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Teutonico F, Volpe C, Proto A, Costi I, Cavallari U, Doneda P, Iascone M, Sturiale L, Barone R, Martinelli S, Vignoli A. Early onset epileptic and developmental encephalopathy and MOGS variants: a new diagnosis in the whole exome sequencing (WES) ERA : Report of a new patient and review of the literature. Neurogenetics 2024; 25:281-286. [PMID: 38498292 DOI: 10.1007/s10048-024-00754-y] [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: 02/06/2024] [Accepted: 03/07/2024] [Indexed: 03/20/2024]
Abstract
Mannosyl-oligosaccharide glucosidase - congenital disorder of glycosylation (MOGS-CDG) is determined by biallelic mutations in the mannosyl-oligosaccharide glucosidase (glucosidase I) gene. MOGS-CDG is a rare disorder affecting the processing of N-Glycans (CDG type II) and is characterized by prominent neurological involvement including hypotonia, developmental delay, seizures and movement disorders. To the best of our knowledge, 30 patients with MOGS-CDG have been published so far. We described a child who is compound heterozygous for two novel variants in the MOGS gene. He presented Early Infantile Developmental and Epileptic Encephalopathy (EI-DEE) in the absence of other specific systemic involvement and unrevealing first-line biochemical findings. In addition to the previously described features, the patient presented a Hirschprung disease, never reported before in individuals with MOGS-CDG.
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Affiliation(s)
- Federica Teutonico
- Childhood and Adolescence Neurology and Psychiatry Unit, ASST GOM Niguarda, Milan, Italy
| | - Clara Volpe
- Health Sciences Department, University of Milan, Milan, Italy
| | - Alice Proto
- Neonatal Intensive Care Unit, Maternal Infant Department, ASST GOM Niguarda, Milan, Italy
| | - Ilaria Costi
- Neurophysiology Unit, Department of Neuroscience, ASST GOM Niguarda, Milan, Italy
| | - Ugo Cavallari
- Medical Genetics Unit, ASST GOM Niguarda, Milan, Italy
| | - Paola Doneda
- Neuroradiology Unit, ASST GOM Niguarda, Milan, Italy
| | - Maria Iascone
- Medical Genetics Unit, Papa Giovanni XXIII Hospital, Bergamo, Italy
| | - Luisella Sturiale
- CNR - Institute for Polymers, Composites and Biomaterials, Catania, Italy
| | - Rita Barone
- CNR - Institute for Polymers, Composites and Biomaterials, Catania, Italy
- Child Neuropsychiatry Unit, Department of Clinical and Experimental Medicine, University of Catania, Catania, Italy
| | - Stefano Martinelli
- Neonatal Intensive Care Unit, Maternal Infant Department, ASST GOM Niguarda, Milan, Italy
| | - Aglaia Vignoli
- Childhood and Adolescence Neurology and Psychiatry Unit, ASST GOM Niguarda, Milan, Italy.
- Health Sciences Department, University of Milan, Milan, Italy.
- Health Sciences Department, University of Milan, Via di Rudinì 8, Milan, 20142, Italy.
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2
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Post MA, de Wit I, Zijlstra FSM, Engelke UFH, van Rooij A, Christodoulou J, Tan TY, Le Fevre A, Jin D, Yaplito-Lee J, Lee BH, Low KJ, Mallick AA, Õunap K, Pitt J, Reardon W, Vals MA, Wortmann SB, Wessels HJCT, Bärenfänger M, van Karnebeek CDM, Lefeber DJ. MOGS-CDG: Quantitative analysis of the diagnostic Glc 3 Man tetrasaccharide and clinical spectrum of six new cases. J Inherit Metab Dis 2023; 46:313-325. [PMID: 36651519 DOI: 10.1002/jimd.12588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/19/2023]
Abstract
Congenital disorders of glycosylation (CDG) are a clinically and biochemically heterogeneous subgroup of inherited metabolic disorders. Most CDG with abnormal N-glycosylation can be detected by transferrin screening, however, MOGS-CDG escapes this routine screening. Combined with the clinical heterogeneity of reported cases, diagnosing MOGS-CDG can be challenging. Here, we clinically characterize ten MOGS-CDG cases including six previously unreported individuals, showing a phenotype characterized by dysmorphic features, global developmental delay, muscular hypotonia, and seizures in all patients and in a minority vision problems and hypogammaglobulinemia. Glycomics confirmed accumulation of a Glc3 Man7 GlcNAc2 glycan in plasma. For quantification of the diagnostic Glcα1-3Glcα1-3Glcα1-2Man tetrasaccharide in urine, we developed and validated a liquid chromatography-mass spectrometry method of 2-aminobenzoic acid (2AA) labeled urinary glycans. As an internal standard, isotopically labeled 13 C6 -2AA Glc3 Man was used, while labeling efficiency was controlled by use of 12 C6 -2AA and 13 C6 -2AA labeled laminaritetraose. Recovery, linearity, intra- and interassay coefficients of variability of these labeled compounds were determined. Furthermore, Glc3 Man was specifically identified by retention time matching against authentic MOGS-CDG urine and compared with Pompe urine. Glc3 Man was increased in all six analyzed cases, ranging from 34.1 to 618.0 μmol/mmol creatinine (reference <5 μmol). In short, MOGS-CDG has a broad manifestation of symptoms but can be diagnosed with the use of a quantitative method for analysis of urinary Glc3 Man excretion.
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Affiliation(s)
- Merel A Post
- Department of Neurology, Donders institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Isis de Wit
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
- On behalf of United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Fokje S M Zijlstra
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Udo F H Engelke
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Arno van Rooij
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - John Christodoulou
- Genomic Medicine Research Theme, Murdoch Children's Research Institute and Department of Pediatrics, University of Melbourne, Melbourne, Australia
| | - Tiong Yang Tan
- Genomic Medicine Research Theme, Murdoch Children's Research Institute and Department of Pediatrics, University of Melbourne, Melbourne, Australia
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - Anna Le Fevre
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - Danqun Jin
- Pediatric Intensive Care Unit, Anhui Provincial Children's Hospital, Hefei, China
| | - Joy Yaplito-Lee
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
- Department of Metabolic Medicine, The Royal Children's Hospital Melbourne, Parkville, Australia
| | - Beom Hee Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, South Korea
| | - Karen J Low
- School of Clinical Sciences, University of Bristol, Bristol, UK
- Clinical Genetics, St. Michael's Hospital, University Hospitals NHS Trust, Bristol, UK
| | - Andrew A Mallick
- Department of Pediatric Neurology, Bristol Royal Hospital for Children, Bristol, UK
| | - Katrin Õunap
- Department of Clinical Genetics, Genetics and Personalized Medicine Clinic, Tartu University Hospital, Tartu, Estonia
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
| | - James Pitt
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Melbourne, Australia
| | - William Reardon
- Clinical Genetics, Children's Health Ireland (CHI), Crumlin, Ireland
| | - Mari-Anne Vals
- Department of Clinical Genetics, Institute of Clinical Medicine, University of Tartu, Tartu, Estonia
- Children's Clinic, Tartu University Hospital, Tartu, Estonia
| | - Saskia B Wortmann
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
- University Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Hans J C T Wessels
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Melissa Bärenfänger
- Department of Neurology, Donders institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
- Division of Bioanalytical Chemistry, VU Amsterdam, Amsterdam, The Netherlands
| | - Clara D M van Karnebeek
- Department of Pediatrics, Amalia Children's Hospital, Radboud University Medical Center, Nijmegen, The Netherlands
- On behalf of United for Metabolic Diseases, Amsterdam, The Netherlands
- Departments of Pediatrics and Human Genetics, Emma Center for Personalized Medicine, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Dirk J Lefeber
- Department of Neurology, Donders institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
- On behalf of United for Metabolic Diseases, Amsterdam, The Netherlands
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
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Abuduxikuer K, Wang L, Zou L, Cao CY, Yu L, Guo HM, Liang XM, Wang JS, Chen L. Updated clinical and glycomic features of mannosyl-oligosaccharide glucosidase deficiency: Two case reports. World J Clin Cases 2022; 10:7397-7408. [PMID: 36158009 PMCID: PMC9353930 DOI: 10.12998/wjcc.v10.i21.7397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/16/2021] [Accepted: 06/17/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Mannosyl-oligosaccharide glucosidase (MOGS) deficiency is an extremely rare type of congenital disorder of glycosylation (CDG), with only 12 reported cases. Its clinical, genetic, and glycomic features are still expanding. Our aim is to update the novel clinical and glycosylation features of 2 previously reported patients with MOGS-CDG.
CASE SUMMARY We collected comprehensive clinical information, and conducted the immunoglobulin G1 glycosylation assay using nano-electrospray ionization source quadruple time-of-flight mass spectrometry. Novel dysmorphic features included an enlarged tongue, forwardly rotated earlobes, a birth mark, overlapped toes, and abnormal fat distribution. Novel imaging findings included pericardial effusion, a deep interarytenoid groove, mild congenital subglottic stenosis, and laryngomalacia. Novel laboratory findings included peripheral leukocytosis with neutrophil predominance, elevated C-reactive protein and creatine kinase, dyslipidemia, coagulopathy, complement 3 and complement 4 deficiencies, decreased proportions of T lymphocytes and natural killer cells, and increased serum interleukin 6. Glycosylation studies showed a significant increase of hypermannosylated glycopeptides (Glc3Man7GlcNAc2/N2H10 and Man5GlcNAc2/N2H5) and hypersialylated glycopeptides. A compensatory glycosylation pathway leading to an increase in Man5GlcNAc2/N2H5 was indicated with the glycosylation profile.
CONCLUSION We confirmed abnormal glycomics in 1 patient, expanding the clinical and glycomic spectrum of MOGS-CDG. We also postulated a compensatory glycosylation pathway, leading to a possible serum biomarker for future diagnosis.
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Affiliation(s)
| | - Lei Wang
- Department of Research and Development, SysDiagno Biomedtech, Nanjing 211800, Jiangsu Province, China
| | - Lin Zou
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Cui-Yan Cao
- Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, Liaoning Province, China
| | - Long Yu
- Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, Liaoning Province, China
| | - Hong-Mei Guo
- Department of Gastroenterology, Children's Hospital Affiliated to Nanjing Medical University, Nanjing 210008, Jiangsu Province, China
| | - Xin-Miao Liang
- Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, Liaoning Province, China
| | - Jian-She Wang
- Department of Hepatology, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Li Chen
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
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Shimada S, Ng BG, White AL, Nickander KK, Turgeon C, Liedtke KL, Lam CT, Font-Montgomery E, Lourenço CM, He M, Peck DS, Umaña LA, Uhles CL, Haynes D, Wheeler PG, Bamshad MJ, Nickerson DA, Cushing T, Gates R, Gomez-Ospina N, Byers HM, Scalco FB, Martinez NN, Sachdev R, Smith L, Poduri A, Malone S, Harris R, Scheffer IE, Rosenzweig SD, Adams DR, Gahl WA, Malicdan MCV, Raymond KM, Freeze HH, Wolfe LA. Clinical, biochemical and genetic characteristics of MOGS-CDG: a rare congenital disorder of glycosylation. J Med Genet 2022; 59:jmedgenet-2021-108177. [PMID: 35790351 PMCID: PMC9813274 DOI: 10.1136/jmedgenet-2021-108177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 04/18/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE To summarise the clinical, molecular and biochemical phenotype of mannosyl-oligosaccharide glucosidase-related congenital disorders of glycosylation (MOGS-CDG), which presents with variable clinical manifestations, and to analyse which clinical biochemical assay consistently supports diagnosis in individuals with bi-allelic variants in MOGS. METHODS Phenotypic characterisation was performed through an international and multicentre collaboration. Genetic testing was done by exome sequencing and targeted arrays. Biochemical assays on serum and urine were performed to delineate the biochemical signature of MOGS-CDG. RESULTS Clinical phenotyping revealed heterogeneity in MOGS-CDG, including neurological, immunological and skeletal phenotypes. Bi-allelic variants in MOGS were identified in 12 individuals from 11 families. The severity in each organ system was variable, without definite genotype correlation. Urine oligosaccharide analysis was consistently abnormal for all affected probands, whereas other biochemical analyses such as serum transferrin analysis was not consistently abnormal. CONCLUSION The clinical phenotype of MOGS-CDG includes multisystemic involvement with variable severity. Molecular analysis, combined with biochemical testing, is important for diagnosis. In MOGS-CDG, urine oligosaccharide analysis via matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry can be used as a reliable biochemical test for screening and confirmation of disease.
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Affiliation(s)
- Shino Shimada
- Medical Genetic Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Bobby G. Ng
- Human Genetics Program, Sanford Burnham Prebys, La Jolla, CA, USA
| | - Amy L. White
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Kim. K. Nickander
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Coleman Turgeon
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Kristen L. Liedtke
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Christina T. Lam
- Division of Genetic Medicine, Department of Pediatrics, Seattle Children’s Hospital and University of Washington, Seattle, WA, USA
| | | | - Charles M. Lourenço
- Faculdade de Medicina, Centro Universitario Estácio de Ribeirão Preto, Ribeirão Preto, SP, Brazil
- Neurogenetics Unit, Faculdade de Medicina de São José do Rio Preto (FAMERP), São José do Rio Preto, SP, Brazil
| | - Miao He
- Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Dawn S. Peck
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Luis A. Umaña
- Division of Genetics and Metabolism, Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Crescenda L. Uhles
- Department of Genetics, Children’s Medical Center Dallas, Dallas, TX, USA
| | - Devon Haynes
- Division of Genetics, Arnold Palmer Hospital for Children, Orlando Health, Orlando, FL, USA
| | - Patricia G. Wheeler
- Division of Genetics, Arnold Palmer Hospital for Children, Orlando Health, Orlando, FL, USA
| | - Michael J. Bamshad
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Tom Cushing
- Division of Pediatric Genetics, Department of Pediatrics, School of Medicine, University of New Mexico, Albuquerque, NM, USA
| | - Ryan Gates
- Division of Medical Genetics, Stanford University, Stanford, CA, USA
| | | | - Heather M. Byers
- Division of Medical Genetics, Stanford University, Stanford, CA, USA
| | | | - Fernanda B. Scalco
- Laboratório de Erros Inatos do Metabolismo/LABEIM, Instituto de Química, Universidade Federal do Rio de Janeiro, Departamento de Bioquímica, Avenida Horácio Macedo, 1281, Bloco C, Polo de Química, Cidade Universitária, Rio de Janeiro, RJ, Brazil
| | - Noelia N. Martinez
- Center for Clinical Genetics, Sydney Children’s Hospital-Randwick, Sydney, New South Wales, Australia
| | - Rani Sachdev
- Center for Clinical Genetics, Sydney Children’s Hospital-Randwick, Sydney, New South Wales, Australia
- School of Women’s & Children’s Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Lacey Smith
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Annapurna Poduri
- Department of Neurology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Stephen Malone
- Department of Neurosciences, Queensland Children’s Hospital, Brisbane, Queensland, Australia
| | - Rebekah Harris
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia
| | - Ingrid E. Scheffer
- Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia
- Department of Pediatrics, The University of Melbourne, Royal Children’s Hospital, Parkville, VIC, Australia
- Murdoch Children’s Research Institute and Florey Institute, Melbourne, VIC, Australia
| | - Sergio D. Rosenzweig
- Department of Laboratory Medicine, Clinical Center, and Primary Immunodeficiency Clinic, National Institute of Allergy and Infectious Diseases, National Institute of Health, Bethesda, MD, USA
| | - David R. Adams
- Medical Genetic Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - William A. Gahl
- Medical Genetic Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - May CV. Malicdan
- Medical Genetic Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Senior authors and contributed equally
| | - Kimiyo M. Raymond
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Senior authors and contributed equally
| | - Hudson H. Freeze
- Human Genetics Program, Sanford Burnham Prebys, La Jolla, CA, USA
- Senior authors and contributed equally
| | - Lynne A. Wolfe
- Medical Genetic Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Undiagnosed Diseases Program, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
- Senior authors and contributed equally
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OUP accepted manuscript. Glycobiology 2022; 32:380-390. [DOI: 10.1093/glycob/cwac003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 12/14/2021] [Accepted: 01/26/2022] [Indexed: 11/13/2022] Open
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Anzai R, Tsuji M, Yamashita S, Wada Y, Okamoto N, Saitsu H, Matsumoto N, Goto T. Congenital disorders of glycosylation type IIb with MOGS mutations cause early infantile epileptic encephalopathy, dysmorphic features, and hepatic dysfunction. Brain Dev 2021; 43:402-410. [PMID: 33261925 DOI: 10.1016/j.braindev.2020.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 10/11/2020] [Accepted: 10/25/2020] [Indexed: 01/05/2023]
Abstract
AIM MOGS mutations cause congenital disorders of glycosylation type IIb (CDG-IIb or GCS1-CDG). The specific manifestations caused by the mutations in this gene remain unknown. We aimed to describe the clinical features of CDG- IIb and the effectiveness of urinary oligosaccharide analysis in the diagnosis of CDG- IIb. METHODS Patient 1 was analyzed with whole-exome sequencing (WES) to identify the causative gene of intractable epilepsy and severe developmental delay. After detecting MOGS mutation in patient 1, we analyzed patients 2 and 3 who were siblings and had clinical features similar to those in patient 1. Urinary oligosaccharide analysis was performed to confirm CDG- IIb diagnosis in patient 1. The clinical features of these patients were analyzed and compared with those in eight published cases. RESULTS Our three patients presented with early infantile epileptic encephalopathy, generalized hypotonia, hepatic dysfunction and dysmorphic features. In two cases, compound heterozygous mutations in MOGS were identified by WES. Isolation and characterization of the urinary oligosaccharide was performed in one of these cases to confirm the diagnosis of CDG-IIb. Although the isoelectric focusing of transferrin (IEF-T) of serum in this patient was normal, urinary excretion of Hex4 corresponding to Glc3Man was observed by mass spectrometry. CONCLUSION This report provides clinical manifestations of CDG-IIb with MOGS mutation. CDG-IIb shows a normal IEF profile of serum transferrin and cannot be detected by structural analysis of the patient's glycoproteins. Characterization of urinary oligosaccharides should be considered to detect this disorder.
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Affiliation(s)
- Rie Anzai
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan.
| | - Megumi Tsuji
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Sumimasa Yamashita
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Yoshinao Wada
- Department of Molecular Medicine, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Nobuhiko Okamoto
- Department of Molecular Medicine, Osaka Women's and Children's Hospital, Osaka, Japan; Department of Medical Genetics, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Hirotomo Saitsu
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomohide Goto
- Division of Neurology, Kanagawa Children's Medical Center, Yokohama, Japan
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