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Paprocka J. Neurological Consequences of Congenital Disorders of Glycosylation. ADVANCES IN NEUROBIOLOGY 2023; 29:219-253. [PMID: 36255677 DOI: 10.1007/978-3-031-12390-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The chapter is devoted to neurological aspects of congenital disorders of glycosylation (CDG). At the beginning, the various types of CDG with neurological presentation of symptoms are summarized. Then, the occurrence of various neurological constellation of abnormalities (for example: epilepsy, brain anomalies on neuroimaging, ataxia, stroke-like episodes, autistic features) in different CDG types are discussed followed by data on possible biomarkers and limited treatment options.
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Affiliation(s)
- Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Sciences, Medical University of Silesia, Katowice, Poland.
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2
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Alsharhan H, Ng BG, Daniel EJP, Friedman J, Pivnick EK, Al-Hashem A, Faqeih EA, Liu P, Engelhardt NM, Keller KN, Chen J, Mazzeo PA, Rosenfeld JA, Bamshad MJ, Nickerson DA, Raymond KM, Freeze HH, He M, Edmondson AC, Lam C. Expanding the phenotype, genotype and biochemical knowledge of ALG3-CDG. J Inherit Metab Dis 2021; 44:987-1000. [PMID: 33583022 PMCID: PMC8282734 DOI: 10.1002/jimd.12367] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/15/2021] [Accepted: 02/10/2021] [Indexed: 12/11/2022]
Abstract
Congenital disorders of glycosylation (CDGs) are a continuously expanding group of monogenic disorders of glycoprotein and glycolipid biosynthesis that cause multisystem diseases. Individuals with ALG3-CDG frequently exhibit severe neurological involvement (epilepsy, microcephaly, and hypotonia), ocular anomalies, dysmorphic features, skeletal anomalies, and feeding difficulties. We present 10 unreported individuals diagnosed with ALG3-CDG based on molecular and biochemical testing with 11 novel variants in ALG3, bringing the total to 40 reported individuals. In addition to the typical multisystem disease seen in ALG3-CDG, we expand the symptomatology of ALG3-CDG to now include endocrine abnormalities, neural tube defects, mild aortic root dilatation, immunodeficiency, and renal anomalies. N-glycan analyses of these individuals showed combined deficiencies of hybrid glycans and glycan extension beyond Man5 GlcNAc2 consistent with their truncated lipid-linked precursor oligosaccharides. This spectrum of N-glycan changes is unique to ALG3-CDG. These expanded features of ALG3-CDG facilitate diagnosis and suggest that optimal management should include baseline endocrine, renal, cardiac, and immunological evaluation at the time of diagnosis and with ongoing monitoring.
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Affiliation(s)
- Hind Alsharhan
- Department of Pediatrics, Division of Human Genetics,
Section of Metabolism, The Children’s Hospital of Philadelphia, Philadelphia,
Pennsylvania
- Department of Pathology and Laboratory Medicine,
Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
- Department of Pediatrics, Faculty of Medicine, Kuwait
University, Kuwait City, Kuwait
| | - Bobby G. Ng
- Human Genetics Program, Sanford Burnham Prebys Medical
Discovery Institute, La Jolla, California
| | - Earnest James Paul Daniel
- Department of Pathology and Laboratory Medicine,
Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Jennifer Friedman
- Division of Neurosciences and Pediatrics, University of
California San Diego and Rady Children’s Hospital, San Diego,
California
| | - Eniko K. Pivnick
- Department of Pediatrics, Division of Medical Genetics,
University of Tennessee Health Science Center (UTHSC), Memphis, Tennessee
| | - Amal Al-Hashem
- Department of Pediatrics, Prince Sultan Military Medical
City, Riyadh, Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Saudi
Arabia
| | - Eissa Ali Faqeih
- Section of Medical Genetics, Children’s Specialist
Hospital King Fahad Medical City, Riyadh, Saudi Arabia
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor
College of Medicine, Houston, Texas
- Baylor Genetics Laboratories, Houston, Texas
| | - Nicole M. Engelhardt
- Department of Pediatrics, Division of Human Genetics,
Section of Metabolism, The Children’s Hospital of Philadelphia, Philadelphia,
Pennsylvania
| | - Kierstin N. Keller
- Department of Pediatrics, Division of Human Genetics,
Section of Metabolism, The Children’s Hospital of Philadelphia, Philadelphia,
Pennsylvania
| | - Jie Chen
- Department of Pathology and Laboratory Medicine,
Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Pamela A. Mazzeo
- Department of Pediatrics, The Children’s Hospital
of Philadelphia, Philadelphia, Pennsylvania
| | | | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor
College of Medicine, Houston, Texas
- Baylor Genetics Laboratories, Houston, Texas
| | - Michael J. Bamshad
- Division of Genetic Medicine, Department of Pediatrics,
University of Washington School of Medicine, Seattle, Washington
- Department of Genome Sciences, University of Washington,
Seattle, Washington
- Brotman-Baty Institute, Seattle, Washington
| | - Deborah A. Nickerson
- Department of Genome Sciences, University of Washington,
Seattle, Washington
- Brotman-Baty Institute, Seattle, Washington
| | - Kimiyo M. Raymond
- Department of Laboratory Medicine and Pathology, Mayo
Clinic, Rochester, Minnesota
| | - Hudson H. Freeze
- Human Genetics Program, Sanford Burnham Prebys Medical
Discovery Institute, La Jolla, California
| | - Miao He
- Department of Pathology and Laboratory Medicine,
Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Andrew C. Edmondson
- Department of Pediatrics, Division of Human Genetics,
Section of Metabolism, The Children’s Hospital of Philadelphia, Philadelphia,
Pennsylvania
| | - Christina Lam
- Division of Genetic Medicine, Department of Pediatrics,
University of Washington School of Medicine, Seattle, Washington
- Center of Integrated Brain Research, Seattle
Children’s Research Institute, Seattle, Washington
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ALG3-CDG: a patient with novel variants and review of the genetic and ophthalmic findings. BMC Ophthalmol 2021; 21:249. [PMID: 34090370 PMCID: PMC8180164 DOI: 10.1186/s12886-021-02013-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/26/2021] [Indexed: 12/01/2022] Open
Abstract
Background ALG3-CDG is a rare autosomal recessive disease. It is characterized by deficiency of alpha-1,3-mannosyltransferase caused by pathogenic variants in the ALG3 gene. Patients manifest with severe neurologic, cardiac, musculoskeletal and ophthalmic phenotype in combination with dysmorphic features, and almost half of them die before or during the neonatal period. Case presentation A 23 months-old girl presented with severe developmental delay, epilepsy, cortical atrophy, cerebellar vermis hypoplasia and ocular impairment. Facial dysmorphism, clubfeet and multiple joint contractures were observed already at birth. Transferrin isoelectric focusing revealed a type 1 pattern. Funduscopy showed hypopigmentation and optic disc pallor. Profound retinal ganglion cell loss and inner retinal layer thinning was documented on spectral-domain optical coherence tomography imaging. The presence of optic nerve hypoplasia was also supported by magnetic resonance imaging. A gene panel based next-generation sequencing and subsequent Sanger sequencing identified compound heterozygosity for two novel variants c.116del p.(Pro39Argfs*40) and c.1060 C > T p.(Arg354Cys) in ALG3. Conclusions Our study expands the spectrum of pathogenic variants identified in ALG3. Thirty-three variants in 43 subjects with ALG3-CDG have been reported. Literature review shows that visual impairment in ALG3-CDG is most commonly linked to optic nerve hypoplasia.
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Paprocka J, Jezela-Stanek A, Tylki-Szymańska A, Grunewald S. Congenital Disorders of Glycosylation from a Neurological Perspective. Brain Sci 2021; 11:brainsci11010088. [PMID: 33440761 PMCID: PMC7827962 DOI: 10.3390/brainsci11010088] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
Most plasma proteins, cell membrane proteins and other proteins are glycoproteins with sugar chains attached to the polypeptide-glycans. Glycosylation is the main element of the post-translational transformation of most human proteins. Since glycosylation processes are necessary for many different biological processes, patients present a diverse spectrum of phenotypes and severity of symptoms. The most frequently observed neurological symptoms in congenital disorders of glycosylation (CDG) are: epilepsy, intellectual disability, myopathies, neuropathies and stroke-like episodes. Epilepsy is seen in many CDG subtypes and particularly present in the case of mutations in the following genes: ALG13, DOLK, DPAGT1, SLC35A2, ST3GAL3, PIGA, PIGW, ST3GAL5. On brain neuroimaging, atrophic changes of the cerebellum and cerebrum are frequently seen. Brain malformations particularly in the group of dystroglycanopathies are reported. Despite the growing number of CDG patients in the world and often neurological symptoms dominating in the clinical picture, the number of performed screening tests eg transferrin isoforms is systematically decreasing as broadened genetic testing is recently more favored. The aim of the review is the summary of selected neurological symptoms in CDG described in the literature in one paper. It is especially important for pediatric neurologists not experienced in the field of metabolic medicine. It may help to facilitate the diagnosis of this expanding group of disorders. Biochemically, this paper focuses on protein glycosylation abnormalities.
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Affiliation(s)
- Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Science in Katowice, Medical University of Silesia, 40-752 Katowice, Poland
- Correspondence: ; Tel.: +48-606-415-888
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland;
| | - Anna Tylki-Szymańska
- Department of Pediatrics, Nutrition and Metabolic Diseases, The Children’s Memorial Health Institute, W 04-730 Warsaw, Poland;
| | - Stephanie Grunewald
- NIHR Biomedical Research Center (BRC), Metabolic Unit, Great Ormond Street Hospital and Institute of Child Health, University College London, London SE1 9RT, UK;
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PAKETCI C, EDEM P, HIZ S, SONMEZLER E, SOYDEMIR D, UZAN GS, OKTAY Y, O’HEIR E, BELTRAN S, LAURIE S, TÖPF A, LOCHMULLER H, HORVATH R, YIS U. Successful treatment of intractable epilepsy with ketogenic diet therapy in twins with ALG3-CDG. Brain Dev 2020; 42:539-545. [PMID: 32389449 PMCID: PMC7906126 DOI: 10.1016/j.braindev.2020.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/23/2020] [Accepted: 04/19/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Congenital disorders of glycosylation (CDG) is a heterogeneous group of congenital metabolic diseases with multisystem clinical involvement. ALG3-CDG is a very rare subtype with only 24 cases reported so far. CASE Here, we report two siblings with dysmorphic features, growth retardation, microcephaly, intractable epilepsy, and hemangioma in the frontal, occipital and lumbosacral regions. RESULTS We studied two siblings by whole exome sequencing. A pathogenic variant in ALG3 (NM_005787.6: c.165C > T; p.Gly55=) that had been previously associated with congenital glycolysis defect type 1d was identified. Their intractable seizures were controlled by ketogenic diet. CONCLUSION Although prominent findings of growth retardation and microcephaly seen in our patients have been extensively reported before, presence of hemangioma is a novel finding that may be used as an indication for ALG3-CDG diagnosis. Our patients are the first reported cases whose intractable seizures were controlled with ketogenic diet. This report adds ketogenic diet as an option for treatment of intractable epilepsy in ALG3-CDG.
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Affiliation(s)
- C PAKETCI
- Department of Paediatric Neurology, School of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - P EDEM
- Department of Paediatric Neurology, School of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - S HIZ
- Department of Paediatric Neurology, School of Medicine, Dokuz Eylul University, Izmir, Turkey.,Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey
| | - E SONMEZLER
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey.,Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - D SOYDEMIR
- Department of Paediatric Neurology, School of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - GS UZAN
- Department of Paediatric Neurology, School of Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Y OKTAY
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Izmir, Turkey.,Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, Turkey
| | - E O’HEIR
- Center for Mendelian Genomics and Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.,Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA 02114, USA
| | - S BELTRAN
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - S LAURIE
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - A TÖPF
- John Walton Muscular Dystrophy Research Centre, Institute of Translational and Clinical Research, Newcastle University and Newcastle Hospitals, Newcastle upon Tyne, UK
| | - H LOCHMULLER
- Department of Neuropediatrics and Muscle Disorders, Medical Center – University of Freiburg, Faculty of Medicine, Freiburg, Germany,Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Catalonia, Spain,Children’s Hospital of Eastern Ontario Research Institute; Division of Neurology, Department of Medicine, The Ottawa Hospital; and Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - R HORVATH
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - U YIS
- Department of Paediatric Neurology, School of Medicine, Dokuz Eylul University, Izmir, Turkey
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6
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ALG3-CDG: lethal phenotype and novel variants in Chinese siblings. J Hum Genet 2020; 65:1129-1134. [PMID: 32655146 DOI: 10.1038/s10038-020-0798-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 06/17/2020] [Accepted: 06/28/2020] [Indexed: 11/08/2022]
Abstract
Congenital disorders of glycosylation (CDG) are a group of genetic, mostly multisystem disorders, which often involve the central nervous system. ALG3-CDG is one the some 130 known CDG. Here we report two siblings with a severe phenotype and intrauterine death. Whole-exome sequencing revealed two novel variants in ALG3: NM_005787.6:c.512G>T (p.Arg171Leu) inherited from the mother and NM_005787.6:c.511C>T (p.Arg171Trp) inherited from the father.
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van Tol W, Ashikov A, Korsch E, Abu Bakar N, Willemsen MA, Thiel C, Lefeber DJ. A mutation in mannose-phosphate-dolichol utilization defect 1 reveals clinical symptoms of congenital disorders of glycosylation type I and dystroglycanopathy. JIMD Rep 2019; 50:31-39. [PMID: 31741824 PMCID: PMC6850978 DOI: 10.1002/jmd2.12060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/25/2019] [Accepted: 05/29/2019] [Indexed: 12/11/2022] Open
Abstract
Congenital disorders of glycosylation type I (CDG-I) are inborn errors of metabolism, generally characterized by multisystem clinical manifestations, including developmental delay, hepatopathy, hypotonia, and skin, skeletal, and neurological abnormalities. Among others, dolichol-phosphate-mannose (DPM) is the mannose donor for N-glycosylation as well as O-mannosylation. DOLK-CDG, DPM1-CDG, DPM2-CDG, and DPM3-CDG are defects in the DPM synthesis showing both CDG-I abnormalities and reduced O-mannosylation of alpha-dystroglycan (αDG), which leads to muscular dystrophy-dystroglycanopathy. Mannose-phosphate-dolichol utilization defect 1 (MPDU1) plays a role in the utilization of DPM. Here, we report two MPDU1-CDG patients without skin involvement, but with massive dilatation of the biliary duct system and dystroglycanopathy characteristics including hypotonia, elevated creatine kinase, dilated cardiomyopathy, buphthalmos, and congenital glaucoma. Biochemical analyses revealed elevated disialotransferrin in serum, and analyses in fibroblasts showed shortened lipid linked oligosaccharides and DPM, and reduced O-mannosylation of αDG. Thus, MPDU1-CDG can be added to the list of disorders with overlapping biochemical and clinical abnormalities of CDG-I and dystroglycanopathy. SYNOPSIS Mannose-phosphate-dolichol utilization defect 1 patients can have overlapping biochemical and clinical abnormalities of congenital disorders of glycosylation type I and dystroglycanopathy.
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Affiliation(s)
- Walinka van Tol
- Department of Neurology, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Angel Ashikov
- Department of Neurology, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Eckhard Korsch
- Children's Hospital of the City of CologneCologneGermany
| | - Nurulamin Abu Bakar
- Department of Neurology, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Michèl A. Willemsen
- Department of Pediatric Neurology, Amalia Children's Hospital, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Christian Thiel
- Center for Child and Adolescent Medicine, Kinderheilkunde IUniversity of HeidelbergHeidelbergGermany
| | - Dirk J. Lefeber
- Department of Neurology, Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
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8
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Himmelreich N, Dimitrov B, Geiger V, Zielonka M, Hutter AM, Beedgen L, Hüllen A, Breuer M, Peters V, Thiemann KC, Hoffmann GF, Sinning I, Dupré T, Vuillaumier-Barrot S, Barrey C, Denecke J, Kölfen W, Düker G, Ganschow R, Lentze MJ, Moore S, Seta N, Ziegler A, Thiel C. Novel variants and clinical symptoms in four new ALG3-CDG patients, review of the literature, and identification of AAGRP-ALG3 as a novel ALG3 variant with alanine and glycine-rich N-terminus. Hum Mutat 2019; 40:938-951. [PMID: 31067009 DOI: 10.1002/humu.23764] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 04/03/2019] [Accepted: 04/09/2019] [Indexed: 12/20/2022]
Abstract
ALG3-CDG is one of the very rare types of congenital disorder of glycosylation (CDG) caused by variants in the ER-mannosyltransferase ALG3. Here, we summarize the clinical, biochemical, and genetic data of four new ALG3-CDG patients, who were identified by a type I pattern of serum transferrin and the accumulation of Man5 GlcNAc2 -PP-dolichol in LLO analysis. Additional clinical symptoms observed in our patients comprise sensorineural hearing loss, right-descending aorta, obstructive cardiomyopathy, macroglossia, and muscular hypertonia. We add four new biochemically confirmed variants to the list of ALG3-CDG inducing variants: c.350G>C (p.R117P), c.1263G>A (p.W421*), c.1037A>G (p.N346S), and the intron variant c.296+4A>G. Furthermore, in Patient 1 an additional open-reading frame of 141 bp (AAGRP) in the coding region of ALG3 was identified. Additionally, we show that control cells synthesize, to a minor degree, a hybrid protein composed of the polypeptide AAGRP and ALG3 (AAGRP-ALG3), while in Patient 1 expression of this hybrid protein is significantly increased due to the homozygous variant c.160_196del (g.165C>T). By reviewing the literature and combining our findings with previously published data, we further expand the knowledge of this rare glycosylation defect.
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Affiliation(s)
- Nastassja Himmelreich
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Bianca Dimitrov
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Virginia Geiger
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Matthias Zielonka
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Anna-Marlen Hutter
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Lars Beedgen
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Andreas Hüllen
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Maximilian Breuer
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Verena Peters
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Kai-Christian Thiemann
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Georg F Hoffmann
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Irmgard Sinning
- Biochemistry Center (BZH), Heidelberg University, Heidelberg, Germany
| | - Thierry Dupré
- Department Biochimie, AP-HP, Hôpital Bichat, Biochimie, Paris, France.,Faculté de Médecine Xavier Bichat, INSERM U1149, Université Paris Diderot, Paris, France
| | - Sandrine Vuillaumier-Barrot
- Department Biochimie, AP-HP, Hôpital Bichat, Biochimie, Paris, France.,Faculté de Médecine Xavier Bichat, INSERM U1149, Université Paris Diderot, Paris, France
| | | | - Jonas Denecke
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wolfgang Kölfen
- Zentrum für Kinder und Jugendmedizin, Städtischen Kliniken Mönchengladbach, Mönchengladbach, Germany
| | - Gesche Düker
- Department of Pediatrics, Children's Hospital Medical Center, University Hospitals Bonn, Bonn, Germany
| | - Rainer Ganschow
- Department of Pediatrics, Children's Hospital Medical Center, University Hospitals Bonn, Bonn, Germany
| | - Michael J Lentze
- Department of Pediatrics, Children's Hospital Medical Center, University Hospitals Bonn, Bonn, Germany
| | - Stuart Moore
- Faculté de Médecine Xavier Bichat, INSERM U1149, Université Paris Diderot, Paris, France
| | - Nathalie Seta
- Department Biochimie, AP-HP, Hôpital Bichat, Biochimie, Paris, France
| | - Andreas Ziegler
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
| | - Christian Thiel
- Center for Child and Adolescent Medicine, Department Pediatrics I, University of Heidelberg, Heidelberg, Germany
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9
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Hacker B, Schultheiß C, Kurzik-Dumke U. Sequential cleavage of the proteins encoded by HNOT/ALG3, the human counterpart of the Drosophila NOT and yeast ALG3 gene, results in products acting in distinct cellular compartments. Hum Mol Genet 2018; 27:4231-4248. [PMID: 30192950 DOI: 10.1093/hmg/ddy315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/04/2018] [Indexed: 11/12/2022] Open
Abstract
This study provides first insights into the biosynthesis, structure, biochemistry and complex processing of the proteins encoded by hNOT/ALG3, the human counterpart of the Drosophila Neighbour of TID (NOT) and the yeast asparagine linked glycosylation 3 gene (ALG3), which encodes a mannosyltransferase. Unambiguous evidence that both the fly and human proteins act as mannosyltransferases has not been provided yet. Previously, we showed that hNOT/ALG3 encodes two alternatively spliced main transcripts, hNOT-1/ALG3-1 and hNOT-4/ALG3-4, and their 15 truncated derivatives that lack diverse sets of exons and/or carry point mutations that result in premature termination codons. Here we show that the truncated transcripts are not translated. The two main forms hNOT-1/ALG3-1 and -4, distinguishable by alternative exon 1, encode full-length precursors that undergo a complex posttranslational processing. To specifically detect the two full-length hNOT/ALG3 proteins and their distinct derivatives and to examine their expression profiles and cellular location we generated polyclonal antibodies against diverse parts of the putative full-length proteins. We provide experimental evidence for the N-glycosylation of the two precursors. This modification seems to be a prerequisite for their sequential cleavage resulting in derivatives destined to distinct cellular compartments and links them with the N-glycosylation machinery not as its functional component but as molecules functionally dependent on its action. We present the expression profiles and subcellular location of the two full-length proteins, their N-glycosylated forms and distinct cleavage products. Furthermore, using diverse bioinformatics tools, we characterize the properties and predict the 2D and 3D structure of the two proteins and, for comparative purposes, of their Drosophila counterpart.
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Affiliation(s)
- Benedikt Hacker
- Institute of Medical Microbiology and Hygiene, Laboratory for Comparative Tumour Biology, University Medical Centre, Johannes Gutenberg University, Obere Zahlbacher, Mainz, Germany
| | - Christoph Schultheiß
- Institute of Medical Microbiology and Hygiene, Laboratory for Comparative Tumour Biology, University Medical Centre, Johannes Gutenberg University, Obere Zahlbacher, Mainz, Germany
| | - Ursula Kurzik-Dumke
- Institute of Medical Microbiology and Hygiene, Laboratory for Comparative Tumour Biology, University Medical Centre, Johannes Gutenberg University, Obere Zahlbacher, Mainz, Germany
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10
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Hacker B, Schultheiß C, Döring M, Kurzik-Dumke U. Molecular partners of hNOT/ALG3, the human counterpart of the Drosophila NOT and yeast ALG3 gene, suggest its involvement in distinct cellular processes relevant to congenital disorders of glycosylation, cancer, neurodegeneration and a variety of further pathologies. Hum Mol Genet 2018; 27:1858-1878. [DOI: 10.1093/hmg/ddy087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/06/2018] [Indexed: 01/04/2023] Open
Affiliation(s)
- Benedikt Hacker
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Christoph Schultheiß
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Michael Döring
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Ursula Kurzik-Dumke
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
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Al Teneiji A, Bruun TUJ, Sidky S, Cordeiro D, Cohn RD, Mendoza-Londono R, Moharir M, Raiman J, Siriwardena K, Kyriakopoulou L, Mercimek-Mahmutoglu S. Phenotypic and genotypic spectrum of congenital disorders of glycosylation type I and type II. Mol Genet Metab 2017; 120:235-242. [PMID: 28122681 DOI: 10.1016/j.ymgme.2016.12.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/28/2016] [Accepted: 12/29/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND Congenital disorders of glycosylation (CDG) are inborn defects of glycan metabolism. They are multisystem disorders. Analysis of transferrin isoforms is applied as a screening test for CDG type I (CDG-I) and type II (CDG-II). We performed a retrospective cohort study to determine spectrum of phenotype and genotype and prevalence of the different subtypes of CDG-I and CDG-II. MATERIAL AND METHODS All patients with CDG-I and CDG-II evaluated in our institution's Metabolic Genetics Clinics were included. Electronic and paper patient charts were reviewed. We set-up a high performance liquid chromatography transferrin isoelectric focusing (TIEF) method to measure transferrin isoforms in our Institution. We reviewed the literature for the rare CDG-I and CDG-II subtypes seen in our Institution. RESULTS Fifteen patients were included: 9 with PMM2-CDG and 6 with non-PMM2-CDG (one ALG3-CDG, one ALG9-CDG, two ALG11-CDG, one MPDU1-CDG and one ATP6V0A2-CDG). All patients with PMM2-CDG and 5 patients with non-PMM2-CDG showed abnormal TIEF suggestive of CDG-I or CDG-II pattern. In all patients, molecular diagnosis was confirmed either by single gene testing, targeted next generation sequencing for CDG genes, or by whole exome sequencing. CONCLUSION We report 15 new patients with CDG-I and CDG-II. Whole exome sequencing will likely identify more patients with normal TIEF and expand the phenotypic spectrum of CDG-I and CDG-II.
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Affiliation(s)
- Amal Al Teneiji
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Theodora U J Bruun
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada; Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Sarah Sidky
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Dawn Cordeiro
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ronald D Cohn
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Roberto Mendoza-Londono
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mahendranath Moharir
- Division of Neurology, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | - Lianna Kyriakopoulou
- Division of Genome Diagnostics, Department of Paediatric Laboratory Medicine, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Saadet Mercimek-Mahmutoglu
- Division of Clinical and Metabolic Genetics, Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada; Genetics and Genome Biology Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada; Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada.
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12
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Maratha A, Colhoun HO, Knerr I, Coss KP, Doran P, Treacy EP. Classical Galactosaemia and CDG, the N-Glycosylation Interface. A Review. JIMD Rep 2016; 34:33-42. [PMID: 27502837 PMCID: PMC5509556 DOI: 10.1007/8904_2016_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022] Open
Abstract
Classical galactosaemia is a rare disorder of carbohydrate metabolism caused by galactose-1-phosphate uridyltransferase (GALT) deficiency (EC 2.7.7.12). The disease is life threatening if left untreated in neonates and the only available treatment option is a long-term galactose restricted diet. While this is lifesaving in the neonate, complications persist in treated individuals, and the cause of these, despite early initiation of treatment, and shared GALT genotypes remain poorly understood. Systemic abnormal glycosylation has been proposed to contribute substantially to the ongoing pathophysiology. The gross N-glycosylation assembly defects observed in the untreated neonate correct over time with treatment. However, N-glycosylation processing defects persist in treated children and adults.Congenital disorders of glycosylation (CDG) are a large group of over 100 inherited disorders affecting largely N- and O-glycosylation.In this review, we compare the clinical features observed in galactosaemia with a number of predominant CDG conditions.We also summarize the N-glycosylation abnormalities, which we have described in galactosaemia adult and paediatric patients, using an automated high-throughput HILIC-UPLC analysis of galactose incorporation into serum IgG with analysis of the corresponding N-glycan gene expression patterns and the affected pathways.
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Affiliation(s)
- Ashwini Maratha
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Temple Street, Dublin, Ireland
- University College Dublin Clinical Research Centre, Eccles Street, Dublin, Ireland
| | | | - Ina Knerr
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Temple Street, Dublin, Ireland
| | - Karen P Coss
- Faculty of Life Sciences and Medicine, Department of Infectious Diseases, King's College London, Guy's Hospital, London, UK
| | - Peter Doran
- University College Dublin Clinical Research Centre, Eccles Street, Dublin, Ireland
| | - Eileen P Treacy
- National Centre for Inherited Metabolic Disorders, Children's University Hospital, Temple Street, Dublin, Ireland.
- University College Dublin Clinical Research Centre, Eccles Street, Dublin, Ireland.
- Trinity College, Dublin, Ireland.
- Mater Misericordiae University Hospital, Eccles Street, Dublin, Ireland.
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13
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Neuropädiatrische Differenzialdiagnostik der Mikrozephalie im Kindesalter. MED GENET-BERLIN 2016. [DOI: 10.1007/s11825-016-0081-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Zusammenfassung
Eine Mikrozephalie betrifft 2–3 % der Bevölkerung und geht oftmals mit einer Intelligenzminderung einher. Die zugrunde liegende Reduktion des Gehirnvolumens kann sowohl durch exogene Faktoren als auch durch genetische Ursachen bedingt sein. Problematisch sind sowohl die uneinheitliche Klassifikation als auch die große Heterogenität der hinter dem klinischen Zeichen Mikrozephalie stehenden Erkrankungen. Im vorliegenden Artikel stellen wir unseren Vorschlag für die diagnostische Herangehensweise an ein Kind mit Mikrozephalie aus neuropädiatrischer Sicht vor.
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Abstract
This review presents principles of glycosylation, describes the relevant glycosylation pathways and their related disorders, and highlights some of the neurological aspects and issues that continue to challenge researchers. More than 100 rare human genetic disorders that result from deficiencies in the different glycosylation pathways are known today. Most of these disorders impact the central and/or peripheral nervous systems. Patients typically have developmental delays/intellectual disabilities, hypotonia, seizures, neuropathy, and metabolic abnormalities in multiple organ systems. Among these disorders there is great clinical diversity because all cell types differentially glycosylate proteins and lipids. The patients have hundreds of misglycosylated products, which afflict a myriad of processes, including cell signaling, cell-cell interaction, and cell migration. This vast complexity in glycan composition and function, along with the limited availability of analytic tools, has impeded the identification of key glycosylated molecules that cause pathologies. To date, few critical target proteins have been pinpointed.
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15
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Lepais L, Cheillan D, Frachon SC, Hays S, Matthijs G, Panagiotakaki E, Abel C, Edery P, Rossi M. ALG3-CDG: Report of two siblings with antenatal features carrying homozygous p.Gly96Arg mutation. Am J Med Genet A 2015; 167A:2748-54. [PMID: 26126960 DOI: 10.1002/ajmg.a.37232] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 06/15/2015] [Indexed: 01/20/2023]
Abstract
Congenital disorders of glycosylation (CDG) are a group of inborn errors of metabolism presenting with heterogeneous multisystemic clinical manifestations. To date, more than 60 different types of CDG have been reported. ALG3-CDG is very rare, with only nine patients described so far. We report two affected siblings presenting prenatally with skeletal abnormalities associated with dysmorphic features, cerebellar vermis hypoplasia, corpus callosum agenesis, hepatic fibrosis and poor prognosis. This is the first detailed report of an affected fetus including clinical, radiographic and pathological findings. The patients showed some clinical features previously unreported in ALG3-CDG, such as bone dysplasia, cataract, corneal opacities, and pons hypoplasia. Both patients were homozygous for the previously unreported p.Gly96Arg mutation of the ALG3 gene. One patient showed chondrodysplasia punctata (CDP), which has not been previously reported in CDG. An exhaustive genetic and metabolic assessment, performed in order to rule out other possible causes of CDP, showed abnormally raised levels of anti-nuclear antibodies in the mother who, nevertheless, did not show any clinical sign of autoimmune disease during a 7 years follow-up. We speculate that the observed CDP may be explained by the maternal anti-nuclear antibodies; alternatively, a possible link to the underlying metabolic disorder cannot be ruled out. In conclusion, we report the clinical, pathological, biochemical and molecular characterization of two further patients affected by ALG3-CDG, expanding the phenotypic spectrum of this very rare disease.
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Affiliation(s)
- Laureline Lepais
- Centre de Référence des Anomalies du Développement, Service de Génétique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France
| | - David Cheillan
- Service des Maladies Héréditaires du Métabolisme et Dépistage Néonatal, Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Bron, France.,INSERM U1060/Université Lyon-1, Lyon, France
| | - Sophie Collardeau Frachon
- Service d'Anatomie Pathologique, Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Bron, France.,Université Lyon 1, Lyon, France
| | - Stéphane Hays
- Service de Réanimation Néonatale et Néonatologie, Hôpital de la Croix Rousse, Hospices Civils de Lyon, Lyon, France
| | - Gert Matthijs
- Center for Human Genetics, UZ Gasthuisberg, Leuven, Belgium
| | - Eleni Panagiotakaki
- Service Epilepsie, Sommeil, Explorations Fonctionnelles Neuropédiatriques (ESEFNP), Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France
| | - Carine Abel
- Centre de Référence des Anomalies du Développement, Service de Génétique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France
| | - Patrick Edery
- Centre de Référence des Anomalies du Développement, Service de Génétique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France.,Université Lyon 1, Lyon, France.,INSERM U1028, CNRS UMR5292, CRNL TIGER Team, Bron, France
| | - Massimiliano Rossi
- Centre de Référence des Anomalies du Développement, Service de Génétique, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, Bron, France.,INSERM U1028, CNRS UMR5292, CRNL TIGER Team, Bron, France
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16
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Baycin-Hizal D, Gottschalk A, Jacobson E, Mai S, Wolozny D, Zhang H, Krag SS, Betenbaugh MJ. Physiologic and pathophysiologic consequences of altered sialylation and glycosylation on ion channel function. Biochem Biophys Res Commun 2014; 453:243-53. [PMID: 24971539 PMCID: PMC4544737 DOI: 10.1016/j.bbrc.2014.06.067] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/13/2014] [Indexed: 01/01/2023]
Abstract
Voltage-gated ion channels are transmembrane proteins that regulate electrical excitability in cells and are essential components of the electrically active tissues of nerves, muscle and the heart. Potassium channels are one of the largest subfamilies of voltage sensitive channels and are among the most-studied of the voltage-gated ion channels. Voltage-gated channels can be glycosylated and changes in the glycosylation pattern can affect ion channel function, leading to neurological and neuromuscular disorders and congenital disorders of glycosylation (CDG). Alterations in glycosylation can also be acquired and appear to play a role in development and aging. Recent studies have focused on the impact of glycosylation and sialylation on ion channels, particularly for voltage-gated potassium and sodium channels. The terminal step of sialylation often affects channel activation and inactivation kinetics. The presence of sialic acids on O or N-glycans can alter the gating mechanism and cause conformational changes in the voltage-sensing domains due to sialic acid's negative charges. This manuscript will provide an overview of sialic acids, potassium and sodium channel function, and the impact of sialylation on channel activation and deactivation.
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Affiliation(s)
- Deniz Baycin-Hizal
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States.
| | - Allan Gottschalk
- Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Elena Jacobson
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Sunny Mai
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Daniel Wolozny
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Hui Zhang
- Pathology, Johns Hopkins University, United States
| | - Sharon S Krag
- Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, United States
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von der Hagen M, Pivarcsi M, Liebe J, von Bernuth H, Didonato N, Hennermann JB, Bührer C, Wieczorek D, Kaindl AM. Diagnostic approach to microcephaly in childhood: a two-center study and review of the literature. Dev Med Child Neurol 2014; 56:732-41. [PMID: 24617602 DOI: 10.1111/dmcn.12425] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/15/2014] [Indexed: 12/12/2022]
Abstract
AIM The aim of this study was to assess the diagnostic approach to microcephaly in childhood and to identify the prevalence of the various underlying causes/disease entities. METHOD We conducted a retrospective study on a cohort of 680 children with microcephaly (399 males, 281 females; mean age at presentation 7-8mo, range 1mo-5y) from patients presenting to Charité - University Medicine Berlin (n=474) and University Hospital Dresden (n=206). Patient discharge letters were searched electronically to identify cases of microcephaly, and then the medical records of these patients were used to analyze parameters for distribution. RESULTS The putative aetiology for microcephaly was ascertained in 59% of all patients, leaving 41% without a definite diagnosis. In the cohort of pathogenetically defined microcephaly, genetic causes were identified in about half of the patients, perinatal brain damage accounted for 45%, and postnatal brain damage for 3% of the cases. Microcephaly was associated with intellectual impairment in 65% of participants, epilepsy was diagnosed in 43%, and ophthalmological disorders were found in 30%. Brain magnetic resonance imaging revealed abnormalities in 76% of participants. INTERPRETATION Microcephaly remains a poorly defined condition, and a uniform diagnostic approach is urgently needed. A definite aetiological diagnosis is important in order to predict the prognosis and offer genetic counselling. Identifying gene mutations as causes of microcephaly increases our knowledge of brain development and the clinical spectrum of microcephaly. We therefore propose a standardized initial diagnostic approach to microcephaly.
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Affiliation(s)
- Maja von der Hagen
- Abteilung Neuropaediatrie, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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18
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Wolfe LA, Krasnewich D. Congenital disorders of glycosylation and intellectual disability. ACTA ACUST UNITED AC 2014; 17:211-25. [PMID: 23798010 DOI: 10.1002/ddrr.1115] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/17/2012] [Indexed: 12/31/2022]
Abstract
The congenital disorders of glycosylation (CDG) are a rapidly growing group of inborn errors of metabolism that result from defects in the synthesis of glycans. Glycosylation is a major post-translational protein modification and an estimated 2% of the human genome encodes proteins for glycosylation. The molecular bases for the current 60 disorders, affecting approximately 800 individuals, have been identified, many in the last 5 years. CDG should be considered in any multi-system syndrome or single tissue disorder not explained by the identification of another disorder. The initial clinical presentation varies significantly among individuals, even between affected siblings. However, two thirds of the known CDGs are associated with intellectual disabilities and most affected individuals need support services throughout their lives. Additional disorders of glycosylation are likely to be characterized over time.
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Affiliation(s)
- Lynne A Wolfe
- Genetic Nurse Practitioner, Undiagnosed Diseases Program, National Human Genome Research Institute, Bethesda, Maryland 20892, USA.
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19
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Riess S, Reddihough DS, Howell KB, Dagia C, Jaeken J, Matthijs G, Yaplito-Lee J. ALG3-CDG (CDG-Id): clinical, biochemical and molecular findings in two siblings. Mol Genet Metab 2013; 110:170-5. [PMID: 23791010 DOI: 10.1016/j.ymgme.2013.05.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 05/30/2013] [Accepted: 05/31/2013] [Indexed: 12/01/2022]
Abstract
Congenital disorders of glycosylation (CDG) represent an expanding family of metabolic disorders with a wide range of biochemical, molecular and clinical phenotypes. ALG3-CDG (CDG-Id), due to a defect in endoplasmic reticulum (ER) mannosyltransferase VI, is one of the less common types of CDG-I. We describe two Vietnamese siblings with confirmed ALG3-CDG (CDG-Id) by molecular testing. As far as we are aware, they are the oldest reported patients in the literature at 15 and 21years. They share similar clinical features with previously reported patients including facial dysmorphism, severe psychomotor retardation, microcephaly, seizures, and gastrointestinal symptoms. Furthermore, our sibling pair highlights the intrafamilial variability, the natural clinical course of ALG3-CDG (CDG-Id) and the benefit of reassessing patients with undiagnosed and complex syndromes, particularly when they present with neurological deterioration.
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Affiliation(s)
- Suzi Riess
- Developmental Medicine, Royal Children's Hospital, Melbourne, Australia
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20
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Douillard C, Mention K, Dobbelaere D, Wemeau JL, Saudubray JM, Vantyghem MC. Hypoglycaemia related to inherited metabolic diseases in adults. Orphanet J Rare Dis 2012; 7:26. [PMID: 22587661 PMCID: PMC3458880 DOI: 10.1186/1750-1172-7-26] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 03/19/2012] [Indexed: 12/15/2022] Open
Abstract
In non-diabetic adult patients, hypoglycaemia may be related to drugs, critical illness, cortisol or glucagon insufficiency, non-islet cell tumour, insulinoma, or it may be surreptitious. Nevertheless, some hypoglycaemic episodes remain unexplained, and inborn errors of metabolism (IEM) should be considered, particularly in cases of multisystemic involvement. In children, IEM are considered a differential diagnosis in cases of hypoglycaemia. In adulthood, IEM-related hypoglycaemia can persist in a previously diagnosed childhood disease. Hypoglycaemia may sometimes be a presenting sign of the IEM. Short stature, hepatomegaly, hypogonadism, dysmorphia or muscular symptoms are signs suggestive of IEM-related hypoglycaemia. In both adults and children, hypoglycaemia can be clinically classified according to its timing. Postprandial hypoglycaemia can be an indicator of either endogenous hyperinsulinism linked to non-insulinoma pancreatogenic hypoglycaemia syndrome (NIPHS, unknown incidence in adults) or very rarely, inherited fructose intolerance. Glucokinase-activating mutations (one family) are the only genetic disorder responsible for NIPH in adults that has been clearly identified so far. Exercise-induced hyperinsulinism is linked to an activating mutation of the monocarboxylate transporter 1 (one family). Fasting hypoglycaemia may be caused by IEM that were already diagnosed in childhood and persist into adulthood: glycogen storage disease (GSD) type I, III, 0, VI and IX; glucose transporter 2 deficiency; fatty acid oxidation; ketogenesis disorders; and gluconeogenesis disorders. Fasting hypoglycaemia in adulthood can also be a rare presenting sign of an IEM, especially in GSD type III, fatty acid oxidation [medium-chain acyl-CoA dehydrogenase (MCAD), ketogenesis disorders (3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) lyase deficiency, and gluconeogenesis disorders (fructose-1,6-biphosphatase deficiency)].
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Affiliation(s)
- Claire Douillard
- Service d'Endocrinologie et maladies Métaboliques, Hôpital Claude Huriez, Centre Hospitalier Régional et Universitaire de Lille, France.
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Targeted polymerase chain reaction-based enrichment and next generation sequencing for diagnostic testing of congenital disorders of glycosylation. Genet Med 2012; 13:921-32. [PMID: 21811164 DOI: 10.1097/gim.0b013e318226fbf2] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Congenital disorders of glycosylation are a heterogeneous group of disorders caused by deficient glycosylation, primarily affecting the N-linked pathway. It is estimated that more than 40% of congenital disorders of glycosylation patients lack a confirmatory molecular diagnosis. The purpose of this study was to improve molecular diagnosis for congenital disorders of glycosylation by developing and validating a next generation sequencing panel for comprehensive mutation detection in 24 genes known to cause congenital disorders of glycosylation. METHODS Next generation sequencing validation was performed on 12 positive control congenital disorders of glycosylation patients. These samples were blinded as to the disease-causing mutations. Both RainDance and Fluidigm platforms were used for sequence enrichment and targeted amplification. The SOLiD platform was used for sequencing the amplified products. Bioinformatic analysis was performed using NextGENe® software. RESULTS The disease-causing mutations were identified by next generation sequencing for all 12 positive controls. Additional variants were also detected in three controls that are known or predicted to impair gene function and may contribute to the clinical phenotype. CONCLUSIONS We conclude that development of next generation sequencing panels in the diagnostic laboratory where multiple genes are implicated in a disorder is more cost-effective and will result in improved and faster patient diagnosis compared with a gene-by-gene approach. Recommendations are also provided for data analysis from the next generation sequencing-derived data in the clinical laboratory, which will be important for the widespread use of this technology.
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Van Hove JLK, Lohr NJ. Metabolic and monogenic causes of seizures in neonates and young infants. Mol Genet Metab 2011; 104:214-30. [PMID: 21839663 DOI: 10.1016/j.ymgme.2011.04.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Revised: 04/20/2011] [Accepted: 04/20/2011] [Indexed: 11/22/2022]
Abstract
Seizures in neonates or young infants present a frequent diagnostic challenge. After exclusion of acquired causes, disturbances of the internal homeostasis and brain malformations, the physician must evaluate for inborn errors of metabolism and for other non-malformative genetic disorders as the cause of seizures. The metabolic causes can be categorized into disorders of neurotransmitter metabolism, disorders of energy production, and synthetic or catabolic disorders associated with brain malformation, dysfunction and degeneration. Other genetic conditions involve channelopathies, and disorders resulting in abnormal growth, differentiation and formation of neuronal populations. These conditions are important given their potential for treatment and the risk for recurrence in the family. In this paper, we will succinctly review the metabolic and genetic non-malformative causes of seizures in neonates and infants less than 6 months of age. We will then provide differential diagnostic clues and a practical paradigm for their evaluation.
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Affiliation(s)
- Johan L K Van Hove
- Department of Pediatrics, University of Colorado, Clinical Genetics, Aurora, CO 80045, USA.
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Namavar Y, Barth PG, Poll-The BT, Baas F. Classification, diagnosis and potential mechanisms in pontocerebellar hypoplasia. Orphanet J Rare Dis 2011; 6:50. [PMID: 21749694 PMCID: PMC3159098 DOI: 10.1186/1750-1172-6-50] [Citation(s) in RCA: 132] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 07/12/2011] [Indexed: 01/24/2023] Open
Abstract
Pontocerebellar Hypoplasia (PCH) is group of very rare, inherited progressive neurodegenerative disorders with prenatal onset. Up to now seven different subtypes have been reported (PCH1-7). The incidence of each subtype is unknown. All subtypes share common characteristics, including hypoplasia/atrophy of cerebellum and pons, progressive microcephaly, and variable cerebral involvement. Patients have severe cognitive and motor handicaps and seizures are often reported. Treatment is only symptomatic and prognosis is poor, as most patients die during infancy or childhood. The genetic basis of different subtypes has been elucidated, which makes prenatal testing possible in families with mutations. Mutations in three tRNA splicing endonuclease subunit genes were found to be responsible for PCH2, PCH4 and PCH5. Mutations in the nuclear encoded mitochondrial arginyl- tRNA synthetase gene underlie PCH6. The tRNA splicing endonuclease, the mitochondrial arginyl- tRNA synthetase and the vaccinia related kinase1 are mutated in the minority of PCH1 cases. These genes are involved in essential processes in protein synthesis in general and tRNA processing in particular. In this review we describe the neuroradiological, neuropathological, clinical and genetic features of the different PCH subtypes and we report on in vitro and in vivo studies on the tRNA splicing endonuclease and mitochondrial arginyl-tRNA synthetase and discuss their relation to pontocerebellar hypoplasia.
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Affiliation(s)
- Yasmin Namavar
- Department of Genome Analysis, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Kajiura H, Seki T, Fujiyama K. Arabidopsis thaliana ALG3 mutant synthesizes immature oligosaccharides in the ER and accumulates unique N-glycans. Glycobiology 2010; 20:736-51. [PMID: 20356820 DOI: 10.1093/glycob/cwq028] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The core oligosaccharide Glc(3)Man(9)GlcNAc(2) is assembled by a series of membrane-bound glycosyltransferases as the lipid carrier dolichylpyrophosphate-linked glycan in the endoplasmic reticulum (ER). The first step of this assembly pathway on the ER luminal side is mediated by ALG3 (asparagine-linked glycosylation 3), which is a highly conserved reaction among eukaryotic cells. Complementary genetics compared with Saccharomyces cerevisiae ALG gene families and bioinformatic approaches have enabled the identification of ALG3 from other species. In Arabidopsis thaliana, AtALG3 (At2g47760) was identified as alpha1,3-mannosyltransferase. Complementation analysis showed that AtALG3 rescued the temperature-sensitive phenotype, that lipid-linked oligosaccharide assemblies and that protein underglycosylation of S. cerevisiae ALG3-deficient mutant. In Arabidopsis ALG3 mutant, an immature lipid-linked oligosaccharide structure, M5(ER), was synthesized, and used for protein N-glycosylation, resulting in the blockade of subsequent maturation with the concanavalin A affinoactive and Endo H-insensitive structure. N-Glycan profiling of total proteins from alg3 mutants exhibited a unique structural profile, alg3 has rare N-glycan structures including Man(3)GlcNAc(2), M4(ER), M5(ER) and GlcM5(ER), which are not usually detected in Arabidopsis, and a much less amount of complex-type N-glycan than that in wild type. Interestingly, despite protein N-glycosylation differences compared with wild type, alg3 showed no obvious phenotype under normal and high temperature or salt/osmotic stress conditions. These results indicate that AtALG3 is a critical factor for mature N-glycosylation of proteins, but not essential for cell viability and growth in Arabidopsis.
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Affiliation(s)
- Hiroyuki Kajiura
- The International Center for Biotechnology, Osaka University, 2-1 Yamada-oka, Osaka 565, Japan
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Janssen MJ, Waanders E, Woudenberg J, Lefeber DJ, Drenth JPH. Congenital disorders of glycosylation in hepatology: the example of polycystic liver disease. J Hepatol 2010; 52:432-40. [PMID: 20138683 DOI: 10.1016/j.jhep.2009.12.011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autosomal dominant polycystic liver disease (PCLD) is a rare progressive disorder characterized by an increased liver volume due to many (>20) fluid-filled cysts of biliary origin. Disease causing mutations in PRKCSH or SEC63 are found in approximately 25% of the PCLD patients. Both gene products function in the endoplasmic reticulum, however, the molecular mechanism behind cyst formation remains to be elucidated. As part of the translocon complex, SEC63 plays a role in protein import into the ER and is implicated in the export of unfolded proteins to the cytoplasm during ER-associated degradation (ERAD). PRKCSH codes for the beta-subunit of glucosidase II (hepatocystin), which cleaves two glucose residues of Glc(3)Man(9)GlcNAc(2) N-glycans on proteins. Hepatocystin is thereby directly involved in the protein folding process by regulating protein binding to calnexin/calreticulin in the ER. A separate group of genetic diseases affecting protein N-glycosylation in the ER is formed by the congenital disorders of glycosylation (CDG). In distinct subtypes of this autosomal recessive multisystem disease specific liver symptoms have been reported that overlap with PCLD. Recent research revealed novel insights in PCLD disease pathology such as the absence of hepatocystin from cyst epithelia indicating a two-hit model for PCLD cystogenesis. This opens the way to speculate about a recessive mechanism for PCLD pathophysiology and shared molecular pathways between CDG and PCLD. In this review we will discuss the clinical-genetic features of PCLD and CDG as well as their biochemical pathways with the aim to identify novel directions of research into cystogenesis.
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Affiliation(s)
- Manoe J Janssen
- Department of Gastroenterology and Hepatology, Institute for Genetic & Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Haeuptle MA, Hennet T. Congenital disorders of glycosylation: an update on defects affecting the biosynthesis of dolichol-linked oligosaccharides. Hum Mutat 2010; 30:1628-41. [PMID: 19862844 DOI: 10.1002/humu.21126] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Defects in the biosynthesis of the oligosaccharide precursor for N-glycosylation lead to decreased occupancy of glycosylation sites and thereby to diseases known as congenital disorders of glycosylation (CDG). In the last 20 years, approximately 1,000 CDG patients have been identified presenting with multiple organ dysfunctions. This review sets the state of the art by listing all mutations identified in the 15 genes (PMM2, MPI, DPAGT1, ALG1, ALG2, ALG3, ALG9, ALG12, ALG6, ALG8, DOLK, DPM1, DPM3, MPDU1, and RFT1) that yield a deficiency of dolichol-linked oligosaccharide biosynthesis. The present analysis shows that most mutations lead to substitutions of strongly conserved amino acid residues across eukaryotes. Furthermore, the comparison between the different forms of CDG affecting dolichol-linked oligosaccharide biosynthesis shows that the severity of the disease does not relate to the position of the mutated gene along this biosynthetic pathway.
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Affiliation(s)
- Micha A Haeuptle
- Institute of Physiology, University of Zürich, Zürich, Switzerland
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Yamamoto A, Nakatsu S, Kondo A, Asato T, Okabe M, Fukuzawa M, Miyagawa S. A newly cloned pig dolichyl-phosphate mannosyl-transferase for preventing the transmission of porcine endogenous retrovirus to human cells. Transpl Int 2009; 23:424-31. [PMID: 19912589 DOI: 10.1111/j.1432-2277.2009.00999.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Porcine endogenous retrovirus (PERV) is a major problem associated with successful clinical xenotransplantation. In our previous study, reducing the high mannose type of N-glycan content proved to be very effective in downregulating PERV infectivity. In this study, dolichyl-phosphate mannosyltransferase (D-P-M), an enzyme related to the early stages of N-linked sugar synthesis was studied. The pig cDNA of the encoding D-P-M was newly isolated. The RNA interference (siRNA) for the D-P-M was applied and transfected to PEC(Z)/PB cells, a pig endothelial cell line with the Lac Z gene and PERV-B, to reduce the levels of high mannose type N-glycans. Compared with the mock line, the temporary PEC(Z)/PB lines showed a decreased mRNA expression for pig D-P-M, and each line then showed a clear destruction of PERV infectivity to human cells in the Lac Z pseudotype assay. The PEC(Z)/PB was next transfected with pSXGH-siRNA, H1-RNA gene promoter. The established PEC(Z)/PB clones with pSXGH-siRNA clearly led to the downregulation of PERV infectivity, as evidenced by the decreased levels of the mRNA for pig D-P-M. Reducing D-P-M enzyme activity represents a potentially useful approach to address the problem of PERV infections in clinical xenotransplantations.
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Affiliation(s)
- Aki Yamamoto
- Division of Organ Transplantation, Department of Surgery, and Osaka University Graduate School of Medicine, Japan
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Vantyghem MC, Mention C, Dobbelaere D, Douillard C. Hypoglycémies et manifestations endocriniennes des maladies héréditaires du métabolisme chez l’adulte. ANNALES D'ENDOCRINOLOGIE 2009; 70:25-42. [DOI: 10.1016/j.ando.2008.12.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 12/17/2008] [Indexed: 12/20/2022]
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Rimella-Le-Huu A, Henry H, Kern I, Hanquinet S, Roulet-Perez E, Newman CJ, Superti-Furga A, Bonafé L, Ballhausen D. Congenital disorder of glycosylation type Id (CDG Id): phenotypic, biochemical and molecular characterization of a new patient. J Inherit Metab Dis 2008; 31 Suppl 2:S381-6. [PMID: 18679822 DOI: 10.1007/s10545-008-0959-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 06/20/2008] [Accepted: 06/24/2008] [Indexed: 12/01/2022]
Abstract
Congenital disorders of glycosylation (CDG) are a family of multisystem inherited disorders caused by defects in the biosynthesis of N- or O-glycans. Among the many different subtypes of CDG, the defect of a mannosyltransferase encoded by the human ALG3 gene (chromosome 3q27) is known to cause CDG Id. Six patients with CDG Id have been described in the literature so far. We further delineate the clinical, biochemical, neuroradiological and molecular features of CDG Id by reporting an additional patient bearing a novel missense mutation in the ALG3 gene. All patients with CDG Id display a slowly progressive encephalopathy with microcephaly, severe psychomotor retardation and epileptic seizures. They also share some typical dysmorphic features but they do not present the multisystem involvement observed in other CDG syndromes or any biological marker abnormalities. Unusually marked osteopenia is a feature in some patients and may remain undiagnosed until revealed by pathological fractures. Serum transferrin screening for CDG should be extended to all patients with encephalopathy of unknown origin, even in the absence of multisystem involvement.
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Affiliation(s)
- A Rimella-Le-Huu
- Division of Molecular Pediatrics, University Hospital of Lausanne, Lausanne, Switzerland
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