
- Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Rohani
- Department of Neurology, Hazrat-E-Rasool Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Parviz Karimi
- Department of Pediatric Neurology, Ilam University of Medical Sciences, Ilam, Iran
| | - Hadi Montazer Lotf Elahi
- Department of Pediatric Neurology, Imam Ali Hospital, Alborz University of Medical Sciences, Karaj, Iran
| | - Seyyed Mohamad Mahdi Hosseiny
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Masoumeh Sadat Sadeghzadeh
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran
| | - Hossein Mohebbi
- Department of Pediatric Neurology, AJA University of Medical Sciences, Tehran, Iran
| | - Maryam Hosseini Moghadam
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Hajar Aryan
- Farhud Medical Genetic Laboratory, Tehran University of Medical Sciences, Tehran, Iran
| | - Hassan Vahidnezhad
- Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, USA
- Department of Pediatrics, The University of Pennsylvania School of Medicine, Philadelphia, USA
| | - Mahdieh Soveizi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Bahareh Rabbani
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Rabbani
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nejat Mahdieh
- Growth and Development Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Jalal-Al Ahmad Hwy, Tehran, Iran.
| | - Ali Reza Tavasoli
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, No. 61, Gharib Street, Keshavarz Blvd, Tehran, 1419733151, Iran.
- Pediatric Headache Program, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA.
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10
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Wu C, Wang M, Wang X, Li W, Li S, Chen B, Niu S, Tai H, Pan H, Zhang Z. The genetic and phenotypic spectra of adult genetic leukoencephalopathies in a cohort of 309 patients. Brain 2023; 146:2364-2376. [PMID: 36380532 PMCID: PMC10232248 DOI: 10.1093/brain/awac426] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/30/2022] [Accepted: 11/01/2022] [Indexed: 08/12/2023] Open
Abstract
Genetic leukoencephalopathies (gLEs) are a highly heterogeneous group of rare genetic disorders. The spectrum of gLEs varies among patients of different ages. Distinct from the relatively more abundant studies of gLEs in children, only a few studies that explore the spectrum of adult gLEs have been published, and it should be noted that the majority of these excluded certain gLEs. Thus, to date, no large study has been designed and conducted to characterize the genetic and phenotypic spectra of gLEs in adult patients. We recruited a consecutive series of 309 adult patients clinically suspected of gLEs from Beijing Tiantan Hospital between January 2014 and December 2021. Whole-exome sequencing, mitochondrial DNA sequencing and repeat analysis of NOTCH2NLC, FMR1, DMPK and ZNF9 were performed for patients. We describe the genetic and phenotypic spectra of the set of patients with a genetically confirmed diagnosis and summarize their clinical and radiological characteristics. A total of 201 patients (65%) were genetically diagnosed, while 108 patients (35%) remained undiagnosed. The most frequent diseases were leukoencephalopathies related to NOTCH3 (25%), NOTCH2NLC (19%), ABCD1 (9%), CSF1R (7%) and HTRA1 (5%). Based on a previously proposed pathological classification, the gLEs in our cohort were divided into leukovasculopathies (35%), leuko-axonopathies (31%), myelin disorders (21%), microgliopathies (7%) and astrocytopathies (6%). Patients with NOTCH3 mutations accounted for 70% of the leukovasculopathies, followed by HTRA1 (13%) and COL4A1/2 (9%). The leuko-axonopathies contained the richest variety of associated genes, of which NOTCH2NLC comprised 62%. Among myelin disorders, demyelinating leukoencephalopathies (61%)-mainly adrenoleukodystrophy and Krabbe disease-accounted for the majority, while hypomyelinating leukoencephalopathies (2%) were rare. CSF1R was the only mutated gene detected in microgliopathy patients. Leukoencephalopathy with vanishing white matter disease due to mutations in EIF2B2-5 accounted for half of the astrocytopathies. We characterized the genetic and phenotypic spectra of adult gLEs in a large Chinese cohort. The most frequently mutated genes were NOTCH3, NOTCH2NLC, ABCD1, CSF1R and HTRA1.
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Affiliation(s)
- Chujun Wu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Mengwen Wang
- Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, and Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, 350005 Fuzhou, China
| | - Xingao Wang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Wei Li
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Shaowu Li
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Bin Chen
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Songtao Niu
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Hongfei Tai
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Hua Pan
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
| | - Zaiqiang Zhang
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
- China National Clinical Research Centre for Neurological Disease, Beijing Tiantan Hospital, Capital Medical University, 100070 Beijing, China
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11
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Abrams CK. Mechanisms of Diseases Associated with Mutation in GJC2/Connexin 47. Biomolecules 2023; 13:biom13040712. [PMID: 37189458 DOI: 10.3390/biom13040712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/17/2023] Open
Abstract
Connexins are members of a family of integral membrane proteins that provide a pathway for both electrical and metabolic coupling between cells. Astroglia express connexin 30 (Cx30)-GJB6 and Cx43-GJA1, while oligodendroglia express Cx29/Cx31.3-GJC3, Cx32-GJB1, and Cx47-GJC2. Connexins organize into hexameric hemichannels (homomeric if all subunits are identical or heteromeric if one or more differs). Hemichannels from one cell then form cell-cell channels with a hemichannel from an apposed cell. (These are termed homotypic if the hemichannels are identical and heterotypic if the hemichannels differ). Oligodendrocytes couple to each other through Cx32/Cx32 or Cx47/Cx47 homotypic channels and they couple to astrocytes via Cx32/Cx30 or Cx47/Cx43 heterotypic channels. Astrocytes couple via Cx30/Cx30 and Cx43/Cx43 homotypic channels. Though Cx32 and Cx47 may be expressed in the same cells, all available data suggest that Cx32 and Cx47 cannot interact heteromerically. Animal models wherein one or in some cases two different CNS glial connexins have been deleted have helped to clarify the role of these molecules in CNS function. Mutations in a number of different CNS glial connexin genes cause human disease. Mutations in GJC2 lead to three distinct phenotypes, Pelizaeus Merzbacher like disease, hereditary spastic paraparesis (SPG44) and subclinical leukodystrophy.
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Affiliation(s)
- Charles K Abrams
- Department of Neurology and Rehabilitation, University of Illinois at Chicago College of Medicine, Chicago, IL 60612, USA
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12
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Moore KM, Wolf NI, Hobson G, Bowyer K, McSherry J, Hartin G, Wilde C, Shapiro S, Frank J, Manley D, Junge C. Pelizaeus-Merzbacher Disease: A Caregiver Assessment of Disease Impact. J Child Neurol 2023; 38:78-84. [PMID: 36744386 DOI: 10.1177/08830738231152658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Pelizaeus-Merzbacher disease is a rare X-linked leukodystrophy accompanied by central nervous system hypomyelination with a spectrum of clinical phenotypes. This is the first survey of caregivers of individuals with Pelizaeus-Merzbacher disease to investigate the presenting symptoms, path to diagnosis, identity and impact of most bothersome symptoms, and needs that future treatment should address. One hundred participants completed the survey. Results from this survey demonstrate that the majority of Pelizaeus-Merzbacher disease symptoms manifest before 2 years of age and commonly include deficits in gross and fine motor skills, speech, and communication. Caregivers rated difficulty crawling, standing, or walking as the most bothersome symptoms due to Pelizaeus-Merzbacher disease, with constipation and difficulty with sleep, manual dexterity, and speech and communication rated nearly as high. The most important treatment goals for caregivers were improved mobility and communication. The survey findings present a caregiver perspective of the impact of symptoms in Pelizaeus-Merzbacher disease and provide helpful guidance to affected families, physicians, and drug developers on the often-long path to diagnosis and the unmet medical needs of this patient population.
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Affiliation(s)
| | - Nicole I Wolf
- Department of Child Neurology, Amsterdam Leukodystrophy Centre, Emma Children's Hospital, Amsterdam University Medical Centres, Vrije Universiteit, Amsterdam, Netherlands.,Amsterdam Neuroscience, Cellular & Molecular Mechanisms, Amsterdam, The Netherlands
| | - Grace Hobson
- Department of Research, Nemours Alfred I duPont Hospital for Children, Wilmington, DE, USA
| | | | | | | | | | | | - Jason Frank
- ClarityCo Strategic Group, West Chester, PA, USA
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13
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Kastenberg ZJ, Deneau MR, O'Brien EA, Huynh K, Book LS, Srivastava R, Jensen MK, Jaramillo CM, Guthery SL. Fractionated Bilirubin Among 252,892 Utah Newborns With and Without Biliary Atresia: A 15-year Historical Birth Cohort Study. J Pediatr 2023:113339. [PMID: 36731714 DOI: 10.1016/j.jpeds.2022.12.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/22/2022] [Accepted: 12/20/2022] [Indexed: 02/01/2023]
Abstract
OBJECTIVES To determine whether neonatal conjugated or direct bilirubin levels were elevated in infants with biliary atresia, and to estimate the number of newborns that would have positive screens in the nursery necessitating repeat testing following discharge. STUDY DESIGN We used administrative data from a large integrated healthcare network in Utah to identify newborns who had a fractionated bilirubin recorded during birth admission from 2005 through 2019. Elevated conjugated bilirubin was defined as greater than 0.2 mg/dL and direct bilirubin was defined as greater than 0.5 mg/dL (>97.5th percentile for the assays). We performed simulations to estimate the anticipated number of false positive screens. RESULTS There were 32 cases of biliary atresia and 468,161 live births during the study period (1/14,700). 252,892 newborns had fractionated bilirubin assessed including 26 of those subsequently confirmed to have biliary atresia. Conjugated or direct bilirubin was elevated in all 26 infants with biliary atresia and an additional 3,246 (1.3%) newborns without biliary atresia. Simulated data suggest nine to 21 per 1,000 screened newborns will have an elevated conjugated or direct bilirubin using laboratory-based thresholds for a positive screen. Screening characteristics improved with higher thresholds without increasing false negative tests. CONCLUSIONS This study validates the previous findings that conjugated or direct bilirubin are elevated in the newborn period in patients with biliary atresia. A higher threshold for conjugated bilirubin improved screening performance. Future studies are warranted to determine the optimal screening test for biliary atresia and to assess the effectiveness and cost-effectiveness of implementing such a program.
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Affiliation(s)
- Zachary J Kastenberg
- Division of Pediatric Surgery, Department of Surgery, University of Utah School of Medicine, Salt Lake City, UT.
| | - Mark R Deneau
- Division of Pediatric Gastroenterology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT
| | - Elizabeth A O'Brien
- Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT; Intermountain Healthcare, Salt Lake City, UT
| | - Kelly Huynh
- Intermountain Healthcare, Salt Lake City, UT
| | - Linda S Book
- Division of Pediatric Gastroenterology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT
| | - Rajendu Srivastava
- Intermountain Healthcare, Salt Lake City, UT; Division of Pediatric Hospital Medicine, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT
| | - M Kyle Jensen
- Division of Pediatric Gastroenterology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT
| | - Catalina M Jaramillo
- Division of Pediatric Gastroenterology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT
| | - Stephen L Guthery
- Division of Pediatric Gastroenterology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT
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14
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Zhu J, Guo X, Ran N, Liang J, Liu F, Liu J, Wang R, Jiang L, Yang D, Liu M. Leukoencephalopathy hypomyelination with brainstem and spinal cord involvement and leg spasticity caused by DARS1 mutations. Front Genet 2023; 13:1009230. [PMID: 36712860 PMCID: PMC9878823 DOI: 10.3389/fgene.2022.1009230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 11/15/2022] [Indexed: 01/13/2023] Open
Abstract
Hypomyelination with brainstem and spinal cord involvement and leg spasticity (HBSL), caused by aspartyl-tRNA synthetase (DARS1) gene mutations, is extremely rare, with only a few cases reported worldwide; thus, reports on HBSL treatment are few. In this review, we summarized the clinical manifestations, imaging features, treatment methods, and gene mutations responsible for HBSL based on relevant studies and cases.
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Affiliation(s)
- Jingyi Zhu
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaomin Guo
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ningjing Ran
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jingtao Liang
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Fuyou Liu
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Junyan Liu
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Rongyu Wang
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Lianyan Jiang
- School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Dongdong Yang
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Meijun Liu, ; Dongdong Yang,
| | - Meijun Liu
- Neurology Department, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China,*Correspondence: Meijun Liu, ; Dongdong Yang,
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15
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Leucoencefalopatie ereditarie e leucodistrofie dell’adulto. Neurologia 2022. [DOI: 10.1016/s1634-7072(22)47096-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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16
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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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17
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Chang KJ, Wu HY, Yarmishyn AA, Li CY, Hsiao YJ, Chi YC, Lo TC, Dai HJ, Yang YC, Liu DH, Hwang DK, Chen SJ, Hsu CC, Kao CL. Genetics behind Cerebral Disease with Ocular Comorbidity: Finding Parallels between the Brain and Eye Molecular Pathology. Int J Mol Sci 2022; 23:ijms23179707. [PMID: 36077104 PMCID: PMC9456058 DOI: 10.3390/ijms23179707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
Cerebral visual impairments (CVIs) is an umbrella term that categorizes miscellaneous visual defects with parallel genetic brain disorders. While the manifestations of CVIs are diverse and ambiguous, molecular diagnostics stand out as a powerful approach for understanding pathomechanisms in CVIs. Nevertheless, the characterization of CVI disease cohorts has been fragmented and lacks integration. By revisiting the genome-wide and phenome-wide association studies (GWAS and PheWAS), we clustered a handful of renowned CVIs into five ontology groups, namely ciliopathies (Joubert syndrome, Bardet–Biedl syndrome, Alstrom syndrome), demyelination diseases (multiple sclerosis, Alexander disease, Pelizaeus–Merzbacher disease), transcriptional deregulation diseases (Mowat–Wilson disease, Pitt–Hopkins disease, Rett syndrome, Cockayne syndrome, X-linked alpha-thalassaemia mental retardation), compromised peroxisome disorders (Zellweger spectrum disorder, Refsum disease), and channelopathies (neuromyelitis optica spectrum disorder), and reviewed several mutation hotspots currently found to be associated with the CVIs. Moreover, we discussed the common manifestations in the brain and the eye, and collated animal study findings to discuss plausible gene editing strategies for future CVI correction.
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Affiliation(s)
- Kao-Jung Chang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Hsin-Yu Wu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | | | - Cheng-Yi Li
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yu-Jer Hsiao
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chun Chi
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Tzu-Chen Lo
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - He-Jhen Dai
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chiang Yang
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Ding-Hao Liu
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Chih-Chien Hsu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
| | - Chung-Lan Kao
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Department of Physical Medicine and Rehabilitation, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
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18
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Khalaf G, Mattern C, Begou M, Boespflug-Tanguy O, Massaad C, Massaad-Massade L. Mutation of Proteolipid Protein 1 Gene: From Severe Hypomyelinating Leukodystrophy to Inherited Spastic Paraplegia. Biomedicines 2022; 10:biomedicines10071709. [PMID: 35885014 PMCID: PMC9313024 DOI: 10.3390/biomedicines10071709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/06/2022] [Accepted: 07/12/2022] [Indexed: 01/17/2023] Open
Abstract
Pelizaeus–Merzbacher Disease (PMD) is an inherited leukodystrophy affecting the central nervous system (CNS)—a rare disorder that especially concerns males. Its estimated prevalence is 1.45–1.9 per 100,000 individuals in the general population. Patients affected by PMD exhibit a drastic reduction or absence of myelin sheaths in the white matter areas of the CNS. The Proteolipid Protein 1 (PLP1) gene encodes a transmembrane proteolipid protein. PLP1 is the major protein of myelin, and it plays a key role in the compaction, stabilization, and maintenance of myelin sheaths. Its function is predominant in oligodendrocyte development and axonal survival. Mutations in the PLP1 gene cause the development of a wide continuum spectrum of leukopathies from the most severe form of PMD for whom patients exhibit severe CNS hypomyelination to the relatively mild late-onset type 2 spastic paraplegia, leading to the concept of PLP1-related disorders. The genetic diversity and the biochemical complexity, along with other aspects of PMD, are discussed to reveal the obstacles that hinder the development of treatments. This review aims to provide a clinical and mechanistic overview of this spectrum of rare diseases.
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Affiliation(s)
- Guy Khalaf
- U1195 Diseases and Hormones of the Nervous System, INSERM and Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France;
| | | | - Mélina Begou
- Neuro-Dol, CNRS, Inserm, Université Clermont Auvergne, 63000 Clermont-Ferrand, France;
| | - Odile Boespflug-Tanguy
- UMR 1141, INSERM, NeuroDiderot Université Paris Cité and APH-P, Neuropédiatrie, French Reference Center for Leukodystrophies, LEUKOFRANCE, Hôpital Robert Debré, 75019 Paris, France;
| | - Charbel Massaad
- UMRS 1124, INSERM, Université Paris Cité, 75006 Paris, France
- Correspondence: (C.M.); (L.M.-M.);Tel.: +33-1-49-59-18-30 (L.M.-M.)
| | - Liliane Massaad-Massade
- U1195 Diseases and Hormones of the Nervous System, INSERM and Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France;
- Correspondence: (C.M.); (L.M.-M.);Tel.: +33-1-49-59-18-30 (L.M.-M.)
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19
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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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20
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Yoon Han J, Gon Cho Y, Park J, Jang W. A novel variant of the POLR3A gene in a patient with hypomyelinating POLR3-related leukodystrophy. Clin Chim Acta 2022; 533:15-21. [PMID: 35691411 DOI: 10.1016/j.cca.2022.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/04/2022] [Accepted: 06/05/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypomyelinating POLR3-related leukodystrophy is a group of rare neurological diseases characterized by degeneration of the white matter of the brain with different combinations of major clinical findings. Here we report the first Korean POLR3-related leukodystrophy caused by bi-allelic POLR3A c.1771-6C > G and novel c.1650_1661del variants. METHODS An 18-month-old girl was admitted for evaluation of a seizure-like activity with spasticity that affected her entire body. She showed dental abnormalities, but not suspicious facial dysmorphism. She was in a bed-ridden state with severe cognitive impairments and episodes of dystonic posturing for 1-2 min. Trio exome sequencing (ES) was performed to determine the potential genetic cause of severe developmental delay with leukodystrophy in our proband. RESULTS Trio ES revealed that bi-allelic POLR3A deleterious variants, c.1650_1661del of the exon 13, and c.1771-6C > G of the intron 13 were best candidate as causes of hypomyelinating POLR3-related leukodystrophy. Sanger sequencing confirmed the genetic origin of these POLR3A deleterious variants as autosomal recessive hereditary transmission. CONCLUSION Our report provides additional evidence for a phenotypic continuum of hypomyelinating POLR3-related leukodystrophy caused by bi-allelic POLR3A variants. Further genetic studies are required to understand underlying pleiotropic effects of different POLR3A variants.
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Affiliation(s)
- Ji Yoon Han
- Department of Pediatrics, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Yong Gon Cho
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea; Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea
| | - Joonhong Park
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju, Korea; Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea.
| | - Woori Jang
- Department of Laboratory Medicine, Inha University School of Medicine, Incheon, Korea.
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21
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Klugmann M, Kalotay E, Delerue F, Ittner LM, Bongers A, Yu J, Morris MJ, Housley GD, Fröhlich D. Developmental delay and late onset HBSL pathology in hypomorphic Dars1 M256L mice. Neurochem Res 2022; 47:1972-1984. [PMID: 35357600 PMCID: PMC9217827 DOI: 10.1007/s11064-022-03582-4] [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: 10/05/2021] [Revised: 10/05/2021] [Accepted: 03/15/2022] [Indexed: 12/03/2022]
Abstract
The leukodystrophy Hypomyelination with Brainstem and Spinal cord involvement and Leg spasticity (HBSL) is caused by recessive mutations of the DARS1 gene, which encodes the cytoplasmic aspartyl-tRNA synthetase. HBSL is a spectrum disorder with disease onset usually during early childhood and no available treatment options. Patients display regression of previously acquired motor milestones, spasticity, ataxia, seizures, nystagmus, and intellectual disabilities. Gene-function studies in mice revealed that homozygous Dars1 deletion is embryonically lethal, suggesting that successful modelling of HBSL requires the generation of disease-causing genocopies in mice. In this study, we introduced the pathogenic DARS1M256L mutation located on exon nine of the murine Dars1 locus. Despite causing severe illness in humans, homozygous Dars1M256L mice were only mildly affected. To exacerbate HBSL symptoms, we bred Dars1M256L mice with Dars1-null ‘enhancer’ mice. The Dars1M256L/− offspring displayed increased embryonic lethality, severe developmental delay, reduced body weight and size, hydrocephalus, anophthalmia, and vacuolization of the white matter. Remarkably, the Dars1M256L/− genotype affected energy metabolism and peripheral organs more profoundly than the nervous system and resulted in reduced body fat, increased respiratory exchange ratio, reduced liver steatosis, and reduced hypocellularity of the bone marrow. In summary, homozygous Dars1M256L and compound heterozygous Dars1M256L/− mutation genotypes recapitulate some aspects of HBSL and primarily manifest in developmental delay as well as metabolic and peripheral changes. These aspects of the disease might have been overlooked in HBSL patients with severe neurological deficits but could be included in the differential diagnosis of HBSL in the future.
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Affiliation(s)
- Matthias Klugmann
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia.
| | - Elizabeth Kalotay
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Fabien Delerue
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, 2109, Sydney, NSW, Australia
| | - Lars M Ittner
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, 2109, Sydney, NSW, Australia
| | - Andre Bongers
- Biomedical Resources Imaging Laboratory, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Josephine Yu
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Margaret J Morris
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, 2052, Sydney, NSW, Australia.
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22
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Fröhlich D, Gessler DJ, Klugmann M. Editorial: Myelin Repair: At the Crossing-Lines of Myelin Biology and Gene Therapy. Front Cell Neurosci 2022; 16:853742. [PMID: 35221929 PMCID: PMC8873078 DOI: 10.3389/fncel.2022.853742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Dominic J Gessler
- Horae Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA, United States.,Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, United States.,Department of Neurosurgery, University of Minnesota, Minneapolis, MN, United States
| | - Matthias Klugmann
- Translational Neuroscience Facility, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
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23
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Mazaheri M, Yavari M, Zare Marzouni H, Stufano A, Lovreglio P, D'Amore S, Jahantigh HR. Case Report: Mutation in AIMP2/P38, the Scaffold for the Multi-Trna Synthetase Complex, and Association With Progressive Neurodevelopmental Disorders. Front Genet 2022; 13:816987. [PMID: 35140751 PMCID: PMC8820504 DOI: 10.3389/fgene.2022.816987] [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: 11/17/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Leukodystrophies constitute a heterogeneous group of inherited disorders primarily affecting the white matter of the central nervous system. Aminoacyl-tRNA synthetases (ARSs) catalyze the attachment of an amino acids to their cognate transfer RNAs (tRNAs). Pathogenic variants in both cytosolic and mitochondrial ARSs have been linked to a broad range of neurological disorders, including hypomyelinating leukodystrophies and pontocerebellar hypoplasias (PCH). Aminoacyl tRNA synthetase-interacting multifunctional protein 2 (AIMP2), one of the three non-catalytic components of multi ARS complex, harbors anti-proliferative activity and functions as a proapoptotic factor thus promoting cell death. We report a case of a 7-month-old infant with a complex clinical presentation, including weight loss, severe anemia, skeletal abnormalities, microcephaly and MR imaging features of leukodystrophy with a novel mutation in AIMP2.Methods: Whole-exome sequencing (WES) was performed on the proband. Parental samples were analyzed by PCR amplification and Sanger sequencing.Results: Whole-exome sequencing revealed a novel variant c.A463T in the homozygous state in exon 3 (NM_001,326,607) of AIMP2 [p.(K155X)] in the proband. Parental carrier status was confirmed by target sequencing.Conclusion: Here, we present an Iranian case with leukodystrophy with a novel AIMP2 mutation. This finding broadens the mutational and phenotypic spectra of AIMP2-related leukodystrophy and offers guidance for proper genetic counselling for pre- and post-natal screenings as well as for disease management.
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Affiliation(s)
- Mahta Mazaheri
- Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Mother and Newborn Health Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Dr. Mazaheri’s Medical Genetics Lab, Yazd, Iran
| | - Mahdie Yavari
- Dr. Mazaheri’s Medical Genetics Lab, Yazd, Iran
- Division of Genetics, Department of Cell and Molecular Biology and Microbiology, Faculty of Science and Biotechnology, University of Isfahan, Isfahan, Iran
| | - Hadi Zare Marzouni
- Qaen School of Nursing and Midwifery, Birjand University of Medical Sciences, Birjand, Iran
| | - Angela Stufano
- Department of Veterinary Medicine, University of Bari Aldo Moro, Bari, Italy
- Interdisciplinary Department of Medicine - Section of Occupational Medicine, University of Bari, Bari, Italy
- *Correspondence: Angela Stufano,
| | - Piero Lovreglio
- Interdisciplinary Department of Medicine - Section of Occupational Medicine, University of Bari, Bari, Italy
| | - Simona D'Amore
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Hamid Reza Jahantigh
- Department of Veterinary Medicine, University of Bari Aldo Moro, Bari, Italy
- Interdisciplinary Department of Medicine - Section of Occupational Medicine, University of Bari, Bari, Italy
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24
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Schlüter A, Rodríguez-Palmero A, Verdura E, Vélez-Santamaría V, Ruiz M, Fourcade S, Planas-Serra L, Martínez JJ, Guilera C, Girós M, Artuch R, Yoldi ME, O'Callaghan M, García-Cazorla A, Armstrong J, Marti I, Rezola EM, Redin C, Mandel JL, Conejo D, Sierra-Córcoles C, Beltran S, Gut M, Vázquez E, Del Toro M, Troncoso M, Pérez-Jurado LA, Gutiérrez-Solana LG, López de Munain A, Casasnovas C, Aguilera-Albesa S, Macaya A, Pujol A. Diagnosis of Genetic White Matter Disorders by Singleton Whole-Exome and Genome Sequencing Using Interactome-Driven Prioritization. Neurology 2022; 98:e912-e923. [PMID: 35012964 PMCID: PMC8901178 DOI: 10.1212/wnl.0000000000013278] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 12/21/2021] [Indexed: 11/16/2022] Open
Abstract
Background and Objectives Genetic white matter disorders (GWMD) are of heterogeneous origin, with >100 causal genes identified to date. Classic targeted approaches achieve a molecular diagnosis in only half of all patients. We aimed to determine the clinical utility of singleton whole-exome sequencing and whole-genome sequencing (sWES-WGS) interpreted with a phenotype- and interactome-driven prioritization algorithm to diagnose GWMD while identifying novel phenotypes and candidate genes. Methods A case series of patients of all ages with undiagnosed GWMD despite extensive standard-of-care paraclinical studies were recruited between April 2017 and December 2019 in a collaborative study at the Bellvitge Biomedical Research Institute (IDIBELL) and neurology units of tertiary Spanish hospitals. We ran sWES and WGS and applied our interactome-prioritization algorithm based on the network expansion of a seed group of GWMD-related genes derived from the Human Phenotype Ontology terms of each patient. Results We evaluated 126 patients (101 children and 25 adults) with ages ranging from 1 month to 74 years. We obtained a first molecular diagnosis by singleton WES in 59% of cases, which increased to 68% after annual reanalysis, and reached 72% after WGS was performed in 16 of the remaining negative cases. We identified variants in 57 different genes among 91 diagnosed cases, with the most frequent being RNASEH2B, EIF2B5, POLR3A, and PLP1, and a dual diagnosis underlying complex phenotypes in 6 families, underscoring the importance of genomic analysis to solve these cases. We discovered 9 candidate genes causing novel diseases and propose additional putative novel candidate genes for yet-to-be discovered GWMD. Discussion Our strategy enables a high diagnostic yield and is a good alternative to trio WES/WGS for GWMD. It shortens the time to diagnosis compared to the classical targeted approach, thus optimizing appropriate management. Furthermore, the interactome-driven prioritization pipeline enables the discovery of novel disease-causing genes and phenotypes, and predicts novel putative candidate genes, shedding light on etiopathogenic mechanisms that are pivotal for myelin generation and maintenance.
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Affiliation(s)
- Agatha Schlüter
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Agustí Rodríguez-Palmero
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Pediatric Neurology Unit, Department of Pediatrics. Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, Spain
| | - Edgard Verdura
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Valentina Vélez-Santamaría
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Neuromuscular Unit, Neurology Department, Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Stéphane Fourcade
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Laura Planas-Serra
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Juan José Martínez
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Cristina Guilera
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain
| | - Marisa Girós
- Secció d'Errors Congènits del Metabolisme-IBC, Servei de Bioquímica i Genètica Molecular, Hospital Clínic, IDIBAPS, CIBERER, Barcelona, Spain
| | - Rafael Artuch
- Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Institut de Recerca Pediàtrica-Hospital Sant Joan de Déu (IRP-HSJD), Barcelona, Spain
| | - María Eugenia Yoldi
- Pediatric Neurology Unit, Department of Pediatrics, Navarra Health Service, Navarrabiomed Research Foundation, Pamplona, Spain
| | - Mar O'Callaghan
- Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Institut de Recerca Pediàtrica-Hospital Sant Joan de Déu (IRP-HSJD), Barcelona, Spain
| | - Angels García-Cazorla
- Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Institut de Recerca Pediàtrica-Hospital Sant Joan de Déu (IRP-HSJD), Barcelona, Spain
| | - Judith Armstrong
- Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Itxaso Marti
- Department of Neuropediatrics, Hospital Universitario Donostia, San Sebastián, Spain.,Biodonostia Health Research Institute (Biodonostia HRI), San Sebastián, Spain.,University of the Basque Country (UPV-EHU), San Sebastian, Spain.,Centro de Investigación Biomédica en Red para Enfermedades Neurodegenerativas (CIBERNED), Carlos III Health Institute, Madrid, Spain
| | - Elisabet Mondragón Rezola
- Biodonostia Health Research Institute (Biodonostia HRI), San Sebastián, Spain.,Centro de Investigación Biomédica en Red para Enfermedades Neurodegenerativas (CIBERNED), Carlos III Health Institute, Madrid, Spain.,Department of Neurology, Hospital Universitario Donostia, San Sebastián, Spain
| | - Claire Redin
- Département de Médecine translationnelle et Neurogénétique, IGBMC, CNRS UMR 7104/INSERM U964/Université de Strasbourg, Illkirch, France
| | - Jean Louis Mandel
- Département de Médecine translationnelle et Neurogénétique, IGBMC, CNRS UMR 7104/INSERM U964/Université de Strasbourg, Illkirch, France.,Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Chaire de Génétique Humaine, Collège de France, Illkirch, France
| | - David Conejo
- Complejo asistencial universitario de Burgos, Burgos, Spain
| | | | - Sergi Beltran
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Marta Gut
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Elida Vázquez
- Department of Pediatric Radiology, Hospital Materno-Infantil Vall d'Hebrón, Barcelona, Spain
| | - Mireia Del Toro
- Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Pediatric Neurology Department, Vall d'Hebron University Hospital, Universitat Autónoma de Barcelona, Spain
| | - Mónica Troncoso
- Pediatric Neurology, Hospital Clínico San Borja Arriarán, Central Campus Universidad de Chile, Chile
| | - Luis A Pérez-Jurado
- Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Genetics Service, Hospital del Mar Research Institute (IMIM), Barcelona, Spain.,Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Luis G Gutiérrez-Solana
- Department of Paediatric Neurology, Children's University Hospital Niño Jesús, Madrid, Spain
| | - Adolfo López de Munain
- Biodonostia Health Research Institute (Biodonostia HRI), San Sebastián, Spain.,University of the Basque Country (UPV-EHU), San Sebastian, Spain.,Centro de Investigación Biomédica en Red para Enfermedades Neurodegenerativas (CIBERNED), Carlos III Health Institute, Madrid, Spain.,Department of Neurology, Hospital Universitario Donostia, San Sebastián, Spain
| | - Carlos Casasnovas
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain.,Neuromuscular Unit, Neurology Department, Hospital Universitari de Bellvitge, Universitat de Barcelona, Hospitalet de Llobregat, Spain
| | - Sergio Aguilera-Albesa
- Pediatric Neurology Unit, Department of Pediatrics, Navarra Health Service, Navarrabiomed Research Foundation, Pamplona, Spain
| | - Alfons Macaya
- Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Pediatric Neurology Department, Vall d'Hebron University Hospital, Universitat Autónoma de Barcelona, Spain.,Pediatric Neurology Research Group, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Spain .,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Spain.,Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Catalonia, Spain
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25
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Gavazzi F, Adang L, Waldman A, Jan AK, Liu G, Lorch SA, DeMauro SB, Shults J, Pierce SR, Ballance E, Kornafel T, Harrington A, Glanzman AM, Vanderver A. Reliability of the Telemedicine Application of the Gross Motor Function Measure-88 in Patients With Leukodystrophy. Pediatr Neurol 2021; 125:34-39. [PMID: 34624609 PMCID: PMC8629609 DOI: 10.1016/j.pediatrneurol.2021.09.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND Leukodystrophies are a rare class of disorders characterized by severe neuromotor disability. There is a strong need for research regarding the functional status of people with leukodystrophy which is limited by the need for in-person assessments of mobility. The purpose of this study is to assess the reliability of the Gross Motor Function Measure-88 (GMFM-88) using telemedicine compared with standard in-person assessments in patients with leukodystrophy. METHODS A total of 21 subjects with a diagnosis of leukodystrophy (age range = 1.79-52.82 years) were evaluated by in-person and by telemedicine evaluations with the GMFM-88 by physical therapists. Inter-rater reliability was assessed through evaluation of the same subject by two independent raters within a three-week period (n = 10 encounters), and intrarater reliability was assessed through blinded rescoring of video-recorded assessments after a one-week time interval (n = 6 encounters). RESULTS Remote assessments were performed by caregivers in all 21 subjects using resources found in the home with remote guidance. There was agreement between all paired in-person and remote measurements (Lin's concordance correlation ≥0.995). The Bland-Altman analysis indicated that the paired differences were within ±5%. Intrarater and inter-rater reliability demonstrated an intraclass correlation coefficient of >0.90. CONCLUSIONS These results support that remote application of the GMFM-88 is a feasible and reliable approach to assess individuals with leukodystrophy. Telemedicine application of outcome measures may be of particular value in rare diseases and those with severe neurologic disability that impacts the ability to travel.
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Affiliation(s)
- Francesco Gavazzi
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
| | - Laura Adang
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Amy Waldman
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Amanda K. Jan
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Geraldine Liu
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Scott A. Lorch
- Department of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Sara B. DeMauro
- Department of Neonatology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Justine Shults
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA,Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Samuel R. Pierce
- Departmen of Physical Therapy, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Elizabeth Ballance
- Departmen of Physical Therapy, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Tracy Kornafel
- Departmen of Physical Therapy, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Ann Harrington
- Departmen of Physical Therapy, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Allan M. Glanzman
- Departmen of Physical Therapy, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Adeline Vanderver
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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26
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Small molecule screening as an approach to encounter inefficient myelin repair. Curr Opin Pharmacol 2021; 61:127-135. [PMID: 34753035 DOI: 10.1016/j.coph.2021.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 11/20/2022]
Abstract
While current multiple sclerosis therapies are focused on immunomodulation, thereby slowing down disease progression, scientific interest has nowadays been shifted toward regenerative therapies aiming at reversing already existing deficits. The application of chemical compounds was proven to be valuable for the understanding of oligodendrogenesis and for exposing mechanisms that can boost remyelination. However, sufficient myelin repair has not been achieved yet, thus underscoring the need for more studies toward this unmet clinical goal. In this regard, many research groups have significantly contributed to the field via developing compound screening approaches or using single substances. We, here, present an overview of recent studies addressing the identification of myelin repair drugs and provide insights into technical aspects and identified substances.
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27
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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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28
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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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29
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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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30
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Berdowski WM, Sanderson LE, van Ham TJ. The multicellular interplay of microglia in health and disease: lessons from leukodystrophy. Dis Model Mech 2021; 14:dmm048925. [PMID: 34282843 PMCID: PMC8319551 DOI: 10.1242/dmm.048925] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Microglia are highly dynamic cells crucial for developing and maintaining lifelong brain function and health through their many interactions with essentially all cellular components of the central nervous system. The frequent connection of microglia to leukodystrophies, genetic disorders of the white matter, has highlighted their involvement in the maintenance of white matter integrity. However, the mechanisms that underlie their putative roles in these processes remain largely uncharacterized. Microglia have also been gaining attention as possible therapeutic targets for many neurological conditions, increasing the demand to understand their broad spectrum of functions and the impact of their dysregulation. In this Review, we compare the pathological features of two groups of genetic leukodystrophies: those in which microglial dysfunction holds a central role, termed 'microgliopathies', and those in which lysosomal or peroxisomal defects are considered to be the primary driver. The latter are suspected to have notable microglia involvement, as some affected individuals benefit from microglia-replenishing therapy. Based on overlapping pathology, we discuss multiple ways through which aberrant microglia could lead to white matter defects and brain dysfunction. We propose that the study of leukodystrophies, and their extensively multicellular pathology, will benefit from complementing analyses of human patient material with the examination of cellular dynamics in vivo using animal models, such as zebrafish. Together, this will yield important insight into the cell biological mechanisms of microglial impact in the central nervous system, particularly in the development and maintenance of myelin, that will facilitate the development of new, and refinement of existing, therapeutic options for a range of brain diseases.
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Affiliation(s)
| | | | - Tjakko J. van Ham
- Department of Clinical Genetics, Erasmus MC University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
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31
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Dehnavi AZ, Heidari E, Rasulinezhad M, Heidari M, Ashrafi MR, Hosseini MM, Sadeghzadeh F, Fallah MS, Rostampour N, Bahraini A, Garshasbi M, Tavasoli AR. ACER3-related leukoencephalopathy: expanding the clinical and imaging findings spectrum due to novel variants. Hum Genomics 2021; 15:45. [PMID: 34281620 PMCID: PMC8287746 DOI: 10.1186/s40246-021-00345-0] [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: 05/07/2021] [Accepted: 07/02/2021] [Indexed: 11/29/2022] Open
Abstract
Background Leukodystrophies are the main subgroup of inherited CNS white matter disorders which cause significant mortality and morbidity in early years of life. Diagnosis is mostly based on clinical context and neuroimaging findings; however, genetic tools, particularly whole-exome sequencing (WES), have led to comprehending the causative gene and molecular events contributing to these disorders. Mutation in Alkaline Ceramidase 3 (ACER3) gene which encodes alkaline ceramidase enzyme that plays a crucial role in cellular growth and viability has been stated as an uncommon reason for inherited leukoencephalopathies. Merely only two ACER3 mutations in cases of progressive leukodystrophies have been reported thus far. Results In the current study, we have identified three novel variants in ACER3 gene in cases with new neurological manifestations including developmental regression, dystonia, and spasticity. The detected variants were segregated into family members. Conclusion Our study expands the clinical, neuroimaging, electroencephalographic, and genetic spectrum of ACER3 mutations. Furthermore, we reviewed and compared the findings of all the previously reported cases and the cases identified here in order to facilitate their diagnosis and management. Supplementary Information The online version contains supplementary material available at 10.1186/s40246-021-00345-0.
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Affiliation(s)
- Ali Zare Dehnavi
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Erfan Heidari
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Maryam Rasulinezhad
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Morteza Heidari
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmoud Reza Ashrafi
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Mahdi Hosseini
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Sadeghzadeh
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran
| | | | - Noushin Rostampour
- Metabolic Liver Disease Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Amir Bahraini
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.,KaryoGen, Isfahan, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Ali Reza Tavasoli
- Myelin Disorders Clinic, Pediatric Neurology Division, Children's Medical Center, Pediatrics Center of Excellence, Tehran University of Medical Sciences, Tehran, Iran.
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32
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Derksen A, Shih HY, Forget D, Darbelli L, Tran LT, Poitras C, Guerrero K, Tharun S, Alkuraya FS, Kurdi WI, Nguyen CTE, Laberge AM, Si Y, Gauthier MS, Bonkowsky JL, Coulombe B, Bernard G. Variants in LSM7 impair LSM complexes assembly, neurodevelopment in zebrafish and may be associated with an ultra-rare neurological disease. HGG ADVANCES 2021; 2:100034. [PMID: 35047835 PMCID: PMC8756503 DOI: 10.1016/j.xhgg.2021.100034] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 04/28/2021] [Indexed: 11/15/2022] Open
Abstract
Leukodystrophies, genetic neurodevelopmental and/or neurodegenerative disorders of cerebral white matter, result from impaired myelin homeostasis and metabolism. Numerous genes have been implicated in these heterogeneous disorders; however, many individuals remain without a molecular diagnosis. Using whole-exome sequencing, biallelic variants in LSM7 were uncovered in two unrelated individuals, one with a leukodystrophy and the other who died in utero. LSM7 is part of the two principle LSM protein complexes in eukaryotes, namely LSM1-7 and LSM2-8. Here, we investigate the molecular and functional outcomes of these LSM7 biallelic variants in vitro and in vivo. Affinity purification-mass spectrometry of the LSM7 variants showed defects in the assembly of both LSM complexes. Lsm7 knockdown in zebrafish led to central nervous system defects, including impaired oligodendrocyte development and motor behavior. Our findings demonstrate that variants in LSM7 cause misassembly of the LSM complexes, impair neurodevelopment of the zebrafish, and may be implicated in human disease. The identification of more affected individuals is needed before the molecular mechanisms of mRNA decay and splicing regulation are added to the categories of biological dysfunctions implicated in leukodystrophies, neurodevelopmental and/or neurodegenerative diseases.
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33
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von Jonquieres G, Rae CD, Housley GD. Emerging Concepts in Vector Development for Glial Gene Therapy: Implications for Leukodystrophies. Front Cell Neurosci 2021; 15:661857. [PMID: 34239416 PMCID: PMC8258421 DOI: 10.3389/fncel.2021.661857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Central Nervous System (CNS) homeostasis and function rely on intercellular synchronization of metabolic pathways. Developmental and neurochemical imbalances arising from mutations are frequently associated with devastating and often intractable neurological dysfunction. In the absence of pharmacological treatment options, but with knowledge of the genetic cause underlying the pathophysiology, gene therapy holds promise for disease control. Consideration of leukodystrophies provide a case in point; we review cell type – specific expression pattern of the disease – causing genes and reflect on genetic and cellular treatment approaches including ex vivo hematopoietic stem cell gene therapies and in vivo approaches using adeno-associated virus (AAV) vectors. We link recent advances in vectorology to glial targeting directed towards gene therapies for specific leukodystrophies and related developmental or neurometabolic disorders affecting the CNS white matter and frame strategies for therapy development in future.
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Affiliation(s)
- Georg von Jonquieres
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Caroline D Rae
- Neuroscience Research Australia, Randwick, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW, Australia
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34
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Barczykowski AL, Langan TJ, Vanderver A, Jalal K, Carter RL. Death rates in the U.S. due to Leukodystrophies with pediatric forms. Am J Med Genet A 2021; 185:2361-2373. [PMID: 33960638 DOI: 10.1002/ajmg.a.62248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 03/26/2021] [Accepted: 04/16/2021] [Indexed: 11/08/2022]
Abstract
To use national mortality and state death certificate records to estimate disease specific mortality rates among pediatric and adult populations for 23 leukodystrophies (LDs) with pediatric forms. Additionally, to calculate yearly prevalence and caseload of the most severe LD cases that will eventually result in pediatric death (i.e., pediatric fatality cases). Death certificate records describing cause of death were collected from states based on 10 ICD-10 codes associated with the 23 LDs. Deaths in the U.S. with these codes were distributed into categories based on proportions identified in state death certificate data. Mortality rates, prevalence, and caseload were calculated from resulting expected numbers, population sizes, and average lifetimes. An estimated 1.513 per 1,000,000 0-17 year old's died of these LDs at average age 5.2 years and 0.194 for those ≥18 at an average age of 42.3 years. Prevalence of pediatric fatality cases of these LDs declined from 1999 through 2007 and then remained constant at 6.2 per million children per year through 2012. Epidemiological information, currently lacking for rare diseases, is useful to newborn screening programs, research funding agencies, and care centers for LD patients. Methods used here are generally useful for studying rare diseases.
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Affiliation(s)
- Amy L Barczykowski
- Population Health Observatory, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, USA.,Department of Biostatistics, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, USA
| | - Thomas J Langan
- Hunter James Kelly Research Institute, School of Medicine and Biomedical Sciences School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA.,Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, USA
| | - Adeline Vanderver
- The Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,The Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kabir Jalal
- Population Health Observatory, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, USA.,Department of Biostatistics, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, USA
| | - Randy L Carter
- Population Health Observatory, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, USA.,Department of Biostatistics, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, USA
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35
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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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36
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Roosendaal SD, van de Brug T, Alves CAPF, Blaser S, Vanderver A, Wolf NI, van der Knaap MS. Imaging Patterns Characterizing Mitochondrial Leukodystrophies. AJNR Am J Neuroradiol 2021; 42:1334-1340. [PMID: 34255734 DOI: 10.3174/ajnr.a7097] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/14/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND PURPOSE Achieving a specific diagnosis in leukodystrophies is often difficult due to clinical and genetic heterogeneity. Mitochondrial defects cause 5%-10% of leukodystrophies. Our objective was to define MR imaging features commonly shared by mitochondrial leukodystrophies and to distinguish MR imaging patterns related to specific genetic defects. MATERIALS AND METHODS One hundred thirty-two patients with a mitochondrial leukodystrophy with known genetic defects were identified in the data base of the Amsterdam Leukodystrophy Center. Numerous anatomic structures were systematically assessed on brain MR imaging. Additionally, lesion characteristics were scored. Statistical group analysis was performed for 57 MR imaging features by hierarchic testing on clustered genetic subgroups. RESULTS MR imaging features indicative of mitochondrial disease that were frequently found included white matter rarefaction (n = 50 patients), well-delineated cysts (n = 20 patients), T2 hyperintensity of the middle blade of the corpus callosum (n = 85 patients), and symmetric abnormalities in deep gray matter structures (n = 42 patients). Several disorders or clusters of disorders had characteristic features. The combination of T2 hyperintensity in the brain stem, middle cerebellar peduncles, and thalami was associated with complex 2 deficiency. Predominantly periventricular localization of T2 hyperintensities and cystic lesions with a distinct border was associated with defects in complexes 3 and 4. T2-hyperintense signal of the cerebellar cortex was specifically associated with variants in the gene NUBPL. T2 hyperintensities predominantly affecting the directly subcortical cerebral white matter, globus pallidus, and substantia nigra were associated with Kearns-Sayre syndrome. CONCLUSIONS In a large group of patients with a mitochondrial leukodystrophy, general MR imaging features suggestive of mitochondrial disease were found. Additionally, we identified several MR imaging patterns correlating with specific genotypes. Recognition of these patterns facilitates the diagnosis in future patients.
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Affiliation(s)
| | - T van de Brug
- Epidemiology and Biostatistics (T.v.d.B.), Amsterdam UMC, Amsterdam, the Netherlands
| | | | - S Blaser
- Division of Neuroradiology (S.B.), Department of Diagnostic Imaging, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - A Vanderver
- Department of Radiology and Division of Neurology (A.V.), The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - N I Wolf
- Department of Pediatric Neurology (M.S.v.d.K, N.I.W.), Emma Children's Hospital, Amsterdam UMC, Vrije Universiteit and Amsterdam Neuroscience, Amsterdam, the Netherlands
| | - M S van der Knaap
- Department of Pediatric Neurology (M.S.v.d.K, N.I.W.), Emma Children's Hospital, Amsterdam UMC, Vrije Universiteit and Amsterdam Neuroscience, Amsterdam, the Netherlands.,Department of Functional Genomics (M.S.v.d.K.), Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands
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37
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Ruzhnikov MRZ, Brimble E, Hickey RE. Early Signs and Symptoms of Leukodystrophies: A Case-Based Guide. Pediatr Rev 2021; 42:133-146. [PMID: 33648992 DOI: 10.1542/pir.2019-0184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Maura R Z Ruzhnikov
- Department of Neurology and Neurological Sciences and.,Division of Medical Genetics, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA
| | - Elise Brimble
- Department of Neurology and Neurological Sciences and
| | - Rachel E Hickey
- Department of Medical Genetics, Ann & Robert H. Lurie Children's Hospital, Chicago, IL
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Genetic testing of leukodystrophies unraveling extensive heterogeneity in a large cohort and report of five common diseases and 38 novel variants. Sci Rep 2021; 11:3231. [PMID: 33547378 PMCID: PMC7864965 DOI: 10.1038/s41598-021-82778-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 01/25/2021] [Indexed: 11/08/2022] Open
Abstract
This study evaluates the genetic spectrum of leukodystrophies and leukoencephalopathies in Iran. 152 children, aged from 1 day to 15 years, were genetically tested for leukodystrophies and leukoencephalopathies based on clinical and neuroradiological findings from 2016 to 2019. Patients with a suggestive specific leukodystrophy, e. g. metachromatic leukodystrophy, Canavan disease, Tay-Sachs disease were tested for mutations in single genes (108; 71%) while patients with less suggestive findings were evaluated by NGS. 108 of 152(71%) had MRI patterns and clinical findings suggestive of a known leukodystrophy. In total, 114(75%) affected individuals had (likely) pathogenic variants which included 38 novel variants. 35 different types of leukodystrophies and genetic leukoencephalopathies were identified. The more common identified disorders included metachromatic leukodystrophy (19 of 152; 13%), Canavan disease (12; 8%), Tay-Sachs disease (11; 7%), megalencephalic leukodystrophy with subcortical cysts (7; 5%), X-linked adrenoleukodystrophy (8; 5%), Pelizaeus-Merzbacher-like disease type 1 (8; 5%), Sandhoff disease (6; 4%), Krabbe disease (5; 3%), and vanishing white matter disease (4; 3%). Whole exome sequencing (WES) revealed 90% leukodystrophies and genetic leukoencephalopathies. The total diagnosis rate was 75%. This unique study presents a national genetic data of leukodystrophies; it may provide clues to the genetic pool of neighboring countries. Patients with clinical and neuroradiological evidence of a genetic leukoencephalopathy should undergo a genetic analysis to reach a definitive diagnosis. This will allow a diagnosis at earlier stages of the disease, reduce the burden of uncertainty and costs, and will provide the basis for genetic counseling and family planning.
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Perrier S, Michell-Robinson MA, Bernard G. POLR3-Related Leukodystrophy: Exploring Potential Therapeutic Approaches. Front Cell Neurosci 2021; 14:631802. [PMID: 33633543 PMCID: PMC7902007 DOI: 10.3389/fncel.2020.631802] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 12/28/2020] [Indexed: 12/19/2022] Open
Abstract
Leukodystrophies are a class of rare inherited central nervous system (CNS) disorders that affect the white matter of the brain, typically leading to progressive neurodegeneration and early death. Hypomyelinating leukodystrophies are characterized by the abnormal formation of the myelin sheath during development. POLR3-related or 4H (hypomyelination, hypodontia, and hypogonadotropic hypogonadism) leukodystrophy is one of the most common types of hypomyelinating leukodystrophy for which no curative treatment or disease-modifying therapy is available. This review aims to describe potential therapies that could be further studied for effectiveness in pre-clinical studies, for an eventual translation to the clinic to treat the neurological manifestations associated with POLR3-related leukodystrophy. Here, we discuss the therapeutic approaches that have shown promise in other leukodystrophies, as well as other genetic diseases, and consider their use in treating POLR3-related leukodystrophy. More specifically, we explore the approaches of using stem cell transplantation, gene replacement therapy, and gene editing as potential treatment options, and discuss their possible benefits and limitations as future therapeutic directions.
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Affiliation(s)
- Stefanie Perrier
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC, Canada
| | - Mackenzie A. Michell-Robinson
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC, Canada
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC, Canada
- Department of Pediatrics, McGill University, Montréal, QC, Canada
- Department of Human Genetics, McGill University, Montréal, QC, Canada
- Department of Specialized Medicine, Division of Medical Genetics, Montréal Children’s Hospital and McGill University Health Centre, Montréal, QC, Canada
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Fröhlich D, Mendes MI, Kueh AJ, Bongers A, Herold MJ, Salomons GS, Housley GD, Klugmann M. A Hypomorphic Dars1 D367Y Model Recapitulates Key Aspects of the Leukodystrophy HBSL. Front Cell Neurosci 2021; 14:625879. [PMID: 33551752 PMCID: PMC7855723 DOI: 10.3389/fncel.2020.625879] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/21/2020] [Indexed: 01/18/2023] Open
Abstract
Hypomyelination with brain stem and spinal cord involvement and leg spasticity (HBSL) is a leukodystrophy caused by missense mutations of the aspartyl-tRNA synthetase-encoding gene DARS1. The clinical picture includes the regression of acquired motor milestones, spasticity, ataxia, seizures, nystagmus, and intellectual disabilities. Morphologically, HBSL is characterized by a distinct pattern of hypomyelination in the central nervous system including the anterior brainstem, the cerebellar peduncles and the supratentorial white matter as well as the dorsal columns and the lateral corticospinal tracts of the spinal cord. Adequate HBSL animal models are lacking. Dars1 knockout mice are embryonic lethal precluding examination of the etiology. To address this, we introduced the HBSL-causing Dars1 D367Y point mutation into the mouse genome. Surprisingly, mice carrying this mutation homozygously were phenotypically normal. As hypomorphic mutations are more severe in trans to a deletion, we crossed Dars1 D367Y/D367Y mice with Dars1-null carriers. The resulting Dars1 D367Y/- offspring displayed a strong developmental delay compared to control Dars1 D367Y/+ littermates, starting during embryogenesis. Only a small fraction of Dars1 D367Y/- mice were born, and half of these mice died with hydrocephalus during the first 3 weeks of life. Of the few Dars1 D367Y/- mice that were born at term, 25% displayed microphthalmia. Throughout postnatal life, Dars1 D367Y/- mice remained smaller and lighter than their Dars1 D367Y/+ littermates. Despite this early developmental deficit, once they made it through early adolescence Dars1 D367Y/- mice were phenotypically inconspicuous for most of their adult life, until they developed late onset motor deficits as well as vacuolization and demyelination of the spinal cord white matter. Expression levels of the major myelin proteins were reduced in Dars1 D367Y/- mice compared to controls. Taken together, Dars1 D367Y/- mice model aspects of the clinical picture of the corresponding missense mutation in HBSL. This model will enable studies of late onset deficits, which is precluded in Dars1 knockout mice, and can be leveraged to test potential HBSL therapeutics including DARS1 gene replacement therapy.
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Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility & Department of Physiology, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Marisa I. Mendes
- Metabolic Unit/Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Andrew J. Kueh
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Andre Bongers
- Biomedical Resources Imaging Laboratory, UNSW Sydney, Kensington, NSW, Australia
| | - Marco J. Herold
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Gajja S. Salomons
- Metabolic Unit/Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam Gastroenterology & Metabolism, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Gary D. Housley
- Translational Neuroscience Facility & Department of Physiology, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility & Department of Physiology, School of Medical Sciences, UNSW Sydney, Kensington, NSW, Australia
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Keller SR, Mallack EJ, Rubin JP, Accardo JA, Brault JA, Corre CS, Elizondo C, Garafola J, Jackson-Garcia AC, Rhee J, Seeger E, Shullanberger KC, Tourjee A, Trovato MK, Waldman AT, Wallace JL, Wallace MR, Werner K, White A, Ess KC, Becker C, Eichler FS. Practical Approaches and Knowledge Gaps in the Care for Children With Leukodystrophies. J Child Neurol 2021; 36:65-78. [PMID: 32875938 PMCID: PMC7736398 DOI: 10.1177/0883073820946154] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Leukodystrophies are a group of neurodegenerative genetic disorders that affect approximately 1 in 7500 individuals. Despite therapeutic progress in individual leukodystrophies, guidelines in neurologic care are sparse and consensus among physicians and caregivers remains a challenge. At patient advocacy meetings hosted by Hunter's Hope from 2016-2018, multidisciplinary experts and caregivers met to conduct a literature review, identify knowledge gaps and summarize best practices regarding neurologic care. Stages of severity in leukodystrophies guided recommendations to address different levels of need based on a newly defined system of disease severity. Four core neurologic domains prioritized by families were identified and became the focus of this guideline: sleep, pain, seizures/epilepsy, and language/cognition. Based on clinical severity, the following categories were used: presymptomatic, early symptomatic, intermediate symptomatic, and advanced symptomatic. Across the leukodystrophies, neurologic care should be tailored to stages of severity while accounting for unique aspects of every disease and multiple knowledge gaps present. Standardized tools and surveys can help guide treatment but should not overburden families.
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Affiliation(s)
- Stephanie R. Keller
- Department of Pediatrics, Division of Pediatric Neurology, Emory University/Children’s Healthcare of Atlanta, Atlanta, GA, USA
| | - Eric J. Mallack
- Department of Pediatrics, Division of Child Neurology, Weill Cornell
Medical College/New York-Presbyterian Hospital, New York, NY, USA
| | - Jennifer P. Rubin
- Department of Pediatric Neurology, Northwestern Feinberg School of
Medicine, Chicago, IL, USA
| | - Jennifer A. Accardo
- Department of Neurology, Children’s Hospital of Richmond at VCU,
Richmond, VA, USA
| | - Jennifer A. Brault
- Department of Pediatrics, Division of Pediatric Neurology Vanderbilt University Medical Center, Nashville, TN, USA
| | - Camille S. Corre
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Camila Elizondo
- East Boston Neighborhood Health Canter, East Boston, MA, USA
| | - Jennifer Garafola
- Department of Pediatrics, Division of Pediatric Neurology Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - Jullie Rhee
- Children’s National Health Systems, Washington, DC, USA
| | | | | | - Amanda Tourjee
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Melissa K. Trovato
- Department of Physical Medicine and Rehabilitation, Kennedy Krieger Institute and Johns Hopkins University, Baltimore, MD, USA
| | - Amy T. Waldman
- Division of Neurology, The Children’s Hospital of Philadelphia,
University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - Klaus Werner
- Department of Pediatrics, Duke University, Durham, NC, USA
| | - Angela White
- Department of Pediatrics, Division of Pediatric Neurology Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kevin C. Ess
- Department of Pediatrics, Division of Pediatric Neurology Vanderbilt University Medical Center, Nashville, TN, USA
| | - Catherine Becker
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Florian S. Eichler
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA,Florian S. Eichler, MD, Department of
Neurology, Massachusetts General Hospital, 175 Cambridge Street, Suite 340,
Boston, MA 02114, USA.
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Shukla A, Kaur P, Narayanan DL, do Rosario MC, Kadavigere R, Girisha KM. Genetic disorders with central nervous system white matter abnormalities: An update. Clin Genet 2021; 99:119-132. [PMID: 33047326 PMCID: PMC9951823 DOI: 10.1111/cge.13863] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/21/2020] [Accepted: 10/07/2020] [Indexed: 12/21/2022]
Abstract
Several genetic disorders have variable degree of central nervous system white matter abnormalities. We retrieved and reviewed 422 genetic conditions with prominent and consistent involvement of white matter from the literature. We herein describe the current definitions, classification systems, clinical spectrum, neuroimaging findings, genomics, and molecular mechanisms of these conditions. Though diagnosis for most of these disorders relies mainly on genomic tests, specifically exome sequencing, we collate several clinical and neuroimaging findings still relevant in diagnosis of clinically recognizable disorders. We also review the current understanding of pathophysiology and therapeutics of these disorders.
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Affiliation(s)
- Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Parneet Kaur
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Dhanya Lakshmi Narayanan
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Michelle C do Rosario
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Rajagopal Kadavigere
- Department of Radiodiagnosis, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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Zhang T, Yan C, Liu Y, Cao L, Ji K, Li D, Chi L, Zhao Y. Late-Onset Leukodystrophy Mimicking Hereditary Spastic Paraplegia without Diffuse Leukodystrophy on Neuroimaging. Neuropsychiatr Dis Treat 2021; 17:1451-1458. [PMID: 34012265 PMCID: PMC8126967 DOI: 10.2147/ndt.s296424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 04/12/2021] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Leukodystrophies are frequently regarded as childhood disorders, but they can occur at any age, and the clinical and imaging patterns of the adult-onset form are usually different from the better-known childhood variants. Several reports have shown that various late-onset leukodystrophies, such as X-linked adrenoleukodystrophy and Krabbe disease, may present as spastic paraplegia with the absence of the characteristic white matter lesions on neuroimaging; this can be easily misdiagnosed as hereditary spastic paraplegia. The objective of this study was to investigate the frequency of late-onset leukodystrophies in patients with spastic paraplegia. PATIENTS AND METHODS We performed genetic analysis using a custom-designed gene panel for leukodystrophies in 112 hereditary spastic paraplegia-like patients. RESULTS We identified pathogenic mutations in 13 out of 112 patients, including five patients with adrenomyeloneuropathy, three with Krabbe disease, three with Alexander disease, and two with cerebrotendinous xanthomatosis. In terms of clinical manifestations, in addition to spastic paraplegia, three adrenomyeloneuropathy probands also had adrenocortical insufficiency, two Alexander disease probands developed urinary retention, one CTX proband developed cataracts and chronic diarrhea and the other presented with chronic diarrhea and mild tendon xanthomatosis. None of the patients had evidence of diffuse leukodystrophy on neuroimaging. CONCLUSION Patients with late-onset spastic paraplegia should be screened for underlying leukodystrophies, irrespective of the presence of additional complicating symptoms and neuroimaging abnormalities.
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Affiliation(s)
- Tongxia Zhang
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, People's Republic of China.,School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China
| | - Chuanzhu Yan
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, People's Republic of China.,Mitochondrial Medicine Laboratory, Qilu Hospital (Qingdao), Shandong University, Qingdao, People's Republic of China
| | - Yiming Liu
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, People's Republic of China
| | - Lili Cao
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, People's Republic of China
| | - Kunqian Ji
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, People's Republic of China
| | - Duoling Li
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, People's Republic of China
| | - Lingyi Chi
- School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, People's Republic of China.,Brain Science Research Institute, Qilu Hospital, Shandong University, Jinan, People's Republic of China.,Department of Neurosurgery, Qilu Hospital, Shandong University, Jinan, People's Republic of China
| | - Yuying Zhao
- Research Institute of Neuromuscular and Neurodegenerative Diseases and Department of Neurology, Qilu Hospital, Shandong University, Jinan, People's Republic of China
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Calame DG, Hainlen M, Takacs D, Ferrante L, Pence K, Emrick LT, Chao HT. EIF2AK2-related Neurodevelopmental Disorder With Leukoencephalopathy, Developmental Delay, and Episodic Neurologic Regression Mimics Pelizaeus-Merzbacher Disease. NEUROLOGY-GENETICS 2020; 7:e539. [PMID: 33553620 PMCID: PMC7862097 DOI: 10.1212/nxg.0000000000000539] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 10/16/2020] [Indexed: 11/29/2022]
Abstract
Objective To demonstrate that de novo missense single nucleotide variants (SNVs) in EIF2AK2 cause a neurodevelopmental disorder with leukoencephalopathy resembling Pelizaeus-Merzbacher disease (PMD). Methods A retrospective chart review was performed of 2 unrelated males evaluated at a single institution with de novo EIF2AK2 SNVs identified by clinical exome sequencing (ES). Clinical and radiographic data were reviewed and summarized. Results Both individuals presented in the first year of life with concern for seizures and developmental delay. Common clinical findings included horizontal and/or pendular nystagmus during infancy, axial hypotonia, appendicular hypertonia, spasticity, and episodic neurologic regression with febrile viral illnesses. MRI of the brain demonstrated severely delayed myelination in infancy. A hypomyelinating pattern was confirmed on serial imaging at age 4 years for proband 1. In proband 2, repeat imaging at age 13 months confirmed persistent delayed myelination. These clinical and radiographic features led to a strong suspicion of PMD. However, neither PLP1 copy number variants nor pathogenic SNVs were detected by chromosomal microarray and trio ES, respectively. Reanalysis of trio ES identified heterozygous de novo EIF2AK2 missense variant c.290C>T (p.Ser97Phe) in proband 1 and c.326C>T (p.Ala109Val) in proband 2. Conclusions The autosomal dominant EIF2AK2-related leukoencephalopathy, developmental delay, and episodic neurologic regression syndrome should be considered in the differential diagnosis for PMD and other hypomyelinating leukodystrophies (HLDs). A characteristic history of developmental regression with febrile illnesses may help distinguish it from other HLDs.
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Affiliation(s)
- Daniel G Calame
- Division of Neurology and Developmental Neuroscience (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Department of Pediatrics, BCM, Houston, TX; Texas Children's Hospital (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Houston, TX; Department of Neurology and Neurotherapeutics (M.H.), UTSW, Dallas, TX; Department of Molecular and Human Genetics (L.T.E., H.-T.C.), BCM, Houston, TX; Department of Neuroscience (H.-T.C.), BCM, Houston, TX; Program in Development (H.-T.C.), Disease Models, and Therapeutics, BCM, Houston, TX; McNair Medical Institute (H.-T.C.), The Robert and Janice McNair Foundation, Houston, TX; and Jan and Dan Duncan Neurological Research Institute (H.-T.C.), Texas Children's Hospital, Houston, TX
| | - Meagan Hainlen
- Division of Neurology and Developmental Neuroscience (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Department of Pediatrics, BCM, Houston, TX; Texas Children's Hospital (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Houston, TX; Department of Neurology and Neurotherapeutics (M.H.), UTSW, Dallas, TX; Department of Molecular and Human Genetics (L.T.E., H.-T.C.), BCM, Houston, TX; Department of Neuroscience (H.-T.C.), BCM, Houston, TX; Program in Development (H.-T.C.), Disease Models, and Therapeutics, BCM, Houston, TX; McNair Medical Institute (H.-T.C.), The Robert and Janice McNair Foundation, Houston, TX; and Jan and Dan Duncan Neurological Research Institute (H.-T.C.), Texas Children's Hospital, Houston, TX
| | - Danielle Takacs
- Division of Neurology and Developmental Neuroscience (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Department of Pediatrics, BCM, Houston, TX; Texas Children's Hospital (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Houston, TX; Department of Neurology and Neurotherapeutics (M.H.), UTSW, Dallas, TX; Department of Molecular and Human Genetics (L.T.E., H.-T.C.), BCM, Houston, TX; Department of Neuroscience (H.-T.C.), BCM, Houston, TX; Program in Development (H.-T.C.), Disease Models, and Therapeutics, BCM, Houston, TX; McNair Medical Institute (H.-T.C.), The Robert and Janice McNair Foundation, Houston, TX; and Jan and Dan Duncan Neurological Research Institute (H.-T.C.), Texas Children's Hospital, Houston, TX
| | - Leah Ferrante
- Division of Neurology and Developmental Neuroscience (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Department of Pediatrics, BCM, Houston, TX; Texas Children's Hospital (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Houston, TX; Department of Neurology and Neurotherapeutics (M.H.), UTSW, Dallas, TX; Department of Molecular and Human Genetics (L.T.E., H.-T.C.), BCM, Houston, TX; Department of Neuroscience (H.-T.C.), BCM, Houston, TX; Program in Development (H.-T.C.), Disease Models, and Therapeutics, BCM, Houston, TX; McNair Medical Institute (H.-T.C.), The Robert and Janice McNair Foundation, Houston, TX; and Jan and Dan Duncan Neurological Research Institute (H.-T.C.), Texas Children's Hospital, Houston, TX
| | - Kayla Pence
- Division of Neurology and Developmental Neuroscience (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Department of Pediatrics, BCM, Houston, TX; Texas Children's Hospital (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Houston, TX; Department of Neurology and Neurotherapeutics (M.H.), UTSW, Dallas, TX; Department of Molecular and Human Genetics (L.T.E., H.-T.C.), BCM, Houston, TX; Department of Neuroscience (H.-T.C.), BCM, Houston, TX; Program in Development (H.-T.C.), Disease Models, and Therapeutics, BCM, Houston, TX; McNair Medical Institute (H.-T.C.), The Robert and Janice McNair Foundation, Houston, TX; and Jan and Dan Duncan Neurological Research Institute (H.-T.C.), Texas Children's Hospital, Houston, TX
| | - Lisa T Emrick
- Division of Neurology and Developmental Neuroscience (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Department of Pediatrics, BCM, Houston, TX; Texas Children's Hospital (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Houston, TX; Department of Neurology and Neurotherapeutics (M.H.), UTSW, Dallas, TX; Department of Molecular and Human Genetics (L.T.E., H.-T.C.), BCM, Houston, TX; Department of Neuroscience (H.-T.C.), BCM, Houston, TX; Program in Development (H.-T.C.), Disease Models, and Therapeutics, BCM, Houston, TX; McNair Medical Institute (H.-T.C.), The Robert and Janice McNair Foundation, Houston, TX; and Jan and Dan Duncan Neurological Research Institute (H.-T.C.), Texas Children's Hospital, Houston, TX
| | - Hsiao-Tuan Chao
- Division of Neurology and Developmental Neuroscience (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Department of Pediatrics, BCM, Houston, TX; Texas Children's Hospital (D.G.C., D.T., L.F., K.P., L.T.E., H.-T.C.), Houston, TX; Department of Neurology and Neurotherapeutics (M.H.), UTSW, Dallas, TX; Department of Molecular and Human Genetics (L.T.E., H.-T.C.), BCM, Houston, TX; Department of Neuroscience (H.-T.C.), BCM, Houston, TX; Program in Development (H.-T.C.), Disease Models, and Therapeutics, BCM, Houston, TX; McNair Medical Institute (H.-T.C.), The Robert and Janice McNair Foundation, Houston, TX; and Jan and Dan Duncan Neurological Research Institute (H.-T.C.), Texas Children's Hospital, Houston, TX
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Bonkowsky JL, Wilkes J, Ying J, Wei WQ. Novel and known morbidities of leukodystrophies identified using a phenome-wide association study. Neurol Clin Pract 2020; 10:406-414. [PMID: 33299668 DOI: 10.1212/cpj.0000000000000783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/23/2019] [Indexed: 11/15/2022]
Abstract
Objective To determine shared comorbidities and to identify underrecognized or unexpected morbidities in children with leukodystrophies using an unbiased phenome-wide association study (PheWAS) analysis of a nationwide pediatric clinical and financial database. Methods Data were extracted from the Pediatric Health Information System database. Patients with leukodystrophy were identified with International Classification of Diseases, 10th revision, clinical modification, diagnostic codes for any of 4 specific leukodystrophies (X-linked adrenoleukodystrophy (E71.52x), Hurler disease (E76.01), Krabbe disease (E75.23), and metachromatic leukodystrophy (E75.25)) over a 3-year time period. Confirmed leukodystrophy cases (n = 553) were matched with 1659 controls. A PheWAS analysis was performed on all available ICD diagnostic codes for cases and controls. Comparisons were performed for all 4 leukodystrophies as a group and individually. Results We found 174 phecodes (grouped ICD codes) associated with leukodystrophies, including 28 codes with a rate difference (RD) > 20%. Known comorbidities of leukodystrophies including developmental delay, epilepsy, and adrenal insufficiency were identified. Unexpected associations identified included hypertension (RD 30%, OR 25), hearing loss (RD 28%, OR 15), and cardiac dysrhythmias (RD 27%, OR 9). Hurler disease had a greater number of unique disease conditions. Conclusions PheWAS analysis from a national database demonstrates shared and unique features of leukodystrophies. Developmental delay, cardiac dysrhythmias, fluid and electrolyte disturbances, and respiratory issues were common to all 4 leukodystrophy diseases. Use of a PheWAS in leukodystrophies and other pediatric neurologic diseases offers a method for targeting improved care for patients by identification of morbidities.
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Affiliation(s)
- Joshua L Bonkowsky
- Division of Pediatric Neurology (JLB), Department of Pediatrics, University of Utah School of Medicine; Brain and Spine Center (JLB), Primary Children's Hospital, Intermountain Healthcare, Salt Lake City; Intermountain Healthcare (JW), Salt Lake City; Department of Internal Medicine (JY), University of Utah School of Medicine, Salt Lake City; and Department of Biomedical Informatics (W-QW), Vanderbilt University Medical Center, Nashville, TN
| | - Jacob Wilkes
- Division of Pediatric Neurology (JLB), Department of Pediatrics, University of Utah School of Medicine; Brain and Spine Center (JLB), Primary Children's Hospital, Intermountain Healthcare, Salt Lake City; Intermountain Healthcare (JW), Salt Lake City; Department of Internal Medicine (JY), University of Utah School of Medicine, Salt Lake City; and Department of Biomedical Informatics (W-QW), Vanderbilt University Medical Center, Nashville, TN
| | - Jian Ying
- Division of Pediatric Neurology (JLB), Department of Pediatrics, University of Utah School of Medicine; Brain and Spine Center (JLB), Primary Children's Hospital, Intermountain Healthcare, Salt Lake City; Intermountain Healthcare (JW), Salt Lake City; Department of Internal Medicine (JY), University of Utah School of Medicine, Salt Lake City; and Department of Biomedical Informatics (W-QW), Vanderbilt University Medical Center, Nashville, TN
| | - Wei-Qi Wei
- Division of Pediatric Neurology (JLB), Department of Pediatrics, University of Utah School of Medicine; Brain and Spine Center (JLB), Primary Children's Hospital, Intermountain Healthcare, Salt Lake City; Intermountain Healthcare (JW), Salt Lake City; Department of Internal Medicine (JY), University of Utah School of Medicine, Salt Lake City; and Department of Biomedical Informatics (W-QW), Vanderbilt University Medical Center, Nashville, TN
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46
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Dermer E, Spahr A, Tran LT, Mirchi A, Pelletier F, Guerrero K, Ahmed S, Brais B, Braverman N, Buhas D, Chandratre S, Chenier S, Chrestian N, Desmeules M, Dilenge ME, Laflamme J, Larbrisseau A, Legault G, Lim KY, Maftei C, Major P, Malvey-Dorn E, Marois P, Mitchell J, Nadeau A, Osterman B, Paradis I, Pohl D, Reggin J, Riou E, Roedde G, Rossignol E, Sébire G, Shevell M, Srour M, Sylvain M, Tarnopolsky M, Venkateswaran S, Sullivan M, Bernard G. Stress in Parents of Children With Genetically Determined Leukoencephalopathies: A Pilot Study. J Child Neurol 2020; 35:901-907. [PMID: 32720856 DOI: 10.1177/0883073820938645] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Genetically determined leukoencephalopathies comprise a group of rare inherited white matter disorders. The majority are progressive diseases resulting in early death. We performed a cross-sectional pilot study including 55 parents from 36 families to assess the level of stress experienced by parents of patients with genetically determined leukoencephalopathies, aged 1 month to 12 years. Thirty-four mothers and 21 fathers completed the Parenting Stress Index-4th Edition. One demographic questionnaire was completed per family. Detailed clinical data was gathered on all patients. Statistical analysis was performed with total stress percentile score as the primary outcome. Mothers and fathers had significantly higher stress levels compared with the normative sample; 20% of parents had high levels of stress whereas 11% had clinically significant levels of stress. Mothers and fathers had comparable total stress percentile scores. We identified pediatric behavioral difficulties and gross motor function to be factors influencing stress in mothers. Our study is the first to examine parental stress in this population and highlights the need for parental support early in the disease course. In this pilot study, we demonstrated that using the Parenting Stress Index-4th Edition to assess stress levels in parents of patients with genetically determined leukoencephalopathies is feasible, leads to valuable and actionable results, and should be used in larger, prospective studies.
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Affiliation(s)
- E Dermer
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada.,E. Dermer and A. Spahr are co-first authors of this article
| | - A Spahr
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada.,E. Dermer and A. Spahr are co-first authors of this article
| | - L T Tran
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - A Mirchi
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - F Pelletier
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - K Guerrero
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - S Ahmed
- 27364North Bay Regional Health Centre, North Bay, Ontario, Canada
| | - B Brais
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada
| | - N Braverman
- Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - D Buhas
- Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada
| | - S Chandratre
- Department of Pediatric Neurology, 6397Oxford University Hospitals, Oxford, United Kingdom
| | - S Chenier
- Department of Medical Genetics, 7321University of Sherbrooke, Sherbrooke, Québec, Canada
| | - N Chrestian
- Division of Pediatric Neurology, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada.,Department of Pediatrics, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada
| | - M Desmeules
- Department of Pediatrics, Saguenay, Chicoutimi, Québec, Canada
| | - M E Dilenge
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada
| | - J Laflamme
- Department of Pediatrics, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada
| | - A Larbrisseau
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada.,Department of Neurology, CHU Saint-Justine, Montréal, Québec, Canada
| | - G Legault
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada
| | - K Y Lim
- Department of Pediatric Neurology, Providence Pediatric Neurology-St. Vincent, Portland, OR, USA
| | - C Maftei
- Department of Pediatrics, Division of Medical Genetics, CHU Saint-Justine, Montreal University, Montréal, Québec, Canada
| | - P Major
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada
| | - E Malvey-Dorn
- Department of Pediatrics, All About Children Pediatrics Eden Prairie, St. Louis Park, MN, USA
| | - P Marois
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada
| | - J Mitchell
- Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - A Nadeau
- Department of Pediatric Neurology, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - B Osterman
- Department of Pediatrics, 5622University of Montreal, Montréal, Québec, Canada.,Department of Neurology, CHU Saint-Justine, Montréal, Québec, Canada
| | - I Paradis
- CIUSSS de l'Est-de-l'Île-de-Montréal, CLSC de Rivière-des-Prairies, Montréal, Québec, Canada
| | - D Pohl
- Division of Neurology, 274065Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario, Canada
| | - J Reggin
- Department of Pediatric Neurology, Providence Child Neurology, Spokane, Washington, United States
| | - E Riou
- Department of Pediatric Neurology, University of Sherbrooke, Sherbrooke, Québec, Canada
| | - G Roedde
- Latchford Medical Centre, Latchford, Ontario, Canada
| | - E Rossignol
- Brain and Child Development, CHU Saint-Justine Research Center, Montréal, Québec, Canada
| | - G Sébire
- Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - M Shevell
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - M Srour
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
| | - M Sylvain
- Division of Pediatric Neurology, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada.,Department of Pediatrics, 12369Centre Mère-Enfant Soleil du CHU de Québec-Université Laval, Québec, Canada
| | - M Tarnopolsky
- Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - S Venkateswaran
- Department of Pediatrics, CHEO Research Institute, Ottawa, Ontario, Canada
| | - M Sullivan
- Department of Psychology, McGill University, Montréal, Québec, Canada
| | - G Bernard
- Department of Neurology and Neurosurgery, 54473McGill University, Montréal, Québec Canada.,Department of Pediatrics, 54473McGill University, Montréal, Québec Canada.,Department of Human Genetics, 54473McGill University, Montréal, Québec, Canada.,Department of Specialized Medicine, Division of Medical Genetics, 507266McGill University Health Centre, Montréal, Québec, Canada.,Child Health and Human Development Program, 507266Research Institute of the McGill University Health Center, Montréal, Québec, Canada
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47
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Soderholm HE, Chapin AB, Bayrak-Toydemir P, Bonkowsky JL. Elevated Leukodystrophy Incidence Predicted From Genomics Databases. Pediatr Neurol 2020; 111:66-69. [PMID: 32951664 PMCID: PMC7506144 DOI: 10.1016/j.pediatrneurol.2020.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Leukodystrophies are genetic diseases affecting the white matter and leading to early death. Our objective was to determine leukodystrophy incidence, using genomics sequencing databases allele frequencies of disease-causing variants. METHODS From 49 genes, representing the standardly defined group of leukodystrophies, we identified potential disease-causing variants from publications in the Human Genetic Mutation Database and from predictions in the Genome Aggregation Database. Allele frequencies were estimated from Genome Aggregation Database. Allele frequencies for each gene were summed to generate a super allele frequency and we used the Hardy-Weinberg equation to calculate overall expected live birth incidence associated with the gene in question. RESULTS We identified 4564 pathogenic variants for 25 discrete leukodystrophies. The largest effect was from GALC variants (Krabbe disease), which had a predicted incidence of one in 12,080 live births, 8.3 times higher than published estimates. The second most frequently predicted leukodystrophy was the RNA polymerase III-related disorders, which had an incidence of 1:26,160. Overall, we found a leukodystrophy incidence of 1 in 4733 live births, significantly higher than previous estimates. CONCLUSIONS Our data are consistent with a significant underdiagnosis of leukodystrophy patients. An intriguing additional consideration is that there may be genetic modifiers that lead to weaker, absent, or adult-onset disease phenotypes.
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Affiliation(s)
- Haille E. Soderholm
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
| | - Alexander B. Chapin
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah,Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Pinar Bayrak-Toydemir
- ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah,Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah
| | - Joshua L. Bonkowsky
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah,Brain and Spine Center, Primary Children’s Hospital, Salt Lake City, Utah,Primary Children’s Center for Personalized Medicine, Salt Lake City Utah,Address correspondence to: Josh Bonkowsky, Department of Pediatrics, 295 Chipeta Way/Williams Building, Salt Lake City, Utah 84108, , Phone: 801-581-6756, Fax: 801-581-4233
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48
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Garcia LM, Hacker JL, Sase S, Adang L, Almad A. Glial cells in the driver seat of leukodystrophy pathogenesis. Neurobiol Dis 2020; 146:105087. [PMID: 32977022 DOI: 10.1016/j.nbd.2020.105087] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 08/16/2020] [Accepted: 09/18/2020] [Indexed: 01/24/2023] Open
Abstract
Glia cells are often viewed as support cells in the central nervous system, but recent discoveries highlight their importance in physiological functions and in neurological diseases. Central to this are leukodystrophies, a group of progressive, neurogenetic disease affecting white matter pathology. In this review, we take a closer look at multiple leukodystrophies, classified based on the primary glial cell type that is affected. While white matter diseases involve oligodendrocyte and myelin loss, we discuss how astrocytes and microglia are affected and impinge on oligodendrocyte, myelin and axonal pathology. We provide an overview of the leukodystrophies covering their hallmark features, clinical phenotypes, diverse molecular pathways, and potential therapeutics for clinical trials. Glial cells are gaining momentum as cellular therapeutic targets for treatment of demyelinating diseases such as leukodystrophies, currently with no treatment options. Here, we bring the much needed attention to role of glia in leukodystrophies, an integral step towards furthering disease comprehension, understanding mechanisms and developing future therapeutics.
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Affiliation(s)
- Luis M Garcia
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Julia L Hacker
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Sunetra Sase
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Laura Adang
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Akshata Almad
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA.
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49
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Bibi F, Haider N, Din SU, Shah M, Krishin J, Qayyum N, Raja GK, Houlden H, Ahmad W, Khaliq T, Ullah A. Sequence variants in three genes underlying leukodystrophy in Pakistani families. Int J Dev Neurosci 2020; 80:380-388. [PMID: 32403196 DOI: 10.1002/jdn.10036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/29/2020] [Accepted: 05/03/2020] [Indexed: 11/09/2022] Open
Abstract
Leukodystrophies (LDs) are a heterogeneous group of rare and progressive genetic diseases that affect brain, spinal cord, and often the peripheral nerves. They are characterized by abnormal development or destruction of the myelin sheath of the brain. This study was aimed to search for the causative variants in three unrelated consanguineous families presented with LD. Detailed clinical investigations were carried out on probands in three unrelated consanguineous families of Pakistani origin. Targeted gene sequencing and Whole Exome Sequencing (WES) were performed for variant identification. Candidate variants were checked for co-segregation with the phenotype using Sanger sequencing. Public databases including ExAC, gnomAD, dbSNP, and the 1,000 Genome Project were searched to determine frequencies of the alleles. Conservation of the missense variants was ensured by aligning orthologous protein sequences from diverse vertebrate species. Targeted gene sequencing identified a novel homozygous missense mutation [c.2135G > A, p.(Arg712His) in the ATP Binding Cassette Subfamily D Member 1 (ABCD1; OMIM# 300371) in three affected siblings in family A.WES followed by validation by Sanger sequencing revealed previously reported homozygous missense variants [c.162C > A; p.(Asn54Lys)] in ASPA (OMIM# 608034) in family B and [c.361G > C,p.(Gly121Arg)] in ARSA (OMIM# 607574) in family C. Investigation of three families underlies importance of WES as an amazing diagnostic tool for conclusive determination of a specific type of LD. Further, the study would assist in carrier testing and prenatal diagnosis of the affected families. In addition, searching for common variants in the genes causing LD would help in designing low-cost targeted variation testing in patients.
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Affiliation(s)
- Farah Bibi
- University Institute of Biochemistry & Biotechnology, PMAS-Arid Agriculture University, Rawalpindi, Pakistan
- Department of Neuromuscular Disorders, UCL Institute of Neurology, London, UK
| | - Nighat Haider
- Department of Paediatric Medicine, Shaheed Zulfiqar Ali Bhutto Medical University, Children Hospital, Pakistan Institute of Medical Sciences, Islamabad, Pakistan
| | - Shahab Ud Din
- Department of Molecular Biology, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Muqadar Shah
- Department of Paediatric Medicine, Shaheed Zulfiqar Ali Bhutto Medical University, Children Hospital, Pakistan Institute of Medical Sciences, Islamabad, Pakistan
| | - Jai Krishin
- Department of Paediatric Medicine, Shaheed Zulfiqar Ali Bhutto Medical University, Children Hospital, Pakistan Institute of Medical Sciences, Islamabad, Pakistan
| | - Naila Qayyum
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Ghazala Kaukab Raja
- University Institute of Biochemistry & Biotechnology, PMAS-Arid Agriculture University, Rawalpindi, Pakistan
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Institute of Neurology, London, UK
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Tanwir Khaliq
- Department of Molecular Biology, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Asmat Ullah
- Department of Molecular Biology, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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50
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Urbik VM, Schmiedel M, Soderholm H, Bonkowsky JL. Expanded Phenotypic Definition Identifies Hundreds of Potential Causative Genes for Leukodystrophies and Leukoencephalopathies. Child Neurol Open 2020; 7:2329048X20939003. [PMID: 32704519 PMCID: PMC7359642 DOI: 10.1177/2329048x20939003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/22/2020] [Accepted: 06/08/2020] [Indexed: 12/28/2022] Open
Abstract
Background: The genes responsible for genetic white matter disorders (GWMD; leukodystrophies and leukoencephalopathies) are incompletely known. Our goal was to revise the list of genes considered to cause GWMD. We considered a GWMD to consist of any genetic disease causing T2 signal white matter changes in magnetic resonance images. Methods and Results: Using a systematic review of PubMed, Google, published literature reviews, and commercial gene panels, we identified 399 unique genes meeting the GWMD definition. Of this, 87 (22%) genes were hypomyelinating. Only 3 genes had contrast enhancement on magnetic resonance imaging (MRI): ABCD1, GFAP, and UNC13D. Conclusions: A significantly greater number of genes than previously recognized, 399, are associated with white matter signal changes on T2 MRI. This expansion of GWMD genes can be useful in analysis and interpretation of next-generation sequencing results for GWMD diagnosis, and for understanding shared pathophysiological mechanisms of GWMDs.
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Affiliation(s)
| | | | - Haille Soderholm
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Joshua L Bonkowsky
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.,Brain and Spine Center, Primary Children's Hospital, Salt Lake City, UT, USA.,Primary Children's Center for Personalized Medicine, Salt Lake City, UT, USA
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