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Woods E, Holmes N, Albaba S, Evans IR, Balasubramanian M. ASXL3-related disorder: Molecular phenotyping and comprehensive review providing insights into disease mechanism. Clin Genet 2024; 105:470-487. [PMID: 38420660 DOI: 10.1111/cge.14506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 03/02/2024]
Abstract
ASXL3-related disorder, sometimes referred to as Bainbridge-Ropers syndrome, was first identified as a distinct neurodevelopmental disorder by Bainbridge et al. in 2013. Since then, there have been a number of case series and single case reports published worldwide. A comprehensive review of the literature was carried out. Abstracts were screened, relevant literature was analysed, and descriptions of common phenotypic features were quantified. ASXL3 variants were collated and categorised. Common phenotypic features comprised global developmental delay or intellectual disability (97%), feeding problems (76%), hypotonia (88%) and characteristic facial features (93%). The majority of genetic variants were de novo truncating variants in exon 11 or 12 of the ASXL3 gene. Several gaps in our knowledge of this disorder were identified, namely, underlying pathophysiology and disease mechanism, disease contribution of missense variants, relevance of variant location, prevalence and penetrance data. Clinical information is currently limited by patient numbers and lack of longitudinal data, which this review aims to address.
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Affiliation(s)
- Emily Woods
- Sheffield Clinical Genetics Service, Sheffield Children's Hospital, Sheffield, UK
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
| | - Nicola Holmes
- Sheffield Diagnostic Genetics Service, Sheffield Children's Hospital, Sheffield, UK
| | - Shadi Albaba
- Sheffield Diagnostic Genetics Service, Sheffield Children's Hospital, Sheffield, UK
| | - Iwan R Evans
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- The Bateson Centre, University of Sheffield, Sheffield, UK
| | - Meena Balasubramanian
- Sheffield Clinical Genetics Service, Sheffield Children's Hospital, Sheffield, UK
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK
- The Bateson Centre, University of Sheffield, Sheffield, UK
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Wang Q, Zhang J, Jiang N, Xie J, Yang J, Zhao X. De novo nonsense variant in ASXL3 in a Chinese girl causing Bainbridge-Ropers syndrome: A case report and review of literature. Mol Genet Genomic Med 2022; 10:e1924. [PMID: 35276034 PMCID: PMC9034677 DOI: 10.1002/mgg3.1924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/18/2022] [Accepted: 02/28/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Bainbridge-Ropers syndrome (BRPS, OMIM #615485) was first identified in 2013 by Bainbridge et al. and is a neurodevelopment disorder characterized by failure to thrive, facial dysmorphism and severe developmental delay. BRPS is caused by heterozygous loss-of-function (LOF) variants in the additional sex combs-like 3 (ASXL3) gene. Due to the limited specific recognizable features and overlapping symptoms with Bohring-Opitz syndrome (BOS, OMIM #612990), clinical diagnosis of BRPS is challenging. METHODS In this study, a 2-year-8-month-old Chinese girl was referred for genetic evaluation of severe developmental delay. The reduced fetal movement was found during the antenatal period and bilateral varus deformity of feet was observed at birth. Whole-exome sequencing and Sanger sequencing were used to detect and confirm the variant. RESULTS A novel nonsense variant c.1063G>T (p.E355*) in the ASXL3 gene (NM_030632.3) was identified in the proband and the clinical symptoms were compatible with BRPS. The parents were physical and genetic normal and prenatal diagnosis was requested for her pregnant mother with a negative Sanger sequencing result. CONCLUSION The study revealed a de novo LOF variant in the ASXL3 gene and expanded the mutation spectrum for this clinical condition. By performing a literature review, we summarized genetic results and the clinical phenotypes of all BPRSs reported so far. More cases study may help to elucidate the function of the ASXL3 gene may be critical to understand the genetic aetiology of this syndrome and assist in accurate genetic counselling, informed decision making and prenatal diagnosis.
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Affiliation(s)
- Qin Wang
- Affiliated Shenzhen Maternity & Child Healthcare HospitalSouthern Medical UniversityShenzhenChina
| | - Jianming Zhang
- Affiliated Shenzhen Maternity & Child Healthcare HospitalSouthern Medical UniversityShenzhenChina
| | - Nan Jiang
- Affiliated Shenzhen Maternity & Child Healthcare HospitalSouthern Medical UniversityShenzhenChina
| | - Jiansheng Xie
- Affiliated Shenzhen Maternity & Child Healthcare HospitalSouthern Medical UniversityShenzhenChina
- The University of Hong Kong‐Shenzhen Hospital ShenzhenShenzhenChina
| | - Jingxin Yang
- Affiliated Shenzhen Maternity & Child Healthcare HospitalSouthern Medical UniversityShenzhenChina
| | - Xiaoshan Zhao
- Affiliated Shenzhen Maternity & Child Healthcare HospitalSouthern Medical UniversityShenzhenChina
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Wu K, Cong Y. Case report : a novel ASXL3 gene variant in a Sudanese boy. BMC Pediatr 2021; 21:557. [PMID: 34886823 PMCID: PMC8655995 DOI: 10.1186/s12887-021-03038-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 11/30/2021] [Indexed: 12/04/2022] Open
Abstract
Background Bainbridge-Ropers syndrome (BRPS) [OMIM#615485] is a neurodevelopmental disorder, characterized by delayed psychomotor development with generalized hypotonia, moderate to severe intellectual disability, poor or absent speech, feeding difficulties, growth failure, dysmorphic craniofacial features and minor skeletal features. The aim of this study was to investigate the genetic etiology of a Sudanese boy with severe developmental delay, intellectual disability, and craniofacial phenotype using trio-based whole-exome sequencing. To our knowledge, no patients with ASXL3 gene variant c.3043C>T have been reported detailedly in literature. Case presentation The patient (male, 3 years 6 months) was the first born of a healthy non-consanguineous couple originating from Sudan, treated for “psychomotor retardation” for more than 8 months in Yiwu. The patient exhibited severely delayed milestones in physiological and intellectual developmental stages, language impairment, poor eye-contact, lack of subtle motions of fingers, fear of claustrophobic space, hypotonia, clinodactyly, autistic features. Peripheral blood samples were collected from the patient and his parents. Trio-based whole-exome sequencing(Trio-WES) identified a de novo heterozygous ASXL3 gene variant c.3043C>T;p.Q1015X. Sanger sequencing verified variants of this family. Conclusion Trio-WES analysis identified a de novo nonsense variant (c.3043C>T) of ASXL3 gene in a Sudanese boy. To our knowledge, the patient with this variant has not been reported previously in literature. This study presents a new case for ASXL3 gene variants, which expanded the mutational and phenotypic spectrum.
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Affiliation(s)
- Ke Wu
- Prenatal Diganosis Center, Yiwu Maternity and Child Health Care Hospital, Xinke Road C100, Yiwu, 322000, Zhejiang Province, People's Republic of China
| | - Yan Cong
- Rehabilitation Department, Yiwu Maternity and Child Health Care Hospital, Xinke Road C100, Yiwu, 322000, Zhejiang Province, People's Republic of China.
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Schirwani S, Albaba S, Carere DA, Guillen Sacoto MJ, Milan Zamora F, Si Y, Rabin R, Pappas J, Renaud DL, Hauser N, Reid E, Blanchet P, Foulds N, Dixit A, Fisher R, Armstrong R, Isidor B, Cogne B, Schrier Vergano S, Demirdas S, Dykzeul N, Cohen JS, Grand K, Morel D, Slavotinek A, Albassam HF, Naik S, Dean J, Ragge N, Costa C, Tedesco MG, Harrison RE, Bouman A, Palen E, Challman TD, Willemsen MH, Vogt J, Cunniff C, Bergstrom K, Walia JS, Bruel AL, Kini U, Alkuraya FS, Slegesky V, Meeks N, Girotto P, Johnson D, Newbury-Ecob R, Ockeloen CW, Prontera P, Lynch SA, Li D, Graham JM, Pierson TM, Balasubramanian M. Expanding the phenotype of ASXL3-related syndrome: A comprehensive description of 45 unpublished individuals with inherited and de novo pathogenic variants in ASXL3. Am J Med Genet A 2021; 185:3446-3458. [PMID: 34436830 DOI: 10.1002/ajmg.a.62465] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/10/2021] [Accepted: 07/08/2021] [Indexed: 12/15/2022]
Abstract
The study aimed at widening the clinical and genetic spectrum of ASXL3-related syndrome, a neurodevelopmental disorder, caused by truncating variants in the ASXL3 gene. In this international collaborative study, we have undertaken a detailed clinical and molecular analysis of 45 previously unpublished individuals with ASXL3-related syndrome, as well as a review of all previously published individuals. We have reviewed the rather limited functional characterization of pathogenic variants in ASXL3 and discuss current understanding of the consequences of the different ASXL3 variants. In this comprehensive analysis of ASXL3-related syndrome, we define its natural history and clinical evolution occurring with age. We report familial ASXL3 pathogenic variants, characterize the phenotype in mildly affected individuals and discuss nonpenetrance. We also discuss the role of missense variants in ASXL3. We delineate a variable but consistent phenotype. The most characteristic features are neurodevelopmental delay with consistently limited speech, significant neuro-behavioral issues, hypotonia, and feeding difficulties. Distinctive features include downslanting palpebral fissures, hypertelorism, tubular nose with a prominent nasal bridge, and low-hanging columella. The presented data will inform clinical management of individuals with ASXL3-related syndrome and improve interpretation of new ASXL3 sequence variants.
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Affiliation(s)
- Schaida Schirwani
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK
- Academic Unit of Child Health, Department of Oncology & Metabolism, University of Sheffield, Sheffield, UK
| | - Shadi Albaba
- Sheffield Diagnostic Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | | | | | | | - Yue Si
- GeneDx, Inc, Gaithersburg, Maryland, USA
| | - Rachel Rabin
- Department of Pediatrics, New York University School of Medicine, New York, New York, USA
| | - John Pappas
- Department of Pediatrics, New York University School of Medicine, New York, New York, USA
| | - Deborah L Renaud
- Division of Child and Adolescent Neurology, Departments of Neurology and Pediatrics, Mayo Clinic, Rochester, Minnesota, USA
| | - Natalie Hauser
- Department of Pediatrics, Division of Medical Genomics, Inova Health System, Falls Church, Virginia, USA
| | - Evan Reid
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Patricia Blanchet
- Département de Génétique Médicale, CHU de Montpellier, Montpellier, France
| | - Nichola Foulds
- Wessex Clinical Genetics Services, University Hospital Southampton NHS Foundation Trust, Southampton, UK
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - Abhijit Dixit
- Clinical Genetics Service, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Richard Fisher
- Teesside Genetics Unit, The James Cook University Hospital, Middlesbrough, UK
| | - Ruth Armstrong
- Departments of Medical Genetics and Paediatric Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | | | - Benjamin Cogne
- Service de génétique médicale, CHU Nantes, Nantes, France
| | - Samantha Schrier Vergano
- Medical Genetics and Metabolism, Children's Hospital of The King's Daughters, Eastern Virginia Medical School, Norfolk, Virginia, USA
| | - Serwet Demirdas
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Natalie Dykzeul
- Lucile Packard Children's Hospital, Stanford Children's Health, Palo Alto, California, USA
| | - Julie S Cohen
- Division of Neurogenetics, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Katheryn Grand
- Department of Pediatrics, Medical Genetics, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Dayna Morel
- University of Miami, Miller School of Medicine, Miami, Florida, USA
| | - Anne Slavotinek
- Department of Pediatrics, Division of Genetics, University of California, San Francisco, San Francisco, California, USA
| | - Hessa F Albassam
- Department of Pediatrics, Care National Hospital, Riyadh, Saudi Arabia
| | - Swati Naik
- West Midlands Regional Genetics Service, Birmingham Women's and Children's Hospital, Birmingham, UK
| | - John Dean
- Clinical Genetics Service, NHS Grampian, Aberdeen Royal Infirmary, Aberdeen, UK
| | - Nicola Ragge
- West Midlands Regional Genetics Service, Birmingham Women's and Children's Hospital, Birmingham, UK
| | - Cinzia Costa
- Neurology Clinic, Department of Medicine, Santa Maria della Misericordia Hospital, University of Perugia, Perugia, Italy
| | - Maria Giovanna Tedesco
- Medical Genetics Unit, Santa Maria della Misericordia Hospital, University of Perugia, Perugia, Italy
- Genetics Unit, "Mauro Baschirotto" Institute for Rare Diseases (B.I.R.D.), Costozza di Longare, Vicenza, Italy
| | - Rachel E Harrison
- Clinical Genetics Service, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Arjan Bouman
- Department of Clinical Genetics, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Emily Palen
- Autism & Developmental Medicine Institute, Geisinger, Danville, Pennsylvania, USA
| | - Thomas D Challman
- Autism & Developmental Medicine Institute, Geisinger, Danville, Pennsylvania, USA
| | - Marjolein H Willemsen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Julie Vogt
- West Midlands Regional Genetics Service, Birmingham Women's and Children's Hospital, Birmingham, UK
| | - Christopher Cunniff
- Division of Medical Genetics, Department of Pediatrics, Weill Cornell Medical College, New York, New York, USA
| | - Katherine Bergstrom
- Division of Medical Genetics, Department of Pediatrics, Weill Cornell Medical College, New York, New York, USA
| | - Jagdeep S Walia
- Divsion of Medical Genetics, Departments of Pediatrics, Queen's University, Kingston, Ontario, Canada
| | - Ange-Line Bruel
- UFR Des Sciences de Santé, INSERM-Université de Bourgogne UMR1231 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Dijon, France
| | - Usha Kini
- Department of Clinical Genetics, Oxford University Hospitals NHS Trust, Oxford, UK
| | - Fowzan S Alkuraya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Valerie Slegesky
- University of Colorado & Children's Hospital Colorado, Denver, Colorado, USA
| | - Naomi Meeks
- University of Colorado & Children's Hospital Colorado, Denver, Colorado, USA
| | - Paula Girotto
- Division of Child Neurology, Department of Pediatrics, Santa Casa de São Paulo School of Medical Sciences, São Paulo, Brazil
| | - Diana Johnson
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK
- EDS National Diagnostic Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK
| | - Ruth Newbury-Ecob
- Bristol Regional Genetics Service, St Michael's Hospital, Bristol, UK
| | - Charlotte W Ockeloen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Paolo Prontera
- Medical Genetics Unit, Santa Maria della Misericordia Hospital, University of Perugia, Perugia, Italy
| | - Sally Ann Lynch
- Department of Clinical Genetics, Temple Street Children's Hospital, Dublin, Ireland
| | - Dong Li
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - John M Graham
- Cedars-Sinai Medical Center, Harbor-UCLA Medical Center, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Tyler Mark Pierson
- Departments of Pediatrics, Neurology, Cedars-Sinai Center for the Undiagnosed Patient, and Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles CA, USA
| | - Meena Balasubramanian
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK
- Academic Unit of Child Health, Department of Oncology & Metabolism, University of Sheffield, Sheffield, UK
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Tønne E, Due-Tønnessen BJ, Mero IL, Wiig US, Kulseth MA, Vigeland MD, Sheng Y, von der Lippe C, Tveten K, Meling TR, Helseth E, Heimdal KR. Benefits of clinical criteria and high-throughput sequencing for diagnosing children with syndromic craniosynostosis. Eur J Hum Genet 2021; 29:920-929. [PMID: 33288889 PMCID: PMC8187391 DOI: 10.1038/s41431-020-00788-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 11/04/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022] Open
Abstract
An accurate diagnosis of syndromic craniosynostosis (CS) is important for personalized treatment, surveillance, and genetic counselling. We describe detailed clinical criteria for syndromic CS and the distribution of genetic diagnoses within the cohort. The prospective registry of the Norwegian National Unit for Craniofacial Surgery was used to retrieve individuals with syndromic CS born between 1 January 2002 and 30 June 2019. All individuals were assessed by a clinical geneticist and classified using defined clinical criteria. A stepwise approach consisting of single-gene analysis, comparative genomic hybridization (aCGH), and exome-based high-throughput sequencing, first filtering for 72 genes associated with syndromic CS, followed by an extended trio-based panel of 1570 genes were offered to all syndromic CS cases. A total of 381 individuals were registered with CS, of whom 104 (27%) were clinically classified as syndromic CS. Using the single-gene analysis, aCGH, and custom-designed panel, a genetic diagnosis was confirmed in 73% of the individuals (n = 94). The diagnostic yield increased to 84% after adding the results from the extended trio-based panel. Common causes of syndromic CS were found in 53 individuals (56%), whereas 26 (28%) had other genetic syndromes, including 17 individuals with syndromes not commonly associated with CS. Only 15 individuals (16%) had negative genetic analyses. Using the defined combination of clinical criteria, we detected among the highest numbers of syndromic CS cases reported, confirmed by a high genetic diagnostic yield of 84%. The observed genetic heterogeneity encourages a broad genetic approach in diagnosing syndromic CS.
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Affiliation(s)
- Elin Tønne
- Faculty of Medicine, University of Oslo, Oslo, Norway.
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway.
- Norwegian National Unit for Craniofacial Surgery, Oslo University Hospital, Oslo, Norway.
| | - Bernt Johan Due-Tønnessen
- Norwegian National Unit for Craniofacial Surgery, Oslo University Hospital, Oslo, Norway
- Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
| | - Inger-Lise Mero
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Ulrikke Straume Wiig
- Norwegian National Unit for Craniofacial Surgery, Oslo University Hospital, Oslo, Norway
- Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
| | - Mari Ann Kulseth
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Magnus Dehli Vigeland
- Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Ying Sheng
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Charlotte von der Lippe
- Centre for Rare Disorders, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Department of Medical Genetics, Telemark Hospital Trust, Skien, Norway
| | - Kristian Tveten
- Department of Medical Genetics, Telemark Hospital Trust, Skien, Norway
| | - Torstein Ragnar Meling
- Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Department of Neurosurgery, Geneva University Hospitals, Geneva, Switzerland
| | - Eirik Helseth
- Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Neurosurgery, Oslo University Hospital, Oslo, Norway
| | - Ketil Riddervold Heimdal
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
- Norwegian National Unit for Craniofacial Surgery, Oslo University Hospital, Oslo, Norway
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Lichtig H, Artamonov A, Polevoy H, Reid CD, Bielas SL, Frank D. Modeling Bainbridge-Ropers Syndrome in Xenopus laevis Embryos. Front Physiol 2020; 11:75. [PMID: 32132929 PMCID: PMC7040374 DOI: 10.3389/fphys.2020.00075] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 01/23/2020] [Indexed: 12/14/2022] Open
Abstract
The Additional sex combs-like (ASXL1-3) genes are linked to human neurodevelopmental disorders. The de novo truncating variants in ASXL1-3 proteins serve as the genetic basis for severe neurodevelopmental diseases such as Bohring-Opitz, Shashi-Pena, and Bainbridge-Ropers syndromes, respectively. The phenotypes of these syndromes are similar but not identical, and include dramatic craniofacial defects, microcephaly, developmental delay, and severe intellectual disability, with a loss of speech and language. Bainbridge-Ropers syndrome resulting from ASXL3 gene mutations also includes features of autism spectrum disorder. Human genomic studies also identified missense ASXL3 variants associated with autism spectrum disorder, but lacking more severe Bainbridge-Ropers syndromic features. While these findings strongly implicate ASXL3 in mammalian brain development, its functions are not clearly understood. ASXL3 protein is a component of the polycomb deubiquitinase complex that removes mono-ubiquitin from Histone H2A. Dynamic chromatin modifications play important roles in the specification of cell fates during early neural patterning and development. In this study, we utilize the frog, Xenopus laevis as a simpler and more accessible vertebrate neurodevelopmental model system to understand the embryological cause of Bainbridge-Ropers syndrome. We have found that ASXL3 protein knockdown during early embryo development highly perturbs neural cell fate specification, potentially resembling the Bainbridge-Ropers syndrome phenotype in humans. Thus, the frog embryo is a powerful tool for understanding the etiology of Bainbridge-Ropers syndrome in humans.
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Affiliation(s)
- Hava Lichtig
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Artyom Artamonov
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Hanna Polevoy
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Christine D Reid
- Department of Genetics, Stanford University, Stanford, CA, United States
| | - Stephanie L Bielas
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Dale Frank
- Department of Biochemistry, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
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Fu C, Luo S, Zhang Y, Fan X, D'Gama AM, Zhang X, Zheng H, Su J, Li C, Luo J, Agrawal PB, Li Q, Chen S. Chromosomal microarray and whole exome sequencing identify genetic causes of congenital hypothyroidism with extra-thyroidal congenital malformations. Clin Chim Acta 2018; 489:103-108. [PMID: 30508507 DOI: 10.1016/j.cca.2018.11.035] [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: 09/12/2018] [Revised: 10/24/2018] [Accepted: 11/29/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder. Although most patients present with isolated CH, some patients present with CH and extra-thyroidal congenital malformations (ECMs), for which less is known about the underlying genetics. The aim of this study was to investigate the genetic mechanisms in patients with CH and ECMs using chromosomal microarray (CMA) and whole exome sequencing (WES). METHODS Peripheral venous blood samples were collected from 16 patients with CH and ECMs. Genomic DNA was extracted from peripheral blood leukocytes. CMA and WES were performed to detect copy number and single nucleotide variants. RESULTS CMA identified clinically significant copy number variants in 7 patients consistent with their phenotypes. For 6 of them, the genotype and phenotype suggested a syndromic diagnosis, and the remaining patient carried a pathogenic microdeletion and microduplication including GLIS3. WES analysis identified 9 different variants in 7 additional patients. The variants included 2 known mutations (c.1096C>T (p.Arg366Trp) in KCNQ1 and c.848C>A (p.Pro283Gln) in NKX2-5) and 7 novel variants: one nonsense mutation (c.4330C>T (p.Arg1444*) in ASXL3), one frameshift mutation (c.1253_1259delACTCTGG (p.Asp418fs) in TG), three missense variants (c.1472C>T (p.Thr491Ile) in TG, c.4604A>G (p.Asp1535Gly) in TG, and c.2139G>T (p.Glu713Asp) in DUOX2, and two splice site variants (c.944-1G>C and c.3693 + 1G>T) in DUOX2. CONCLUSIONS We report the first genetic study of CH patients with ECMs using CMA and WES. Overall, our detection rate for pathogenic and possibly pathogenic variants was 87.5% (14/16). We report 7 novel variants, expanding the mutational spectrum of TG, DUOX2, and ASXL3.
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Affiliation(s)
- Chunyun Fu
- Medical Science Laboratory, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China; Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Shiyu Luo
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Yue Zhang
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Xin Fan
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Alissa M D'Gama
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Xiaofei Zhang
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Haiyang Zheng
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Jiasun Su
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Chuan Li
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Jingsi Luo
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China
| | - Pankaj B Agrawal
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | - Qifei Li
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; The Manton Center for Orphan Disease Research, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA; Division of Newborn Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| | - Shaoke Chen
- Department of Genetic Metabolism, Children's Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning 530003, People's Republic of China.
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Haratz KK, Lerman-Sagie T. Prenatal diagnosis of brainstem anomalies. Eur J Paediatr Neurol 2018; 22:1016-1026. [PMID: 30448280 DOI: 10.1016/j.ejpn.2018.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 10/28/2022]
Abstract
Prenatal diagnosis of brainstem anomalies is important due to the usually associated neurodevelopmental impairment and genetic implications. The extreme developmental changes that the brainstem and cerebellum undergo during fetal life pose a challenge for the characterization and definition of the different malformations. The present review aims to demonstrate the normal development of the fetal brainstem and to present the main features required for diagnosis of its anomalies according to available data in the medical literature.
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Affiliation(s)
- Karina Krajden Haratz
- Fetal Neurology Clinic, Ultrasound in Ob-Gyn Unit, Wolfson Medical Center, Holon, Israel; Lis Maternity Hospital, Tel Aviv Medical Center, Tel Aviv, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Tally Lerman-Sagie
- Fetal Neurology Clinic, Ultrasound in Ob-Gyn Unit, Wolfson Medical Center, Holon, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel; Pediatric Neurology Unit, Wolfson Medical Center, Holon, Israel
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9
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Wojcik MH, Okada K, Prabhu SP, Nowakowski DW, Ramsey K, Balak C, Rangasamy S, Brownstein CA, Schmitz-Abe K, Cohen JS, Fatemi A, Shi J, Grant EP, Narayanan V, Ho HYH, Agrawal PB. De novo variant in KIF26B is associated with pontocerebellar hypoplasia with infantile spinal muscular atrophy. Am J Med Genet A 2018; 176:2623-2629. [PMID: 30151950 DOI: 10.1002/ajmg.a.40493] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/13/2018] [Accepted: 07/02/2018] [Indexed: 12/14/2022]
Abstract
KIF26B is a member of the kinesin superfamily with evolutionarily conserved functions in controlling aspects of embryogenesis, including the development of the nervous system, though its function is incompletely understood. We describe an infant with progressive microcephaly, pontocerebellar hypoplasia, and arthrogryposis secondary to the involvement of anterior horn cells and ventral (motor) nerves. We performed whole exome sequencing on the trio and identified a de novo KIF26B missense variant, p.Gly546Ser, in the proband. This variant alters a highly conserved amino acid residue that is part of the phosphate-binding loop motif and motor-like domain and is deemed pathogenic by several in silico methods. Functional analysis of the variant protein in cultured cells revealed a reduction in the KIF26B protein's ability to promote cell adhesion, a defect that potentially contributes to its pathogenicity. Overall, KIF26B may play a critical role in the brain development and, when mutated, cause pontocerebellar hypoplasia with arthrogryposis.
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Affiliation(s)
- Monica H Wojcik
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Kyoko Okada
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, California
| | - Sanjay P Prabhu
- Neuroradiology Division, Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomic Research Institute, Phoenix, Arizona
| | - Chris Balak
- Center for Rare Childhood Disorders, Translational Genomic Research Institute, Phoenix, Arizona
| | - Sampath Rangasamy
- Center for Rare Childhood Disorders, Translational Genomic Research Institute, Phoenix, Arizona
| | - Catherine A Brownstein
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Klaus Schmitz-Abe
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Julie S Cohen
- Division of Neurogenetics, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland
| | - Ali Fatemi
- Division of Neurogenetics, Hugo W. Moser Research Institute, Kennedy Krieger Institute, Baltimore, Maryland.,Departments of Neurology and Pediatrics, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Jiahai Shi
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, Hong Kong SAR
| | - Ellen P Grant
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Neuroradiology Division, Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomic Research Institute, Phoenix, Arizona
| | - Hsin-Yi Henry Ho
- Department of Cell Biology and Human Anatomy, University of California Davis School of Medicine, Davis, California
| | - Pankaj B Agrawal
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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