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Wang Y, Bi S, Shi X, Dai L. Optical Genome Mapping Identifies a Novel Unbalanced Translocation Between Chromosomes 4q and 6q Leading to Feeding Difficulties and Hypotonia in a Neonate: A Case Report. Appl Clin Genet 2024; 17:63-69. [PMID: 38828444 PMCID: PMC11141715 DOI: 10.2147/tacg.s465244] [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: 02/21/2024] [Accepted: 05/14/2024] [Indexed: 06/05/2024] Open
Abstract
Optical Genome Mapping (OGM) technology has garnered growing interest for the identification of chromosomal structural variations (SVs), particularly complex ones that are implicated in genetic diseases in humans. In this study, we performed genetic diagnostics on a neonatal patient who presented with feeding difficulties, hypotonia, and an atrial septal defect. We utilized a combination of trio-whole exome sequencing and OGM for our analysis. The results revealed an unbalanced translocation between maternal chromosomes 4 and 6 in the proband, ogm[GRch38]t(4:6)(q35.2;q25.3), resulting in a 2.8 Mb deletion at the 4q35 terminal and a 10.2 Mb duplication at the 6q25 terminal. In summary, this study highlights how OGM, in conjunction with other genetic approaches, can unveil the genetic etiology of complex clinical syndromes. Neonatal patients often exhibit low specific phenotypes, underlining the significance of SV detection.
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Affiliation(s)
- Ying Wang
- Division of Neonatology, Anhui Provincial Children’s Hospital, Hefei, Anhui, 230051, People’s Republic of China
| | - Shaohua Bi
- Division of Neonatology, Anhui Provincial Children’s Hospital, Hefei, Anhui, 230051, People’s Republic of China
| | - Xiaoqing Shi
- Division of Neonatology, Anhui Provincial Children’s Hospital, Hefei, Anhui, 230051, People’s Republic of China
| | - Liying Dai
- Division of Neonatology, Anhui Provincial Children’s Hospital, Hefei, Anhui, 230051, People’s Republic of China
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2
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de Sainte Agathe JM, Pode-Shakked B, Naudion S, Michaud V, Arveiler B, Fergelot P, Delmas J, Keren B, Poirsier C, Alkuraya FS, Tabarki B, Bend E, Davis K, Bebin M, Thompson ML, Bryant EM, Wagner M, Hannibal I, Lenberg J, Krenn M, Wigby KM, Friedman JR, Iascone M, Cereda A, Miao T, LeGuern E, Argilli E, Sherr E, Caluseriu O, Tidwell T, Bayrak-Toydemir P, Hagedorn C, Brugger M, Vill K, Morneau-Jacob FD, Chung W, Weaver KN, Owens JW, Husami A, Chaudhari BP, Stone BS, Burns K, Li R, de Lange IM, Biehler M, Ginglinger E, Gérard B, Stottmann RW, Trimouille A. ARF1-related disorder: phenotypic and molecular spectrum. J Med Genet 2023; 60:999-1005. [PMID: 37185208 PMCID: PMC10579487 DOI: 10.1136/jmg-2022-108803] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 04/07/2023] [Indexed: 05/17/2023]
Abstract
PURPOSE ARF1 was previously implicated in periventricular nodular heterotopia (PVNH) in only five individuals and systematic clinical characterisation was not available. The aim of this study is to provide a comprehensive description of the phenotypic and genotypic spectrum of ARF1-related neurodevelopmental disorder. METHODS We collected detailed phenotypes of an international cohort of individuals (n=17) with ARF1 variants assembled through the GeneMatcher platform. Missense variants were structurally modelled, and the impact of several were functionally validated. RESULTS De novo variants (10 missense, 1 frameshift, 1 splice altering resulting in 9 residues insertion) in ARF1 were identified among 17 unrelated individuals. Detailed phenotypes included intellectual disability (ID), microcephaly, seizures and PVNH. No specific facial characteristics were consistent across all cases, however microretrognathia was common. Various hearing and visual defects were recurrent, and interestingly, some inflammatory features were reported. MRI of the brain frequently showed abnormalities consistent with a neuronal migration disorder. CONCLUSION We confirm the role of ARF1 in an autosomal dominant syndrome with a phenotypic spectrum including severe ID, microcephaly, seizures and PVNH due to impaired neuronal migration.
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Affiliation(s)
| | - Ben Pode-Shakked
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Sophie Naudion
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
| | - Vincent Michaud
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
- Maladies Rares : Génétique et Métabolisme (MRGM), U1211, INSERM, Bordeaux, France
| | - Benoit Arveiler
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
- Maladies Rares : Génétique et Métabolisme (MRGM), U1211, INSERM, Bordeaux, France
| | - Patricia Fergelot
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
- Maladies Rares : Génétique et Métabolisme (MRGM), U1211, INSERM, Bordeaux, France
| | - Jean Delmas
- Pediatric and Prenatal Imaging Department, Centre Hospitalier Universitaire de Bordeaux Groupe hospitalier Pellegrin, Bordeaux, France
| | - Boris Keren
- Department of Medical Genetics, Groupe Hospitalo-Universitaire Pitié-Salpêtrière, AP-HP.Sorbonne Université, Paris, France
| | | | - Fowzan S Alkuraya
- Department of Translational Genomic, Center for Genomic Medicine, King Faisal Specialist Hospital & Research Center, Riyadh, Saudi Arabia
| | - Brahim Tabarki
- Division of Pediatric Neurology, Department of Pediatrics, Prince Sultan Military and Medical City, Riyadh, Saudi Arabia
| | - Eric Bend
- PreventionGenetics LLC, Marshfield, Wisconsin, USA
| | - Kellie Davis
- Division of Medical Genetics, Royal University Hospital, Saskatoon, Saskatchewan, Canada
| | - Martina Bebin
- UAB Epilepsy Center, The University of Alabama at Birmingham Hospital, Birmingham, Alabama, USA
| | - Michelle L Thompson
- Greg Cooper's Laboratory, HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA
| | - Emily M Bryant
- Gillette Children's Specialty Healthcare, Ann and Robert H Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Matias Wagner
- Institute of Human Genetics, Technische Universitat Munchen, Munchen, Germany
- Institute of Neurogenomics, Helmholtz Zentrum Munchen Deutsches Forschungszentrum fur Umwelt und Gesundheit, Neuherberg, Germany
| | - Iris Hannibal
- Department of Pediatrics, University Hospital Munich, Munchen, Germany
| | - Jerica Lenberg
- Rady Children's Institute for Genomic Medicine, San Diego, California, USA
| | - Martin Krenn
- Department of Neurology, Medizinische Universitat Wien, Wien, Austria
| | - Kristen M Wigby
- Rady Children's Hospital-San Diego, University of California, San Diego, California, USA
| | - Jennifer R Friedman
- Department of Neuroscience, Rady Children's Institute for Genomic Medicine, San Diego, California, USA
- Division of Neurology, Rady Children's Hospital San Diego, San Diego, California, USA
| | - Maria Iascone
- Laboratorio di Genetica Medica, ASST Papa Giovanni XXIII, Bergamo, Italy
| | - Anna Cereda
- Pediatric Department, ASST Papa Giovanni XXIII, Bergamo, Italy
| | - Térence Miao
- Department of Medical Genetics, Groupe Hospitalo-Universitaire Pitié-Salpêtrière, AP-HP.Sorbonne Université, Paris, France
- École d'ingénieurs biotechnologies Paris - SupBiotech, Sup'Biotech, Paris, France
| | - Eric LeGuern
- Department of Medical Genetics, Groupe Hospitalo-Universitaire Pitié-Salpêtrière, AP-HP.Sorbonne Université, Paris, France
- ICM, INSERM, Paris, France
| | - Emanuela Argilli
- Department of Neurology, University of California San Francisco Division of Hospital Medicine, San Francisco, California, USA
| | - Elliott Sherr
- Department of Neurology, University of California San Francisco Division of Hospital Medicine, San Francisco, California, USA
| | - Oana Caluseriu
- Department of Medical Genetics, University of Alberta Hospital, Edmonton, Alberta, Canada
| | | | | | - Caroline Hagedorn
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Melanie Brugger
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munchen, Germany
| | - Katharina Vill
- Fachbereich Neuromuskuläre Erkrankungen und klinische Neurophysiologie, Dr. v. Hauner Children's Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | | | - Wendy Chung
- Departments of Pediatrics and Medicine, Columbia University, New York City, New York, USA
| | - Kathryn N Weaver
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Joshua W Owens
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Ammar Husami
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Bimal P Chaudhari
- Divisions of Neonatology, Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio, USA
- Steve and Cindy Rasmussen Institute for Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Brandon S Stone
- Divisions of Genetics and Genomic Medicine, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Katie Burns
- Sanford Children's Specialty Clinic, Sioux Falls, South Dakota, USA
| | - Rachel Li
- Department of Pediatrics, University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota, USA
| | - Iris M de Lange
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Margaux Biehler
- Laboratories of Genetic Diagnosis, Institut de Génétique Médicale d'Alsace (IGMA), Strasbourg University Hospitals, Strasbourg, France
| | | | - Bénédicte Gérard
- Laboratories of Genetic Diagnosis, Institut de Génétique Médicale d'Alsace (IGMA), Strasbourg University Hospitals, Strasbourg, France
| | - Rolf W Stottmann
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, University of Cincinnati School of Medicine, Cincinnati, Ohio, USA
| | - Aurélien Trimouille
- Service de Génétique Médicale, Centre Hospitalier Universitaire de Bordeaux, Bordeaux, France
- Maladies Rares : Génétique et Métabolisme (MRGM), U1211, INSERM, Bordeaux, France
- Service de Pathologie, University Hospital Centre Bordeaux Pellegrin Hospital Group, Bordeaux, France
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3
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Hu Y, Yuan S, Du X, Liu J, Zhou W, Wei F. Comparative analysis reveals epigenomic evolution related to species traits and genomic imprinting in mammals. Innovation (N Y) 2023; 4:100434. [PMID: 37215528 PMCID: PMC10196708 DOI: 10.1016/j.xinn.2023.100434] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 04/25/2023] [Indexed: 05/24/2023] Open
Abstract
DNA methylation is an epigenetic modification that plays a crucial role in various regulatory processes, including gene expression regulation, transposable element repression, and genomic imprinting. However, most studies on DNA methylation have been conducted in humans and other model species, whereas the dynamics of DNA methylation across mammals remain poorly explored, limiting our understanding of epigenomic evolution in mammals and the evolutionary impacts of conserved and lineage-specific DNA methylation. Here, we generated and gathered comparative epigenomic data from 13 mammalian species, including two marsupial species, to demonstrate that DNA methylation plays critical roles in several aspects of gene evolution and species trait evolution. We found that the species-specific DNA methylation of promoters and noncoding elements correlates with species-specific traits such as body patterning, indicating that DNA methylation might help establish or maintain interspecies differences in gene regulation that shape phenotypes. For a broader view, we investigated the evolutionary histories of 88 known imprinting control regions across mammals to identify their evolutionary origins. By analyzing the features of known and newly identified potential imprints in all studied mammals, we found that genomic imprinting may function in embryonic development through the binding of specific transcription factors. Our findings show that DNA methylation and the complex interaction between the genome and epigenome have a significant impact on mammalian evolution, suggesting that evolutionary epigenomics should be incorporated to develop a unified evolutionary theory.
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Affiliation(s)
- Yisi Hu
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Shenli Yuan
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xin Du
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiang Liu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenliang Zhou
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Fuwen Wei
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Evolution and Conservation Biology, Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
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4
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Liu J, Hu J, Duan Y, Qin R, Guo C, Zhou H, Liu H, Liu C. Genetic analysis of periventricular nodular heterotopia 7 caused by a novel NEDD4L missense mutation: Case and literature summary. Mol Genet Genomic Med 2023:e2169. [PMID: 36934385 DOI: 10.1002/mgg3.2169] [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: 11/21/2022] [Revised: 02/01/2023] [Accepted: 03/01/2023] [Indexed: 03/20/2023] Open
Abstract
BACKGROUND Neurodevelopmental disorders associated with periventricular nodular heterotopia (PVNH) are characterized by phenotypic and genetic heterogeneity. NEDD4L mutation can lead to PVNH7. However, at present, only eight NEDD4L pathogenic variants have been identified across 15 cases of PVNH7 worldwide. Given this dearth of evidence, the precise correlations between genetic pathogenesis and phenotypes remain to be determined. METHODS This report discusses the case of a 19-month-old male child with cleft palate, seizures, psychomotor retardation, and hypotonia, for whom we verified the genetic etiology using Trio-whole-exome and Sanger sequencing to analyze the potential pathogenicity of the mutant protein structure. Mutant plasmids were constructed for in vitro analyses. After transfection into human 293 T cells, the mutant transcription process was analyzed using real-time PCR (RT-PCR), and levels of mutant protein expression were examined using western blotting (WB) and immunofluorescence (IF) experiments. RESULTS Genetic analyses revealed a novel missense mutation Gln900Arg, located in the homologous to E6-APC terminal (HECT) domain of NEDD4L and that the parents were wild-type, suggestive of a de novo mutation. The variant was predicted to be pathogenic by bioinformatics software, which also suggested alterations in the structural stability of the mutant protein. RT-PCR results indicated that the mutation did not affect mRNA expression, whereas WB and IF results indicated that the level of mutant protein was significantly reduced by 41.07%. CONCLUSION Functional experiments demonstrated that Gln900Arg probably did not lead to transcriptional abnormalities in this patient, instead leading to increased ubiquitination activity owing to the constitutive activation of the HECT domain, thereby promoting protein degradation. Extensive clinical reports should be generated for patients presenting with PVNH and/or polymicrogyria, developmental delay, syndactyly, and hypotonia to increase the pool of evidence related to NEDD4L.
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Affiliation(s)
- Juan Liu
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
| | - Jihong Hu
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
| | - Yaqing Duan
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
| | - Rong Qin
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
| | - Chunguang Guo
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
| | - Hongtao Zhou
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
| | - Hua Liu
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
| | - Chunlei Liu
- Department of Rehabilitation, Hunan Children's Hospital, Changsha, China
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5
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Engwerda A, Kerstjens-Frederikse WS, Corsten-Janssen N, Dijkhuizen T, van Ravenswaaij-Arts CMA. The phenotypic spectrum of terminal 6q deletions based on a large cohort derived from social media and literature: a prominent role for DLL1. Orphanet J Rare Dis 2023; 18:59. [PMID: 36935482 PMCID: PMC10024851 DOI: 10.1186/s13023-023-02658-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/27/2023] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND Terminal 6q deletions are rare, and the number of well-defined published cases is limited. Since parents of children with these aberrations often search the internet and unite via international social media platforms, these dedicated platforms may hold valuable knowledge about additional cases. The Chromosome 6 Project is a collaboration between researchers and clinicians at the University Medical Center Groningen and members of a Chromosome 6 support group on Facebook. The aim of the project is to improve the surveillance of patients with chromosome 6 aberrations and the support for their families by increasing the available information about these rare aberrations. This parent-driven research project makes use of information collected directly from parents via a multilingual online questionnaire. Here, we report our findings on 93 individuals with terminal 6q deletions and 11 individuals with interstitial 6q26q27 deletions, a cohort that includes 38 newly identified individuals. RESULTS Using this cohort, we can identify a common terminal 6q deletion phenotype that includes microcephaly, dysplastic outer ears, hypertelorism, vision problems, abnormal eye movements, dental abnormalities, feeding problems, recurrent infections, respiratory problems, spinal cord abnormalities, abnormal vertebrae, scoliosis, joint hypermobility, brain abnormalities (ventriculomegaly/hydrocephaly, corpus callosum abnormality and cortical dysplasia), seizures, hypotonia, ataxia, torticollis, balance problems, developmental delay, sleeping problems and hyperactivity. Other frequently reported clinical characteristics are congenital heart defects, kidney problems, abnormalities of the female genitalia, spina bifida, anal abnormalities, positional foot deformities, hypertonia and self-harming behaviour. The phenotypes were comparable up to a deletion size of 7.1 Mb, and most features could be attributed to the terminally located gene DLL1. Larger deletions that include QKI (> 7.1 Mb) lead to a more severe phenotype that includes additional clinical characteristics. CONCLUSIONS Terminal 6q deletions cause a common but highly variable phenotype. Most clinical characteristics can be linked to the smallest terminal 6q deletions that include the gene DLL1 (> 500 kb). Based on our findings, we provide recommendations for clinical follow-up and surveillance of individuals with terminal 6q deletions.
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Affiliation(s)
- Aafke Engwerda
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | | | - Nicole Corsten-Janssen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Trijnie Dijkhuizen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Conny M A van Ravenswaaij-Arts
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
- ATN/Jonx, Groningen, The Netherlands.
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6
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Halliday BJ, Baynam G, Ewans L, Greenhalgh L, Leventer RJ, Pilz DT, Sachdev R, Scheffer IE, Markie DM, McGillivray G, Robertson SP, Mandelstam S. Distinctive Brain Malformations in Zhu-Tokita-Takenouchi-Kim Syndrome. AJNR Am J Neuroradiol 2022; 43:1660-1666. [PMID: 36229163 PMCID: PMC9731255 DOI: 10.3174/ajnr.a7663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 08/08/2022] [Indexed: 02/01/2023]
Abstract
BACKGROUND AND PURPOSE Zhu-Tokita-Takenouchi-Kim syndrome is a severe multisystem malformation disorder characterized by developmental delay and a diverse array of congenital abnormalities. However, these currently identified phenotypic components provide limited guidance in diagnostic situations, due to both the nonspecificity and variability of these features. Here we report a case series of 7 individuals with a molecular diagnosis of Zhu-Tokita-Takenouchi-Kim syndrome, 5 ascertained by their presentation with the neuronal migration disorder, periventricular nodular heterotopia. MATERIALS AND METHODS Individuals with a molecular diagnosis of Zhu-Tokita-Takenouchi-Kim syndrome were recruited from 2 sources, a high-throughput sequencing study of individuals with periventricular nodular heterotopia or from clinical diagnostic sequencing studies. We analyzed available brain MR images of recruited individuals to characterize periventricular nodular heterotopia distribution and to identify the presence of any additional brain abnormalities. RESULTS Pathogenic variants in SON, causative of Zhu-Tokita-Takenouchi-Kim syndrome, were identified in 7 individuals. Brain MR images from these individuals were re-analyzed. A characteristic set of imaging anomalies in addition to periventricular nodular heterotopia was identified, including the elongation of the pituitary stalk, cerebellar enlargement with an abnormally shaped posterior fossa, rounding of the caudate nuclei, hippocampal malformations, and cortical anomalies including polymicrogyria or dysgyria. CONCLUSIONS The recurrent neuroradiologic changes identified here represent an opportunity to guide diagnostic formulation of Zhu-Tokita-Takenouchi-Kim syndrome on the basis of brain MR imaging evaluation.
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Affiliation(s)
- B J Halliday
- From the Departments of Women's and Children's Health (B.J.H., S.P.R.)
| | - G Baynam
- Western Australian Register of Developmental Anomalies and Genetic Services of Western Australia (G.B.), Undiagnosed Diseases Program, King Edward Memorial Hospital, Perth, Australia
| | - L Ewans
- Centre for Population Genomics (L.E.), Garvan Institute of Medical Research, Sydney, Australia
- Centre for Clinical Genetics (L.E., R.S.), Sydney Children's Hospital, Sydney, Australia
| | - L Greenhalgh
- Liverpool Centre for Genomic Medicine (L.G.), Liverpool Women's Hospital, Liverpool, England
| | - R J Leventer
- Murdoch Children's Research Institute (R.J.L., I.E.S., G.M., S.M.), Melbourne, Australia
- Department of Paediatrics (R.J.L., I.E.S., S.M.), Epilepsy Research Centre
- Departments of Neurology (R.J.L., I.E.S.)
| | - D T Pilz
- West of Scotland Genetics Service (D.T.P.), Queen Elizabeth University Hospital, Glasgow, UK
| | - R Sachdev
- Centre for Clinical Genetics (L.E., R.S.), Sydney Children's Hospital, Sydney, Australia
| | - I E Scheffer
- Murdoch Children's Research Institute (R.J.L., I.E.S., G.M., S.M.), Melbourne, Australia
- Department of Paediatrics (R.J.L., I.E.S., S.M.), Epilepsy Research Centre
- Austin Health (I.E.S.)
- Florey Institute (I.E.S.), University of Melbourne, Melbourne, Australia
- Departments of Neurology (R.J.L., I.E.S.)
| | - D M Markie
- Pathology (D.M.M.), OtagoMedical School, University of Otago, Dunedin, New Zealand
| | - G McGillivray
- Murdoch Children's Research Institute (R.J.L., I.E.S., G.M., S.M.), Melbourne, Australia
- Victorian Clinical Genetics Services (G.M.), Murdoch Children's Research Institute, Melbourne, Australia
| | - S P Robertson
- From the Departments of Women's and Children's Health (B.J.H., S.P.R.)
| | - S Mandelstam
- Murdoch Children's Research Institute (R.J.L., I.E.S., G.M., S.M.), Melbourne, Australia
- Department of Paediatrics (R.J.L., I.E.S., S.M.), Epilepsy Research Centre
- Radiology (S.M.), Royal Children's Hospital, Melbourne, Australia
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7
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Third-Generation Cytogenetic Analysis: Diagnostic Application of Long-Read Sequencing. J Mol Diagn 2022; 24:711-718. [PMID: 35526834 DOI: 10.1016/j.jmoldx.2022.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 02/23/2022] [Accepted: 03/25/2022] [Indexed: 11/21/2022] Open
Abstract
Copy number variants (CNVs) play important roles in the pathogenesis of several genetic syndromes. Traditional and molecular karyotyping are considered the first-tier diagnostic tests to detect macroscopic and cryptic deletions/duplications. However, their time-consuming and laborious experimental protocols protract diagnostic times from 3 to 15 days. Nanopore sequencing has the ability to reduce time to results for the detection of CNVs with the same resolution of current state-of-the-art diagnostic tests. Nanopore sequencing was compared to molecular karyotyping for the detection of pathogenic CNVs of seven patients with previously diagnosed causative CNVs of different sizes and cellular fractions. Larger chromosomal anomalies included trisomy 21 and mosaic tetrasomy 12p. Among smaller CNVs, two genomic imbalances of 1.3 Mb, a small deletion of 170 kb, and two mosaic deletions (1.2 Mb and 408 kb) were tested. DNA was sequenced and data generated during runs were analyzed in online mode. All pathogenic CNVs were identified with detection time inversely proportional to size and cellular fraction. Aneuploidies were called after only 30 minutes of sequencing, whereas 30 hours were needed to call small CNVs. These results demonstrate the clinical utility of our approach that allows the molecular diagnosis of genomic disorders within a 30-minute to 30-hour time frame and its easy implementation as a routinary diagnostic tool.
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8
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Genotype–Phenotype Correlations for Putative Haploinsufficient Genes in Deletions of 6q26-q27: Report of Eight Patients and Review of Literature. Glob Med Genet 2022; 9:166-174. [PMID: 35707784 PMCID: PMC9192176 DOI: 10.1055/s-0042-1743568] [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: 12/30/2021] [Accepted: 01/11/2022] [Indexed: 11/06/2022] Open
Abstract
Background
Cytogenomic analyses have been used to detect pathogenic copy number variants. Patients with deletions at 6q26-q27 present variable clinical features. We reported clinical and cytogenomic findings of eight unrelated patients with a deletion of 6q26-q27. A systematic review of the literature found 28 patients with a deletion of 6q26-q27 from 2010 to 2020.
Results
For these 36 patients, the sex ratio showed equal occurrence between males and females; 29 patients (81%) had a terminal deletion and seven patients (19%) had a proximal or distal interstitial deletion. Of the 22 patients with parental studies, deletions of de novo, maternal, paternal, and bi-parental inheritance accounted for 64, 18, 14, and 4% of patients, respectively. The most common clinical findings were brain abnormalities (100%) in fetuses observed by ultrasonography followed by developmental delay and intellectual disability (81%), brain abnormalities (72%), facial dysmorphism (66%), hypotonia (63%), learning difficulty or language delay (50%), and seizures (47%) in pediatric and adult patients. Anti-epilepsy treatment showed the effect on controlling seizures in these patients. Cytogenomic mapping defined one proximal critical region at 6q26 containing the putative haploinsufficient gene
PRKN
and one distal critical region at 6q27 containing two haploinsufficient genes
DLL1
and
TBP
. Deletions involving the
PRKN
gene could associate with early-onset Parkinson disease and autism spectrum disorder; deletions involving the
DLL1
gene correlate with the 6q terminal deletion syndrome.
Conclusion
The genotype–phenotype correlations for putative haploinsufficient genes in deletions of 6q26-q27 provided evidence for precise diagnostic interpretation, genetic counseling, and clinical management of patients with a deletion of 6q26-q27.
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Lesieur-Sebellin M, Till M, Khau Van Kien P, Herve B, Bourgon N, Dupont C, Tabet AC, Barrois M, Coussement A, Loeuillet L, Mousty E, Ea V, El Assal A, Mary L, Jaillard S, Beneteau C, Le Vaillant C, Coutton C, Devillard F, Goumy C, Delabaere A, Redon S, Laurent Y, Lamouroux A, Massardier J, Turleau C, Sanlaville D, Cantagrel V, Sonigo P, Vialard F, Salomon LJ, Malan V. Terminal 6q deletions cause brain malformations, a phenotype mimicking heterozygous DLL1 pathogenic variants: A multicenter retrospective case series. Prenat Diagn 2021; 42:118-135. [PMID: 34894355 DOI: 10.1002/pd.6074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Terminal 6q deletion is a rare genetic condition associated with a neurodevelopmental disorder characterized by intellectual disability and structural brain anomalies. Interestingly, a similar phenotype is observed in patients harboring pathogenic variants in the DLL1 gene. Our study aimed to further characterize the prenatal phenotype of this syndrome as well as to attempt to establish phenotype-genotype correlations. METHOD We collected ultrasound findings from 22 fetuses diagnosed with a pure 6qter deletion. We reviewed the literature and compared our 22 cases with 14 fetuses previously reported as well as with patients with heterozygous DLL1 pathogenic variants. RESULTS Brain structural alterations were observed in all fetuses. The most common findings (>70%) were cerebellar hypoplasia, ventriculomegaly, and corpus callosum abnormalities. Gyration abnormalities were observed in 46% of cases. Occasional findings included cerebral heterotopia, aqueductal stenosis, vertebral malformations, dysmorphic features, and kidney abnormalities. CONCLUSION This is the first series of fetuses diagnosed with pure terminal 6q deletion. Based on our findings, we emphasize the prenatal sonographic anomalies, which may suggest the syndrome. Furthermore, this study highlights the importance of chromosomal microarray analysis to search for submicroscopic deletions of the 6q27 region involving the DLL1 gene in fetuses with these malformations.
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Affiliation(s)
- Marion Lesieur-Sebellin
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
- Faculté de Médecine, Sorbonne Université, Paris, France
| | - Marianne Till
- Laboratoire de Cytogénétique, service de Génétique, Hospices Civils de Lyon, Groupement Hospitalier Est, Bron, France
| | | | - Bérénice Herve
- Département de Génétique, CHI Poissy Saint-Germain, Saint-Germain, France
- Université Paris-Saclay, UVSQ, INRAE, BREED, Jouy-en-Josas, France
| | - Nicolas Bourgon
- Service d'Obstétrique et de Médecine Fœtale, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - Céline Dupont
- Département de Génétique, Unité de Cytogénétique, Hôpital Robert Debré, APHP Nord, Paris, France
| | - Anne-Claude Tabet
- Département de Génétique, Unité de Cytogénétique, Hôpital Robert Debré, APHP Nord, Paris, France
- Génétique Humaine et Fonctions Cognitives, Institut Pasteur, UMR3571 CNRS, Université de Paris, Paris, France
| | - Mathilde Barrois
- Maternité Port Royal, APHP Centre, Hôpital Cochin, Paris, France
| | - Aurélie Coussement
- Service des Maladies Génétiques de système et d'organes, APHP-Centre, Hôpital Cochin, Paris, France
| | - Laurence Loeuillet
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - Eve Mousty
- Service de Gynécologie Obstétrique, Hôpital Caremeau, Nîmes, France
| | - Vuthy Ea
- UF de Cytogénétique et Génétique Médicale, Hôpital Caremeau, Nîmes, France
| | - Amal El Assal
- Département de Gynécologie Obstétrique, CHI Poissy Saint-Germain, Saint-Germain, France
| | - Laura Mary
- Service d'Anatomie Pathologique, CHU Rennes, Rennes, France
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
| | - Sylvie Jaillard
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
- INSERM, EHESP, IRSET, Université Rennes 1, Rennes, France
| | - Claire Beneteau
- Service de Génétique Médicale, CHU Nantes, Nantes, France
- UF de Fœtopathologie et Génétique, CHU de Nantes, Nantes, France
| | | | - Charles Coutton
- Service de Génétique, Génomique et Procréation, Hôpital Couple Enfant, CHU Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institut pour l'Avancée des Biosciences, Equipe Génétique, Epigénétique et Thérapies de l'infertilité, Grenoble, France
| | - Françoise Devillard
- Service de Génétique, Génomique et Procréation, Hôpital Couple Enfant, CHU Grenoble Alpes, Grenoble, France
| | - Carole Goumy
- Cytogénétique Médicale, CHU Clermont-Ferrand, CHU Estaing, Université Clermont Auvergne, INSERM, U1240 Imagerie Moléculaire et Stratégies Théranostiques, Clermont-Ferrand, France
| | | | - Sylvia Redon
- CHU Brest, Inserm, Université de Brest, Brest, France
| | - Yves Laurent
- Service de Gynécologie et Obstétrique, GHBS Lorient, Lorient, France
| | - Audrey Lamouroux
- Service de Génétique Clinique, CHU Montpellier, Université de Montpellier, Montpellier, France
- Service de Gynécologie Obstétrique, CHU Nîmes, Université de Montpellier, Nîmes, France
| | - Jérôme Massardier
- Service de Gynécologie et Obstétrique, Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, Bron, France
| | - Catherine Turleau
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - Damien Sanlaville
- Laboratoire de Cytogénétique, service de Génétique, Hospices Civils de Lyon, Groupement Hospitalier Est, Bron, France
| | - Vincent Cantagrel
- Université de Paris, Institut Imagine, Laboratoire de génétique des troubles du neurodéveloppement, Paris, France
- Université de Paris, Paris, France
| | - Pascale Sonigo
- Service de Radiologie Pédiatrique, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - François Vialard
- Département de Génétique, CHI Poissy Saint-Germain, Saint-Germain, France
- Université Paris-Saclay, UVSQ, INRAE, BREED, Jouy-en-Josas, France
| | - Laurent J Salomon
- Service d'Obstétrique et de Médecine Fœtale, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
- Université de Paris, Paris, France
| | - Valérie Malan
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
- Université de Paris, Institut Imagine, Laboratoire de génétique des troubles du neurodéveloppement, Paris, France
- Université de Paris, Paris, France
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10
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Budisteanu M, Papuc S, Erbescu A, Iliescu C, Dobre M, Barca D, Tarta‑arsene O, Motoescu C, Dica A, Sandu C, Anghelescu C, Craiu D, Arghir A. Clinical and genomic findings in brain heterotopia: Report of a pediatric patient cohort from Romania. Exp Ther Med 2021; 23:101. [PMID: 34976143 PMCID: PMC8674960 DOI: 10.3892/etm.2021.11024] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/09/2021] [Indexed: 11/08/2022] Open
Abstract
Brain heterotopia is a group of rare malformations with a heterogeneous phenotype, ranging from asymptomatic to a severe clinical picture (drug-resistant epilepsy, severe developmental delay). The etiology is multifactorial, including both genetic and environmental factors. In the present study, a cohort of 15 pediatric patients with brain heterotopia were investigated by clinical examination, electroencephalographic studies, brain imaging, and genomic tests. Most of the patients had epileptic seizures, often difficult to control with one antiepileptic drug; another frequent characteristic in the cohort was developmental delay or intellectual disability, in some cases associated with behavioral problems. The genomic studies revealed an interstitial 22q11.2 microduplication, an anomaly not reported previously in heterotopia patients. Comparing the cohort of the present study with that of a previous series of heterotopia patients, both adult and pediatric, similar aspects, such as the high frequency of drug-resistant epilepsy were observed as well as some differences, such as no systemic malformations and no cases with fatal evolution. The current findings add new data to existing knowledge on a rare heterogeneous disorder. The detailed clinical description, including the epilepsy phenotypes, and genomic profiles bring new insights into a group of disorders, yet to be fully understood.
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Affiliation(s)
- Magdalena Budisteanu
- Medical Genetics Laboratory, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania
| | - Sorina Papuc
- Medical Genetics Laboratory, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania
| | - Alina Erbescu
- Medical Genetics Laboratory, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania
| | - Catrinel Iliescu
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Maria Dobre
- Medical Genetics Laboratory, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania
| | - Diana Barca
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Oana Tarta‑arsene
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Cristina Motoescu
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Alice Dica
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Carmen Sandu
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Cristina Anghelescu
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Dana Craiu
- Department of Pediatric Neurology, Expertise Centre for Rare Diseases in Pediatric Neurology, Member of The EpiCARE European Reference Network, ‘Prof. Dr. Alex. Obregia’ Clinical Hospital, 041914 Bucharest, Romania
| | - Aurora Arghir
- Medical Genetics Laboratory, Victor Babes National Institute of Pathology, 050096 Bucharest, Romania
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11
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Vriend I, Oegema R. Genetic causes underlying grey matter heterotopia. Eur J Paediatr Neurol 2021; 35:82-92. [PMID: 34666232 DOI: 10.1016/j.ejpn.2021.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/21/2021] [Indexed: 11/15/2022]
Abstract
Grey matter heterotopia (GMH) can cause of seizures and are associated with a wide range of neurodevelopmental disorders and syndromes. They are caused by a failure of neuronal migration during fetal development, leading to clusters of neurons that have not reached their final destination in the cerebral cortex. We have performed an extensive literature search in Pubmed, OMIM, and Google scholar and provide an overview of known genetic associations with periventricular nodular heterotopia (PNVH), subcortical band heterotopia (SBH) and other subcortical heterotopia (SUBH). We classified the heterotopias as PVNH, SBH, SUBH or other and collected the genetic information, frequency, imaging features and salient features in tables for every subtype of heterotopia. This resulted in 105 PVNH, 16 SBH and 25 SUBH gene/locus associations, making a total of 146 genes and chromosomal loci. Our study emphasizes the extreme genetic heterogeneity underlying GMH. It will aid the clinician in establishing an differential diagnosis and eventually a molecular diagnosis in GMH patients. A diagnosis enables proper counseling of prognosis and recurrence risks, and enables individualized patient management.
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Affiliation(s)
- Ilona Vriend
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Renske Oegema
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
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12
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Kobow K, Baulac S, von Deimling A, Lee JH. Molecular diagnostics in drug-resistant focal epilepsy define new disease entities. Brain Pathol 2021; 31:e12963. [PMID: 34196984 PMCID: PMC8412082 DOI: 10.1111/bpa.12963] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 03/31/2021] [Indexed: 01/16/2023] Open
Abstract
Structural brain lesions, including the broad range of malformations of cortical development (MCD) and glioneuronal tumors, are among the most common causes of drug-resistant focal epilepsy. Epilepsy surgery can provide a curative treatment option in respective patients. The currently available pre-surgical multi-modal diagnostic armamentarium includes high- and ultra-high resolution magnetic resonance imaging (MRI) and intracerebral EEG to identify a focal structural brain lesion as epilepsy underlying etiology. However, specificity and accuracy in diagnosing the type of lesion have proven to be limited. Moreover, the diagnostic process does not stop with the decision for surgery. The neuropathological diagnosis remains the gold standard for disease classification and patient stratification, but is particularly complex with high inter-observer variability. Here, the identification of lesion-specific mosaic variants together with epigenetic profiling of lesional brain tissue became new tools to more reliably identify disease entities. In this review, we will discuss how the paradigm shifts from histopathology toward an integrated diagnostic approach in cancer and the more recent development of the DNA methylation-based brain tumor classifier have started to influence epilepsy diagnostics. Some examples will be highlighted showing how the diagnosis and our mechanistic understanding of difficult to classify structural brain lesions associated with focal epilepsy has improved with molecular genetic data being considered in decision making.
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Affiliation(s)
- Katja Kobow
- Department of NeuropathologyUniversitätsklinikum ErlangenFriedrich‐Alexander‐University of Erlangen‐Nürnberg (FAU)ErlangenGermany
| | - Stéphanie Baulac
- Institut du Cerveau—Paris Brain Institute—ICMInsermCNRSSorbonne UniversitéParisFrance
| | - Andreas von Deimling
- Department of NeuropathologyUniversitätsklinikum HeidelbergHeidelbergGermany
- CCU NeuropathologyGerman Cancer Research Center (DKFZ)HeidelbergGermany
| | - Jeong Ho Lee
- Graduate School of Medical Science and EngineeringKAISTDaejeonKorea
- SoVarGen, IncDaejeonRepublic of Korea
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13
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Síndrome de deleção 6q. SCIENTIA MEDICA 2021. [DOI: 10.15448/1980-6108.2021.1.37395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Objetivos: Síndrome da deleção 6q é considerada uma anomalia cromossômica rara. Assim, nosso objetivo foi relatar um caso de um menino com essa síndrome, em Manaus/Amazonas.Descrição do caso: Menino com quatro anos de idade que apresenta atraso do crescimento e do desenvolvimento neuropsicomotor, dificuldades de ganho de peso e anormalidades na retina. A análise citogenética do paciente revelou cariótipo com 46, XY, del(6)(q25-qter).Conclusões: Este relato demonstrou a importância das análises citogenéticas para o diagnóstico preciso das anomalias congênitas, pois auxiliam no encaminhamento de tratamentos adequados aos pacientes e na ampliação de conhecimento científico relacionado a essa deleção.
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14
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Stern S, Hacohen N, Meiner V, Yagel S, Zenvirt S, Shkedi-Rafid S, Macarov M, Valsky DV, Porat S, Yanai N, Frumkin A, Daum H. Universal chromosomal microarray analysis reveals high proportion of copy-number variants in low-risk pregnancies. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2021; 57:813-820. [PMID: 32202684 DOI: 10.1002/uog.22026] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/12/2020] [Accepted: 03/16/2020] [Indexed: 06/10/2023]
Abstract
OBJECTIVES To evaluate the yield and utility of the routine use of chromosomal microarray analysis (CMA) for prenatal genetic diagnosis in a large cohort of pregnancies with normal ultrasound (US) at the time of genetic testing, compared with pregnancies with abnormal US findings. METHODS We reviewed all prenatal CMA results in our center between November 2013 and December 2018. The prevalence of different CMA results in pregnancies with normal US at the time of genetic testing ('low-risk pregnancies'), was compared with that in pregnancies with abnormal US findings ('high-risk pregnancies'). Medical records were searched in order to evaluate subsequent US follow-up and the outcome of pregnancies with a clinically relevant copy-number variant (CNV), i.e. a pathogenic or likely pathogenic CNV or a susceptibility locus for disease with > 10% penetrance, related to early-onset disease in the low-risk group. RESULTS In a cohort of 6431 low-risk pregnancies that underwent CMA, the prevalence of a clinically significant CNV related to early-onset disease was 1.1% (72/6431), which was significantly lower than the prevalence in high-risk pregnancies (4.9% (65/1326)). Of the low-risk pregnancies, 0.4% (27/6431) had a pathogenic or likely pathogenic CNV, and another 0.7% (45/6431) had a susceptibility locus with more than 10% penetrance. Follow-up of the low-risk pregnancies with a clinically significant early-onset CNV revealed that 31.9% (23/72) were terminated, while outcome data were missing in 26.4% (19/72). In 16.7% (12/72) of low-risk pregnancies, an US abnormality was discovered later on in gestation, after genetic testing had been performed. CONCLUSION Although the background risk of identifying a clinically significant early-onset abnormal CMA result in pregnancies with a low a-priori risk is lower than that observed in high-risk pregnancies, the risk is substantial and should be conveyed to all pregnant women. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- S Stern
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - N Hacohen
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - V Meiner
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Yagel
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Zenvirt
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Shkedi-Rafid
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - M Macarov
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - D V Valsky
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Porat
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - N Yanai
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - A Frumkin
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - H Daum
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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15
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De Angelis C, Byrne AB, Morrow R, Feng J, Ha T, Wang P, Schreiber AW, Babic M, Taranath A, Manton N, King-Smith SL, Schwarz Q, Arts P, Scott HS, Barnett C. Compound heterozygous variants in LAMC3 in association with posterior periventricular nodular heterotopia. BMC Med Genomics 2021; 14:64. [PMID: 33639934 PMCID: PMC7916305 DOI: 10.1186/s12920-021-00911-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 01/25/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Periventricular nodular heterotopia (PNH) is a malformation of cortical development characterized by nodules of abnormally migrated neurons. The cause of posteriorly placed PNH is not well characterised and we present a case that provides insights into the cause of posterior PNH. CASE PRESENTATION We report a fetus with extensive posterior PNH in association with biallelic variants in LAMC3. LAMC3 mutations have previously been shown to cause polymicrogyria and pachygyria in the occipital cortex, but not PNH. The occipital location of PNH in our case and the proposed function of LAMC3 in cortical development suggest that the identified LAMC3 variants may be causal of PNH in this fetus. CONCLUSION We hypothesise that this finding extends the cortical phenotype associated with LAMC3 and provides valuable insight into genetic cause of posterior PNH.
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Affiliation(s)
- Carla De Angelis
- Paediatric and Reproductive Genetics Unit, Women's and Children's Hospital, North Adelaide, SA, Australia
- School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Alicia B Byrne
- Genetics and Molecular Pathology Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
| | - Rebecca Morrow
- Genetics and Molecular Pathology Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
| | - Jinghua Feng
- ACRF Cancer Genomics Facility, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, SA, Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
| | - Thuong Ha
- Genetics and Molecular Pathology Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
- ACRF Cancer Genomics Facility, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, SA, Australia
| | - Paul Wang
- ACRF Cancer Genomics Facility, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, SA, Australia
| | - Andreas W Schreiber
- ACRF Cancer Genomics Facility, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, SA, Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Milena Babic
- Genetics and Molecular Pathology Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
| | - Ajay Taranath
- South Australian Medical Imaging, Women's and Children's Hospital, North Adelaide, SA, Australia
- School of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - Nick Manton
- Department of Surgical Pathology, Women's and Children's Hospital/SA Pathology, North Adelaide, SA, Australia
| | - Sarah L King-Smith
- Genetics and Molecular Pathology Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
- Australian Genomic Health Alliance, Melbourne, VIC, Australia
| | - Quenten Schwarz
- Neurovascular Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
| | - Peer Arts
- Genetics and Molecular Pathology Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
| | - Hamish S Scott
- Genetics and Molecular Pathology Research Laboratory, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, Australia
- ACRF Cancer Genomics Facility, Centre for Cancer Biology, An Alliance Between SA Pathology and the University of South Australia, Adelaide, SA, Australia
- School of Medicine, University of Adelaide, Adelaide, SA, Australia
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
- Australian Genomic Health Alliance, Melbourne, VIC, Australia
| | - Christopher Barnett
- Paediatric and Reproductive Genetics Unit, Women's and Children's Hospital, North Adelaide, SA, Australia.
- School of Medicine, University of Adelaide, Adelaide, SA, Australia.
- SA Clinical Genetics Service, Women's and Children's Hospital, 72 King William Road, North Adelaide, SA, 5006, Australia.
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16
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Ferent J, Zaidi D, Francis F. Extracellular Control of Radial Glia Proliferation and Scaffolding During Cortical Development and Pathology. Front Cell Dev Biol 2020; 8:578341. [PMID: 33178693 PMCID: PMC7596222 DOI: 10.3389/fcell.2020.578341] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/08/2020] [Indexed: 01/14/2023] Open
Abstract
During the development of the cortex, newly generated neurons migrate long-distances in the expanding tissue to reach their final positions. Pyramidal neurons are produced from dorsal progenitors, e.g., radial glia (RGs) in the ventricular zone, and then migrate along RG processes basally toward the cortex. These neurons are hence dependent upon RG extensions to support their migration from apical to basal regions. Several studies have investigated how intracellular determinants are required for RG polarity and subsequent formation and maintenance of their processes. Fewer studies have identified the influence of the extracellular environment on this architecture. This review will focus on extracellular factors which influence RG morphology and pyramidal neuronal migration during normal development and their perturbations in pathology. During cortical development, RGs are present in different strategic positions: apical RGs (aRGs) have their cell bodies located in the ventricular zone with an apical process contacting the ventricle, while they also have a basal process extending radially to reach the pial surface of the cortex. This particular conformation allows aRGs to be exposed to long range and short range signaling cues, whereas basal RGs (bRGs, also known as outer RGs, oRGs) have their cell bodies located throughout the cortical wall, limiting their access to ventricular factors. Long range signals impacting aRGs include secreted molecules present in the embryonic cerebrospinal fluid (e.g., Neuregulin, EGF, FGF, Wnt, BMP). Secreted molecules also contribute to the extracellular matrix (fibronectin, laminin, reelin). Classical short range factors include cell to cell signaling, adhesion molecules and mechano-transduction mechanisms (e.g., TAG1, Notch, cadherins, mechanical tension). Changes in one or several of these components influencing the RG extracellular environment can disrupt the development or maintenance of RG architecture on which neuronal migration relies, leading to a range of cortical malformations. First, we will detail the known long range signaling cues impacting RG. Then, we will review how short range cell contacts are also important to instruct the RG framework. Understanding how RG processes are structured by their environment to maintain and support radial migration is a critical part of the investigation of neurodevelopmental disorders.
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Affiliation(s)
- Julien Ferent
- Inserm, U 1270, Paris, France.,Sorbonne University, UMR-S 1270, IFM, Paris, France.,Institut du Fer á Moulin, Paris, France
| | - Donia Zaidi
- Inserm, U 1270, Paris, France.,Sorbonne University, UMR-S 1270, IFM, Paris, France.,Institut du Fer á Moulin, Paris, France
| | - Fiona Francis
- Inserm, U 1270, Paris, France.,Sorbonne University, UMR-S 1270, IFM, Paris, France.,Institut du Fer á Moulin, Paris, France
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17
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Accogli A, Severino M, Riva A, Madia F, Balagura G, Iacomino M, Carlini B, Baldassari S, Giacomini T, Croci C, Pisciotta L, Messana T, Boni A, Russo A, Bilo L, Tonziello R, Coppola A, Filla A, Mecarelli O, Casalone R, Pisani F, Falsaperla R, Marino S, Parisi P, Ferretti A, Elia M, Luchetti A, Milani D, Vanadia F, Silvestri L, Rebessi E, Parente E, Vatti G, Mancardi MM, Nobili L, Capra V, Salpietro V, Striano P, Zara F. Targeted re-sequencing in malformations of cortical development: genotype-phenotype correlations. Seizure 2020; 80:145-152. [DOI: 10.1016/j.seizure.2020.05.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/15/2020] [Accepted: 05/29/2020] [Indexed: 12/25/2022] Open
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18
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Domínguez MG, Rivera H, Dávalos-Pulido RM, Dávalos-Rodríguez IP. A paternal t(6;22)(q25.3;p12) leading to a deleted and satellited der(6) in a short-lived infant. J Clin Lab Anal 2020; 34:e23355. [PMID: 32399990 PMCID: PMC7439351 DOI: 10.1002/jcla.23355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/13/2020] [Accepted: 04/15/2020] [Indexed: 11/25/2022] Open
Abstract
Background Non‐acrocentric satellited chromosomes mostly result from familial balanced insertions or translocations with p12 or p13 of any acrocentric. Although all non‐acrocentrics have been involved, only 12 instances of chromosome 6 involvement are known. Case presentation A female infant exhibited clinical features typical of 6qter deletions and also generalized hypertrichosis and synophrys, traits seldom reported in patients with similar imbalances or haploinsufficiency of ARID1B located in 6q25.3. She had a paternal derivative satellited 6q of a t(6;22)(q25.3;p12)pat entailing a 6q terminal deletion, karyotype 46,XX,der(6)t(6;22)(q25.3;p12)pat [16].ish del 6q subtel–. Conclusion Male and female carriers of reciprocal translocations or insertions between chromosome 6 and the short arm of any acrocentric have few unbalanced offspring mostly by adjacent‐1 segregation. In addition, spontaneous abortions or male infertility was present in 7/13 instances of satellited chromosome 6.
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Affiliation(s)
| | - Horacio Rivera
- División de Genética, CIBO, Instituto Mexicano del Seguro Social, Guadalajara, México.,Doctorado en Genética Humana, CUCS, Universidad de Guadalajara, Guadalajara, México
| | | | - Ingrid Patricia Dávalos-Rodríguez
- División de Genética, CIBO, Instituto Mexicano del Seguro Social, Guadalajara, México.,Doctorado en Genética Humana, CUCS, Universidad de Guadalajara, Guadalajara, México
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19
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Guerrini R, Parrini E, Esposito A, Fassio A, Conti V. Lesional and non-lesional epilepsies: A blurring genetic boundary. Eur J Paediatr Neurol 2020; 24:24-29. [PMID: 31875834 DOI: 10.1016/j.ejpn.2019.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 01/02/2023]
Abstract
There has been a traditional conceptual partition between the so-called non-lesional genetic epilepsies and the genetically determined interposed epileptogenic structural abnormalities. In this review, we summarise how growing evidence acquired through neuroimaging and neurobiology modelling is demonstrating that a distinction between lesional and functional (or non-lesional) epileptogenesis is less obvious than previously thought, particularly for epileptogenic neurodevelopmental disorders, but also for most genetically determined epilepsies.
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Affiliation(s)
- Renzo Guerrini
- Paediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital Anna Meyer-University of Florence, 50139, Florence, Italy.
| | - Elena Parrini
- Paediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital Anna Meyer-University of Florence, 50139, Florence, Italy
| | - Alessandro Esposito
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16100, Genoa, Italy; Department of Experimental Medicine, University of Genoa, 16100, Genoa, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genoa, 16100, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, 16100, Genoa, Italy
| | - Valerio Conti
- Paediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital Anna Meyer-University of Florence, 50139, Florence, Italy
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20
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Hanna MD, Moretti PN, P de Oliveira C, A Rosa MT, R Versiani B, de Oliveira SF, Pic-Taylor A, F Mazzeu J. Defining the Critical Region for Intellectual Disability and Brain Malformations in 6q27 Microdeletions. Mol Syndromol 2019; 10:202-208. [PMID: 31602192 DOI: 10.1159/000501008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2019] [Indexed: 11/19/2022] Open
Abstract
Terminal microdeletions of the long arm of chromosome 6 are associated with a phenotype that includes multiple brain malformations, intellectual disability, and epilepsy. A 1.7-Mb region has been proposed to contain a gene responsible for the brain anomalies. Here, we present the case of a 12-year-old girl with multiple brain alterations and moderate intellectual disability with a 18-kb deletion in chromosome 6q27, which is smaller than the microdeletions previously described by microarray analysis. We refined the smallest region of overlap possibly associated with the phenotype of brain malformations and intellectual disability to a segment of 325 kb, comprising the DLL1, PSMB1, TBP, and PDCD2 genes since these genes were structurally and/or functionally lost in the smaller deletions described to date. We hypothesize that DLL1 is responsible for brain malformations and possibly interacts with other adjacent genes. The TBP gene encodes a transcription factor which is potentially related to cognitive development. TBP is linked to PSMB1 and PDCD2 in a conserved manner among mammals, suggesting a potential interaction between these genes. In conclusion, the 6q27 microdeletion is a complex syndrome with variable expressivity of brain malformations and intellectual disability phenotypes which are possibly triggered by the 4 genes described and adjacent genes susceptible to gene regulation changes.
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Affiliation(s)
- Marcela D Hanna
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | | | | | - Maria T A Rosa
- Secretaria de Estado de Saúde do Distrito Federal, Brasília, Brazil
| | - Beatriz R Versiani
- Hospital Universitário de Brasília, Universidade de Brasília, Brasília, Brazil
| | - Silviene F de Oliveira
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | - Aline Pic-Taylor
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | - Juliana F Mazzeu
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil
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21
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Haploinsufficiency of the Notch Ligand DLL1 Causes Variable Neurodevelopmental Disorders. Am J Hum Genet 2019; 105:631-639. [PMID: 31353024 DOI: 10.1016/j.ajhg.2019.07.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 07/03/2019] [Indexed: 02/07/2023] Open
Abstract
Notch signaling is an established developmental pathway for brain morphogenesis. Given that Delta-like 1 (DLL1) is a ligand for the Notch receptor and that a few individuals with developmental delay, intellectual disability, and brain malformations have microdeletions encompassing DLL1, we hypothesized that insufficiency of DLL1 causes a human neurodevelopmental disorder. We performed exome sequencing in individuals with neurodevelopmental disorders. The cohort was identified using known Matchmaker Exchange nodes such as GeneMatcher. This method identified 15 individuals from 12 unrelated families with heterozygous pathogenic DLL1 variants (nonsense, missense, splice site, and one whole gene deletion). The most common features in our cohort were intellectual disability, autism spectrum disorder, seizures, variable brain malformations, muscular hypotonia, and scoliosis. We did not identify an obvious genotype-phenotype correlation. Analysis of one splice site variant showed an in-frame insertion of 12 bp. In conclusion, heterozygous DLL1 pathogenic variants cause a variable neurodevelopmental phenotype and multi-systemic features. The clinical and molecular data support haploinsufficiency as a mechanism for the pathogenesis of this DLL1-related disorder and affirm the importance of DLL1 in human brain development.
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22
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Multiple genomic copy number variants associated with periventricular nodular heterotopia indicate extreme genetic heterogeneity. Eur J Hum Genet 2019; 27:909-918. [PMID: 30683929 DOI: 10.1038/s41431-019-0335-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 12/18/2018] [Indexed: 12/27/2022] Open
Abstract
Periventricular nodular heterotopia (PNH) is a brain malformation in which nodules of neurons are ectopically retained along the lateral ventricles. Genetic causes include FLNA abnormalities (classical X-linked PNH), rare variants in ARFGEF2, DCHS1, ERMARD, FAT4, INTS8, MAP1B, MCPH1, and NEDD4L, as well as several chromosomal abnormalities. We performed array-CGH in 106 patients with different malformations of cortical development (MCD) and looked for common pathways possibly involved in PNH. Forty-two patients, including two parent/proband couples, exhibited PNH associated or not with other brain abnormalities, 44 had polymicrogyria and 20 had rarer MCDs. We found an enrichment of either large rearrangements or cryptic copy number variants (CNVs) in PNH (15/42, 35.7%) vs polymicrogyria (4/44, 9.1%) (i.e., 5.6 times increased risk for PNH of carrying a pathogenic CNV). CNVs in seven genomic regions (2p11.2q12.1, 4p15, 14q11.2q12, 16p13.3, 19q13.33, 20q13.33, 22q11) represented novel, potentially causative, associations with PNH. Through in silico analysis of genes included in imbalances whose breakpoints were clearly detailed, we detected in 9/12 unrelated patients in our series and in 15/24 previously published patients, a significant (P < 0.05) overrepresentation of genes involved in vesicle-mediated transport. Rare genomic imbalances, either small CNVs or large rearrangements, are cumulatively a frequent cause of PNH. Dysregulation of specific cellular mechanisms might play a key pathogenic role in PNH but it remains to be determined whether this is exerted through single genes or the cumulative dosage effect of more genes. Array-CGH should be considered as a first-line diagnostic test in PNH, especially if sporadic and non-classical.
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23
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Buchsbaum IY, Cappello S. Neuronal migration in the CNS during development and disease: insights from in vivo and in vitro models. Development 2019; 146:146/1/dev163766. [DOI: 10.1242/dev.163766] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
ABSTRACT
Neuronal migration is a fundamental process that governs embryonic brain development. As such, mutations that affect essential neuronal migration processes lead to severe brain malformations, which can cause complex and heterogeneous developmental and neuronal migration disorders. Our fragmented knowledge about the aetiology of these disorders raises numerous issues. However, many of these can now be addressed through studies of in vivo and in vitro models that attempt to recapitulate human-specific mechanisms of cortical development. In this Review, we discuss the advantages and limitations of these model systems and suggest that a complementary approach, using combinations of in vivo and in vitro models, will broaden our knowledge of the molecular and cellular mechanisms that underlie defective neuronal positioning in the human cerebral cortex.
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Affiliation(s)
- Isabel Yasmin Buchsbaum
- Developmental Neurobiology, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, 82152 Planegg, Germany
| | - Silvia Cappello
- Developmental Neurobiology, Max Planck Institute of Psychiatry, 80804 Munich, Germany
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24
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Iwamoto H, Muroi A, Sekine T, Tsurubuchi T, Ishikawa E, Matsumura A. Unusual Form of Obstructive Hydrocephalus in Association with 6q Terminal Deletion Syndrome: A Case Report and Literature Review. Pediatr Neurosurg 2019; 54:419-423. [PMID: 31597145 DOI: 10.1159/000503108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 09/03/2019] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Terminal deletion of chromosome 6q is a rare chromosomal abnormality associated with intellectual disabilities and various structural brain abnormalities. We present a case of 6q terminal deletion syndrome with unusual magnetic resonance imaging (MRI) findings in a neonate. CASE PRESENTATION The neonate, who was prenatally diagnosed with dilation of both lateral ventricles, was born at 38 weeks of gestation. MRI demonstrated abnormal membranous structure continuing to the hypertrophic massa intermedia in the third ventricle that had obscured the cerebrospinal fluid pathway, causing hydrocephalus. G-band analysis revealed a terminal deletion of 6q with the karyotype 46, XY, add(6)(q25.3) or del(6)(q26). He underwent ventriculoperitoneal shunt successfully, and his head circumference has been stable. DISCUSSION/CONCLUSION 6q terminal deletion impacts the molecular pathway, which is an essential intracellular signaling cascade inducing neurological proliferation, migration, and differentiation during neuronal development. In patients with hydrocephalus in association with hypertrophy of the massa intermedia, this chromosomal abnormality should be taken into consideration. This case may offer an insight into the pathogenesis of hydrocephalus in this rare chromosomal abnormality.
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Affiliation(s)
- Hirofumi Iwamoto
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Ai Muroi
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan,
| | - Tomokazu Sekine
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Takao Tsurubuchi
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Eiichi Ishikawa
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Akira Matsumura
- Department of Neurosurgery, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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25
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Deloison B, Sonigo P, Millischer-Bellaiche AE, Quibel T, Cavallin M, Benoist G, Quelin C, Jouk PS, Lev D, Alison M, Baumann C, Beldjord C, Razavi F, Bessières B, Boddaert N, Ville Y, Salomon LJ, Bahi-Buisson N. Prenatally diagnosed periventricular nodular heterotopia: Further delineation of the imaging phenotype and outcome. Eur J Med Genet 2018; 61:773-782. [PMID: 30391507 DOI: 10.1016/j.ejmg.2018.10.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 10/24/2018] [Accepted: 10/28/2018] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Periventricular nodular heterotopia (PNH) is a malformation of cortical development which presents with heterogeneous imaging, neurological phenotype and outcome. There is a paucity of comprehensive description detailing the prenatal diagnosis of PNH. The aim of this study is to report neuroimaging features and correlated outcomes in order to delineate the spectrum of prenatally diagnosed PNH. METHODS It was a retrospective study over 15 years in five tertiary centers. All fetuses with prenatally diagnosed PNH were collected. Fetal ultrasound and MRI were reviewed and genetic screening collected. Prenatal findings were analyzed in correlation to fetopathological analyses and post-natal follow up. RESULTS Thirty fetuses (22 females and 8 males) with PNH were identified. The two major ultrasound signs were ventriculomegaly associated with dysmorphic frontal horns (60%) and posterior fossa anomalies (73.3%). On MRI, two groups of PNH were identified: the contiguous and diffuse PNH (n = 15, 50%), often associated with megacisterna magna, and the non-diffuse, either anterior, posterior or unilateral PNH. FLNA mutations were found in 6/11 cases with diffuse PNH. Additional cortical malformations were exclusively observed in non diffuse PNH (9/15; 60%). Twenty-four pregnancies (80%) were terminated. Six children aged 6 months to 5 years are alive. Five have normal neurodevelopment (all had diffuse PNH) whereas one case with non diffuse PNH has developmental delay and epilepsy. CONCLUSION PNH is heterogeneous but patients with diffuse PNH are a common subgroup with specific findings on prenatal imaging and implications for prenatal counseling.
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Affiliation(s)
- B Deloison
- Department of Obstetrics and Gynecology and SFAPE Société Française pour l'Amélioration des Pratiques Echographiques, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Université Paris Descartes - Sorbonne Paris Cités, France; EA 7328 FETUS, Université Paris Descartes, France
| | - P Sonigo
- Pediatric Radiology, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - A E Millischer-Bellaiche
- Pediatric Radiology, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - T Quibel
- Department of Obstetrics and Gynecology, Poissy Saint-Germain Hospital, Poissy, France
| | - M Cavallin
- Université Paris Descartes - Sorbonne Paris Cités, France; Institut Imagine-INSERM UMR-1163, Embryology and genetics of congenital malformations, France; Pediatric Neurology, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - G Benoist
- Department of Obstetrics and Gynecology, Caen Hospital, Caen Basse Normandie University, France
| | - C Quelin
- Clinical Genetic Department, Rennes Hospital, France
| | - P S Jouk
- Clinical Genetic Department, Grenoble Hospital, France
| | - D Lev
- Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel
| | - M Alison
- Pediatric Radiology, Robert Debre Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - C Baumann
- Clinical Genetics Department, Robert Debre Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - C Beldjord
- Department of Molecular Genetics, Cochin-Port-Royal Université Paris Descartes - Sorbonne Paris Cités, Paris, France
| | - F Razavi
- Fetopathology Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - B Bessières
- Fetopathology Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - N Boddaert
- Université Paris Descartes - Sorbonne Paris Cités, France; Pediatric Radiology, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Y Ville
- Department of Obstetrics and Gynecology and SFAPE Société Française pour l'Amélioration des Pratiques Echographiques, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Université Paris Descartes - Sorbonne Paris Cités, France; EA 7328 FETUS, Université Paris Descartes, France
| | - L J Salomon
- Department of Obstetrics and Gynecology and SFAPE Société Française pour l'Amélioration des Pratiques Echographiques, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Université Paris Descartes - Sorbonne Paris Cités, France; EA 7328 FETUS, Université Paris Descartes, France
| | - N Bahi-Buisson
- Université Paris Descartes - Sorbonne Paris Cités, France; Institut Imagine-INSERM UMR-1163, Embryology and genetics of congenital malformations, France; Pediatric Neurology, Necker Enfants Malades Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France.
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26
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Sheth F, Liehr T, Shah V, Shah H, Tewari S, Solanki D, Trivedi S, Sheth J. A child with intellectual disability and dysmorphism due to complex ring chromosome 6: identification of molecular mechanism with review of literature. Ital J Pediatr 2018; 44:114. [PMID: 30305128 PMCID: PMC6180451 DOI: 10.1186/s13052-018-0571-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 09/21/2018] [Indexed: 11/29/2022] Open
Abstract
Background Ring chromosome 6 (r(6)) is a rare disorder that mainly occurs as a ‘de novo’ event. Nonetheless, a wide phenotypic spectrum has been reported in r(6) cases, depending on breakpoints, size of involved region, copy number alterations and mosaicism of cells with r(6) and/or monosomy 6 due to loss of r(6). Case presentation An 11-year-old male was referred with developmental delay, intellectual disability and microcephaly. Physical examination revealed additionally short stature and multiple facial dysmorphisms. Banding cytogenetic studies revealed a karyotype of mos 46,XY,r(6)(p25.3q27)[54]/45,XY,-6[13]/46,XY,r(6)(::p25.3→q27::p25.3→q27::)[13]/46,XY[6]/47,XY,r(6)(p25.3q27)×2[2]dn. Additionally, molecular karyotyping and molecular cytogenetics confirmed the breakpoints and characterized a 1.3 Mb contiguous duplication at 6p25.3. Conclusion The present study has accurately identified copy number alterations caused by ring chromosome formation. A review of the literature suggests that hemizygous expression of TBP gene in 6q27~qter, is likely to be the underlying cause of the phenotype. The phenotypic correlation and clinical severity in r(6) cases continue to remain widely diverse in spite of numerous reports of genomic variations.
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Affiliation(s)
- Frenny Sheth
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380009, India.
| | - Thomas Liehr
- University Clinic Jena, Institute of Human Genetics, Am Klinikum 1, 07747, Jena, Germany
| | - Viraj Shah
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380009, India
| | - Hillary Shah
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380009, India
| | - Stuti Tewari
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380009, India
| | - Dhaval Solanki
- Mantra Child Neurology & Epilepsy Hospital, 3rd floor, Oarnate complex, Kalubha road, Kalanala, Bhavanagar, 364001, India
| | - Sunil Trivedi
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380009, India
| | - Jayesh Sheth
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380009, India
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27
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Abstract
PURPOSE OF REVIEW This article provides an overview of the most common nervous system malformations and serves as a reference for the latest advances in diagnosis and treatment. RECENT FINDINGS Major advances have occurred in recognizing the genetic basis of nervous system malformations. Environmental causes of nervous system malformations, such as perinatal infections including Zika virus, are also reviewed. Treatment for nervous system malformations begins prior to birth with prevention. Folic acid supplementation reduces the risk of neural tube defects and is an important part of health maintenance for pregnant women. Fetal surgery is now available for prenatal repair of myelomeningocele and has been demonstrated to improve outcomes. SUMMARY Each type of nervous system malformation is relatively uncommon, but, collectively, they constitute a large population of neurologic patients. The diagnosis of nervous system malformations begins with radiographic characterization. Genetic studies, including chromosomal microarray, targeted gene sequencing, and next-generation sequencing, are increasingly important aspects of the assessment. A genetic diagnosis may identify an associated medical condition and is necessary for family planning. Treatment consists primarily of supportive therapies for developmental delays and epilepsy, but prenatal surgery for myelomeningocele offers a glimpse of future possibilities. Prognosis depends on multiple clinical factors, including the examination findings, imaging characteristics, and genetic results. Treatment is best conducted in a multidisciplinary setting with neurology, neurosurgery, developmental pediatrics, and genetics working together as a comprehensive team.
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28
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Heinzen EL, O'Neill AC, Zhu X, Allen AS, Bahlo M, Chelly J, Chen MH, Dobyns WB, Freytag S, Guerrini R, Leventer RJ, Poduri A, Robertson SP, Walsh CA, Zhang M. De novo and inherited private variants in MAP1B in periventricular nodular heterotopia. PLoS Genet 2018; 14:e1007281. [PMID: 29738522 PMCID: PMC5965900 DOI: 10.1371/journal.pgen.1007281] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 05/23/2018] [Accepted: 02/27/2018] [Indexed: 11/19/2022] Open
Abstract
Periventricular nodular heterotopia (PVNH) is a malformation of cortical development commonly associated with epilepsy. We exome sequenced 202 individuals with sporadic PVNH to identify novel genetic risk loci. We first performed a trio-based analysis and identified 219 de novo variants. Although no novel genes were implicated in this initial analysis, PVNH cases were found overall to have a significant excess of nonsynonymous de novo variants in intolerant genes (p = 3.27x10-7), suggesting a role for rare new alleles in genes yet to be associated with the condition. Using a gene-level collapsing analysis comparing cases and controls, we identified a genome-wide significant signal driven by four ultra-rare loss-of-function heterozygous variants in MAP1B, including one de novo variant. In at least one instance, the MAP1B variant was inherited from a parent with previously undiagnosed PVNH. The PVNH was frontally predominant and associated with perisylvian polymicrogyria. These results implicate MAP1B in PVNH. More broadly, our findings suggest that detrimental mutations likely arising in immediately preceding generations with incomplete penetrance may also be responsible for some apparently sporadic diseases.
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Affiliation(s)
- Erin L. Heinzen
- Institute for Genomic Medicine, Columbia University Medical Center, New York, New York, United States of America
- * E-mail: Corresponding author on behalf of the Epi4K Consortium,
| | - Adam C. O'Neill
- Department of Women’s and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Xiaolin Zhu
- Institute for Genomic Medicine, Columbia University Medical Center, New York, New York, United States of America
| | - Andrew S. Allen
- Center for Statistical Genetics and Genomics, Duke University Medical Center, Durham, North Carolina, United States of America
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, School of Mathematics and Statistics, University of Melbourne, Parkville, Victoria, Australia
| | - Jamel Chelly
- Pôle de Biologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- IGBMC, INSERM U964, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
| | - Ming Hui Chen
- Department of Cardiology and Division of Genetics and Genomics, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - William B. Dobyns
- Departments of Pediatrics and Neurology, University of Washington, Seattle, Washington, United States of America
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States of America
| | - Saskia Freytag
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Anna Meyer-University of Florence, Florence, Italy
| | - Richard J. Leventer
- Department of Neurology Royal Children’s Hospital, University of Melbourne, Parkville, Victoria, Australia
- Murdoch Children’s Research Institute, University of Melbourne, Parkville, Victoria, Australia
- Department of Pediatrics, University of Melbourne, Parkville, Victoria, Australia
| | - Annapurna Poduri
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Stephen P. Robertson
- Department of Women’s and Children's Health, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Christopher A. Walsh
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research and Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Departments of Pediatrics and Neurology, Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Mengqi Zhang
- Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America
- Program in Computational Biology and Bioinformatics, Duke University, Durham, NC, United States of America
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29
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Wiszniewski W, Gawlinski P, Gambin T, Bekiesinska-Figatowska M, Obersztyn E, Antczak-Marach D, Akdemir ZHC, Harel T, Karaca E, Jurek M, Sobecka K, Nowakowska B, Kruk M, Terczynska I, Goszczanska-Ciuchta A, Rudzka-Dybala M, Jamroz E, Pyrkosz A, Jakubiuk-Tomaszuk A, Iwanowski P, Gieruszczak-Bialek D, Piotrowicz M, Sasiadek M, Kochanowska I, Gurda B, Steinborn B, Dawidziuk M, Castaneda J, Wlasienko P, Bezniakow N, Jhangiani SN, Hoffman-Zacharska D, Bal J, Szczepanik E, Boerwinkle E, Gibbs RA, Lupski JR. Comprehensive genomic analysis of patients with disorders of cerebral cortical development. Eur J Hum Genet 2018; 26:1121-1131. [PMID: 29706646 DOI: 10.1038/s41431-018-0137-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 02/28/2018] [Accepted: 03/02/2018] [Indexed: 11/09/2022] Open
Abstract
Malformations of cortical development (MCDs) manifest with structural brain anomalies that lead to neurologic sequelae, including epilepsy, cerebral palsy, developmental delay, and intellectual disability. To investigate the underlying genetic architecture of patients with disorders of cerebral cortical development, a cohort of 54 patients demonstrating neuroradiologic signs of MCDs was investigated. Individual genomes were interrogated for single-nucleotide variants (SNV) and copy number variants (CNV) with whole-exome sequencing and chromosomal microarray studies. Variation affecting known MCDs-associated genes was found in 16/54 cases, including 11 patients with SNV, 2 patients with CNV, and 3 patients with both CNV and SNV, at distinct loci. Diagnostic pathogenic SNV and potentially damaging variants of unknown significance (VUS) were identified in two groups of seven individuals each. We demonstrated that de novo variants are important among patients with MCDs as they were identified in 10/16 individuals with a molecular diagnosis. Three patients showed changes in known MCDs genes and a clinical phenotype beyond the usual characteristics observed, i.e., phenotypic expansion, for a particular known disease gene clinical entity. We also discovered 2 likely candidate genes, CDH4, and ASTN1, with human and animal studies supporting their roles in brain development, and 5 potential candidate genes. Our findings emphasize genetic heterogeneity of MCDs disorders and postulate potential novel candidate genes involved in cerebral cortical development.
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Affiliation(s)
- Wojciech Wiszniewski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA. .,Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland. .,Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA.
| | - Pawel Gawlinski
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Tomasz Gambin
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland.,Institute of Computer Science, Warsaw University of Technology, Warsaw, Poland
| | | | - Ewa Obersztyn
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Dorota Antczak-Marach
- Clinic of Neurology of Children and Adolescents, Institute of Mother and Child, Warsaw, Poland
| | | | - Tamar Harel
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Ender Karaca
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Marta Jurek
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Katarzyna Sobecka
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Beata Nowakowska
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Malgorzata Kruk
- Clinic of Neurology of Children and Adolescents, Institute of Mother and Child, Warsaw, Poland
| | - Iwona Terczynska
- Clinic of Neurology of Children and Adolescents, Institute of Mother and Child, Warsaw, Poland
| | | | - Mariola Rudzka-Dybala
- Clinic of Neurology of Children and Adolescents, Institute of Mother and Child, Warsaw, Poland
| | - Ewa Jamroz
- School of Medicine in Katowice, Department of Pediatrics and Developmental Age Neurology, Medical University of Silesia, Katowice, Poland
| | - Antoni Pyrkosz
- Department of Medical Genetics, University of Rzeszow, Rzeszow, Poland
| | - Anna Jakubiuk-Tomaszuk
- Department of Pediatric Neurology and Rehabilitation, Medical University of Bialystok, Bialystok, Poland
| | - Piotr Iwanowski
- Department of Medical Genetics, Children's Memorial Health Institute, Warsaw, Poland
| | - Dorota Gieruszczak-Bialek
- Department of Medical Genetics, Children's Memorial Health Institute, Warsaw, Poland.,Department of Pediatrics, Medical University of Warsaw, Warsaw, Poland
| | - Malgorzata Piotrowicz
- Department of Genetics, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland
| | - Maria Sasiadek
- Department of Genetics, Wroclaw Medical University, Wroclaw, Poland
| | - Iwona Kochanowska
- Individual Medical Practice in Pediatric Neurology, Szczecin, Poland
| | - Barbara Gurda
- Department of Developmental Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Barbara Steinborn
- Department of Developmental Neurology, Poznan University of Medical Sciences, Poznan, Poland
| | - Mateusz Dawidziuk
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Jennifer Castaneda
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Pawel Wlasienko
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Natalia Bezniakow
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | | | - Jerzy Bal
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Elzbieta Szczepanik
- Clinic of Neurology of Children and Adolescents, Institute of Mother and Child, Warsaw, Poland
| | - Eric Boerwinkle
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA.,Human Genetics Center and Institute of Molecular Medicine, University of Texas-Houston Health Science Center, Houston, TX, USA
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital, Houston, TX, USA
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30
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Esdal HCD, Ghbeis MB, Saltzman DA, Hess D, Hume JR, Reed RC, Berry SA, Hoggard E, Hirsch B, Baughn LB, Schimmenti LA. Necrotizing Enterocolitis in Two Siblings and an Unrelated Infant with Overlapping Chromosome 6q25 Deletions. Mol Syndromol 2018; 9:141-148. [PMID: 29928179 DOI: 10.1159/000488817] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2018] [Indexed: 11/19/2022] Open
Abstract
The pathogenesis of necrotizing enterocolitis (NEC) remains poorly understood but is thought to be multifactorial. There are no specific recurring chromosomal abnormalities previously associated with NEC. We report 3 cases of intestinal necrosis associated with large chromosome 6 deletions. The first patient was found to have a 7.9-Mb deletion of chromosome 6 encompassing over 40 genes, arr[GRCh37] 6q25.3q26(155699183_163554531)×1. The second patient had a 19.5-Mb deletion of chromosome 6 generated by an unbalanced translocation with chromosome 18, 46,XY,der(6)t (6;18)(q25.1;p11.23), arr[GRCh37] 6q25.1q27(151639526_ 171115067)×1, 18p11.32p11.23(131700_7694199)×3, which included the whole 7.9-Mb region deleted in the first patient. The third patient was the younger sibling of the second patient with an identical derivative chromosome 6. The shared abnormal chromosome 6 region includes multiple genes of interest, particularly EZR. Mouse models have demonstrated that Ezr is expressed in microvillar epithelium and helps regulate cell-cell adhesion in the gut. We hypothesize that deletion of this shared region of 6q leads to gastrointestinal vulnerability which may predispose patients to intestinal necrosis.
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Affiliation(s)
- Hannah C D Esdal
- Department of Pediatrics, University of Minnesota, Minneapolis, USA
| | - Muhammad B Ghbeis
- Division of Cardiovascular Critical Care, Department of Cardiology, Boston Children's Hospital, Boston, MA, USA
| | - Daniel A Saltzman
- Department of Pediatric Surgery, Divisions of, University of Minnesota Masonic Children's Hospital, Minneapolis, USA
| | - Donavon Hess
- Department of Pediatric Surgery, Divisions of, University of Minnesota Masonic Children's Hospital, Minneapolis, USA
| | - Janet R Hume
- Critical Care, University of Minnesota Masonic Children's Hospital, Minneapolis, USA
| | - Robyn C Reed
- Department of Pathology, Children's Hospitals and Clinics of Minnesota, Minneapolis, MN, USA
| | - Susan A Berry
- Genetics and Metabolism, Department of Pediatrics, University of Minnesota Masonic Children's Hospital, Minneapolis, USA
| | - Eric Hoggard
- Division of Pediatric Radiology, Department of Radiology, University of Minnesota Masonic Children's Hospital, Minneapolis, USA
| | - Betsy Hirsch
- Division of Molecular Pathology and Genomics, Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, USA
| | - Linda B Baughn
- Division of Laboratory Genetics and Genomics, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Lisa A Schimmenti
- Department of Otorhinolaryngology and Clinical Genomics, Mayo Clinic, Rochester, MN, USA
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31
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Liu S, Wang Z, Wei S, Liang J, Chen N, OuYang H, Zeng W, Chen L, Xie X, Jiang J. Gray Matter Heterotopia, Mental Retardation, Developmental Delay, Microcephaly, and Facial Dysmorphisms in a Boy with Ring Chromosome 6: A 10-Year Follow-Up and Literature Review. Cytogenet Genome Res 2018; 154:201-208. [DOI: 10.1159/000488692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Indexed: 11/19/2022] Open
Abstract
Ring chromosome 6, r(6), is an extremely rare cytogenetic abnormality with clinical heterogeneity which arises typically de novo. The phenotypes of r(6) can be highly variable, ranging from almost normal to severe malformations and neurological defects. Up to now, only 33 cases have been reported in the literature. In this 10-year follow-up study, we report a case presenting distinctive facial features, severe developmental delay, and gray matter heterotopia with r(6) and terminal deletions of 6p25.3 (115426-384174, 268 kb) and 6q26-27 (168697778-170732033, 2.03 Mb) encompassing 2 and 15 candidate genes, respectively, which were detected using G-banding karyotyping, FISH, and chromosomal microarray analysis. We also analyzed the available information on the clinical features of the reported r(6) cases in order to provide more valuable information on genotype-phenotype correlations. To the best of our knowledge, this is the first report of gray matter heterotopia manifested in a patient with r(6) in China, and the deletions of 6p and 6q in our case are the smallest with the precise size of euchromatic material loss currently known.
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32
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Genetics and mechanisms leading to human cortical malformations. Semin Cell Dev Biol 2018; 76:33-75. [DOI: 10.1016/j.semcdb.2017.09.031] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/21/2017] [Accepted: 09/21/2017] [Indexed: 02/06/2023]
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33
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Farhan SMK, Nixon KCJ, Everest M, Edwards TN, Long S, Segal D, Knip MJ, Arts HH, Chakrabarti R, Wang J, Robinson JF, Lee D, Mirsattari SM, Rupar CA, Siu VM, Poulter MO, Hegele RA, Kramer JM. Identification of a novel synaptic protein, TMTC3, involved in periventricular nodular heterotopia with intellectual disability and epilepsy. Hum Mol Genet 2018; 26:4278-4289. [PMID: 28973161 PMCID: PMC5886076 DOI: 10.1093/hmg/ddx316] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/08/2017] [Indexed: 12/30/2022] Open
Abstract
Defects in neuronal migration cause brain malformations, which are associated with intellectual disability (ID) and epilepsy. Using exome sequencing, we identified compound heterozygous variants (p.Arg71His and p. Leu729ThrfsTer6) in TMTC3, encoding transmembrane and tetratricopeptide repeat containing 3, in four siblings with nocturnal seizures and ID. Three of the four siblings have periventricular nodular heterotopia (PVNH), a common brain malformation caused by failure of neurons to migrate from the ventricular zone to the cortex. Expression analysis using patient-derived cells confirmed reduced TMTC3 transcript levels and loss of the TMTC3 protein compared to parental and control cells. As TMTC3 function is currently unexplored in the brain, we gathered support for a neurobiological role for TMTC3 by generating flies with post-mitotic neuron-specific knockdown of the highly conserved Drosophila melanogaster TMTC3 ortholog, CG4050/tmtc3. Neuron-specific knockdown of tmtc3 in flies resulted in increased susceptibility to induced seizures. Importantly, this phenotype was rescued by neuron-specific expression of human TMTC3, suggesting a role for TMTC3 in seizure biology. In addition, we observed co-localization of TMTC3 in the rat brain with vesicular GABA transporter (VGAT), a presynaptic marker for inhibitory synapses. TMTC3 is localized at VGAT positive pre-synaptic terminals and boutons in the rat hypothalamus and piriform cortex, suggesting a role for TMTC3 in the regulation of GABAergic inhibitory synapses. TMTC3 did not co-localize with Vglut2, a presynaptic marker for excitatory neurons. Our data identified TMTC3 as a synaptic protein that is involved in PVNH with ID and epilepsy, in addition to its previously described association with cobblestone lissencephaly.
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Affiliation(s)
- Sali M K Farhan
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Biochemistry
| | - Kevin C J Nixon
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Michelle Everest
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Tara N Edwards
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Shirley Long
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Dmitri Segal
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Maria J Knip
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Heleen H Arts
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre Nijmegen, The Netherlands
| | - Rana Chakrabarti
- Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics
| | - Jian Wang
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7
| | - John F Robinson
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7
| | | | - Seyed M Mirsattari
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.,Departments of Clinical Neurological Sciences, Medical Biophysics, Medical Imaging and Psychology
| | - C Anthony Rupar
- Department of Biochemistry.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics.,Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Victoria M Siu
- Department of Biochemistry.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Pediatrics
| | | | - Michael O Poulter
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1
| | - Robert A Hegele
- Molecular Medicine Research Group, Robarts Research Institute, London, ON, Canada, N6A 5B7.,Department of Biochemistry
| | - Jamie M Kramer
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada, N6A 5C1.,Division of Genetics and Development, Children's Health Research Institute, London, ON, Canada, N6A 5W9.,Department of Biology, Faculty of Science, Western University, London, ON, Canada, N6A 5B7
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34
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O'Neill AC, Kyrousi C, Einsiedler M, Burtscher I, Drukker M, Markie DM, Kirk EP, Götz M, Robertson SP, Cappello S. Mob2 Insufficiency Disrupts Neuronal Migration in the Developing Cortex. Front Cell Neurosci 2018; 12:57. [PMID: 29593499 PMCID: PMC5857600 DOI: 10.3389/fncel.2018.00057] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 02/19/2018] [Indexed: 12/29/2022] Open
Abstract
Disorders of neuronal mispositioning during brain development are phenotypically heterogeneous and their genetic causes remain largely unknown. Here, we report biallelic variants in a Hippo signaling factor—MOB2—in a patient with one such disorder, periventricular nodular heterotopia (PH). Genetic and cellular analysis of both variants confirmed them to be loss-of-function with enhanced sensitivity to transcript degradation via nonsense mediated decay (NMD) or increased protein turnover via the proteasome. Knockdown of Mob2 within the developing mouse cortex demonstrated its role in neuronal positioning. Cilia positioning and number within migrating neurons was also impaired with comparable defects detected following a reduction in levels of an upstream modulator of Mob2 function, Dchs1, a previously identified locus associated with PH. Moreover, reduced Mob2 expression increased phosphorylation of Filamin A, an actin cross-linking protein frequently mutated in cases of this disorder. These results reveal a key role for Mob2 in correct neuronal positioning within the developing cortex and outline a new candidate locus for PH development.
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Affiliation(s)
- Adam C O'Neill
- Department of Women's and Children's Health, University of Otago, Dunedin, New Zealand.,Helmholtz Center, Institute of Stem Cell Research, Munich, Germany
| | | | | | - Ingo Burtscher
- Helmholtz Center, Institute of Stem Cell Research, Munich, Germany.,Helmholtz Center Munich, Institute of Diabetes and Regeneration Research, Garching, Germany
| | - Micha Drukker
- Helmholtz Center, Institute of Stem Cell Research, Munich, Germany.,Helmholtz Center, iPSC Core Facility, Munich, Germany
| | - David M Markie
- Department of Pathology, University of Otago, Dunedin, New Zealand
| | - Edwin P Kirk
- Sydney Children's Hospital, University of New South Wales and New South Wales Health Pathology, Randwick, NSW, Australia
| | - Magdalena Götz
- Helmholtz Center, Institute of Stem Cell Research, Munich, Germany.,Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Munich, Germany.,Excellence Cluster of Systems Neurology (SYNERGY), Munich, Germany
| | - Stephen P Robertson
- Department of Women's and Children's Health, University of Otago, Dunedin, New Zealand
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35
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Zou Z, Huang L, Lin S, He Z, Zhu H, Zhang Y, Fang Q, Luo Y. Prenatal diagnosis of posterior fossa anomalies: Additional value of chromosomal microarray analysis in fetuses with cerebellar hypoplasia. Prenat Diagn 2018; 38:91-98. [PMID: 29171036 DOI: 10.1002/pd.5190] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 11/02/2017] [Accepted: 11/15/2017] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To elucidate the relationship between copy number variations (CNVs) detected by high-resolution chromosomal microarray analysis (CMA) and the type of prenatal posterior fossa anomalies (PFAs), especially cerebellar hypoplasia (CH). METHODS This study involved 77 pregnancies with PFAs who underwent CMA. RESULTS Chromosomal aberrations including pathogenic CNVs and variants of unknown significance were detected in 31.2% (24/77) of all cases by CMA and in 18.5% (12/65) in fetuses with normal karyotypes. The high detection rate of clinically significant CNVs was evident in fetuses with cerebellar hypoplasia (54.6%, 6/11), vermis hypoplasia (33.3%, 1/3), and Dandy-Walker malformation (25.0%, 3/12). Compare with fetuses without other anomalies, cases with CH and additional malformations had the higher CMA detection rate (33.3% vs 88.9%). Three cases of isolated unilateral CH with intact vermis and normal CMA result had normal outcomes. The deletion of 5p15, 6q terminal deletion, and X chromosome aberrations were the most frequent genetic defects associated with cerebellar hypoplasia. CONCLUSION Among fetuses with PFA, those with cerebellar hypoplasia, vermis hypoplasia, or Dandy-Walker malformation are at the highest risk of clinically significant CNVs. Chromosomal microarray analysis revealed the most frequent chromosomal aberrations associated with CH.
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Affiliation(s)
- Zhiyong Zou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Linhuan Huang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Shaobin Lin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Zhiming He
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Hui Zhu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Yi Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Qun Fang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Yanmin Luo
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
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36
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De Cinque M, Palumbo O, Mazzucco E, Simone A, Palumbo P, Ciavatta R, Maria G, Ferese R, Gambardella S, Angiolillo A, Carella M, Garofalo S. Developmental Coordination Disorder in a Patient with Mental Disability and a Mild Phenotype Carrying Terminal 6q26-qter Deletion. Front Genet 2017; 8:206. [PMID: 29270193 PMCID: PMC5723635 DOI: 10.3389/fgene.2017.00206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/24/2017] [Indexed: 11/13/2022] Open
Abstract
Terminal deletion of chromosome 6q is a rare chromosomal abnormality associated with variable phenotype spectrum. Although intellectual disability, facial dysmorphism, seizures and brain abnormalities are typical features of this syndrome, genotype-phenotype correlation needs to be better understood. We report the case of a 6-year-old Caucasian boy with a clinical diagnosis of intellectual disability, delayed language development and dyspraxia who carries an approximately 8 Mb de novo heterozygous microdeletion in the 6q26-q27 locus identified by karyotype and defined by high-resolution SNP-array analysis. This patient has no significant structural brain or other organ malformation, and he shows a very mild phenotype compared to similar 6q26-qter deletion. The patient phenotype also suggests that a dyspraxia susceptibility gene is located among the deleted genes.
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Affiliation(s)
- Marianna De Cinque
- Dipartimento di Medicina e Scienze della Salute "V. Tiberio", Università degli Studi del Molise, Campobasso, Italy.,Unità Operativa di Medicina Trasfusionale, Azienda Sanitaria Regionale del Molise, Presidio Ospedaliero San Timoteo, Termoli, Italy
| | - Orazio Palumbo
- Unità Operativa Complessa di Genetica Medica, Poliambulatorio "Giovanni Paolo II", IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Ermelinda Mazzucco
- Dipartimento di Medicina e Scienze della Salute "V. Tiberio", Università degli Studi del Molise, Campobasso, Italy
| | - Antonella Simone
- Dipartimento di Medicina e Scienze della Salute "V. Tiberio", Università degli Studi del Molise, Campobasso, Italy.,Unità Operativa di Medicina Trasfusionale, Azienda Sanitaria Regionale del Molise, Presidio Ospedaliero San Timoteo, Termoli, Italy
| | - Pietro Palumbo
- Unità Operativa Complessa di Genetica Medica, Poliambulatorio "Giovanni Paolo II", IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Renata Ciavatta
- Ufficio per la Tutela della Salute Neurologica e Psichica dell'Età Evolutiva, Azienda Sanitaria Regionale del Molise, Termoli, Italy
| | - Giuliana Maria
- Ufficio per la Tutela della Salute Neurologica e Psichica dell'Età Evolutiva, Azienda Sanitaria Regionale del Molise, Termoli, Italy
| | | | | | - Antonella Angiolillo
- Dipartimento di Medicina e Scienze della Salute "V. Tiberio", Università degli Studi del Molise, Campobasso, Italy
| | - Massimo Carella
- Unità Operativa Complessa di Genetica Medica, Poliambulatorio "Giovanni Paolo II", IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Silvio Garofalo
- Dipartimento di Medicina e Scienze della Salute "V. Tiberio", Università degli Studi del Molise, Campobasso, Italy
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37
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Conti V, Carabalona A, Pallesi-Pocachard E, Leventer RJ, Schaller F, Parrini E, Deparis AA, Watrin F, Buhler E, Novara F, Lise S, Pagnamenta AT, Kini U, Taylor JC, Zuffardi O, Represa A, Keays DA, Guerrini R, Falace A, Cardoso C. A Novel Strategy Combining Array-CGH, Whole-exome Sequencing and In Utero Electroporation in Rodents to Identify Causative Genes for Brain Malformations. J Vis Exp 2017. [PMID: 29286390 DOI: 10.3791/53570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Birth defects that involve the cerebral cortex - also known as malformations of cortical development (MCD) - are important causes of intellectual disability and account for 20-40% of drug-resistant epilepsy in childhood. High-resolution brain imaging has facilitated in vivo identification of a large group of MCD phenotypes. Despite the advances in brain imaging, genomic analysis and generation of animal models, a straightforward workflow to systematically prioritize candidate genes and to test functional effects of putative mutations is missing. To overcome this problem, an experimental strategy enabling the identification of novel causative genes for MCD was developed and validated. This strategy is based on identifying candidate genomic regions or genes via array-CGH or whole-exome sequencing and characterizing the effects of their inactivation or of overexpression of specific mutations in developing rodent brains via in utero electroporation. This approach led to the identification of the C6orf70 gene, encoding for a putative vesicular protein, to the pathogenesis of periventricular nodular heterotopia, a MCD caused by defective neuronal migration.
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Affiliation(s)
| | | | | | - Richard J Leventer
- Royal Children's Hospital; Murdoch Children's Research Institute; University of Melbourne
| | - Fabienne Schaller
- INSERM INMED; Aix-Marseille University; Plateforme postgenomique INMED
| | | | | | | | - Emmanuelle Buhler
- INSERM INMED; Aix-Marseille University; Plateforme postgenomique INMED
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38
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Goffinet AM. The evolution of cortical development: the synapsid-diapsid divergence. Development 2017; 144:4061-4077. [PMID: 29138289 DOI: 10.1242/dev.153908] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The cerebral cortex covers the rostral part of the brain and, in higher mammals and particularly humans, plays a key role in cognition and consciousness. It is populated with neuronal cell bodies distributed in radially organized layers. Understanding the common and lineage-specific molecular mechanisms that orchestrate cortical development and evolution are key issues in neurobiology. During evolution, the cortex appeared in stem amniotes and evolved divergently in two main branches of the phylogenetic tree: the synapsids (which led to present day mammals) and the diapsids (reptiles and birds). Comparative studies in organisms that belong to those two branches have identified some common principles of cortical development and organization that are possibly inherited from stem amniotes and regulated by similar molecular mechanisms. These comparisons have also highlighted certain essential features of mammalian cortices that are absent or different in diapsids and that probably evolved after the synapsid-diapsid divergence. Chief among these is the size and multi-laminar organization of the mammalian cortex, and the propensity to increase its area by folding. Here, I review recent data on cortical neurogenesis, neuronal migration and cortical layer formation and folding in this evolutionary perspective, and highlight important unanswered questions for future investigation.
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Affiliation(s)
- Andre M Goffinet
- University of Louvain, Avenue Mounier, 73 Box B1.73.16, B1200 Brussels, Belgium
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39
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Podolska A, Kobelt A, Fuchs S, Hackmann K, Rump A, Schröck E, Kutsche K, Di Donato N. Functional monosomy of 6q27-qter and functional disomy of Xpter-p22.11 due to X;6 translocation with an atypical X-inactivation pattern. Am J Med Genet A 2017; 173:1334-1341. [PMID: 28371302 DOI: 10.1002/ajmg.a.38183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 12/20/2016] [Accepted: 01/26/2017] [Indexed: 12/20/2022]
Abstract
Pattern of X chromosome inactivation (XCI) is typically random in females. However, chromosomal rearrangements affecting the X chromosome can result in XCI skewing due to cell growth disadvantage. In case of an X;autosome translocation, this usually leads to an XCI pattern of 100:0 with the derivative X being the active one in the majority of females. A de novo balanced X;6 translocation [46,X,t(X;6)(p22.1;q27)] and a completely skewed XCI pattern (100:0) were detected in a female patient with microcephaly, cerebellar vermis hypoplasia, heart defect, and severe developmental delay. We mapped the breakpoint regions using fluorescence in situ hybridization and found the X-linked gene POLA1 to be disrupted. POLA1 codes for the catalytic subunit of the polymerase α-primase complex which is responsible for initiation of the DNA replication process; absence of POLA1 is probably incompatible with life. Consequently, by RBA banding we determined which of the X chromosomes was the active one in the patient. In all examined lymphocytes the wild-type X chromosome was active. We propose that completely skewed XCI favoring the normal X chromosome resulted from death of cells with an active derivative X that was caused by a non-functional POLA1 gene. In summary, we conclude that functional monosomy of 6q27-qter and functional disomy of Xpter-p22.11 are responsible for the clinical phenotype of the patient. This case demonstrates the importance of determining which one of the X chromosomes underwent inactivation to correlate clinical features of a female with an X;autosome translocation with the nature of the genetic alteration.
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Affiliation(s)
- Anna Podolska
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Sigrid Fuchs
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Karl Hackmann
- Institute for Clinical Genetics, TU Dresden, Dresden, Germany
| | - Andreas Rump
- Institute for Clinical Genetics, TU Dresden, Dresden, Germany
| | - Evelin Schröck
- Institute for Clinical Genetics, TU Dresden, Dresden, Germany
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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40
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Shahrabi S, Rezaeeyan H, Ahmadzadeh A, Shahjahani M, Saki N. Bone Marrow Blood Vessels: Normal and Neoplastic Niche. Oncol Rev 2016; 10:306. [PMID: 27994770 PMCID: PMC5136754 DOI: 10.4081/oncol.2016.306] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 11/11/2016] [Accepted: 11/17/2016] [Indexed: 12/13/2022] Open
Abstract
Blood vessels are among the most important factors in the transport of materials such as nutrients and oxygen. This study will review the role of blood vessels in normal bone marrow hematopoiesis as well as pathological conditions like leukemia and metastasis. Relevant literature was identified by a Pubmed search (1992-2016) of English-language papers using the terms bone marrow, leukemia, metastasis, and vessel. Given that blood vessels are conduits for the transfer of nutrients, they create a favorable situation for cancer cells and cause their growth and development. On the other hand, blood vessels protect leukemia cells against chemotherapy drugs. Finally, it may be concluded that the vessels are an important factor in the development of malignant diseases.
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Affiliation(s)
- Saeid Shahrabi
- Department of Biochemistry and Hematology, Semnan University of Medical Sciences, Semnan, Iran
| | - Hadi Rezaeeyan
- Golestan Hospital Clinical Research Development Unit, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ahmad Ahmadzadeh
- Health Research Institute, Research Center of Thalassemia & Hemoglobinopathy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mohammad Shahjahani
- Golestan Hospital Clinical Research Development Unit, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Najmaldin Saki
- Health Research Institute, Research Center of Thalassemia & Hemoglobinopathy, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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41
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Mutations in the HECT domain of NEDD4L lead to AKT-mTOR pathway deregulation and cause periventricular nodular heterotopia. Nat Genet 2016; 48:1349-1358. [PMID: 27694961 PMCID: PMC5086093 DOI: 10.1038/ng.3676] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 08/24/2016] [Indexed: 12/16/2022]
Abstract
Neurodevelopmental disorders with periventricular nodular heterotopia (PNH) are etiologically heterogeneous, and their genetic causes remain in many cases unknown. Here we show that missense mutations in NEDD4L mapping to the HECT domain of the encoded E3 ubiquitin ligase lead to PNH associated with toe syndactyly, cleft palate and neurodevelopmental delay. Cellular and expression data showed sensitivity of PNH-associated mutants to proteasome degradation. Moreover, an in utero electroporation approach showed that PNH-related mutants and excess wild-type NEDD4L affect neurogenesis, neuronal positioning and terminal translocation. Further investigations, including rapamycin-based experiments, found differential deregulation of pathways involved. Excess wild-type NEDD4L leads to disruption of Dab1 and mTORC1 pathways, while PNH-related mutations are associated with deregulation of mTORC1 and AKT activities. Altogether, these data provide insights into the critical role of NEDD4L in the regulation of mTOR pathways and their contributions in cortical development.
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Abstract
Malformations of cortical development (MCD) represent a major cause of developmental disabilities, severe epilepsy, and reproductive disadvantage. Genes that have been associated to MCD are mainly involved in cell proliferation and specification, neuronal migration, and late cortical organization. Lissencephaly-pachygyria-severe band heterotopia are diffuse neuronal migration disorders causing severe global neurological impairment. Abnormalities of the LIS1, DCX, ARX, RELN, VLDLR, ACTB, ACTG1, TUBG1, KIF5C, KIF2A, and CDK5 genes have been associated with these malformations. More recent studies have also established a relationship between lissencephaly, with or without associated microcephaly, corpus callosum dysgenesis as well as cerebellar hypoplasia, and at times, a morphological pattern consistent with polymicrogyria with mutations of several genes (TUBA1A, TUBA8, TUBB, TUBB2B, TUBB3, and DYNC1H1), regulating the synthesis and function of microtubule and centrosome key components and hence defined as tubulinopathies. MCD only affecting subsets of neurons, such as mild subcortical band heterotopia and periventricular heterotopia, have been associated with abnormalities of the DCX, FLN1A, and ARFGEF2 genes and cause neurological and cognitive impairment that vary from severe to mild deficits. Polymicrogyria results from abnormal late cortical organization and is inconstantly associated with abnormal neuronal migration. Localized polymicrogyria has been associated with anatomo-specific deficits, including disorders of language and higher cognition. Polymicrogyria is genetically heterogeneous, and only in a small minority of patients, a definite genetic cause has been identified. Megalencephaly with normal cortex or polymicrogyria by MRI imaging, hemimegalencephaly and focal cortical dysplasia can all result from mutations in genes of the PI3K-AKT-mTOR pathway. Postzygotic mutations have been described for most MCD and can be limited to the dysplastic tissue in the less diffuse forms.
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Affiliation(s)
- Elena Parrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - Valerio Conti
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A. Meyer Children's Hospital, University of Florence, Florence, Italy
| | - William B Dobyns
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, and Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Wash., USA
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Department of Neuroscience, A. Meyer Children's Hospital, University of Florence, Florence, Italy
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43
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Fernández V, Llinares-Benadero C, Borrell V. Cerebral cortex expansion and folding: what have we learned? EMBO J 2016; 35:1021-44. [PMID: 27056680 PMCID: PMC4868950 DOI: 10.15252/embj.201593701] [Citation(s) in RCA: 222] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/23/2016] [Accepted: 03/17/2016] [Indexed: 01/22/2023] Open
Abstract
One of the most prominent features of the human brain is the fabulous size of the cerebral cortex and its intricate folding. Cortical folding takes place during embryonic development and is important to optimize the functional organization and wiring of the brain, as well as to allow fitting a large cortex in a limited cranial volume. Pathological alterations in size or folding of the human cortex lead to severe intellectual disability and intractable epilepsy. Hence, cortical expansion and folding are viewed as key processes in mammalian brain development and evolution, ultimately leading to increased intellectual performance and, eventually, to the emergence of human cognition. Here, we provide an overview and discuss some of the most significant advances in our understanding of cortical expansion and folding over the last decades. These include discoveries in multiple and diverse disciplines, from cellular and molecular mechanisms regulating cortical development and neurogenesis, genetic mechanisms defining the patterns of cortical folds, the biomechanics of cortical growth and buckling, lessons from human disease, and how genetic evolution steered cortical size and folding during mammalian evolution.
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Affiliation(s)
- Virginia Fernández
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
| | - Cristina Llinares-Benadero
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
| | - Víctor Borrell
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas & Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
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44
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Schumann M, Hofmann A, Krutzke SK, Hilger AC, Marsch F, Stienen D, Gembruch U, Ludwig M, Merz WM, Reutter H. Array-based molecular karyotyping in fetuses with isolated brain malformations identifies disease-causing CNVs. J Neurodev Disord 2016; 8:11. [PMID: 27087860 PMCID: PMC4832534 DOI: 10.1186/s11689-016-9144-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 03/15/2016] [Indexed: 11/21/2022] Open
Abstract
Background The overall birth prevalence for congenital malformations of the central nervous system (CNS) among Europeans may be as high as 1 in 100 live births. The etiological factors remain largely unknown. The aim of this study was to detect causative copy number variations (CNVs) in fetuses of terminated pregnancies with prenatally detected isolated brain malformations. Methods Array-based molecular karyotyping was performed in a cohort of 35 terminated fetuses with isolated CNS malformations. Identified putative disease-causing CNVs were confirmed using quantitative polymerase chain reaction or multiplex ligation-dependent probe amplification. Results Based on their de novo occurrence and/or their established association with congenital brain malformations, we detected five disease-causing CNVs in four fetuses involving chromosomal regions 6p25.1-6p25.3 (FOXC1), 6q27, 16p12.3, Xp22.2-Xp22.32 (MID1), and Xp22.32-Xp22.33. Furthermore, we detected a probably disease-causing CNV involving chromosomal region 3p26.3 in one fetus, and in addition, we detected 12 CNVs in nine fetuses of unknown clinical significance. All CNVs except for two were absent in 1307 healthy in-house controls (frequency <0.0008). Each of the two CNVs present in in-house controls was present only once (frequency = 0.0008). Furthermore, our data suggests the involvement of CNTN6 and KLHL15 in the etiology of agenesis of the corpus callosum, the involvement of RASD1 and PTPRD in Dandy-Walker malformation, and the involvement of ERMARD in ventriculomegaly. Conclusions Our study suggests that CNVs play an important role in the etiology of isolated brain malformations.
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Affiliation(s)
- Madita Schumann
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Andrea Hofmann
- Institute of Human Genetics, University of Bonn, Bonn, Germany ; Department of Genomics, Life and Brain Center, University of Bonn, Bonn, Germany
| | | | - Alina C Hilger
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - Florian Marsch
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | | | - Ulrich Gembruch
- Department of Obstetrics and Prenatal Medicine, University of Bonn Medical School, Bonn, Germany
| | - Michael Ludwig
- Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Bonn, Germany
| | - Waltraut M Merz
- Department of Obstetrics and Prenatal Medicine, University of Bonn Medical School, Bonn, Germany
| | - Heiko Reutter
- Institute of Human Genetics, University of Bonn, Bonn, Germany ; Department of Neonatology and Pediatric Intensive Care & Institute of Human Genetics, University of Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany
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45
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Sanchez-Castro M, Eldjouzi H, Charpentier E, Busson PF, Hauet Q, Lindenbaum P, Delasalle-Guyomarch B, Baudry A, Pichon O, Pascal C, Lefort B, Bajolle F, Pezard P, Schott JJ, Dina C, Redon R, Gournay V, Bonnet D, Le Caignec C. Search for Rare Copy-Number Variants in Congenital Heart Defects Identifies Novel Candidate Genes and a Potential Role for FOXC1 in Patients With Coarctation of the Aorta. ACTA ACUST UNITED AC 2016; 9:86-94. [DOI: 10.1161/circgenetics.115.001213] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/03/2015] [Indexed: 12/16/2022]
Abstract
Background—
Congenital heart defects are the most frequent malformations among newborns and a frequent cause of morbidity and mortality. Although genetic variation contributes to congenital heart defects, their precise molecular bases remain unknown in the majority of patients.
Methods and Results—
We analyzed, by high-resolution array comparative genomic hybridization, 316 children with sporadic, nonsyndromic congenital heart defects, including 76 coarctation of the aorta, 159 transposition of the great arteries, and 81 tetralogy of Fallot, as well as their unaffected parents. We identified by array comparative genomic hybridization, and validated by quantitative real-time polymerase chain reaction, 71 rare de novo (n=8) or inherited (n=63) copy-number variants (CNVs; 50 duplications and 21 deletions) in patients. We identified 113 candidate genes for congenital heart defects within these CNVs, including
BTRC
,
CHRNB3
,
CSRP2BP
,
ERBB2
,
ERMARD
,
GLIS3
,
PLN
,
PTPRJ
,
RLN3
, and
TCTE3
. No de novo CNVs were identified in patients with transposition of the great arteries in contrast to coarctation of the aorta and tetralogy of Fallot (
P
=0.002; Fisher exact test). A search for transcription factor binding sites showed that 93% of the rare CNVs identified in patients with coarctation of the aorta contained at least 1 gene with FOXC1-binding sites. This significant enrichment (
P
<0.0001; permutation test) was not observed for the CNVs identified in patients with transposition of the great arteries and tetralogy of Fallot. We hypothesize that these CNVs may alter the expression of genes regulated by FOXC1. Foxc1 belongs to the forkhead transcription factors family, which plays a critical role in cardiovascular development in mice.
Conclusions—
These data suggest that deregulation of
FOXC1
or its downstream genes play a major role in the pathogenesis of coarctation of the aorta in humans.
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46
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Lu L, Guo D, Chen X, Xiong W, Jie S, Li H. Abnormal miRNAs Targeting Chromosome Open Reading Frame Genes were Enriched in Microvesicles Derived from the Circulation of HCC. Biochem Genet 2015; 54:120-33. [PMID: 26615601 DOI: 10.1007/s10528-015-9705-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 11/21/2015] [Indexed: 02/06/2023]
Abstract
In this study, we detected the expression profiles of microRNAs (miRNAs) packaged within microvesicles (MVs) from blood samples of HCC patients and healthy donors. Using microarray analysis, there were 83 down-regulated and 92 over-expressed miRNAs in HCC circulation-derived MVs relative to control group. Then potential functions of the dysregulated MVs miRNAs were investigated with bioinformatic tools. We found that 664 Corf genes were targeted by 72 altered MVs miRNAs and some of these target genes were reported to be associated with tumorous activities. Gene Ontology annotation demonstrated that biological roles of the target Corf genes mainly contained the regulation of growth, cell death, macromolecule metabolism, etc. As regulated by abnormal MVs miRNAs, functions of target Corf genes might be interrupted, which were much likely to contribute to HCC occurrence and progression.
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Affiliation(s)
- Li Lu
- Center for Stem Cell Research and Application, Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dongmei Guo
- Center for Stem Cell Research and Application, Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Affiliated Hospital of Jining Medical College, Jining, Shandong, China
| | - Xiaomei Chen
- Center for Stem Cell Research and Application, Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Xiong
- Center for Stem Cell Research and Application, Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shenghua Jie
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huiyu Li
- Center for Stem Cell Research and Application, Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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Stouffer MA, Golden JA, Francis F. Neuronal migration disorders: Focus on the cytoskeleton and epilepsy. Neurobiol Dis 2015; 92:18-45. [PMID: 26299390 DOI: 10.1016/j.nbd.2015.08.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/05/2015] [Accepted: 08/12/2015] [Indexed: 01/28/2023] Open
Abstract
A wide spectrum of focal, regional, or diffuse structural brain abnormalities, collectively known as malformations of cortical development (MCDs), frequently manifest with intellectual disability (ID), epilepsy, and/or autistic spectrum disorder (ASD). As the acronym suggests, MCDs are perturbations of the normal architecture of the cerebral cortex and hippocampus. The pathogenesis of these disorders remains incompletely understood; however, one area that has provided important insights has been the study of neuronal migration. The amalgamation of human genetics and experimental studies in animal models has led to the recognition that common genetic causes of neurodevelopmental disorders, including many severe epilepsy syndromes, are due to mutations in genes regulating the migration of newly born post-mitotic neurons. Neuronal migration genes often, though not exclusively, code for proteins involved in the function of the cytoskeleton. Other cellular processes, such as cell division and axon/dendrite formation, which similarly depend on cytoskeletal functions, may also be affected. We focus here on how the susceptibility of the highly organized neocortex and hippocampus may be due to their laminar organization, which involves the tight regulation, both temporally and spatially, of gene expression, specialized progenitor cells, the migration of neurons over large distances and a birthdate-specific layering of neurons. Perturbations in neuronal migration result in abnormal lamination, neuronal differentiation defects, abnormal cellular morphology and circuit formation. Ultimately this results in disorganized excitatory and inhibitory activity leading to the symptoms observed in individuals with these disorders.
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Affiliation(s)
- Melissa A Stouffer
- INSERM UMRS 839, Paris, France; Sorbonne Universités, Université Pierre et Marie Curie, Paris, France; Institut du Fer à Moulin, Paris, France
| | - Jeffrey A Golden
- Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Fiona Francis
- INSERM UMRS 839, Paris, France; Sorbonne Universités, Université Pierre et Marie Curie, Paris, France; Institut du Fer à Moulin, Paris, France.
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48
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Nishigaki S, Hamazaki T, Saito M, Yamamoto T, Seto T, Shintaku H. Periventricular heterotopia and white matter abnormalities in a girl with mosaic ring chromosome 6. Mol Cytogenet 2015. [PMID: 26213576 PMCID: PMC4514952 DOI: 10.1186/s13039-015-0162-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Ring chromosome 6 is a rare chromosome abnormality that arises typically de novo. The phenotypes can be highly variable, ranging from almost normal to severe malformations and neurological defects. We report a case of a 3-year-old girl with mosaic ring chromosome 6 who presented with being small for gestational age and intellectual disability, and whose brain MRI later revealed periventricular heterotopia and white matter abnormalities. Mosaicism was identified in peripheral blood cells examined by standard G-bands, mos 46,XX,r(6)(p25q27)[67]/45,XX,-6[25]/46,XX,dic r(6:6)(p25q27:p25q27)[6]/47,XX,r(6)(p25q27) × 2[2]. Using array-comparative genomic hybridization, we identified terminal deletion of 6q27 (1.5 Mb) and no deletion on 6p. To our knowledge, this is the first report of periventricular heterotopia and white matter abnormalities manifested in a patient with ring chromosome 6. These central nervous system malformations are further discussed in relation to molecular genetics.
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Affiliation(s)
- Satsuki Nishigaki
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Takashi Hamazaki
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Mika Saito
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Toshiyuki Yamamoto
- Institute for Integrated Medical Sciences, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ward, Tokyo, 162-8666 Japan
| | - Toshiyuki Seto
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
| | - Haruo Shintaku
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan
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Barkovich AJ, Dobyns WB, Guerrini R. Malformations of cortical development and epilepsy. Cold Spring Harb Perspect Med 2015; 5:a022392. [PMID: 25934463 DOI: 10.1101/cshperspect.a022392] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Malformations of cortical development (MCDs) are an important cause of epilepsy and an extremely interesting group of disorders from the perspective of brain development and its perturbations. Many new MCDs have been described in recent years as a result of improvements in imaging, genetic testing, and understanding of the effects of mutations on the ability of their protein products to correctly function within the molecular pathways by which the brain functions. In this review, most of the major MCDs are reviewed from a clinical, embryological, and genetic perspective. The most recent literature regarding clinical diagnosis, mechanisms of development, and future paths of research are discussed.
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Affiliation(s)
- A James Barkovich
- Department of Radiology and Biomedical Imaging, Neurology, Pediatrics, and Neurosurgery, University of California, San Francisco, San Francisco, California 94143-0628
| | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington 98101
| | - Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer, University of Florence, Florence 50139, Italy
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Doisy ET, Wenzel HJ, Mu Y, Nguyen DV, Schwartzkroin PA. Nodule excitability in an animal model of periventricular nodular heterotopia: c-fos activation in organotypic hippocampal slices. Epilepsia 2015; 56:626-35. [PMID: 25752321 DOI: 10.1111/epi.12945] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Aberrations in brain development may lead to dysplastic structures such as periventricular nodules. Although these abnormal collections of neurons are often associated with difficult-to-control seizure activity, there is little consensus regarding the epileptogenicity of the nodules themselves. Because one common treatment option is surgical resection of suspected epileptic nodules, it is important to determine whether these structures in fact give rise, or essentially contribute, to epileptic activities. METHODS To study the excitability of aberrant nodules, we have examined c-fos activation in organotypic hippocampal slice cultures generated from an animal model of periventricular nodular heterotopia created by treating pregnant rats with methylazoxymethanol acetate. Using this preparation, we have also attempted to assess tissue excitability when the nodule is surgically removed from the culture. We then compared c-fos activation in this in vitro preparation to c-fos activation generated in an intact rat treated with kainic acid. RESULTS Quantitative analysis of c-fos activation failed to show enhanced nodule excitability compared to neocortex or CA1 hippocampus. However, when we compared cultures with and without a nodule, presence of a nodule did affect the excitability of CA1 and cortex, at least as reflected in c-fos labeling. Surgical removal of the nodule did not result in a consistent decrease in excitability as reflected in the c-fos biomarker. SIGNIFICANCE Our results from the organotypic culture were generally consistent with our observations on excitability in the intact rat-as seen not only with c-fos but also in previous electrophysiologic studies. At least in this model, the nodule does not appear to be responsible for enhanced excitability (or, presumably, seizure initiation). Excitability is different in tissue that contains a nodule, suggesting altered network function, perhaps reflecting the abnormal developmental pattern that gave rise to the nodule.
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Affiliation(s)
- Emily T Doisy
- Department of Neurological Surgery, University of California, Davis, Davis, California, U.S.A
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