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Lancione M, Cencini M, Scaffei E, Cipriano E, Buonincontri G, Schulte RF, Pirkl CM, Buchignani B, Pasquariello R, Canapicchi R, Battini R, Biagi L, Tosetti M. Magnetic resonance fingerprinting-based myelin water fraction mapping for the assessment of white matter maturation and integrity in typical development and leukodystrophies. NMR IN BIOMEDICINE 2024; 37:e5114. [PMID: 38390667 DOI: 10.1002/nbm.5114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 02/24/2024]
Abstract
A quantitative biomarker for myelination, such as myelin water fraction (MWF), would boost the understanding of normative and pathological neurodevelopment, improving patients' diagnosis and follow-up. We quantified the fraction of a rapidly relaxing pool identified as MW using multicomponent three-dimensional (3D) magnetic resonance fingerprinting (MRF) to evaluate white matter (WM) maturation in typically developing (TD) children and alterations in leukodystrophies (LDs). We acquired DTI and 3D MRF-based R1, R2 and MWF data of 15 TD children and 17 LD patients (9 months-12.5 years old) at 1.5 T. We computed normative maturation curves in corpus callosum and corona radiata and performed WM tract profile analysis, comparing MWF with R1, R2 and fractional anisotropy (FA). Normative maturation curves demonstrated a steep increase for all tissue parameters in the first 3 years of age, followed by slower growth for MWF while R1, R2R2 and FA reached a plateau. Unlike FA, MWF values were similar for regions of interest (ROIs) with different degrees of axonal packing, suggesting independence from fiber bundle macro-organization and higher myelin specificity. Tract profile analysis indicated a specific spatial pattern of myelination in the major fiber bundles, consistent across subjects. LD were better distinguished from TD by MWF rather than FA, showing reduced MWF with respect to age-matched controls in both ROI-based and tract analysis. In conclusion, MRF-based MWF provides myelin-specific WM maturation curves and is sensitive to alteration due to LDs, suggesting its potential as a biomarker for WM disorders. As MRF allows fast simultaneous acquisition of relaxometry and MWF, it can represent a valuable diagnostic tool to study and follow up developmental WM disorders in children.
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Affiliation(s)
| | - Matteo Cencini
- Pisa Division, National Institute for Nuclear Physics (INFN), Pisa, Italy
| | | | - Emilio Cipriano
- IRCCS Stella Maris Foundation, Pisa, Italy
- Department of Physics, University of Pisa, Pisa, Italy
| | | | | | | | | | | | | | - Roberta Battini
- IRCCS Stella Maris Foundation, Pisa, Italy
- Department of Clinical and Experimental Medicine, Università di Pisa, Pisa, Italy
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2
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Zhang F, Guo H, Zhou X, Deng Z, Xu Q, Wang Q, Yuan H, Luo J. Novel PIP5K1C variant identified in a Chinese pedigree with lethal congenital contractural syndrome 3. BMC Pediatr 2024; 24:182. [PMID: 38491417 PMCID: PMC10941444 DOI: 10.1186/s12887-024-04674-6] [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: 09/20/2023] [Accepted: 02/26/2024] [Indexed: 03/18/2024] Open
Abstract
BACKGROUND Biallelic pathogenic variants in PIP5K1C (MIM #606,102) lead to lethal congenital contractural syndrome 3 (LCCS3, MIM #611,369), a rare autosomal recessive genetic disorder characterized by small gestational age, severe multiple joint contractures and muscle atrophy, early death due to respiratory failure. Currently, 5 individuals with LCCS3 were reported and 5 pathogenic variants in PIP5K1C were identified. Here, we reported the two fetuses in a Chinese pedigree who displayed multiple joint contractures and other congenital anomalies. METHODS Trio-based whole-exome sequencing (WES) was performed for the parents and the recent fetus to detect the genetic cause for fetus phenotype. RESULTS A novel variant, NM_012398.3: c.949_952dup, p.S318Ifs*28 and a previously reported variant, c.688_689del, p.G230Qfs*114 (ClinVar database) in PIP5K1C, were detected in the individuals, and these variants were inherited from the mother and father, respectively. We described the features of multiple joint contractures in our fetuses, including bilateral talipes equinovarus, stiffness in the limbs, extended knees, persistently closed hands and overlapping fingers, which have not been delineated detailedly in previously reported LCCS3 individuals. Furthermore, novel phenotype, bilateral dilated lateral ventricles, was revealed in one fetus. CONCLUSIONS These findings expanded the genetic variant spectrum of PIP5K1C and enriched the clinical features of LCCS3, which will help with the prenatal diagnosis and genetic counseling for this family.
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Affiliation(s)
- Fang Zhang
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China
| | - Hongmei Guo
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China
| | - Xinlong Zhou
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China
- Key Laboratory for Precision Diagnosis and Treatment of Severe Infectious Diseases in Children, Dongguan, 523120, China
| | - Zhengxi Deng
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China
| | - Qiuhong Xu
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China
| | - Qingming Wang
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China
- Department of Medical Genetics, Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China
| | - Haiming Yuan
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China.
- Department of Medical Genetics, Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China.
| | - Jianhua Luo
- Dongguan Maternal and Child Health Care Hospital, Dongguan, 523120, China.
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3
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Gavazzi F, Gonzalez CD, Arnold K, Swantkowski M, Charlton L, Modesti N, Dar AA, Vanderver A, Bennett M, Adang LA. Nucleotide metabolism, leukodystrophies, and CNS pathology. J Inherit Metab Dis 2024. [PMID: 38421058 DOI: 10.1002/jimd.12721] [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: 12/22/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 03/02/2024]
Abstract
The balance between a protective and a destructive immune response can be precarious, as exemplified by inborn errors in nucleotide metabolism. This class of inherited disorders, which mimics infection, can result in systemic injury and severe neurologic outcomes. The most common of these disorders is Aicardi Goutières syndrome (AGS). AGS results in a phenotype similar to "TORCH" infections (Toxoplasma gondii, Other [Zika virus (ZIKV), human immunodeficiency virus (HIV)], Rubella virus, human Cytomegalovirus [HCMV], and Herpesviruses), but with sustained inflammation and ongoing potential for complications. AGS was first described in the early 1980s as familial clusters of "TORCH" infections, with severe neurology impairment, microcephaly, and basal ganglia calcifications (Aicardi & Goutières, Ann Neurol, 1984;15:49-54) and was associated with chronic cerebrospinal fluid (CSF) lymphocytosis and elevated type I interferon levels (Goutières et al., Ann Neurol, 1998;44:900-907). Since its first description, the clinical spectrum of AGS has dramatically expanded from the initial cohorts of children with severe impairment to including individuals with average intelligence and mild spastic paraparesis. This broad spectrum of potential clinical manifestations can result in a delayed diagnosis, which families cite as a major stressor. Additionally, a timely diagnosis is increasingly critical with emerging therapies targeting the interferon signaling pathway. Despite the many gains in understanding about AGS, there are still many gaps in our understanding of the cell-type drivers of pathology and characterization of modifying variables that influence clinical outcomes and achievement of timely diagnosis.
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Affiliation(s)
- Francesco Gavazzi
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | | - Kaley Arnold
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Meghan Swantkowski
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Lauren Charlton
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Nicholson Modesti
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Asif A Dar
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mariko Bennett
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Laura A Adang
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Michell-Robinson MA, Watt KEN, Grouza V, Macintosh J, Pinard M, Tuznik M, Chen X, Darbelli L, Wu CL, Perrier S, Chitsaz D, Uccelli NA, Liu H, Cox TC, Müller CW, Kennedy TE, Coulombe B, Rudko DA, Trainor PA, Bernard G. Hypomyelination, hypodontia and craniofacial abnormalities in a Polr3b mouse model of leukodystrophy. Brain 2023; 146:5070-5085. [PMID: 37635302 PMCID: PMC10690025 DOI: 10.1093/brain/awad249] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 06/23/2023] [Accepted: 07/06/2023] [Indexed: 08/29/2023] Open
Abstract
RNA polymerase III (Pol III)-related hypomyelinating leukodystrophy (POLR3-HLD), also known as 4H leukodystrophy, is a severe neurodegenerative disease characterized by the cardinal features of hypomyelination, hypodontia and hypogonadotropic hypogonadism. POLR3-HLD is caused by biallelic pathogenic variants in genes encoding Pol III subunits. While approximately half of all patients carry mutations in POLR3B encoding the RNA polymerase III subunit B, there is no in vivo model of leukodystrophy based on mutation of this Pol III subunit. Here, we determined the impact of POLR3BΔ10 (Δ10) on Pol III in human cells and developed and characterized an inducible/conditional mouse model of leukodystrophy using the orthologous Δ10 mutation in mice. The molecular mechanism of Pol III dysfunction was determined in human cells by affinity purification-mass spectrometry and western blot. Postnatal induction with tamoxifen induced expression of the orthologous Δ10 hypomorph in triple transgenic Pdgfrα-Cre/ERT; R26-Stopfl-EYFP; Polr3bfl mice. CNS and non-CNS features were characterized using a variety of techniques including microCT, ex vivo MRI, immunofluorescence, immunohistochemistry, spectral confocal reflectance microscopy and western blot. Lineage tracing and time series analysis of oligodendrocyte subpopulation dynamics based on co-labelling with lineage-specific and/or proliferation markers were performed. Proteomics suggested that Δ10 causes a Pol III assembly defect, while western blots demonstrated reduced POLR3BΔ10 expression in the cytoplasm and nucleus in human cells. In mice, postnatal Pdgfrα-dependent expression of the orthologous murine mutant protein resulted in recessive phenotypes including severe hypomyelination leading to ataxia, tremor, seizures and limited survival, as well as hypodontia and craniofacial abnormalities. Hypomyelination was confirmed and characterized using classic methods to quantify myelin components such as myelin basic protein and lipids, results which agreed with those produced using modern methods to quantify myelin based on the physical properties of myelin membranes. Lineage tracing uncovered the underlying mechanism for the hypomyelinating phenotype: defective oligodendrocyte precursor proliferation and differentiation resulted in a failure to produce an adequate number of mature oligodendrocytes during postnatal myelinogenesis. In summary, we characterized the Polr3bΔ10 mutation and developed an animal model that recapitulates features of POLR3-HLD caused by POLR3B mutations, shedding light on disease pathogenesis, and opening the door to the development of therapeutic interventions.
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Affiliation(s)
- Mackenzie A Michell-Robinson
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Kristin E N Watt
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Vladimir Grouza
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
| | - Julia Macintosh
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Maxime Pinard
- Translational Proteomics Research Unit, Montreal Clinical Research Institute, Montréal, QC H2W 1R7, Canada
| | - Marius Tuznik
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
| | - Xiaoru Chen
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Lama Darbelli
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Chia-Lun Wu
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Stefanie Perrier
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Daryan Chitsaz
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
| | - Nonthué A Uccelli
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
| | - Hanwen Liu
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
| | - Timothy C Cox
- Department of Oral and Craniofacial Sciences, School of Dentistry, and Pediatrics, School of Medicine, University of Missouri – Kansas City, Kansas City, MO 64108, USA
| | - Christoph W Müller
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Timothy E Kennedy
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
| | - Benoit Coulombe
- Translational Proteomics Research Unit, Montreal Clinical Research Institute, Montréal, QC H2W 1R7, Canada
- Department of Biochemistry and Molecular Medicine, University of Montréal, Montréal, QC H3C 3J7, Canada
| | - David A Rudko
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, Montreal, QC H3A 2B4, Canada
- Department of Biomedical Engineering, McGill University, Montréal, QC H3A 2B4, Canada
| | - Paul A Trainor
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
- Department of Anatomy and Cell Biology, The University of Kansas School of Medicine, Kansas City, KS 66160, USA
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 1A1, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
- Department of Pediatrics, McGill University, Montréal, QC H4A 3J1, Canada
- Department of Human Genetics, McGill University, Montréal, QC H4A 0C7, Canada
- Department of Specialized Medicine, Division of Medical Genetics, Montreal Children’s Hospital and McGill University Health Centre, Montréal, QC H4A 3J1, Canada
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5
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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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6
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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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7
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Li Y, Xu J, Xu Y, Li C, Wu Y, Liu Z. Clinical, genetic, and molecular characteristics in a central-southern Chinese cohort of genetic leukodystrophies. Ann Clin Transl Neurol 2023; 10:1556-1568. [PMID: 37434390 PMCID: PMC10502626 DOI: 10.1002/acn3.51845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/06/2023] [Accepted: 06/25/2023] [Indexed: 07/13/2023] Open
Abstract
OBJECTIVE Leukodystrophies are a diverse group of rare inherited disorders that affect the white matter of the central nervous system with a wide phenotypic spectrum. We aimed to characterize the clinical and genetic features of leukodystrophies in a central-southern Chinese cohort. METHODS A cohort of 16 Chinese probands with leukodystrophy was recruited and performed genetic analysis by targeted panels or whole-exome sequencing. Further functional analysis of identified mutations in the colony stimulating factor 1 receptor (CSF1R) gene was explored. RESULTS A total of eight pathogenic variants (3 novel, 5 documented) were identified in genes including AARS2, ABCD1, CSF1R, and GALC. Common symptoms of leukodystrophy such as cognitive decline, behavioral symptoms, bradykinesia, and spasticity were observed in mutation carriers as well as other rare features (e.g., seizure, dysarthric, and vision impairment). Overexpressing CSF1R mutants p.M875I and p.F971Sfs*7 in vitro showed pronounced cleavage CSF1R and suppressed protein expression, respectively, and reduced transcripts of both mutants were observed. CSF1 treatment revealed deficient and suppressed CSF1R phospho-activation with the mutants. In contrast to the plasma membrane and endoplasmic reticulum (ER) localized wild-type CSF1R, M875I mutant showed much less membrane association and greater detainment in the ER, whereas F971Sfs*7 mutation led to aberrant non-ER localization. Both mutations caused suppressed cell viability, which was partially resulted from deficient/suppressed CSF1R-ERK signaling. INTERPRETATION In summary, our findings expand the mutation spectrum of these genes in leukodystrophies. Supported by in vitro validation of the pathogenicity of heterozygous CSF1R mutations, our data also provide insights into the pathogenic mechanisms of CSF1R-related leukodystrophy.
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Affiliation(s)
- Yingjie Li
- Department of Neurology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Jiaming Xu
- Department of Neurology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Yan Xu
- Department of Neurology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Chuanzhou Li
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Yan Wu
- Department of Neurology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Zhijun Liu
- Department of Neurology, Union Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
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8
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Muthaffar OY, Jan MMS, Alyazidi AS, Alotibi TK, Alsulami EA. Insight into Genetic Mutations of SZT2: Is It a Syndrome? Biomedicines 2023; 11:2402. [PMID: 37760843 PMCID: PMC10525120 DOI: 10.3390/biomedicines11092402] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 08/21/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND The seizure threshold 2 (SZT2) gene encodes a protein of unknown function, which is widely expressed, confers a low seizure threshold, and enhances epileptogenesis. It also comprises the KICSTOR protein complex, which inhibits the mTORC1 pathway. A pathogenic variant in the SZT2 gene could result in hyperactive mTORC1 signaling, which can lead to several neurological disorders. AIM OF THE STUDY To review every reported case and present two novel cases to expand the current knowledge and understanding of the mutation. METHODS Whole exome sequencing (WES) was used to identify the novel cases and present their clinical and radiological findings. A detailed revision of the literature was conducted to illustrate and compare findings. The clinical, genetical, neuroimaging, and electrophysiological data were extracted. RESULTS The study included 16 female patients and 13 male patients in addition to the 2 novel male cases. Eighteen patients had heterozygous mutations; others were homozygous. The majority presented with facial dysmorphism (n = 22). Seizures were noted as the predominant hallmark (n = 26). Developmental delay and hypotonia were reported in 27 and 15 patients, respectively. The majority of patients had multifocal epileptiform discharges on the electroencephalogram (EEG) and short and thick corpus callosum on the magnetic resonance imaging (MRI). CONCLUSION Several promising features are becoming strongly linked to patients with SZT2 mutations. High variability among the cases was observed. Developmental delay and facial dysmorphism can be investigated as potential hallmarks; aiding clinicians in diagnosing the condition and optimizing management plans.
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Affiliation(s)
- Osama Y. Muthaffar
- Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.Y.M.); (M.M.S.J.)
| | - Mohammed M. S. Jan
- Department of Pediatrics, Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (O.Y.M.); (M.M.S.J.)
| | - Anas S. Alyazidi
- Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (T.K.A.); (E.A.A.)
| | - Taif K. Alotibi
- Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (T.K.A.); (E.A.A.)
| | - Eman A. Alsulami
- Faculty of Medicine, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (T.K.A.); (E.A.A.)
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9
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Muthusamy K, Sivadasan A, Dixon L, Sudhakar S, Thomas M, Danda S, Wszolek ZK, Wierenga K, Dhamija R, Gavrilova R. Adult-onset leukodystrophies: a practical guide, recent treatment updates, and future directions. Front Neurol 2023; 14:1219324. [PMID: 37564735 PMCID: PMC10410460 DOI: 10.3389/fneur.2023.1219324] [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: 05/08/2023] [Accepted: 06/19/2023] [Indexed: 08/12/2023] Open
Abstract
Adult-onset leukodystrophies though individually rare are not uncommon. This group includes several disorders with isolated adult presentations, as well as several childhood leukodystrophies with attenuated phenotypes that present at a later age. Misdiagnoses often occur due to the clinical and radiological overlap with common acquired disorders such as infectious, immune, inflammatory, vascular, metabolic, and toxic etiologies. Increased prevalence of non-specific white matter changes in adult population poses challenges during diagnostic considerations. Clinico-radiological spectrum and molecular landscape of adult-onset leukodystrophies have not been completely elucidated at this time. Diagnostic approach is less well-standardized when compared to the childhood counterpart. Absence of family history and reduced penetrance in certain disorders frequently create a dilemma. Comprehensive evaluation and molecular confirmation when available helps in prognostication, early initiation of treatment in certain disorders, enrollment in clinical trials, and provides valuable information for the family for reproductive counseling. In this review article, we aimed to formulate an approach to adult-onset leukodystrophies that will be useful in routine practice, discuss common adult-onset leukodystrophies with usual and unusual presentations, neuroimaging findings, recent advances in treatment, acquired mimics, and provide an algorithm for comprehensive clinical, radiological, and genetic evaluation that will facilitate early diagnosis and consider active treatment options when available. A high index of suspicion, awareness of the clinico-radiological presentations, and comprehensive genetic evaluation are paramount because treatment options are available for several disorders when diagnosed early in the disease course.
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Affiliation(s)
- Karthik Muthusamy
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, United States
| | - Ajith Sivadasan
- Department of Neurological Sciences, Christian Medical College, Tamil Nadu, Vellore, India
| | - Luke Dixon
- Department of Radiology, Imperial College, NHS Trust, London, United Kingdom
| | - Sniya Sudhakar
- Department of Radiology, Great Ormond Street Hospital, London, United Kingdom
| | - Maya Thomas
- Department of Neurological Sciences, Christian Medical College, Tamil Nadu, Vellore, India
| | - Sumita Danda
- Department of Medical Genetics, Christian Medical College, Vellore, Tamil Nadu, India
| | | | - Klaas Wierenga
- Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, United States
| | - Radhika Dhamija
- Department of Clinical Genomics and Neurology, Mayo Clinic, Phoenix, AZ, United States
| | - Ralitza Gavrilova
- Department of Clinical Genomics and Neurology, Mayo Clinic, Rochester, MN, United States
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10
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Gärtner J, Schröder S. Next-generation sequencing and its clinical application in leukoencephalopathies and other pediatric neurological disorders. Eur J Paediatr Neurol 2023; 45:A2-A3. [PMID: 37414653 DOI: 10.1016/j.ejpn.2023.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Affiliation(s)
- Jutta Gärtner
- Dept. Pediatrics and Adolescent Medicine, Div. Pediatric Neurology, University Medical Center Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany.
| | - Simone Schröder
- Dept. Pediatrics and Adolescent Medicine, Div. Pediatric Neurology, University Medical Center Göttingen, Georg-August-Universität Göttingen, Göttingen, Germany
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11
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Zerem A, Libzon S, Ben Sira L, Meirson H, Hausman-Kedem M, Haviv N, Yosovich K, Mory A, Baris Feldman H, Lev D, Lerman-Sagie T, Fattal-Valevski A, Hacohen Y, Marom D. Utility of genetic testing in children with leukodystrophy. Eur J Paediatr Neurol 2023; 45:29-35. [PMID: 37267771 DOI: 10.1016/j.ejpn.2023.05.008] [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: 02/04/2023] [Accepted: 05/22/2023] [Indexed: 06/04/2023]
Abstract
BACKGROUND Leukodystrophies are monogenic disorders primarily affecting the white matter. We aimed to evaluate the utility of genetic testing and time-to-diagnosis in a retrospective cohort of children with suspected leukodystrophy. METHODS Medical records of patients who attended the leukodystrophy clinic at the Dana-Dwek Children's Hospital between June 2019 and December 2021 were retrieved. Clinical, molecular, and neuroimaging data were reviewed, and the diagnostic yield was compared across genetic tests. RESULTS Sixty-seven patients (Female/Male ratio 35/32) were included. Median age at symptom onset was 9 months (interquartile range (IQR) 3-18 months), and median length of follow-up was 4.75 years (IQR 3-8.5). Time from symptom onset to a confirmed genetic diagnosis was 15months (IQR 11-30). Pathogenic variants were identified in 60/67 (89.6%) patients; classic leukodystrophy (55/67, 82.1%), leukodystrophy mimics (5/67, 7.5%). Seven patients (10.4%) remained undiagnosed. Exome sequencing showed the highest diagnostic yield (34/41, 82.9%), followed by single-gene sequencing (13/24, 54%), targeted panels (3/9, 33.3%) and chromosomal microarray (2/25, 8%). Familial pathogenic variant testing confirmed the diagnosis in 7/7 patients. A comparison between patients who presented before (n = 31) and after (n = 21) next-generation sequencing (NGS) became clinically available in Israel revealed that the time-to-diagnosis was shorter in the latter group with a median of 12months (IQR 3.5-18.5) vs. a median of 19 months (IQR 13-51) (p = 0.005). CONCLUSIONS NGS carries the highest diagnostic yield in children with suspected leukodystrophy. Access to advanced sequencing technologies accelerates speed to diagnosis, which is increasingly crucial as targeted treatments become available.
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Affiliation(s)
- Ayelet Zerem
- Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Stephanie Libzon
- Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel; Magen Rare Disease Center, Pediatric Neurology Unit, Wolfson Medical Center, Holon, Israel
| | - Liat Ben Sira
- Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel; Pediatric Radiology, Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Hadas Meirson
- Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Hausman-Kedem
- Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Noam Haviv
- Statistical Advisor and Senior Lecturer, The Ashkelon Academic College, Israel
| | - Keren Yosovich
- Magen Rare Disease Center, Genetics Institute, Wolfson Medical Center, Holon, Israel
| | - Adi Mory
- Genetics Institute and Genomic Center, Tel Aviv Sourasky Medical Center, Israel
| | - Hagit Baris Feldman
- Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel; Genetics Institute and Genomic Center, Tel Aviv Sourasky Medical Center, Israel
| | - Dorit Lev
- Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel; Magen Rare Disease Center, Genetics Institute, Wolfson Medical Center, Holon, Israel
| | - Tally Lerman-Sagie
- Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel; Magen Rare Disease Center, Pediatric Neurology Unit, Wolfson Medical Center, Holon, Israel
| | - Aviva Fattal-Valevski
- Pediatric Neurology Institute, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yael Hacohen
- Queen Square MS Centre, UCL Queen Square Institute of Neurology, Faculty of Brain Sciences, University College London, London, United Kingdom; Department of Neurology, Great Ormond Street Hospital for Children, London, United Kingdom
| | - Daphna Marom
- Sackler Faulty of Medicine, Tel Aviv University, Tel Aviv, Israel; Genetics Institute and Genomic Center, Tel Aviv Sourasky Medical Center, Israel
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12
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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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13
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Du Z, Zhou X, Lai Y, Xu J, Zhang Y, Zhou S, Feng Z, Yu L, Tang Y, Wang W, Yu L, Tian C, Ran T, Chen H, Guddat LW, Liu F, Gao Y, Rao Z, Gong H. Structure of the human respiratory complex II. Proc Natl Acad Sci U S A 2023; 120:e2216713120. [PMID: 37098072 PMCID: PMC10161127 DOI: 10.1073/pnas.2216713120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 03/10/2023] [Indexed: 04/26/2023] Open
Abstract
Human complex II is a key protein complex that links two essential energy-producing processes: the tricarboxylic acid cycle and oxidative phosphorylation. Deficiencies due to mutagenesis have been shown to cause mitochondrial disease and some types of cancers. However, the structure of this complex is yet to be resolved, hindering a comprehensive understanding of the functional aspects of this molecular machine. Here, we have determined the structure of human complex II in the presence of ubiquinone at 2.86 Å resolution by cryoelectron microscopy, showing it comprises two water-soluble subunits, SDHA and SDHB, and two membrane-spanning subunits, SDHC and SDHD. This structure allows us to propose a route for electron transfer. In addition, clinically relevant mutations are mapped onto the structure. This mapping provides a molecular understanding to explain why these variants have the potential to produce disease.
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Affiliation(s)
- Zhanqiang Du
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Xiaoting Zhou
- State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot 010070, China
| | - Yuezheng Lai
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Jinxu Xu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Yuying Zhang
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Shan Zhou
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Ziyan Feng
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Long Yu
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Yanting Tang
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
| | - Weiwei Wang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Lu Yu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Changlin Tian
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Ting Ran
- Innovative Center For Pathogen Research, Guangzhou Laboratory, Guangzhou 510005, China
| | - Hongming Chen
- Innovative Center For Pathogen Research, Guangzhou Laboratory, Guangzhou 510005, China
| | - Luke W Guddat
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Fengjiang Liu
- Innovative Center For Pathogen Research, Guangzhou Laboratory, Guangzhou 510005, China
| | - Yan Gao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zihe Rao
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China
| | - Hongri Gong
- State Key Laboratory of Medicinal Chemical Biology, Frontiers Science Center for Cell Responses, College of Life Sciences, Nankai University, Tianjin 300353, China
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14
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Baalmann N, Spielmann M, Gillessen-Kaesbach G, Hanker B, Schmidt J, Lill CM, Hellenbroich Y, Greiten B, Lohmann K, Trinh J, Hüning I. Phenotypic specificity in patients with neurodevelopmental delay does not correlate with diagnostic yield of trio-exome sequencing. Eur J Med Genet 2023; 66:104774. [PMID: 37120078 DOI: 10.1016/j.ejmg.2023.104774] [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: 10/24/2022] [Revised: 03/12/2023] [Accepted: 04/26/2023] [Indexed: 05/01/2023]
Abstract
In this study, we aimed to examine the diagnostic yield achieved by applying a trio approach in exome sequencing (ES) and the interdependency between the clinical specificity in families with neurodevelopmental delay. Thirty-seven families were recruited and trio-ES as well as three criteria for estimating the clinical phenotypic specificity were suggested and applied to the underaged children. All our patients showed neurodevelopmental delay and most of them a large spectrum of congenital anomalies. Applying the pathogenicity guidelines of the American College of Medical Genetics (ACMG), likely pathogenic (29.7%) and pathogenic variants (8.1%) were found in 40,5% of our index patients. Additionally, we found four variants of uncertain significance (VUS; according to ACMG) and two genes of interest (GOI; going beyond ACMG classification) (GLRA4, NRXN2). Spastic Paraplegia 4 (SPG4) caused by a formerly known SPAST variant was diagnosed in a patient with a complex phenotype, in whom a second genetic disorder may be present. A potential pathogenic variant linked to severe intellectual disability in GLRA4 requires further investigation. No interdependency between the diagnostic yield and the clinical specificity of the phenotypes could be observed. In consequence, trio-ES should be used early in the diagnostic process, independently from the specificity of the patient.
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Affiliation(s)
- Nadja Baalmann
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | - Malte Spielmann
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | | | - Britta Hanker
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | - Julia Schmidt
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany; Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany.
| | - Christina M Lill
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany; Institute of Neurogenetics, University of Lübeck, Lübeck, Germany; Lübeck Interdisciplinary Platform for Genome Analytics, University of Lübeck, Germany; Ageing Epidemiology Research Unit (AGE), School of Public Health, Imperial College London, London, UK.
| | | | - Bianca Greiten
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
| | - Joanne Trinh
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany.
| | - Irina Hüning
- Institute of Human Genetics, University of Lübeck, Lübeck, Germany.
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15
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Perrier S, Guerrero K, Tran LT, Michell-Robinson MA, Legault G, Brais B, Sylvain M, Dorman J, Demos M, Köhler W, Pastinen T, Thiffault I, Bernard G. Solving inherited white matter disorder etiologies in the neurology clinic: Challenges and lessons learned using next-generation sequencing. Front Neurol 2023; 14:1148377. [PMID: 37077564 PMCID: PMC10108901 DOI: 10.3389/fneur.2023.1148377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 02/23/2023] [Indexed: 04/05/2023] Open
Abstract
IntroductionRare neurodevelopmental disorders, including inherited white matter disorders or leukodystrophies, often present a diagnostic challenge on a genetic level given the large number of causal genes associated with a range of disease subtypes. This study aims to demonstrate the challenges and lessons learned in the genetic investigations of leukodystrophies through presentation of a series of cases solved using exome or genome sequencing.MethodsEach of the six patients had a leukodystrophy associated with hypomyelination or delayed myelination on MRI, and inconclusive clinical diagnostic genetic testing results. We performed next generation sequencing (case-based exome or genome sequencing) to further investigate the genetic cause of disease.ResultsFollowing different lines of investigation, molecular diagnoses were obtained for each case, with patients harboring pathogenic variants in a range of genes including TMEM106B, GJA1, AGA, POLR3A, and TUBB4A. We describe the lessons learned in reaching the genetic diagnosis, including the importance of (a) utilizing proper multi-gene panels in clinical testing, (b) assessing the reliability of biochemical assays in supporting diagnoses, and (c) understanding the limitations of exome sequencing methods in regard to CNV detection and region coverage in GC-rich areas.DiscussionThis study illustrates the importance of applying a collaborative diagnostic approach by combining detailed phenotyping data and metabolic results from the clinical environment with advanced next generation sequencing analysis techniques from the research environment to increase the diagnostic yield in patients with genetically unresolved leukodystrophies.
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Affiliation(s)
- Stefanie Perrier
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Kether Guerrero
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Luan T. Tran
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Mackenzie A. Michell-Robinson
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Geneviève Legault
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Department of Pediatrics, McGill University, Montreal, QC, Canada
| | - Bernard Brais
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Michel Sylvain
- Division of Pediatric Neurology, Centre Mère-Enfant Soleil du CHU de Québec - Université Laval, Québec City, QC, Canada
| | - James Dorman
- John H. Stroger Jr. Hospital of Cook County, Chicago, IL, United States
- Department of Neurological Sciences, Rush Medical College, Chicago, IL, United States
| | - Michelle Demos
- Division of Neurology, Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
| | - Wolfgang Köhler
- Leukodystrophy Center, University of Leipzig Medical Center, Leipzig, Germany
| | - Tomi Pastinen
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, United States
- University of Missouri Kansas City School of Medicine, Kansas City, MO, United States
| | - Isabelle Thiffault
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, MO, United States
- University of Missouri Kansas City School of Medicine, Kansas City, MO, United States
- Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, United States
- Isabelle Thiffault
| | - Geneviève Bernard
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Department of Pediatrics, McGill University, Montreal, QC, Canada
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- Department of Specialized Medicine, Division of Medical Genetics, McGill University Health Center, Montreal, QC, Canada
- *Correspondence: Geneviève Bernard
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Papadopoulou E, Pepe G, Konitsiotis S, Chondrogiorgi M, Grigoriadis N, Kimiskidis VK, Tsivgoulis G, Mitsikostas DD, Chroni E, Domouzoglou E, Tsaousis G, Nasioulas G. The evolution of comprehensive genetic analysis in neurology: Implications for precision medicine. J Neurol Sci 2023; 447:120609. [PMID: 36905813 DOI: 10.1016/j.jns.2023.120609] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/07/2023]
Abstract
Technological advancements have facilitated the availability of reliable and thorough genetic analysis in many medical fields, including neurology. In this review, we focus on the importance of selecting the appropriate genetic test to aid in the accurate identification of disease utilizing currently employed technologies for analyzing monogenic neurological disorders. Moreover, the applicability of comprehensive analysis via NGS for various genetically heterogeneous neurological disorders is reviewed, revealing its efficiency in clarifying a frequently cloudy diagnostic picture and delivering a conclusive and solid diagnosis that is essential for the proper management of the patient. The feasibility and effectiveness of medical genetics in neurology require interdisciplinary cooperation among several medical specialties and geneticists, to select and perform the most relevant test according to each patient's medical history, using the most appropriate technological tools. The prerequisites for a comprehensive genetic analysis are discussed, highlighting the utility of appropriate gene selection, variant annotation, and classification. Moreover, genetic counseling and interdisciplinary collaboration could improve diagnostic yield further. Additionally, a sub-analysis is conducted on the 1,502,769 variation records with submitted interpretations in the Clinical Variation (ClinVar) database, with a focus on neurology-related genes, to clarify the value of suitable variant categorization. Finally, we review the current applications of genetic analysis in the diagnosis and personalized management of neurological patients and the advances in the research and scientific knowledge of hereditary neurological disorders that are evolving the utility of genetic analysis towards the individualization of the treatment strategy.
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Affiliation(s)
| | - Georgia Pepe
- GeneKor Medical SA, Spaton 52, Gerakas 15344, Greece
| | - Spiridon Konitsiotis
- Department of Neurology, University of Ioannina, Stavrou Niarchou Avenue, Ioannina 45500, Greece
| | - Maria Chondrogiorgi
- Department of Neurology, University of Ioannina, Stavrou Niarchou Avenue, Ioannina 45500, Greece
| | - Nikolaos Grigoriadis
- Second Department of Neurology, "AHEPA" University Hospital, Aristotle University of Thessaloniki, St. Kiriakidis 1, Thessaloniki 54636, Greece
| | - Vasilios K Kimiskidis
- First Department of Neurology, "AHEPA" University hospital, Aristotle University of Thessaloniki, St. Kiriakidis 1, Thessaloniki 54636, Greece
| | - Georgios Tsivgoulis
- Second Department of Neurology, School of Medicine, "Attikon" University Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Dimos D Mitsikostas
- First Department of Neurology, Aeginition Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Elisabeth Chroni
- Department of Neurology, School of Medicine, University of Patras, Rio-Patras, Greece
| | - Eleni Domouzoglou
- Department of Pediatrics, University Hospital of Ioannina, Stavrou Niarchou Avenue, Ioannina 45500, Greece
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Akbari M, Ebrahimi Tapeh Z, Zaersabet M, Rahimi H, Ganji M. Novel pyrroline-5-carboxylate reductase 2 (PYCR2) mutation in an Iranian patient with hypomyelinating leukodystrophy: findings of molecular and in silico investigations. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2023. [DOI: 10.1186/s43042-023-00393-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abstract
Background
Hypomyelinating leukodystrophy (HLD) is a specific group of leukodystrophies and is characterized by progressive postnatal growth delay that represents a type of clinically overlapping but genetically heterogeneous diseases with autosomal recessive inheritance. Loss-of-function mutations in PYCR2 are one of the main causes of HLD type 10 (HLD10), which is identified by cerebral hypomyelination, inadequate growth, brain atrophy, and movement abnormality. This study aimed to investigate the molecular etiology of HLD10 disorder in an Iranian patient from a consanguineous marriage family.
Results
The DNA samples were extracted from the patient, a 9-year-old girl, and her parents. Whole-exome sequencing was conducted for these samples and the results were eventually confirmed and segregated via Sanger sequencing. Our findings demonstrated a novel homozygous frameshift mutation in PYCR2 gene, c.135dup (NM_013328.4). The heterozygous state of this variant was confirmed in parents. Additionally, this mutation was predicted to exhibit damaging effects through protein sequence alteration.
Conclusions
Such findings are of importance for understanding the underlying pathogenicity mechanisms and for improving genetic counseling knowledge of HLD patients for families.
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18
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Zheng F, Lin Z, Hu Y, Shi X, Zhao Q, Lin Z. Identification of a Novel Non-Canonical Splice-Site Variant in ABCD1. J Clin Med 2023; 12:jcm12020473. [PMID: 36675402 PMCID: PMC9863105 DOI: 10.3390/jcm12020473] [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: 11/29/2022] [Revised: 12/27/2022] [Accepted: 12/27/2022] [Indexed: 01/09/2023] Open
Abstract
Cerebral adrenoleukodystrophy (CALD) is a fatal genetic disease characterized by rapid, devastating neurological decline, with a narrow curative treatment window in the early stage. Non-canonical splice-site (NCSS) variants can easily be missed during genomic DNA analyses, and only a few of them in ABCD1 have been explored. Here, we studied a Chinese patient with clinical features similar to those of early-stage CALD but with a negative molecular diagnosis and a sibling who had presumably died of CALD. Trio-based whole-exome sequencing (trio-WES) and RNA sequencing (RNA-Seq) revealed a novel hemizygote NCSS variant c.901-25_901-9 del in ABCD1 intron 1, resulting in a complex splicing pattern. The in vitro minigene assay revealed that the c.901-25_901-9 del construct contained two aberrant transcripts that caused skipping of exon 2 and a small 48-bp deletion on left of the same exon. We identified a novel NCSS variant, that extends the spectrum of the known ABCD1 variants, and demonstrated the pathogenicity of this gene variant. Our findings highlight the importance of combining RNA-Seq and WES techniques for prompt diagnosis of leukodystrophy with NCSS variants.
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Affiliation(s)
- Feixia Zheng
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
- Wenzhou Key Laboratory of Perinatal Medicine, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
| | - Zhongdong Lin
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
| | - Ying Hu
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
| | - Xulai Shi
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
| | - Qianlei Zhao
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
- Wenzhou Key Laboratory of Perinatal Medicine, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
| | - Zhenlang Lin
- Department of Pediatrics, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
- Wenzhou Key Laboratory of Perinatal Medicine, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou 325027, China
- Correspondence: ; Tel.: +86-13-80-668-9800
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Attard TJ, Welburn JPI, Marsh JA. Understanding molecular mechanisms and predicting phenotypic effects of pathogenic tubulin mutations. PLoS Comput Biol 2022; 18:e1010611. [PMID: 36206299 PMCID: PMC9581425 DOI: 10.1371/journal.pcbi.1010611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/19/2022] [Accepted: 09/28/2022] [Indexed: 11/21/2022] Open
Abstract
Cells rely heavily on microtubules for several processes, including cell division and molecular trafficking. Mutations in the different tubulin-α and -β proteins that comprise microtubules have been associated with various diseases and are often dominant, sporadic and congenital. While the earliest reported tubulin mutations affect neurodevelopment, mutations are also associated with other disorders such as bleeding disorders and infertility. We performed a systematic survey of tubulin mutations across all isotypes in order to improve our understanding of how they cause disease, and increase our ability to predict their phenotypic effects. Both protein structural analyses and computational variant effect predictors were very limited in their utility for differentiating between pathogenic and benign mutations. This was even worse for those genes associated with non-neurodevelopmental disorders. We selected tubulin-α and -β disease mutations that were most poorly predicted for experimental characterisation. These mutants co-localise to the mitotic spindle in HeLa cells, suggesting they may exert dominant-negative effects by altering microtubule properties. Our results show that tubulin mutations represent a blind spot for current computational approaches, being much more poorly predicted than mutations in most human disease genes. We suggest that this is likely due to their strong association with dominant-negative and gain-of-function mechanisms.
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Affiliation(s)
- Thomas J. Attard
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Julie P. I. Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Joseph A. Marsh
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
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20
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Adang L. Leukodystrophies. Continuum (Minneap Minn) 2022; 28:1194-1216. [PMID: 35938662 DOI: 10.1212/con.0000000000001130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE OF REVIEW This article reviews the most common leukodystrophies and is focused on diagnosis, clinical features, and emerging therapeutic options. RECENT FINDINGS In the past decade, the recognition of leukodystrophies has exponentially increased, and now this class includes more than 30 distinct disorders. Classically recognized as progressive and fatal disorders affecting young children, it is now understood that leukodystrophies are associated with an increasing spectrum of neurologic trajectories and can affect all ages. Next-generation sequencing and newborn screening allow the opportunity for the recognition of presymptomatic and atypical cases. These new testing opportunities, in combination with growing numbers of natural history studies and clinical consensus guidelines, have helped improve diagnosis and clinical care. Additionally, a more granular understanding of disease outcomes informs clinical trial design and has led to several recent therapeutic advances. This review summarizes the current understanding of the clinical manifestations of disease and treatment options for the most common leukodystrophies. SUMMARY As early testing becomes more readily available through next-generation sequencing and newborn screening, neurologists will better understand the true incidence of the leukodystrophies and be able to diagnose children within the therapeutic window. As targeted therapies are developed, it becomes increasingly imperative that this broad spectrum of disorders is recognized and diagnosed. This work summarizes key advances in the leukodystrophy field.
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21
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Stutterd CA, Vanderver A, Lockhart PJ, Helman G, Pope K, Uebergang E, Love C, Delatycki MB, Thorburn D, Mackay MT, Peters H, Kornberg AJ, Patel C, Rodriguez-Casero V, Waak M, Silberstein J, Sinclair A, Nolan M, Field M, Davis MR, Fahey M, Scheffer IE, Freeman JL, Wolf NI, Taft RJ, van der Knaap MS, Simons C, Leventer RJ. Unclassified white matter disorders: A diagnostic journey requiring close collaboration between clinical and laboratory services. Eur J Med Genet 2022; 65:104551. [PMID: 35803560 DOI: 10.1016/j.ejmg.2022.104551] [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: 01/23/2022] [Revised: 05/27/2022] [Accepted: 06/18/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Next generation sequencing studies have revealed an ever-increasing number of causes for genetic disorders of central nervous system white matter. A substantial number of disorders are identifiable from their specific pattern of biochemical and/or imaging findings for which single gene testing may be indicated. Beyond this group, the causes of genetic white matter disorders are unclear and a broader approach to genomic testing is recommended. AIM This study aimed to identify the genetic causes for a group of individuals with unclassified white matter disorders with suspected genetic aetiology and highlight the investigations required when the initial testing is non-diagnostic. METHODS Twenty-six individuals from 22 families with unclassified white matter disorders underwent deep phenotyping and genome sequencing performed on trio, or larger, family groups. Functional studies and transcriptomics were used to resolve variants of uncertain significance with potential clinical relevance. RESULTS Causative or candidate variants were identified in 15/22 (68.2%) families. Six of the 15 implicated genes had been previously associated with white matter disease (COL4A1, NDUFV1, SLC17A5, TUBB4A, BOLA3, DARS2). Patients with variants in the latter two presented with an atypical phenotype. The other nine genes had not been specifically associated with white matter disease at the time of diagnosis and included genes associated with monogenic syndromes, developmental disorders, and developmental and epileptic encephalopathies (STAG2, LSS, FIG4, GLS, PMPCA, SPTBN1, AGO2, SCN2A, SCN8A). Consequently, only 46% of the diagnoses would have been made via a current leukodystrophy gene panel test. DISCUSSION These results confirm the importance of broad genomic testing for patients with white matter disorders. The high diagnostic yield reflects the integration of deep phenotyping, whole genome sequencing, trio analysis, functional studies, and transcriptomic analyses. CONCLUSIONS Genetic white matter disorders are genetically and phenotypically heterogeneous. Deep phenotyping together with a range of genomic technologies underpin the identification of causes of unclassified white matter disease. A molecular diagnosis is essential for prognostication, appropriate management, and accurate reproductive counseling.
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Affiliation(s)
- C A Stutterd
- Murdoch Children's Research Institute, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - A Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - P J Lockhart
- Murdoch Children's Research Institute, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - G Helman
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Queensland, Australia
| | - K Pope
- Murdoch Children's Research Institute, Victoria, Australia
| | - E Uebergang
- Murdoch Children's Research Institute, Victoria, Australia
| | - C Love
- Murdoch Children's Research Institute, Victoria, Australia
| | - M B Delatycki
- Murdoch Children's Research Institute, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - D Thorburn
- Murdoch Children's Research Institute, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - M T Mackay
- Murdoch Children's Research Institute, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - H Peters
- Murdoch Children's Research Institute, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia; Department of Metabolic Medicine, Royal Children's Hospital, Victoria, Australia
| | - A J Kornberg
- Murdoch Children's Research Institute, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - C Patel
- Genetic Health Queensland, Royal Brisbane and Women's Children's Hospital, South Brisbane Queensland, Australia; Centre for Children's Health Research, The University of Queensland, Queensland, Australia
| | - V Rodriguez-Casero
- Murdoch Children's Research Institute, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - M Waak
- Centre for Children's Health Research, The University of Queensland, Queensland, Australia; Department of Neurosciences, Queensland Children's Hospital, Brisbane, Queensland, Australia
| | - J Silberstein
- Princess Margaret Hospital, Perth, Western Australia, Australia
| | - A Sinclair
- Department of Neurosciences, Queensland Children's Hospital, Brisbane, Queensland, Australia
| | - M Nolan
- Department of Paediatric Neurology, Starship Children's Health, Auckland, New Zealand
| | - M Field
- Genetics of Learning Disability (GOLD) Service, Hunter Genetics, Newcastle, New South Wales, Australia
| | - M R Davis
- Department of Diagnostic Genomics, Path West Laboratory Medicine, QEII Medical Centre, Hospital Avenue, Nedlands, WA, Australia
| | - M Fahey
- Department of Paediatrics, Monash University, Victoria, Australia
| | - I E Scheffer
- Murdoch Children's Research Institute, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia; Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria, 3084, Australia; The Florey Institute of Neuroscience and Mental Health and Murdoch Children's Research Institute, Parkville, Victoria, 3052, Australia
| | - J L Freeman
- Murdoch Children's Research Institute, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia
| | - N I Wolf
- Amsterdam Leukodystrophy Center, Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, VU University, Amsterdam Neuroscience, Amsterdam, the Netherlands; Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands
| | - R J Taft
- Illumina Inc, San Diego, CA, USA
| | - M S van der Knaap
- Amsterdam Leukodystrophy Center, Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, VU University, Amsterdam Neuroscience, Amsterdam, the Netherlands; Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, the Netherlands
| | - C Simons
- Murdoch Children's Research Institute, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia.
| | - R J Leventer
- Murdoch Children's Research Institute, Victoria, Australia; Department of Neurology, Royal Children's Hospital, Victoria, Australia; Department of Paediatrics, University of Melbourne, Victoria, Australia.
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22
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Schobers G, Schieving JH, Yntema HG, Pennings M, Pfundt R, Derks R, Hofste T, de Wijs I, Wieskamp N, van den Heuvel S, Galbany JC, Gilissen C, Nelen M, Brunner HG, Kleefstra T, Kamsteeg EJ, Willemsen MAAP, Vissers LELM. Reanalysis of exome negative patients with rare disease: a pragmatic workflow for diagnostic applications. Genome Med 2022; 14:66. [PMID: 35710456 PMCID: PMC9204949 DOI: 10.1186/s13073-022-01069-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 06/07/2022] [Indexed: 11/10/2022] Open
Abstract
Background Approximately two third of patients with a rare genetic disease remain undiagnosed after exome sequencing (ES). As part of our post-test counseling procedures, patients without a conclusive diagnosis are advised to recontact their referring clinician to discuss new diagnostic opportunities in due time. We performed a systematic study of genetically undiagnosed patients 5 years after their initial negative ES report to determine the efficiency of diverse reanalysis strategies. Methods We revisited a cohort of 150 pediatric neurology patients originally enrolled at Radboud University Medical Center, of whom 103 initially remained genetically undiagnosed. We monitored uptake of physician-initiated routine clinical and/or genetic re-evaluation (ad hoc re-evaluation) and performed systematic reanalysis, including ES-based resequencing, of all genetically undiagnosed patients (systematic re-evaluation). Results Ad hoc re-evaluation was initiated for 45 of 103 patients and yielded 18 diagnoses (including 1 non-genetic). Subsequent systematic re-evaluation identified another 14 diagnoses, increasing the diagnostic yield in our cohort from 31% (47/150) to 53% (79/150). New genetic diagnoses were established by reclassification of previously identified variants (10%, 3/31), reanalysis with enhanced bioinformatic pipelines (19%, 6/31), improved coverage after resequencing (29%, 9/31), and new disease-gene associations (42%, 13/31). Crucially, our systematic study also showed that 11 of the 14 further conclusive genetic diagnoses were made in patients without a genetic diagnosis that did not recontact their referring clinician. Conclusions We find that upon re-evaluation of undiagnosed patients, both reanalysis of existing ES data as well as resequencing strategies are needed to identify additional genetic diagnoses. Importantly, not all patients are routinely re-evaluated in clinical care, prolonging their diagnostic trajectory, unless systematic reanalysis is facilitated. We have translated our observations into considerations for systematic and ad hoc reanalysis in routine genetic care. Supplementary Information The online version contains supplementary material available at 10.1186/s13073-022-01069-z.
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Affiliation(s)
- Gaby Schobers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Jolanda H Schieving
- Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Department of Pediatric Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Helger G Yntema
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maartje Pennings
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ronny Derks
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tom Hofste
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ilse de Wijs
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Nienke Wieskamp
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Simone van den Heuvel
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jordi Corominas Galbany
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Marcel Nelen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Han G Brunner
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Department of Clinical Genetics, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Michèl A A P Willemsen
- Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Department of Pediatric Neurology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lisenka E L M Vissers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands. .,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
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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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24
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[Research advances in the clinical genetics of leukodystrophy in children]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2022; 24:711-716. [PMID: 35762440 PMCID: PMC9250391 DOI: 10.7499/j.issn.1008-8830.2202020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Leukodystrophy (LD) is a group of genetic heterogeneous diseases characterized by primary abnormalities in glial cells and myelin sheath, and it is a common nervous system disease in children and has significant genotype-phenotype correlation. In recent years, the improvement in high-throughput sequencing has changed the diagnostic and therapeutic mode of LD, and elaborative phenotype analysis, such as the collection of natural history and multimodal neuroimaging evaluation during development, also provides important information for subsequent genetic diagnosis. This article reviews LD from the perspective of clinical genetics, in order to improve the awareness of this disease among pediatricians in China.
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25
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Hashiguchi M, Monden Y, Nozaki Y, Watanabe K, Nakashima M, Saitsu H, Yamagata T, Osaka H. A TUBB4A Met363Thr variant in pediatric hypomyelination without atrophy of the basal ganglia. Hum Genome Var 2022; 9:19. [PMID: 35661708 PMCID: PMC9166743 DOI: 10.1038/s41439-022-00198-6] [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: 03/17/2022] [Revised: 04/21/2022] [Accepted: 05/02/2022] [Indexed: 01/11/2023] Open
Abstract
TUBB4A gene variants cause dystonia type 4 and hypomyelination with atrophy of the basal ganglia and cerebellum. We report the case of a child with delayed motor development, intellectual disability, and dystonia. Magnetic resonance imaging revealed hypomyelination and progressive cerebellar atrophy without atrophy of the basal ganglia. Whole-exome sequencing revealed a de novo heterozygous variant, c.1088T > C, p.(Met363Thr), in TUBB4A. The present case further supports the vulnerability of the cerebellum in patients with TUBB4A pathogenic variants.
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Affiliation(s)
- Marina Hashiguchi
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yukifumi Monden
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yasuyuki Nozaki
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan ,Department of Pediatrics, Shin-Oyama City Hospital, Tochigi, Japan
| | - Kazuki Watanabe
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Mitsuko Nakashima
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Hirotomo Saitsu
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Takanori Yamagata
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Hitoshi Osaka
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
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26
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Vision and sensorimotor defects associated with loss of Vps11 function in a zebrafish model of genetic leukoencephalopathy. Sci Rep 2022; 12:3511. [PMID: 35241734 PMCID: PMC8894412 DOI: 10.1038/s41598-022-07448-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 02/17/2022] [Indexed: 12/05/2022] Open
Abstract
Genetic Leukoencephalopathies (gLEs) are heritable white matter disorders that cause progressive neurological abnormalities. A founder mutation in the human endolysosomal trafficking protein VPS11 has been identified in Ashkenazi Jewish patients manifesting classic gLE symptoms of hypomyelination, developmental delay, motor and systemic deficits. In this study, we characterized the visual and sensorimotor function of two zebrafish vps11 mutant lines: the previously reported vps11(plt), and a new vps11(−/−) null mutant line, using behavioral analysis to track larval motor responses to visual and acoustic stimuli. We found that mutant larvae from both vps11(plt) and vps11(−/−) lines were able to visually distinguish light and dark, but showed a progressive loss of a normal sensorimotor response to visual stimuli from 5 days post fertilization (dpf) to 7dpf. Additionally, optokinetic response analysis performed at 5dpf indicated that the mutants were significantly visually impaired. Both mutant lines also displayed a progressively lower sensorimotor response to a singular acoustic stimulus from 5-7dpf. Next, we tested the habituation response of the mutant lines to series of acoustic taps. We found both mutant lines habituated faster than their siblings, and that vps11(plt) mutants habituated faster than the vps11(−/−) mutants. Together, these data suggest that loss of Vps11 function results in progressive visual and sensorimotor abnormalities in the zebrafish vps11(plt) and vps11(−/−) mutant lines. This is the first study to characterize behavioral deficits in a vertebrate model of Vps11-dependent gLE. The mutants and behavioral assays described here could be a valuable model system in which to test potential pharmacological interventions for gLE.
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27
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Mickeviciute GC, Valiuskyte M, Plattén M, Wszolek ZK, Andersen O, Danylaité Karrenbauer V, Ineichen BV, Granberg T. Neuroimaging phenotypes of CSF1R-related leukoencephalopathy: Systematic review, meta-analysis, and imaging recommendations. J Intern Med 2022; 291:269-282. [PMID: 34875121 DOI: 10.1111/joim.13420] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy is a rare but fatal microgliopathy. The diagnosis is often delayed due to multifaceted symptoms that can mimic several other neurological disorders. Imaging provides diagnostic clues that help identify cases. The objective of this study was to integrate the literature on neuroimaging phenotypes of CSF1R-related leukoencephalopathy. A systematic review and meta-analysis were performed for neuroimaging findings of CSF1R-related leukoencephalopathy via PubMed, Web of Science, and Embase on 25 August 2021. The search included cases with confirmed CSF1R mutations reported under the previous terms hereditary diffuse leukoencephalopathy with spheroids, pigmentary orthochromatic leukodystrophy, and adult-onset leukoencephalopathy with axonal spheroids and pigmented glia. In 78 studies providing neuroimaging data, 195 cases were identified carrying CSF1R mutations in 14 exons and five introns. Women had a statistically significant earlier age of onset (p = 0.041, 40 vs 43 years). Mean delay between symptom onset and neuroimaging was 2.3 years. Main magnetic resonance imaging (MRI) findings were frontoparietal white matter lesions, callosal thinning, and foci of restricted diffusion. The hallmark computed tomography (CT) finding was white matter calcifications. Widespread cerebral hypometabolism and hypoperfusion were reported using positron emission tomography and single-photon emission computed tomography. In conclusion, CSF1R-related leukoencephalopathy is associated with progressive white matter lesions and brain atrophy that can resemble other neurodegenerative/-inflammatory disorders. However, long-lasting diffusion restriction and parenchymal calcifications are more specific findings that can aid the differential diagnosis. Native brain CT and brain MRI (with and without a contrast agent) are recommended with proposed protocols and pictorial examples are provided.
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Affiliation(s)
- Goda-Camille Mickeviciute
- Department of Physical Medicine and Rehabilitation, Vilnius University Hospital Santaros Klinikos, Vilnius, Lithuania
| | - Monika Valiuskyte
- Department of Skin and Venereal Diseases, Hospital of Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Michael Plattén
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden.,School of Chemistry, Biotechnology, and Health, Royal Institute of Technology, Stockholm, Sweden
| | | | - Oluf Andersen
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Virginija Danylaité Karrenbauer
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Benjamin V Ineichen
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Tobias Granberg
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
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Garel P, Lesca G, Ville D, Poulat AL, Chatron N, Sanlaville D, Des Portes V, Arzimanoglou A, Lion-François L. CNTNAP1-encephalopathy: Six novel patients surviving the neonatal period. Eur J Paediatr Neurol 2022; 37:98-104. [PMID: 35182943 DOI: 10.1016/j.ejpn.2022.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 12/29/2021] [Accepted: 01/26/2022] [Indexed: 11/29/2022]
Abstract
CNTNAP1 encodes CASPR1, involved in the paranodal junction. Thirty-three patients, with CNTNAP1 biallelic mutations have been described previously. Most of them had a very severe neurological impairment and passed away in the first months of life. We identified four patients, from two unrelated families, who survived over the neonatal period. Exome sequencing showed compound heterozygous or homozygous variants. Severe hypotonia was a constant feature. When compared to previous reports, the most important clinical differences observed in our patients were the absence of antenatal problems and, in two of them, the lack of respiratory distress. Less commonly reported characteristics such as epileptic seizures, dystonia, and impaired communication skills were also observed. MRIs revealed hypomyelination or abnormal white matter signal, cerebral or cerebellar atrophy. The present observations support a wider than initially reported clinical spectrum, including survival after the neonatal period and additional neurological features. They contribute to better delineate the phenotype-genotype correlations for CNTNAP1. In addition, we report one more family with two sibs who carry a missense variant of uncertain significance which we propose could be associated with a milder phenotype.
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Affiliation(s)
- Pauline Garel
- Department of Pediatrics, Centre Hospitalier Universitaire de Saint Etienne, Saint-Priest-en-Jarez, France.
| | - Gaetan Lesca
- Genetics Department, Member of the ERN EpiCARE, HFME, University Hospitals of Lyon (HCL), Lyon, France; INMG (Institut Neuromyogene), Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, Lyon, France
| | - Dorothée Ville
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Anne-Lise Poulat
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Nicolas Chatron
- Department of Biology and Pathology, University Hospitals of Lyon (HCL), Lyon, France; INMG (Institut Neuromyogene), Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, Lyon, France
| | - Damien Sanlaville
- Department of Biology and Pathology, University Hospitals of Lyon (HCL), Lyon, France; INMG (Institut Neuromyogene), Faculté de Médecine Lyon Est, Université Claude Bernard Lyon 1, Lyon, France
| | - Vincent Des Portes
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Alexis Arzimanoglou
- Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
| | - Laurence Lion-François
- Pediatric Neurology Department, Member of the ERN EpiCARE, University Hospitals of Lyon (HCL), Lyon, France
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29
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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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30
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Fellner A, Goldberg Y, Lev D, Basel-Salmon L, Shor O, Benninger F. In-silico phenotype prediction by normal mode variant analysis in TUBB4A-related disease. Sci Rep 2022; 12:58. [PMID: 34997144 PMCID: PMC8741991 DOI: 10.1038/s41598-021-04337-x] [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: 09/18/2021] [Accepted: 12/21/2021] [Indexed: 11/09/2022] Open
Abstract
TUBB4A-associated disorder is a rare condition affecting the central nervous system. It displays a wide phenotypic spectrum, ranging from isolated late-onset torsion dystonia to a severe early-onset disease with developmental delay, neurological deficits, and atrophy of the basal ganglia and cerebellum, therefore complicating variant interpretation and phenotype prediction in patients carrying TUBB4A variants. We applied entropy-based normal mode analysis (NMA) to investigate genotype–phenotype correlations in TUBB4A-releated disease and to develop an in-silico approach to assist in variant interpretation and phenotype prediction in this disorder. Variants included in our analysis were those reported prior to the conclusion of data collection for this study in October 2019. All TUBB4A pathogenic missense variants reported in ClinVar and Pubmed, for which associated clinical information was available, and all benign/likely benign TUBB4A missense variants reported in ClinVar, were included in the analysis. Pathogenic variants were divided into five phenotypic subgroups. In-silico point mutagenesis in the wild-type modeled protein structure was performed for each variant. Wild-type and mutated structures were analyzed by coarse-grained NMA to quantify protein stability as entropy difference value (ΔG) for each variant. Pairwise ΔG differences between all variant pairs in each structural cluster were calculated and clustered into dendrograms. Our search yielded 41 TUBB4A pathogenic variants in 126 patients, divided into 11 partially overlapping structural clusters across the TUBB4A protein. ΔG-based cluster analysis of the NMA results revealed a continuum of genotype–phenotype correlation across each structural cluster, as well as in transition areas of partially overlapping structural clusters. Benign/likely benign variants were integrated into the genotype–phenotype continuum as expected and were clearly separated from pathogenic variants. We conclude that our results support the incorporation of the NMA-based approach used in this study in the interpretation of variant pathogenicity and phenotype prediction in TUBB4A-related disease. Moreover, our results suggest that NMA may be of value in variant interpretation in additional monogenic conditions.
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Affiliation(s)
- Avi Fellner
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel. .,Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.
| | - Yael Goldberg
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel
| | - Dorit Lev
- Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Metabolic-Neurogenetic Clinic, Wolfson Medical Center, 58220, Holon, Israel.,Rina Mor Institute of Medical Genetics, Wolfson Medical Center, 58220, Holon, Israel
| | - Lina Basel-Salmon
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
| | - Oded Shor
- Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
| | - Felix Benninger
- Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
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Ece Solmaz A, Pariltay E, Talim B, Onay H. A novel bi-allelic variant in the SDHB gene causes a severe mitochondrial complex II deficiency: a case report. Clin Neurol Neurosurg 2021; 212:107039. [PMID: 34839152 DOI: 10.1016/j.clineuro.2021.107039] [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: 08/13/2021] [Revised: 11/06/2021] [Accepted: 11/13/2021] [Indexed: 11/17/2022]
Abstract
Isolated deficiency of complex II is a rare inborn error of metabolism, accounting for approximately 2% of mitochondrial diseases. Mitochondrial complex II deficiency is predominantly seen in cases with bi-allelic SDHA mutations. To our knowledge, only 11 patients and five pathogenic variants have been reported for the SDHB gene. Our patient had a severe clinical presentation with seizures and sepsis, and died at the age of 2 months. Muscle biopsy analysis was compatible with mitochondrial myopathy with complex II deficiency. The family was given a molecular diagnosis for their child 2 years after his death via a clinical exome test of a frozen muscle biopsy specimen and a novel homozygous missense variant c.592 A>G (p.Ser198Gly) in SDHB gene was detected by next-generation sequencing. Here, we present another patient with a novel homozygous SDHB variant causing severe complex II deficiency and early death.
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Affiliation(s)
- Asli Ece Solmaz
- Department of Medical Genetics, Ege University Faculty of Medicine, Izmir, Turkey.
| | - Erhan Pariltay
- Department of Medical Genetics, Ege University Faculty of Medicine, Izmir, Turkey
| | - Beril Talim
- Pediatric Pathology Unit, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Huseyin Onay
- Department of Medical Genetics, Ege University Faculty of Medicine, Izmir, Turkey
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32
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Cherian A, Divya KP, Pavuluri H, Thomas B. The Dysfunctional Gangway: SZT2-associated Epilepsy with Thick Corpus Callosum. J Pediatr Neurosci 2021; 16:289-292. [PMID: 36531768 PMCID: PMC9757505 DOI: 10.4103/jpn.jpn_128_20] [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: 05/22/2020] [Accepted: 07/04/2020] [Indexed: 06/17/2023] Open
Abstract
Mutations in seizure threshold 2 (SZT2) gene on chromosome 1p34.2 are an of late identified cause of epilepsy and epileptic encephalopathy. We report a 3-year-old girl who presented with developmental delay, dysmorphic facies, refractory seizures, and subsequent developmental regression. Despite significant multifocal epileptiform abnormalities on her electroencephalogram, she had a paucity of generalized discharges indicating a functional deficiency of corpus callosum inspite of its increased thickness seen on magnetic resonance imaging. Her clinical exome sequencing revealed a homozygous single base pair duplication in the SZT2 gene that resulted in a frameshift mutation and premature truncation of the protein. Our case emphasizes the role of SZT2 gene in the diagnostic algorithm of early childhood refractory epilepsy especially in the context of a thick yet dysfunctional corpus callosum.
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Affiliation(s)
- Ajith Cherian
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Trivandrum, Kerala, India
| | - Kalikavil Puthanveedu Divya
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Trivandrum, Kerala, India
| | - Harini Pavuluri
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Trivandrum, Kerala, India
| | - Bejoy Thomas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Trivandrum, Kerala, India
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Ayrignac X, Carra-Dallière C, Codjia P, Mouzat K, Castelnovo G, Ellie E, Etcharry-Bouyx F, Belliard S, Marelli C, Portet F, Le Ber I, Durand-Dubief F, Mathey G, Stankoff B, Dorboz I, Drunat S, Boespflug-Tanguy O, Menjot de Champfleur N, Lumbroso S, Mochel F, Labauge P. Evaluation of CSF1R-related adult onset leukoencephalopathy with axonal spheroids and pigmented glia diagnostic criteria. Eur J Neurol 2021; 29:329-334. [PMID: 34541732 DOI: 10.1111/ene.15115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Diagnostic criteria for adult onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) due to colony-stimulating factor 1 receptor (CSF1R) mutation have recently been proposed. Our objective was to assess their accuracy in an independent multicenter cohort. METHODS We evaluated the sensitivity and specificity of the diagnostic criteria for ALSP (including the "probable" and "possible" definitions) in a national cohort of 22 patients with CSF1R mutation, and 59 patients with an alternative diagnosis of adult onset inherited leukoencephalopathy. RESULTS Overall, the sensitivity of the diagnostic criteria for ALSP was 82%, including nine of 22 patients diagnosed as probable and nine of 22 diagnosed as possible. Twenty of the 59 CSF1R mutation-negative leukoencephalopathies fulfilled the diagnostic criteria, leading to a specificity of 66%. CONCLUSIONS Diagnostic criteria for ALSP have an overall limited sensitivity along with a modest specificity. We suggest that in patients suspected of genetic leukoencephalopathy, a comprehensive magnetic resonance imaging pattern-based approach is warranted, together with white matter gene panel or whole exome sequencing.
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Affiliation(s)
- Xavier Ayrignac
- Department of Neurology, INM, INSERM, University of Montpellier, Montpellier University Hospital, Montpellier, France
| | | | - Pekes Codjia
- Department of Neurology A, Neurological Hospital, Civil Hospices of Lyon, Bron, France
| | - Kevin Mouzat
- Laboratory of Biochemistry and Molecular Biology, CHU Nimes, University of Montpellier, Nimes, France
| | | | - Emmanuel Ellie
- Department of Neurology, Bayonne Hospital, Bayonne, France
| | | | - Serge Belliard
- Department of Neurology, Pontchaillou University Hospital, CMRR, Rennes, France.,Laboratory of Neuropsychology, INSERM U 1077, Caen, France
| | - Cecilia Marelli
- EPHE, INSERM, MMDN, University of Montpellier, Montpellier, France.,Expert Center for Neurogenetic Diseases, CHU, Montpellier, France
| | - Florence Portet
- University Department of Adult Psychiatry, La Colombière Hospital, Montpellier University Hospital, Montpellier, France
| | - Isabelle Le Ber
- AP-HP, Reference Center for Rare or Early Onset Dementias, Department of Neurology, DMU Neurosciences, Pitié-Salpêtrière University Hospital, Paris, France.,Sorbonne Université, ICM (Paris Brain Institute), APHP, INSERM, CNRS, Pitié-Salpêtrière University Hospital, Paris, France
| | | | - Guillaume Mathey
- Department of Neurology, Nancy University Hospital, Nancy, France
| | - Bruno Stankoff
- Department of Neurology, St. Antoine Hospital, APHP, ICM, Paris, France
| | - Imen Dorboz
- INSERM UMR1141, Sorbonne Paris Cité, DHU PROTECT, Robert Debré Hospital, Paris Diderot University, Paris, France
| | - Severine Drunat
- Department of Genetics, APHP Robert Debré, Paris, France.,INSERM UMR, 1141, NeuroDiderot, University of Paris, Paris, France
| | - Odile Boespflug-Tanguy
- INSERM UMR1141, Sorbonne Paris Cité, DHU PROTECT, Robert Debré Hospital, Paris Diderot University, Paris, France
| | | | - Serge Lumbroso
- Laboratory of Biochemistry and Molecular Biology, CHU Nimes, University of Montpellier, Nimes, France
| | - Fanny Mochel
- Sorbonne University, ICM (Paris Brain Institute), AP-HP, INSERM, CNRS, Pitié-Salpêtrière University Hospital, Paris, France.,APHP, Department of Genetics, Pitié-Salpêtrière University Hospital, Paris, France
| | - Pierre Labauge
- Department of Neurology, INM, INSERM, University of Montpellier, Montpellier University Hospital, Montpellier, France
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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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35
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Nikam V, Mohammad NS. Tissue-specific DNase I footprint analysis confirms the association of GATAD2B Q470* variant with intellectual disability. J Genet 2021. [DOI: 10.1007/s12041-021-01308-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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36
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Zhang J, Tang W, Bhatia NK, Xu Y, Paudyal N, Liu D, Kim S, Song R, XiangWei W, Shaulsky G, Myers SJ, Dobyns W, Jayaraman V, Traynelis SF, Yuan H, Bozarth X. A de novo GRIN1 Variant Associated With Myoclonus and Developmental Delay: From Molecular Mechanism to Rescue Pharmacology. Front Genet 2021; 12:694312. [PMID: 34413877 PMCID: PMC8369916 DOI: 10.3389/fgene.2021.694312] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/21/2021] [Indexed: 12/17/2022] Open
Abstract
N-Methyl-D-aspartate receptors (NMDARs) are highly expressed in brain and play important roles in neurodevelopment and various neuropathologic conditions. Here, we describe a new phenotype in an individual associated with a novel de novo deleterious variant in GRIN1 (c.1595C>A, p.Pro532His). The clinical phenotype is characterized with developmental encephalopathy, striking stimulus-sensitive myoclonus, and frontal lobe and frontal white matter hypoplasia, with no apparent seizures detected. NMDARs that contained the P532H within the glycine-binding domain of GluN1 with either the GluN2A or GluN2B subunits were evaluated for changes in their pharmacological and biophysical properties, which surprisingly revealed only modest changes in glycine potency but a significant decrease in glutamate potency, an increase in sensitivity to endogenous zinc inhibition, a decrease in response to maximally effective concentrations of agonists, a shortened synaptic-like response time course, a decreased channel open probability, and a reduced receptor cell surface expression. Molecule dynamics simulations suggested that the variant can lead to additional interactions across the dimer interface in the agonist-binding domains, resulting in a more open GluN2 agonist-binding domain cleft, which was also confirmed by single-molecule fluorescence resonance energy transfer measurements. Based on the functional deficits identified, several positive modulators were evaluated to explore potential rescue pharmacology.
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Affiliation(s)
- Jin Zhang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Weiting Tang
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Nidhi K. Bhatia
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center, Houston, TX, United States
| | - Yuchen Xu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Nabina Paudyal
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center, Houston, TX, United States
| | - Ding Liu
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Sukhan Kim
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - Rui Song
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Wenshu XiangWei
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Gil Shaulsky
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Scott J. Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - William Dobyns
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States
| | - Vasanthi Jayaraman
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center, Houston, TX, United States
| | - Stephen F. Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - Hongjie Yuan
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, United States
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta, GA, United States
| | - Xiuhua Bozarth
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, United States
- Division of Pediatric Neurology, Department of Neurology, Seattle Children’s Hospital, University of Washington, Seattle, WA, United States
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37
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Gburek-Augustat J, Schoene-Bake JC, Bültmann E, Haack T, Buchert R, Synofzik M, Biskup S, Feuerhake F, Sorge I, Hartmann H. Pitfalls in Genetic Diagnostics: Why Phenotyping is Essential. Neuropediatrics 2021; 52:274-283. [PMID: 33791999 DOI: 10.1055/s-0041-1726306] [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] [Indexed: 10/21/2022]
Abstract
New genetic testing technologies have revolutionized medicine within the past years. It is foreseeable that the development will continue with the introduction of new techniques. Nevertheless, despite improved technology, an exact clinical description of the phenotype is still necessary and it is important to critically question findings, both before initiating genetic testing and when interpreting the results. We present four brief case vignettes to point out difficulties associated with correctly interpreting genetic findings.
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Affiliation(s)
- Janina Gburek-Augustat
- Division of Neuropediatrics, University Hospital, Hospital for Children and Adolescents, Leipzig, Germany.,Clinic for Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.,Department of Neuropediatrics, Developmental Neurology, Social Paediatrics, University Children's Hospital Tuebingen, Tuebingen, Germany
| | - Jan-Christoph Schoene-Bake
- Clinic for Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.,Gemeinschaftspraxis fuer Humangenetik, Hamburg, Germany
| | - Eva Bültmann
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Tobias Haack
- Department of Medical Genetics and Applied Genomics, Rare Disease Center Tübingen, University of Tübingen, Tübingen, Germany
| | - Rebecca Buchert
- Department of Medical Genetics and Applied Genomics, Rare Disease Center Tübingen, University of Tübingen, Tübingen, Germany
| | - Matthis Synofzik
- Department for Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Saskia Biskup
- CeGaT GmbH, Center for Genomics and Transcriptomics, Tübingen, Germany
| | | | - Ina Sorge
- Department of Pediatric Radiology, University Hospital Leipzig, Leipzig, Germany
| | - Hans Hartmann
- Clinic for Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
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38
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Cao L, Yan Y, Zhao G. NOTCH2NLC-related repeat expansion disorders: an expanding group of neurodegenerative disorders. Neurol Sci 2021; 42:4055-4062. [PMID: 34333668 DOI: 10.1007/s10072-021-05498-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/18/2021] [Indexed: 12/22/2022]
Abstract
The NOTCH2NLC gene 5' untranslated region (UTR) GGC repeat expansion mutations were identified as a genetic contributor of neuronal intranuclear inclusion disease (NIID) in 2019. Since then, the number of reported cases with NOTCH2NLC GGC repeat expansion in Asian and European populations has increased rapidly, indicating that the expanded mutation not only leads to the onset or progression of the NIID, but also may play an important role in multiple progressive neurological disorders, including Parkinson's disease, essential tremor, multiple system atrophy, Alzheimer's disease, frontotemporal dementia, amyotrophic lateral sclerosis, leukoencephalopathy, and oculopharyngodistal myopathy type 3. Nevertheless, the underlying pathogenic mechanism of the NOTCH2NLC 5' UTR region GGC repeat expansion in these disorders remains largely unknown. This review aims to present recent breakthroughs on this mutation and improve our knowledge of a newly defined spectrum of disease: NOTCH2NLC-related repeat expansion disorder.
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Affiliation(s)
- Lanxiao Cao
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, N1 Shangcheng Avenue, Yiwu, 322000, Zhejiang Province, China
| | - Yaping Yan
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China.
| | - Guohua Zhao
- Department of Neurology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, N1 Shangcheng Avenue, Yiwu, 322000, Zhejiang Province, China.
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University School of Medicine, No.88 Jiefang Road, Hangzhou, 310009, Zhejiang Province, China.
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39
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Kaur P, do Rosario MC, Hebbar M, Sharma S, Kausthubham N, Nair K, A S, Bhat Y R, Lewis LES, Nampoothiri S, Patil SJ, Suresh N, Bijarnia Mahay S, Dua Puri R, Pai S, Kaur A, Kc R, Kamath N, Bajaj S, Kumble A, Shetty R, Shenoy R, Kamate M, Shah H, Muranjan MN, Bl Y, Avabratha KS, Subramaniam G, Kadavigere R, Bielas S, Girisha KM, Shukla A. Clinical and genetic spectrum of 104 Indian families with central nervous system white matter abnormalities. Clin Genet 2021; 100:542-550. [PMID: 34302356 PMCID: PMC8918360 DOI: 10.1111/cge.14037] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/15/2022]
Abstract
Genetic disorders with predominant central nervous system white matter abnormalities (CNS WMAs), also called leukodystrophies, are heterogeneous entities. We ascertained 117 individuals with CNS WMAs from 104 unrelated families. Targeted genetic testing was carried out in 16 families and 13 of them received a diagnosis. Chromosomal microarray (CMA) was performed for three families and one received a diagnosis. Mendeliome sequencing was used for testing 11 families and all received a diagnosis. Whole exome sequencing (WES) was performed in 80 families and was diagnostic in 52 (65%). Singleton WES was diagnostic for 50/75 (66.67%) families. Overall, genetic diagnoses were obtained in 77 families (74.03%). Twenty-two of 47 distinct disorders observed in this cohort have not been reported in Indian individuals previously. Notably, disorders of nuclear mitochondrial pathology were most frequent (9 disorders in 20 families). Thirty-seven of 75 (49.33%) disease-causing variants are novel. To sum up, the present cohort describes the phenotypic and genotypic spectrum of genetic disorders with CNS WMAs in our population. It demonstrates WES, especially singleton WES, as an efficient tool in the diagnosis of these heterogeneous entities. It also highlights possible founder events and recurrent disease-causing variants in our population and their implications on the testing strategy.
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Affiliation(s)
- Parneet Kaur
- 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
| | - Malavika Hebbar
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Suvasini Sharma
- Department of Paediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children's Hospital, New Delhi, India
| | - Neethukrishna Kausthubham
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Karthik Nair
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Shrikiran A
- Department of Paediatrics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Ramesh Bhat Y
- Department of Paediatrics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Leslie Edward S Lewis
- Department of Paediatrics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Sheela Nampoothiri
- Department of Paediatric Genetics, Amrita Institute of Medical Sciences and Research Centre, Kochi, India
| | | | - Narayanaswami Suresh
- Department of Paediatrics, Lady Hardinge Medical College and Associated Kalawati Saran Children's Hospital, New Delhi, India
| | - Sunita Bijarnia Mahay
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Ratna Dua Puri
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi, India
| | - Shivanand Pai
- Department of Neurology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India
| | - Anupriya Kaur
- Department of Paediatrics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Rakshith Kc
- Department of Neurology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India
| | - Nutan Kamath
- Department of Paediatrics, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India
| | - Shruti Bajaj
- Jaslok Hospital and Research Centre, Mumbai, India
| | - Ali Kumble
- Department of Paediatrics, Indiana Hospital and Heart Institute, Mangalore, India
| | | | - Rathika Shenoy
- Department of Paediatrics, K.S. Hegde Medical Academy, NITTE University, Mangalore, India
| | - Mahesh Kamate
- Department of Paediatrics, Jawaharlal Nehru Medical College, Belgaum, India
| | - Hitesh Shah
- Department of Orthopaedics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Mamta N Muranjan
- Department of Pediatrics, Genetics Division, Seth Gordhandas Sunderdas Medical College and King Edward VII Memorial Hospital, Mumbai, Maharashtra, India
| | - Yatheesha Bl
- Dheemahi Child Neurology and Development Center, Shimoga, India
| | | | | | - Rajagopal Kadavigere
- Department of Radiodiagnosis, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Stephanie Bielas
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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40
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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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41
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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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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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The Role of White Matter Dysfunction and Leukoencephalopathy/Leukodystrophy Genes in the Aetiology of Frontotemporal Dementias: Implications for Novel Approaches to Therapeutics. Int J Mol Sci 2021; 22:ijms22052541. [PMID: 33802612 PMCID: PMC7961524 DOI: 10.3390/ijms22052541] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 02/22/2021] [Accepted: 03/01/2021] [Indexed: 01/01/2023] Open
Abstract
Frontotemporal dementia (FTD) is a common cause of presenile dementia and is characterized by behavioural and/or language changes and progressive cognitive deficits. Genetics is an important component in the aetiology of FTD, with positive family history of dementia reported for 40% of cases. This review synthesizes current knowledge of the known major FTD genes, including C9orf72 (chromosome 9 open reading frame 72), MAPT (microtubule-associated protein tau) and GRN (granulin), and their impact on neuronal and glial pathology. Further, evidence for white matter dysfunction in the aetiology of FTD and the clinical, neuroimaging and genetic overlap between FTD and leukodystrophy/leukoencephalopathy are discussed. The review highlights the role of common variants and mutations in genes such as CSF1R (colony-stimulating factor 1 receptor), CYP27A1 (cytochrome P450 family 27 subfamily A member 1), TREM2 (triggering receptor expressed on myeloid cells 2) and TMEM106B (transmembrane protein 106B) that play an integral role in microglia and oligodendrocyte function. Finally, pharmacological and non-pharmacological approaches for enhancing remyelination are discussed in terms of future treatments of FTD.
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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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Yan H, Ji H, Kubisiak T, Wu Y, Xiao J, Gu Q, Yang Y, Xie H, Ji T, Gao K, Li D, Xiong H, Shi Z, Li M, Zhang Y, Duan R, Bao X, Jiang Y, Burmeister M, Wang J. Genetic analysis of 20 patients with hypomyelinating leukodystrophy by trio-based whole-exome sequencing. J Hum Genet 2021; 66:761-768. [PMID: 33597727 PMCID: PMC8310791 DOI: 10.1038/s10038-020-00896-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/13/2020] [Accepted: 11/10/2020] [Indexed: 12/02/2022]
Abstract
Hypomyelinating leukodystrophies (HLDs) are a rare group of disorders characterized by myelin deficit of the brain-based on MRI. Here, we studied 20 patients with unexplained HLD to uncover their genetic etiology through whole-exome sequencing (WES). Trio-based WES was performed for 20 unresolved HLDs families after genetic tests for the PLP1 duplication and a panel of 115 known leukodystrophy-related genes. Variants in both known genes that related to HLDs and promising candidate genes were analyzed. Minigene splicing assay was conducted to confirm the effect of splice region variant. All 20 patients were diagnosed with HLDs clinically based on myelin deficit on MRI and impaired motor ability. Through WES, in 11 of 20 trios, 15 causative variants were detected in seven genes TUBB4A, POLR1C, POLR3A, SOX10, TMEM106B, DEGS1, and TMEM63A. The last three genes have just been discovered. Of 15 variants, six were novel. Using minigene splicing assay, splice variant POLR3A c.1770 + 5 G > C was proved to disrupt the normal splicing of intron 13 and led to a premature stop codon at position 618 (p.(P591Vfs*28)). Our analysis determined the molecular diagnosis of 11 HLDs patients. It emphasizes the heterogenicity of HLDs, the diagnostic power of trio-based WES for HLDs. Comprehensive analysis including a focus on candidate genes helps to discover novel disease-causing genes, determine the diagnosis for the first time, and improve the yield of WES. Moreover, novel mutations identified in TUBB4A, POLR3A, and POLR1C expand the mutation spectrum of these genes.
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Affiliation(s)
- Huifang Yan
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA.,Joint International Research Center of Translational and Clinical Research, Beijing, China
| | - Haoran Ji
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Thomas Kubisiak
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA
| | - Ye Wu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Jiangxi Xiao
- Department of Radiology, Peking University First Hospital, Beijing, China
| | - Qiang Gu
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yanling Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Han Xie
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Taoyun Ji
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Kai Gao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Dongxiao Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Hui Xiong
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhen Shi
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ming Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Ruoyu Duan
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Xinhua Bao
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.,Joint International Research Center of Translational and Clinical Research, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - Margit Burmeister
- Molecular & Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA. .,Departments of Computational Medicine & Bioinformatics, Psychiatry and Human Genetics, University of Michigan, Ann Arbor, MI, USA.
| | - Jingmin Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, China. .,Joint International Research Center of Translational and Clinical Research, Beijing, China. .,Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China.
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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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Chen Z, Tan YJ, Lian MM, Tandiono M, Foo JN, Lim WK, Kandiah N, Tan EK, Ng ASL. High Diagnostic Utility Incorporating a Targeted Neurodegeneration Gene Panel With MRI Brain Diagnostic Algorithms in Patients With Young-Onset Cognitive Impairment With Leukodystrophy. Front Neurol 2021; 12:631407. [PMID: 33597917 PMCID: PMC7882677 DOI: 10.3389/fneur.2021.631407] [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: 11/20/2020] [Accepted: 01/11/2021] [Indexed: 12/30/2022] Open
Abstract
Leukodystrophies are a diverse group of genetic disorders that selectively involve the white matter of the brain and are a frequent cause of young-onset cognitive impairment. Genetic diagnosis is challenging. Data on the utility of incorporating brain magnetic resonance imaging (MRI) diagnostic algorithms with next-generation sequencing (NGS) for diagnosis in a real-life clinical setting is limited. We performed sequencing using a custom-designed panel of 200 neurodegeneration-associated genes on 45 patients with young-onset cognitive impairment with leukodystrophy, and classified them based on van der Knaap et al.'s MRI diagnostic algorithm. We found that 20/45 (44.4%) patients carried pathogenic variants or novel variants predicted to be pathogenic (one in CSF1R, two in HTRA1 and 17 in NOTCH3). All patients with an established genetic diagnosis had an MRI brain pattern consistent with a specific genetic condition/s. More than half (19/37, 51.4%) of patients with MRI changes consistent with vascular cognitive impairment secondary to small vessel disease (VCI-SVD) had pathogenic variants, including all patients with pathogenic NOTCH3 (17/19, 89.5%) and HTRA1 variants (2/19, 11.5%). Amongst patients harboring pathogenic NOTCH3 variants, 13/17 (76.5%) carried the p.R544C variant seen predominantly in East Asians. Anterior temporal white matter involvement was seen only in patients with pathogenic NOTCH3 variants (6/17, 35.3%). Overall, we demonstrated a high diagnostic utility incorporating a targeted neurodegeneration gene panel and MRI-based diagnostic algorithms in young-onset cognitive impairment patients with leukodystrophy.
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Affiliation(s)
- Zhiyong Chen
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Yi Jayne Tan
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Michelle M Lian
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Moses Tandiono
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Jia Nee Foo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Human Genetics, Genome Institute of Singapore, ASTAR, Singapore, Singapore
| | - Weng Khong Lim
- Singhealth Duke-NUS Institute of Precision Medicine, Singapore, Singapore.,Cancer & Stem Cell Biology Program, Duke-NUS Medical School, Singapore, Singapore
| | - Nagaendran Kandiah
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore.,Neuroscience and Behavioural Disorders Program, Duke-NUS Medical School, Singapore, Singapore
| | - Eng-King Tan
- Neuroscience and Behavioural Disorders Program, Duke-NUS Medical School, Singapore, Singapore.,Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore, Singapore
| | - Adeline S L Ng
- Department of Neurology, National Neuroscience Institute, Tan Tock Seng Hospital, Singapore, Singapore.,Neuroscience and Behavioural Disorders Program, Duke-NUS Medical School, Singapore, Singapore
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48
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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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49
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Alfadhel M, Almuqbil M, Al Mutairi F, Umair M, Almannai M, Alghamdi M, Althiyab H, Albarakati R, Bashiri FA, Alshuaibi W, Ba-Armah D, Saleh MA, Al-Asmari A, Faqeih E, Altuwaijri W, Al-Rumayyan A, Balwi MA, Ababneh F, Alswaid AF, Eyaid WM, Almontashiri NAM, Alhashem A, Hundallah K, Bertoli-Avella A, Bauer P, Beetz C, Alrifai MT, Alfares A, Tabarki B. The Leukodystrophy Spectrum in Saudi Arabia: Epidemiological, Clinical, Radiological, and Genetic Data. Front Pediatr 2021; 9:633385. [PMID: 34055681 PMCID: PMC8155587 DOI: 10.3389/fped.2021.633385] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 03/22/2021] [Indexed: 12/14/2022] Open
Abstract
Background: Leukodystrophies (LDs) are inherited heterogeneous conditions that affect the central nervous system with or without peripheral nerve involvement. They are individually rare, but collectively, they are common. Thirty disorders were included by the Global Leukodystrophy Initiative Consortium (GLIA) as LDs. Methods: We conducted a retrospective chart review of a consecutive series of patients diagnosed with different types of LD from four large tertiary referral centers in Riyadh, Saudi Arabia. Only those 30 disorders defined by GLIA as LDs were included. Results: In total, 83 children from 61 families were identified and recruited for this study. The male-to-female ratio was 1.5:1, and a consanguinity rate of 58.5% was observed. An estimated prevalence of 1:48,780 or 2.05/100,000 was observed based on the clinical cohort, whereas a minimum of 1:32,857 or 3.04/100,000 was observed based on the local genetic database. The central region of the country exhibited the highest prevalence of LDs (48.5%). The most common LD was metachromatic leukodystrophy (MLD), and it accounted for 25.3%. The most common disorder based on carrier frequency was AGS. Novel variants were discovered in 51% of the cases, but 49% possessed previously reported variants. Missense variants were high in number and accounted for 73% of all cases. Compared with other disorders, MLD due to saposin b deficiency was more common than expected, Pelizaeus-Merzbacher-like disease was more prevalent than Pelizaeus-Merzbacher disease, and X-linked adrenoleukodystrophy was less common than expected. The mortality rate among our patients with LD was 24%. Conclusion: To the best of our knowledge, this is the largest cohort of patients with LD from Saudi Arabia. We present epidemiological, clinical, radiological, and genetic data. Furthermore, we report 18 variants that have not been reported previously. These findings are of great clinical and molecular utility for diagnosing and managing patients with LD.
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Affiliation(s)
- Majid Alfadhel
- Division of Medical Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs (MNGH), Riyadh, Saudi Arabia.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Mohammed Almuqbil
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdullah Specialist Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Fuad Al Mutairi
- Division of Medical Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Muhammad Umair
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs (MNGH), Riyadh, Saudi Arabia
| | - Mohammed Almannai
- Section of Medical Genetics, Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Malak Alghamdi
- Medical Genetics Division, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Hamad Althiyab
- Division of Medical Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Rayyan Albarakati
- Division of Medical Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Fahad A Bashiri
- Division of Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Walaa Alshuaibi
- Medical Genetics Division, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Duaa Ba-Armah
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdullah Specialist Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Mohammed A Saleh
- Section of Medical Genetics, Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Ali Al-Asmari
- Section of Medical Genetics, Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Eissa Faqeih
- Section of Medical Genetics, Children's Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Waleed Altuwaijri
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdullah Specialist Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Ahmed Al-Rumayyan
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdullah Specialist Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Mohammed Ali Balwi
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs (MNGH), Riyadh, Saudi Arabia.,Pathology and Laboratory Medicine, King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Faroug Ababneh
- Division of Medical Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Abdulrahman Faiz Alswaid
- Division of Medical Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Wafaa M Eyaid
- Division of Medical Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Naif A M Almontashiri
- Center for Genetics and Inherited Diseases, Taibah University, Almadinah Almunwarah, Saudi Arabia.,Faculty of Applied Medical Sciences, Taibah University, Almadinah Almunwarah, Saudi Arabia
| | - Amal Alhashem
- Division of Genetics, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Khalid Hundallah
- Division of Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | | | | | | | - Muhammad Talal Alrifai
- College of Medicine, King Saud bin Abdulaziz University for Health Sciences, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia.,Division of Neurology, Department of Pediatrics, King Abdullah Specialist Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (MNG-HA), Riyadh, Saudi Arabia
| | - Ahmed Alfares
- Pathology and Laboratory Medicine, King Abdulaziz Medical City, Riyadh, Saudi Arabia.,Department of Pediatrics, Almulyda, Saudi Arabia. King Abdullah International Medical Research Center (KAIMRC), Qassim University, Riyadh, Saudi Arabia
| | - Brahim Tabarki
- Division of Neurology, Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
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50
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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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