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Madan-Khetarpal S, He M, Wongkittichote P, Dobrowolski SF. Congenital Disorder of Glycosylation in a Child with Macrosomia. Clin Chem 2023; 69:1432-1434. [PMID: 38037438 DOI: 10.1093/clinchem/hvad166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 09/19/2023] [Indexed: 12/02/2023]
Affiliation(s)
- Suneeta Madan-Khetarpal
- Division of Genetics and Genomics, Children's Hospital of Pittsburgh, Pittsburgh, PA, United States
| | - Maio He
- Metabolic and Advanced Diagnostics, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Parith Wongkittichote
- Department of Pathology and Laboratory Medicine, Division of Human Genetics, Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Steven F Dobrowolski
- Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, PA, United States
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2
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Badawi S, Mohamed FE, Varghese DS, Ali BR. Genetic disruption of mammalian endoplasmic reticulum-associated protein degradation: Human phenotypes and animal and cellular disease models. Traffic 2023. [PMID: 37188482 DOI: 10.1111/tra.12902] [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: 03/02/2023] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/17/2023]
Abstract
Endoplasmic reticulum-associated protein degradation (ERAD) is a stringent quality control mechanism through which misfolded, unassembled and some native proteins are targeted for degradation to maintain appropriate cellular and organelle homeostasis. Several in vitro and in vivo ERAD-related studies have provided mechanistic insights into ERAD pathway activation and its consequent events; however, a majority of these have investigated the effect of ERAD substrates and their consequent diseases affecting the degradation process. In this review, we present all reported human single-gene disorders caused by genetic variation in genes that encode ERAD components rather than their substrates. Additionally, after extensive literature survey, we present various genetically manipulated higher cellular and mammalian animal models that lack specific components involved in various stages of the ERAD pathway.
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Affiliation(s)
- Sally Badawi
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Feda E Mohamed
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Divya Saro Varghese
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bassam R Ali
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
- ASPIRE Precision Medicine Research Institute Abu Dhabi, United Arab Emirates University, Al Ain, United Arab Emirates
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3
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Cruz Marino T, Leblanc J, Pratte A, Tardif J, Thomas MJ, Fortin CA, Girard L, Bouchard L. Portrait of autosomal recessive diseases in the French-Canadian founder population of Saguenay-Lac-Saint-Jean. Am J Med Genet A 2023; 191:1145-1163. [PMID: 36786328 DOI: 10.1002/ajmg.a.63147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/16/2023] [Accepted: 01/30/2023] [Indexed: 02/15/2023]
Abstract
The population of the Saguenay-Lac-Saint-Jean (SLSJ) region, located in the province of Quebec, Canada, is recognized as a founder population, where some rare autosomal recessive diseases show a high prevalence. Through the clinical and molecular study of 82 affected individuals from 60 families, this study outlines 12 diseases identified as recurrent in SLSJ. Their carrier frequency was estimated with the contribution of 1059 healthy individuals, increasing the number of autosomal recessive diseases with known carrier frequency in this region from 14 to 25. We review the main clinical and molecular features previously reported for these disorders. Five of the studied diseases have a potential lethal effect and three are associated with intellectual deficiency. Therefore, we believe that the provincial program for carrier screening should be extended to include these eight disorders. The high-carrier frequency, together with the absence of consanguinity in most of these unrelated families, suggest a founder effect and genetic drift for the 12 recurrent variants. We recommend further studies to validate this hypothesis, as well as to extend the present study to other regions in the province of Quebec, since some of these disorders could also be present in other French-Canadian families.
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Affiliation(s)
- Tania Cruz Marino
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | - Josianne Leblanc
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | - Annabelle Pratte
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | - Jessica Tardif
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada
| | | | - Carol-Ann Fortin
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Quebec, Canada
| | - Lysanne Girard
- Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Quebec, Canada
| | - Luigi Bouchard
- Department of Laboratory Medicine, CIUSSS Saguenay-Lac-St-Jean, Quebec, Canada.,Department of Biochemistry and Functional Genomics, Faculty of Medicine and Health Sciences (FMHS), Université de Sherbrooke, Quebec, Canada
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4
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The HIV Restriction Factor Profile in the Brain Is Associated with the Clinical Status and Viral Quantities. Viruses 2023; 15:v15020316. [PMID: 36851531 PMCID: PMC9962287 DOI: 10.3390/v15020316] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023] Open
Abstract
HIV-encoded DNA, RNA and proteins persist in the brain despite effective antiretroviral therapy (ART), with undetectable plasma and cerebrospinal fluid viral RNA levels, often in association with neurocognitive impairments. Although the determinants of HIV persistence have garnered attention, the expression and regulation of antiretroviral host restriction factors (RFs) in the brain for HIV and SIV remain unknown. We investigated the transcriptomic profile of antiretroviral RF genes by RNA-sequencing with confirmation by qRT-PCR in the cerebral cortex of people who are uninfected (HIV[-]), those who are HIV-infected without pre-mortem brain disease (HIV[+]), those who are HIV-infected with neurocognitive disorders (HIV[+]/HAND) and those with neurocognitive disorders with encephalitis (HIV[+]/HIVE). We observed significant increases in RF expression in the brains of HIV[+]/HIVE in association with the brain viral load. Machine learning techniques identified MAN1B1 as a key gene that distinguished the HIV[+] group from the HIV[+] groups with HAND. Analyses of SIV-associated RFs in brains from SIV-infected Chinese rhesus macaques with different ART regimens revealed diminished RF expression among ART-exposed SIV-infected animals, although ART interruption resulted in an induced expression of several RF genes including OAS3, RNASEL, MX2 and MAN1B1. Thus, the brain displays a distinct expression profile of RFs that is associated with the neurological status as well as the brain viral burden. Moreover, ART interruption can influence the brain's RF profile, which might contribute to disease outcomes.
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5
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Zhalsanova IZ, Ravzhaeva EG, Postrigan AE, Seitova GN, Zhigalina DI, Udalova VY, Danina MM, Kanivets IV, Skryabin NA. Case Report: Compound Heterozygous Variants of the MAN1B1 Gene in a Russian Patient with Rafiq Syndrome. Int J Mol Sci 2022; 23:ijms231810606. [PMID: 36142510 PMCID: PMC9502887 DOI: 10.3390/ijms231810606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 12/02/2022] Open
Abstract
Rafiq syndrome (RAFQS) is a congenital disorder of glycosylation (CDG) that is caused by mutations in the MAN1B1 gene and characterized by impaired protein and lipid glycosylation. RAFQS is characterized by a delay in intellectual and motor development, facial and other dysmorphism, truncal obesity, behavior problems, and hypotonia. We describe a Russian patient with delayed intellectual and motor development, a lack of speech, disorientation in space and time, impaired attention and memory, and episodes of aggression. Screening for lysosomal, amino acid, organic acid, and mitochondrial disorders was normal. The patient was referred for the targeted sequencing of the “Hereditary Metabolic Disorders” panel. The genetic testing revealed two heterozygous pathogenic variants in the MAN1B1 gene: the previously reported c.1000C > T (p.Arg334Cys) and the novel c.1065 + 1 G > C. Thus, the patient’s clinical picture and genetic analysis confirmed RAFQS in the patient.
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Affiliation(s)
- Irina Zh. Zhalsanova
- Tomsk National Research Medical Center, Research Institute of Medical Genetics, 634050 Tomsk, Russia
- Correspondence: (I.Z.Z.); (N.A.S.); Tel.: +7-(923)-419-94-94 (I.Z.Z.)
| | - Ekatherina G. Ravzhaeva
- Tomsk National Research Medical Center, Research Institute of Medical Genetics, 634050 Tomsk, Russia
| | - Anna E. Postrigan
- Tomsk National Research Medical Center, Research Institute of Medical Genetics, 634050 Tomsk, Russia
| | - Gulnara N. Seitova
- Tomsk National Research Medical Center, Research Institute of Medical Genetics, 634050 Tomsk, Russia
| | - Daria I. Zhigalina
- Tomsk National Research Medical Center, Research Institute of Medical Genetics, 634050 Tomsk, Russia
| | | | | | | | - Nikolay A. Skryabin
- Tomsk National Research Medical Center, Research Institute of Medical Genetics, 634050 Tomsk, Russia
- Correspondence: (I.Z.Z.); (N.A.S.); Tel.: +7-(923)-419-94-94 (I.Z.Z.)
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6
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Michel N, Young HMR, Atkin ND, Arshad U, Al-Humadi R, Singh S, Manukyan A, Gore L, Burbulis IE, Wang YH, McConnell MJ. Transcription-associated DNA DSBs activate p53 during hiPSC-based neurogenesis. Sci Rep 2022; 12:12156. [PMID: 35840793 PMCID: PMC9287420 DOI: 10.1038/s41598-022-16516-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 07/11/2022] [Indexed: 11/09/2022] Open
Abstract
Neurons are overproduced during cerebral cortical development. Neural progenitor cells (NPCs) divide rapidly and incur frequent DNA double-strand breaks (DSBs) throughout cortical neurogenesis. Although half of the neurons born during neurodevelopment die, many neurons with inaccurate DNA repair survive leading to brain somatic mosaicism. Recurrent DNA DSBs during neurodevelopment are associated with both gene expression level and gene length. We used imaging flow cytometry and a genome-wide DNA DSB capture approach to quantify and map DNA DSBs during human induced pluripotent stem cell (hiPSC)-based neurogenesis. Reduced p53 signaling was brought about by knockdown (p53KD); p53KD led to elevated DNA DSB burden in neurons that was associated with gene expression level but not gene length in neural progenitor cells (NPCs). Furthermore, DNA DSBs incurred from transcriptional, but not replicative, stress lead to p53 activation in neurotypical NPCs. In p53KD NPCs, DNA DSBs accumulate at transcription start sites of genes that are associated with neurological and psychiatric disorders. These findings add to a growing understanding of how neuronal genome dynamics are engaged by high transcriptional or replicative burden during neurodevelopment.
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Affiliation(s)
- Nadine Michel
- Neuroscience Graduate Program, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Heather M Raimer Young
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Naomi D Atkin
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Umar Arshad
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Reem Al-Humadi
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Sandeep Singh
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Arkadi Manukyan
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Lana Gore
- Lieber Institute for Brain Development, 855 N. Wolfe St., Ste. 300, Baltimore, MD, 21205, USA
| | - Ian E Burbulis
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
- Sede de la Patagonia, Facultad de Medicina y Ciencias, Universidad San Sebastián, Puerto Montt, Chile
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Michael J McConnell
- Lieber Institute for Brain Development, 855 N. Wolfe St., Ste. 300, Baltimore, MD, 21205, USA.
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Haslund-Gourley BS, Aziz PV, Heithoff DM, Restagno D, Fried JC, Ilse MB, Bäumges H, Mahan MJ, Lübke T, Marth JD. Establishment of blood glycosidase activities and their excursions in sepsis. PNAS NEXUS 2022; 1:pgac113. [PMID: 35967980 PMCID: PMC9364217 DOI: 10.1093/pnasnexus/pgac113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 07/05/2022] [Indexed: 02/05/2023]
Abstract
Glycosidases are hydrolytic enzymes studied principally in the context of intracellular catabolism within the lysosome. Therefore, glycosidase activities are classically measured in experimentally acidified assay conditions reflecting their low pH optima. However, glycosidases are also present in the bloodstream where they may retain sufficient activity to participate in the regulation of glycoprotein half-lives, proteostasis, and disease pathogenesis. We have, herein, established at physiological pH 7.4 in blood plasma and sera the normal ranges of four major glycosidase activities essential for blood glycoprotein remodeling in healthy mice and humans. These activities included β-galactosidase, β-N-acetylglucosaminidase, α-mannosidase, and α-fucosidase. We have identified their origins to include the mammalian genes Glb1, HexB, Man2a1, and Fuca1. In experimental sepsis, excursions of glycosidase activities occurred with differences in host responses to discrete bacterial pathogens. Among similar excursions in human sepsis, the elevation of β-galactosidase activity was a prognostic indicator of increased likelihood of patient death.
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Affiliation(s)
- Benjamin S Haslund-Gourley
- Sanford-Burnham-Prebys Medical Discovery Institute, Infectious and Inflammatory Diseases Center, La Jolla, CA 92037, USA
| | - Peter V Aziz
- Sanford-Burnham-Prebys Medical Discovery Institute, Infectious and Inflammatory Diseases Center, La Jolla, CA 92037, USA
| | - Douglas M Heithoff
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, CA 93106, USA
| | - Damien Restagno
- Sanford-Burnham-Prebys Medical Discovery Institute, Infectious and Inflammatory Diseases Center, La Jolla, CA 92037, USA
| | - Jeffrey C Fried
- Department of Pulmonary and Critical Care Medicine, Cottage Hospital of Santa Barbara, Santa Barbara, CA 93105, USA
| | - Mai-Britt Ilse
- Department of Chemistry, Biochemistry, Bielefeld University, D-33615, Germany
| | - Hannah Bäumges
- Department of Chemistry, Biochemistry, Bielefeld University, D-33615, Germany
| | - Michael J Mahan
- Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara, CA 93106, USA
| | - Torben Lübke
- Department of Chemistry, Biochemistry, Bielefeld University, D-33615, Germany
| | - Jamey D Marth
- Sanford-Burnham-Prebys Medical Discovery Institute, Infectious and Inflammatory Diseases Center, La Jolla, CA 92037, USA
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8
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Emerging roles of endoplasmic reticulum proteostasis in brain development. Cells Dev 2022; 170:203781. [DOI: 10.1016/j.cdev.2022.203781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/12/2022] [Accepted: 04/20/2022] [Indexed: 11/21/2022]
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Okamoto N, Ohto T, Enokizono T, Wada Y, Kohmoto T, Imoto I, Haga Y, Seino J, Suzuki T. Siblings with MAN1B1-CDG Showing Novel Biochemical Profiles. Cells 2021; 10:cells10113117. [PMID: 34831340 PMCID: PMC8618856 DOI: 10.3390/cells10113117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 11/16/2022] Open
Abstract
Congenital disorders of glycosylation (CDG), inherited metabolic diseases caused by defects in glycosylation, are characterized by a high frequency of intellectual disability (ID) and various clinical manifestations. Two siblings with ID, dysmorphic features, and epilepsy were examined using mass spectrometry of serum transferrin, which revealed a CDG type 2 pattern. Whole-exome sequencing showed that both patients were homozygous for a novel pathogenic variant of MAN1B1 (NM_016219.4:c.1837del) inherited from their healthy parents. We conducted a HPLC analysis of sialylated N-linked glycans released from total plasma proteins and characterized the α1,2-mannosidase I activity of the lymphocyte microsome fraction. The accumulation of monosialoglycans was observed in MAN1B1-deficient patients, indicating N-glycan-processing defects. The enzymatic activity of MAN1B1 was compromised in patient-derived lymphocytes. The present patients exhibited unique manifestations including early-onset epileptic encephalopathy and cerebral infarction. They also showed coagulation abnormalities and hypertransaminasemia. Neither sibling had truncal obesity, which is one of the characteristic features of MAN1B1-CDG.
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Affiliation(s)
- Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Women’s and Children’s Hospital, Izumi 594-1101, Japan
- Department of Molecular Medicine, Research Institute, Osaka Women’s and Children’s Hospital, Izumi 594-1101, Japan;
- Correspondence:
| | - Tatsuyuki Ohto
- Department of Pediatrics, Tsukuba University Faculty of Medicine, Tsukuba 305-8576, Japan; (T.O.); (T.E.)
| | - Takashi Enokizono
- Department of Pediatrics, Tsukuba University Faculty of Medicine, Tsukuba 305-8576, Japan; (T.O.); (T.E.)
| | - Yoshinao Wada
- Department of Molecular Medicine, Research Institute, Osaka Women’s and Children’s Hospital, Izumi 594-1101, Japan;
| | - Tomohiro Kohmoto
- Division of Molecular Genetics, Aichi Cancer Center Research Institute, Nagoya 464-8681, Japan; (T.K.); (I.I.)
- Department of Human Genetics, Graduate School of Biomedical Science, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Issei Imoto
- Division of Molecular Genetics, Aichi Cancer Center Research Institute, Nagoya 464-8681, Japan; (T.K.); (I.I.)
- Department of Human Genetics, Graduate School of Biomedical Science, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Yoshimi Haga
- Glycometabolic Biochemistry Laboratory, RIKEN Cluster for Pioneering Research (CPR), 2-1 Hirosawa, Wako 351-0198, Japan; (Y.H.); (J.S.); (T.S.)
- Cancer Proteomics Group, Cancer Precision Medicine Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550, Japan
| | - Junichi Seino
- Glycometabolic Biochemistry Laboratory, RIKEN Cluster for Pioneering Research (CPR), 2-1 Hirosawa, Wako 351-0198, Japan; (Y.H.); (J.S.); (T.S.)
| | - Tadashi Suzuki
- Glycometabolic Biochemistry Laboratory, RIKEN Cluster for Pioneering Research (CPR), 2-1 Hirosawa, Wako 351-0198, Japan; (Y.H.); (J.S.); (T.S.)
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Kasapkara CS, Olgac A, Kilic M, Keldermans L, Matthijs G, Jaeken J. MAN1B1-CDG: novel patients and novel variant. J Pediatr Endocrinol Metab 2021; 34:1207-1209. [PMID: 34162022 DOI: 10.1515/jpem-2021-0038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 04/12/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Congenital disorders of glycosylation (CDGs) are a group of genetic disorders due to hypoglycosylation of proteins and lipids. A type I pattern is associated with defects in glycan assembly and transfer (CDG-I; cytosol; and endoplasmic reticulum defects), a type II pattern is seen in processing defects of the Golgi apparatus. MAN1B1-CDG is an autosomal recessive CDG-II due to mutations in the α 1,2-mannosidase gene (MAN1B1), mainly characterized by psychomotor disability, facial dysmorphism, truncal obesity, and hypotonia. CASE PRESENTATION Three patients (two males and one female), with MAN1B1-CDG who had elevated transaminase levels are presented. All patients had presented due to dysmorphic and neurological findings and hypertransaminasemia was remarkable. A type 2 pattern was found on serum transferrin isoelectrofocusing analysis of the presented cases. MAN1B1-CDG was confirmed by genetic analysis. CONCLUSIONS Although the cause of the increased serum transaminase levels in the present patients is not clear, no evidence for an infection or underlying liver pathology could be identified. In order to know if this is a consistent feature, we suggest measuring serum transaminase levels regularly in MAN1B1-CDG patients.
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Affiliation(s)
- Cigdem Seher Kasapkara
- Division of Pediatric Metabolism, Ankara City Hospital, Yıldırım Beyazıt University, Ankara, Turkey
| | - Asburce Olgac
- Division of Pediatric Metabolism, Dr. Sami Ulus Maternity and Child Health Training and Research Hospital, University of Health Sciences, Ankara, Turkey
| | - Mustafa Kilic
- Division of Pediatric Metabolism, Dr. Sami Ulus Maternity and Child Health Training and Research Hospital, University of Health Sciences, Ankara, Turkey
| | - Liesbeth Keldermans
- Laboratory for Molecular Diagnosis, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Gert Matthijs
- Laboratory for Molecular Diagnosis, Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Jaak Jaeken
- Department of Pediatrics, Center for Metabolic Diseases, KU Leuven, Leuven, Belgium
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Kemme L, Grüneberg M, Reunert J, Rust S, Park J, Westermann C, Wada Y, Schwartz O, Marquardt T. Translational balancing questioned: Unaltered glycosylation during disulfiram treatment in mannosyl-oligosaccharide alpha-1,2-mannnosidase-congenital disorders of glycosylation (MAN1B1-CDG). JIMD Rep 2021; 60:42-55. [PMID: 34258140 PMCID: PMC8260486 DOI: 10.1002/jmd2.12213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 02/27/2021] [Accepted: 03/02/2021] [Indexed: 12/25/2022] Open
Abstract
MAN1B1-CDG is a multisystem disorder caused by mutations in MAN1B1, encoding the endoplasmic reticulum mannosyl-oligosaccharide alpha-1,2-mannnosidase. A defect leads to dysfunction within the degradation of misfolded glycoproteins. We present two additional patients with MAN1B1-CDG and a resulting defect in endoplasmic reticulum-associated protein degradation. One patient (P2) is carrying the previously undescribed p.E663K mutation. A therapeutic trial in patient 1 (P1) using disulfiram with the rationale to generate an attenuation of translation and thus a balanced, restored ER glycoprotein synthesis failed. No improvement of the transferrin glycosylation profile was seen.
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Affiliation(s)
- Lisa Kemme
- University Children's Hospital MünsterMuensterGermany
| | | | | | - Stephan Rust
- University Children's Hospital MünsterMuensterGermany
| | - Julien Park
- University Children's Hospital MünsterMuensterGermany
- Department of Clinical Sciences, NeurosciencesUmeå UniversityUmeåSweden
| | - Cordula Westermann
- Gerhard‐Domagk‐Institute of PathologyUniversity Hospital MuensterMuensterGermany
| | - Yoshinao Wada
- Osaka Medical Center and Research Institute for Maternal and Child HealthOsakaJapan
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Abstract
Folding of proteins is essential so that they can exert their functions. For proteins that transit the secretory pathway, folding occurs in the endoplasmic reticulum (ER) and various chaperone systems assist in acquiring their correct folding/subunit formation. N-glycosylation is one of the most conserved posttranslational modification for proteins, and in eukaryotes it occurs in the ER. Consequently, eukaryotic cells have developed various systems that utilize N-glycans to dictate and assist protein folding, or if they consistently fail to fold properly, to destroy proteins for quality control and the maintenance of homeostasis of proteins in the ER.
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13
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The cytoplasmic tail of human mannosidase Man1b1 contributes to catalysis-independent quality control of misfolded alpha1-antitrypsin. Proc Natl Acad Sci U S A 2020; 117:24825-24836. [PMID: 32958677 DOI: 10.1073/pnas.1919013117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The failure of polypeptides to achieve conformational maturation following biosynthesis can result in the formation of protein aggregates capable of disrupting essential cellular functions. In the secretory pathway, misfolded asparagine (N)-linked glycoproteins are selectively sorted for endoplasmic reticulum-associated degradation (ERAD) in response to the catalytic removal of terminal alpha-linked mannose units. Remarkably, ER mannosidase I/Man1b1, the first alpha-mannosidase implicated in this conventional N-glycan-mediated process, can also contribute to ERAD in an unconventional, catalysis-independent manner. To interrogate this functional dichotomy, the intracellular fates of two naturally occurring misfolded N-glycosylated variants of human alpha1-antitrypsin (AAT), Null Hong Kong (NHK), and Z (ATZ), in Man1b1 knockout HEK293T cells were monitored in response to mutated or truncated forms of transfected Man1b1. As expected, the conventional catalytic system requires an intact active site in the Man1b1 luminal domain. In contrast, the unconventional system is under the control of an evolutionarily extended N-terminal cytoplasmic tail. Also, N-glycans attached to misfolded AAT are not required for accelerated degradation mediated by the unconventional system, further demonstrating its catalysis-independent nature. We also established that both systems accelerate the proteasomal degradation of NHK in metabolic pulse-chase labeling studies. Taken together, these results have identified the previously unrecognized regulatory capacity of the Man1b1 cytoplasmic tail and provided insight into the functional dichotomy of Man1b1 as a component in the mammalian proteostasis network.
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14
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From Anti-SARS-CoV-2 Immune Responses to COVID-19 via Molecular Mimicry. Antibodies (Basel) 2020; 9:antib9030033. [PMID: 32708525 PMCID: PMC7551747 DOI: 10.3390/antib9030033] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/04/2020] [Accepted: 07/09/2020] [Indexed: 12/21/2022] Open
Abstract
Aim: To define the autoimmune potential of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Methods: Experimentally validated epitopes cataloged at the Immune Epitope DataBase (IEDB) and present in SARS-CoV-2 were analyzed for peptide sharing with the human proteome. Results: Immunoreactive epitopes present in SARS-CoV-2 were mostly composed of peptide sequences present in human proteins that—when altered, mutated, deficient or, however, improperly functioning—may associate with a wide range of disorders, from respiratory distress to multiple organ failure. Conclusions: This study represents a starting point or hint for future scientific–clinical investigations and suggests a range of possible protein targets of autoimmunity in SARS-CoV-2 infection. From an experimental perspective, the results warrant the testing of patients’ sera for autoantibodies against these protein targets. Clinically, the results warrant a stringent surveillance on the future pathologic sequelae of the current SARS-CoV-2 pandemic.
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15
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Khayat W, Hackett A, Shaw M, Ilie A, Dudding-Byth T, Kalscheuer VM, Christie L, Corbett MA, Juusola J, Friend KL, Kirmse BM, Gecz J, Field M, Orlowski J. A recurrent missense variant in SLC9A7 causes nonsyndromic X-linked intellectual disability with alteration of Golgi acidification and aberrant glycosylation. Hum Mol Genet 2019; 28:598-614. [PMID: 30335141 DOI: 10.1093/hmg/ddy371] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 10/12/2018] [Indexed: 11/13/2022] Open
Abstract
We report two unrelated families with multigenerational nonsyndromic intellectual disability (ID) segregating with a recurrent de novo missense variant (c.1543C>T:p.Leu515Phe) in the alkali cation/proton exchanger gene SLC9A7 (also commonly referred to as NHE7). SLC9A7 is located on human X chromosome at Xp11.3 and has not yet been associated with a human phenotype. The gene is widely transcribed, but especially abundant in brain, skeletal muscle and various secretory tissues. Within cells, SLC9A7 resides in the Golgi apparatus, with prominent enrichment in the trans-Golgi network (TGN) and post-Golgi vesicles. In transfected Chinese hamster ovary AP-1 cells, the Leu515Phe mutant protein was correctly targeted to the TGN/post-Golgi vesicles, but its N-linked oligosaccharide maturation as well as that of a co-transfected secretory membrane glycoprotein, vesicular stomatitis virus G (VSVG) glycoprotein, was reduced compared to cells co-expressing SLC9A7 wild-type and VSVG. This correlated with alkalinization of the TGN/post-Golgi compartments, suggestive of a gain-of-function. Membrane trafficking of glycosylation-deficient Leu515Phe and co-transfected VSVG to the cell surface, however, was relatively unaffected. Mass spectrometry analysis of patient sera also revealed an abnormal N-glycosylation profile for transferrin, a clinical diagnostic marker for congenital disorders of glycosylation. These data implicate a crucial role for SLC9A7 in the regulation of TGN/post-Golgi pH homeostasis and glycosylation of exported cargo, which may underlie the cellular pathophysiology and neurodevelopmental deficits associated with this particular nonsyndromic form of X-linked ID.
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Affiliation(s)
- Wujood Khayat
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Anna Hackett
- Genetics of Learning Disability Service, Hunter Genetics, Waratah, NSW, Australia
| | - Marie Shaw
- Adelaide Medical School and Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia
| | - Alina Ilie
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - Tracy Dudding-Byth
- Genetics of Learning Disability Service, Hunter Genetics, Waratah, NSW, Australia
| | - Vera M Kalscheuer
- Research Group Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Louise Christie
- Genetics of Learning Disability Service, Hunter Genetics, Waratah, NSW, Australia
| | - Mark A Corbett
- Adelaide Medical School and Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia
| | | | - Kathryn L Friend
- Genetics and Molecular Pathology, SA Pathology, Adelaide, SA, Australia
| | - Brian M Kirmse
- Department of Pediatrics, Division of Medical Genetics, University of Mississippi Medical Center, Jackson, MS, USA
| | - Jozef Gecz
- Adelaide Medical School and Robinson Research Institute, The University of Adelaide, Adelaide, SA, Australia.,South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Michael Field
- Genetics of Learning Disability Service, Hunter Genetics, Waratah, NSW, Australia
| | - John Orlowski
- Department of Physiology, McGill University, Montreal, Quebec, Canada
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16
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Kvarnung M, Taylan F, Nilsson D, Anderlid BM, Malmgren H, Lagerstedt-Robinson K, Holmberg E, Burstedt M, Nordenskjöld M, Nordgren A, Lundberg ES. Genomic screening in rare disorders: New mutations and phenotypes, highlighting ALG14 as a novel cause of severe intellectual disability. Clin Genet 2018; 94:528-537. [PMID: 30221345 DOI: 10.1111/cge.13448] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 09/04/2018] [Accepted: 09/11/2018] [Indexed: 01/20/2023]
Abstract
We have investigated 20 consanguineous families with multiple children affected by rare disorders. Detailed clinical examinations, exome sequencing of affected as well as unaffected family members and further validation of likely pathogenic variants were performed. In 16/20 families, we identified pathogenic variants in autosomal recessive disease genes (ALMS1, PIGT, FLVCR2, TFG, CYP7B1, ALG14, EXOSC3, MEGF10, ASAH1, WDR62, ASPM, PNPO, ERCC5, KIAA1109, RIPK4, MAN1B1). A number of these genes have only rarely been reported previously and our findings thus confirm them as disease genes, further delineate the associated phenotypes and expand the mutation spectrum with reports of novel variants. We highlight the findings in two affected siblings with splice altering variants in ALG14 and propose a new clinical entity, which includes severe intellectual disability, epilepsy, behavioral problems and mild dysmorphic features, caused by biallelic variants in ALG14.
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Affiliation(s)
- Malin Kvarnung
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Fulya Taylan
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Daniel Nilsson
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Science for Life Laboratory, Karolinska Institutet Science Park, Stockholm, Sweden
| | - Britt-Marie Anderlid
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Helena Malmgren
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Kristina Lagerstedt-Robinson
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Eva Holmberg
- Department of Medical Bioscience, Medical and Clinical Genetics, Umeå University, Umeå, Sweden
| | - Magnus Burstedt
- Department of Medical Bioscience, Medical and Clinical Genetics, Umeå University, Umeå, Sweden
| | - Magnus Nordenskjöld
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Ann Nordgren
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Elisabeth S Lundberg
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
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17
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Duvet S, Mouajjah D, Péanne R, Matthijs G, Raymond K, Jaeken J, Morava E, Foulquier F. Use of Endoglycosidase H as a diagnostic tool for MAN1B1-CDG patients. Electrophoresis 2018; 39:3133-3141. [PMID: 29947113 DOI: 10.1002/elps.201800020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/04/2018] [Accepted: 05/25/2018] [Indexed: 12/18/2022]
Abstract
Congenital disorders of glycosylation (CDG) are heterogeneous group of genetic protein and lipid glycosylation abnormalities. With some 33 reported patients, MAN1B1-CDG belongs to the more frequent causes of CDG-II. MAN1B1 encodes an α1,2-mannosidase that removes the terminal mannose residue from the middle branch. Several methods have been proposed to characterize the glycosylation changes. In MAN1B1-CDG, the abnormal accumulating N-glycan structures are mostly absent or found in trace amounts in total human serum. To overcome this issue, in this study, we present a straightforward procedure based on the use of Endo-β-N-acetylglucosaminidase H to easily diagnose MAN1B1-CDG patients and mannosidase defects.
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Affiliation(s)
- Sandrine Duvet
- CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Univ. Lille, Lille, France.,LIA GLYCOLAB4CDG France/Belgium (International Associated Laboratory "Laboratory for the Research on Congenital Disorders of Glycosylation-from cellular mechanisms to cure"), France
| | - Dounia Mouajjah
- CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Univ. Lille, Lille, France.,LIA GLYCOLAB4CDG France/Belgium (International Associated Laboratory "Laboratory for the Research on Congenital Disorders of Glycosylation-from cellular mechanisms to cure"), France
| | - Romain Péanne
- LIA GLYCOLAB4CDG France/Belgium (International Associated Laboratory "Laboratory for the Research on Congenital Disorders of Glycosylation-from cellular mechanisms to cure"), France.,Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Gert Matthijs
- LIA GLYCOLAB4CDG France/Belgium (International Associated Laboratory "Laboratory for the Research on Congenital Disorders of Glycosylation-from cellular mechanisms to cure"), France.,Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Kimiyo Raymond
- Biochemical Genetics Laboratory, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jaak Jaeken
- Metabolic Center, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium
| | - Eva Morava
- Hayward Genetics Center, Tulane University School of Medicine, New Orleans, LA, USA
| | - François Foulquier
- CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Univ. Lille, Lille, France.,LIA GLYCOLAB4CDG France/Belgium (International Associated Laboratory "Laboratory for the Research on Congenital Disorders of Glycosylation-from cellular mechanisms to cure"), France
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18
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Balasubramanian M, Johnson DS. MAN1B-CDG: Novel variants with a distinct phenotype and review of literature. Eur J Med Genet 2018; 62:109-114. [PMID: 29908352 DOI: 10.1016/j.ejmg.2018.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/13/2018] [Accepted: 06/13/2018] [Indexed: 12/13/2022]
Abstract
BACKGROUND Congenital disorders of glycosylation (CDG) are a group of rare metabolic diseases due to impaired lipid and protein glycosylation. It comprises a characteristic high frequency of intellectual disability (ID) and a wide range of clinical phenotypes. OBJECTIVE To identify the underlying diagnosis in two families each with two siblings with variable level of ID through trio whole exome sequencing. METHODS Both the families were recruited to the Deciphering Developmental Disorders (DDD) study to identify the aetiology for their ID. Further work-up included isoelectric focusing (IEF) of serum transferrin done to add evidence to the molecular diagnosis. RESULTS These patients were found to have three novel variants in MAN1B1 inherited from their healthy parents. Serum transferrin IEF showed a type 2 pattern. DISCUSSION MAN1B1 variants were initially described in association with non-syndromic ID; subsequent literature suggested that variants in MAN1B1 resulted in a CDG-type II syndrome. However, there remains a paucity of literature on detailed clinical phenotyping and it still remains a rare form of CDG. The present patients showed the phenotype previously reported in MAN1B1-CDG: a characteristic facial dysmorphism, hypotonia, truncal obesity and in some, behavioural problems. CONCLUSIONS In unexplained ID, serum transferrin should be included in the first-line screening. With advances in genomic medicine, it is important to diagnose CDG as this has implications for management and recurrence risk counselling.
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Affiliation(s)
- Meena Balasubramanian
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, UK; Highly Specialised Service for Severe, Complex and Atypical OI Service, Sheffield Children's NHS Foundation Trust, Sheffield, UK; Academic Unit of Child Health, University of Sheffield, UK.
| | - Diana S Johnson
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, UK
| | -
- Wellcome Sanger Institute, Cambridge, UK
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19
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Mapping autosomal recessive intellectual disability: combined microarray and exome sequencing identifies 26 novel candidate genes in 192 consanguineous families. Mol Psychiatry 2018; 23:973-984. [PMID: 28397838 DOI: 10.1038/mp.2017.60] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/06/2017] [Accepted: 02/10/2017] [Indexed: 12/14/2022]
Abstract
Approximately 1% of the global population is affected by intellectual disability (ID), and the majority receive no molecular diagnosis. Previous studies have indicated high levels of genetic heterogeneity, with estimates of more than 2500 autosomal ID genes, the majority of which are autosomal recessive (AR). Here, we combined microarray genotyping, homozygosity-by-descent (HBD) mapping, copy number variation (CNV) analysis, and whole exome sequencing (WES) to identify disease genes/mutations in 192 multiplex Pakistani and Iranian consanguineous families with non-syndromic ID. We identified definite or candidate mutations (or CNVs) in 51% of families in 72 different genes, including 26 not previously reported for ARID. The new ARID genes include nine with loss-of-function mutations (ABI2, MAPK8, MPDZ, PIDD1, SLAIN1, TBC1D23, TRAPPC6B, UBA7 and USP44), and missense mutations include the first reports of variants in BDNF or TET1 associated with ID. The genes identified also showed overlap with de novo gene sets for other neuropsychiatric disorders. Transcriptional studies showed prominent expression in the prenatal brain. The high yield of AR mutations for ID indicated that this approach has excellent clinical potential and should inform clinical diagnostics, including clinical whole exome and genome sequencing, for populations in which consanguinity is common. As with other AR disorders, the relevance will also apply to outbred populations.
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20
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Bastaki F, Bizzari S, Hamici S, Nair P, Mohamed M, Saif F, Malik EM, Al-Ali MT, Hamzeh AR. Single-center experience of N-linked Congenital Disorders of Glycosylation with a Summary of Molecularly Characterized Cases in Arabs. Ann Hum Genet 2017; 82:35-47. [PMID: 28940310 DOI: 10.1111/ahg.12220] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 12/18/2022]
Abstract
Congenital disorders of glycosylation (CDG) represent an expanding group of conditions that result from defects in protein and lipid glycosylation. Different subgroups of CDG display considerable clinical and genetic heterogeneity due to the highly complex nature of cellular glycosylation. This is further complicated by ethno-geographic differences in the mutational landscape of each of these subgroups. Ten Arab CDG patients from Latifa Hospital in Dubai, United Arab Emirates, were assessed using biochemical (glycosylation status of transferrin) and molecular approaches (next-generation sequencing [NGS] and Sanger sequencing). In silico tools including CADD and PolyPhen-2 were used to predict the functional consequences of uncovered mutations. In our sample of patients, five novel mutations were uncovered in the genes: MPDU1, PMM2, MAN1B1, and RFT1. In total, 9 mutations were harbored by the 10 patients in 7 genes. These are missense and nonsense mutations with deleterious functional consequences. This article integrates a single-center experience within a list of reported CDG mutations in the Arab world, accompanied by full molecular and clinical details pertaining to the studied cases. It also sheds light on potential ethnic differences that were not noted before in regards to CDG in the Arab world.
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Affiliation(s)
- Fatma Bastaki
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | | | - Sana Hamici
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | | | - Madiha Mohamed
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
| | - Fatima Saif
- Pediatric Department, Latifa Hospital, Dubai Health Authority, Dubai, UAE
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21
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Whole exome sequencing reveals inherited and de novo variants in autism spectrum disorder: a trio study from Saudi families. Sci Rep 2017; 7:5679. [PMID: 28720891 PMCID: PMC5515956 DOI: 10.1038/s41598-017-06033-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 06/06/2017] [Indexed: 12/12/2022] Open
Abstract
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with genetic and clinical heterogeneity. The interplay of de novo and inherited rare variants has been suspected in the development of ASD. Here, we applied whole exome sequencing (WES) on 19 trios from singleton Saudi families with ASD. We developed an analysis pipeline that allows capturing both de novo and inherited rare variants predicted to be deleterious. A total of 47 unique rare variants were detected in 17 trios including 38 which are newly discovered. The majority were either autosomal recessive or X-linked. Our pipeline uncovered variants in 15 ASD-candidate genes, including 5 (GLT8D1, HTATSF1, OR6C65, ITIH6 and DDX26B) that have not been reported in any human condition. The remaining variants occurred in genes formerly associated with ASD or other neurological disorders. Examples include SUMF1, KDM5B and MXRA5 (Known-ASD genes), PRODH2 and KCTD21 (implicated in schizophrenia), as well as USP9X and SMS (implicated in intellectual disability). Consistent with expectation and previous studies, most of the genes implicated herein are enriched for biological processes pertaining to neuronal function. Our findings underscore the private and heterogeneous nature of the genetic architecture of ASD even in a population with high consanguinity rates.
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22
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Khan MA, Khan S, Windpassinger C, Badar M, Nawaz Z, Mohammad RM. The Molecular Genetics of Autosomal Recessive Nonsyndromic Intellectual Disability: a Mutational Continuum and Future Recommendations. Ann Hum Genet 2017; 80:342-368. [PMID: 27870114 DOI: 10.1111/ahg.12176] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 10/03/2016] [Indexed: 12/19/2022]
Abstract
Intellectual disability (ID) is a clinical manifestation of the central nervous system without any major dysmorphologies of the brain. Biologically it affects learning capabilities, memory, and cognitive functioning. The basic defining features of ID are characterized by IQ<70, age of onset before 18 years, and impairment of at least two of the adaptive skills. Clinically it is classified in a syndromic (with additional abnormalities) and a nonsyndromic form (with only cognitive impairment). The study of nonsyndromic intellectual disability (NSID) can best explain the pathophysiology of cognition, intelligence and memory. Genetic analysis in autosomal recessive nonsyndrmic ID (ARNSID) has mapped 51 disease loci, 34 of which have revealed their defective genes. These genes play diverse physiological roles in various molecular processes, including methylation, proteolysis, glycosylation, signal transduction, transcription regulation, lipid metabolism, ion homeostasis, tRNA modification, ubiquitination and neuromorphogenesis. High-density SNP array and whole exome sequencing has increased the pace of gene discoveries and many new mutations are being published every month. The lack of uniform criteria has assigned multiple identifiers (or accession numbers) to the same MRT locus (e.g. MRT7 and MRT22). Here in this review we describe the molecular genetics of ARNSID, prioritize the candidate genes in uncharacterized loci, and propose a new nomenclature to reorganize the mutation data that will avoid the confusion of assigning duplicate accession numbers to the same ID locus and to make the data manageable in the future as well.
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Affiliation(s)
- Muzammil Ahmad Khan
- Genomic Core Facility, Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, 3050, Qatar.,Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I.Khan, 29050 KPK, Pakistan
| | - Saadullah Khan
- Genomic Core Facility, Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, 3050, Qatar.,Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, KPK, Pakistan
| | | | - Muhammad Badar
- Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I.Khan, 29050 KPK, Pakistan
| | - Zafar Nawaz
- Genomic Core Facility, Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, 3050, Qatar
| | - Ramzi M Mohammad
- Genomic Core Facility, Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, 3050, Qatar
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23
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Genetic Defects Underlie the Non-syndromic Autosomal Recessive Intellectual Disability (NS-ARID). Open Life Sci 2017. [DOI: 10.1515/biol-2017-0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
AbstractIntellectual disability (ID) is a neurodevelopmental disorder which appears frequently as the result of genetic mutations and may be syndromic (S-ID) or non-syndromic (NS-ID). ID causes an important economic burden, for patient's family, health systems, and society. Identifying genes that cause S-ID can easily be evaluated due to the clinical symptoms or physical anomalies. However, in the case of NS-ID due to the absence of co-morbid features, the latest molecular genetic techniques can be used to understand the genetic defects that underlie it. Recent studies have shown that non-syndromic autosomal recessive (NS-ARID) is extremely heterogeneous and contributes much more than X-linked ID. However, very little is known about the genes and loci involved in NS-ARID relative to X-linked ID, and whose complete genetic etiology remains obscure. In this review article, the known genetic etiology of NS-ARID and possible relationships between genes and the associated molecular pathways of their encoded proteins has been reviewed which will enhance our understanding about the underlying genes and mechanisms in NS-ARID.
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24
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Frabutt DA, Zheng YH. Arms Race between Enveloped Viruses and the Host ERAD Machinery. Viruses 2016; 8:v8090255. [PMID: 27657106 PMCID: PMC5035969 DOI: 10.3390/v8090255] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/12/2016] [Accepted: 09/12/2016] [Indexed: 12/12/2022] Open
Abstract
Enveloped viruses represent a significant category of pathogens that cause serious diseases in animals. These viruses express envelope glycoproteins that are singularly important during the infection of host cells by mediating fusion between the viral envelope and host cell membranes. Despite low homology at protein levels, three classes of viral fusion proteins have, as of yet, been identified based on structural similarities. Their incorporation into viral particles is dependent upon their proper sub-cellular localization after being expressed and folded properly in the endoplasmic reticulum (ER). However, viral protein expression can cause stress in the ER, and host cells respond to alleviate the ER stress in the form of the unfolded protein response (UPR); the effects of which have been observed to potentiate or inhibit viral infection. One important arm of UPR is to elevate the capacity of the ER-associated protein degradation (ERAD) pathway, which is comprised of host quality control machinery that ensures proper protein folding. In this review, we provide relevant details regarding viral envelope glycoproteins, UPR, ERAD, and their interactions in host cells.
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Affiliation(s)
- Dylan A Frabutt
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
| | - Yong-Hui Zheng
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
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25
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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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26
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Gupta S, Fahiminiya S, Wang T, Dempsey Nunez L, Rosenblatt DS, Gibson WT, Gilfix B, Bergeron JJM, Jerome-Majewska LA. Somatic overgrowth associated with homozygous mutations in both MAN1B1 and SEC23A. Cold Spring Harb Mol Case Stud 2016; 2:a000737. [PMID: 27148587 PMCID: PMC4853519 DOI: 10.1101/mcs.a000737] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Using whole-exome sequencing, we identified homozygous mutations in two unlinked genes, SEC23A c.1200G>C (p.M400I) and MAN1B1 c.1000C>T (p.R334C), associated with congenital birth defects in two patients from a consanguineous family. Patients presented with carbohydrate-deficient transferrin, tall stature, obesity, macrocephaly, and maloccluded teeth. The parents were healthy heterozygous carriers for both mutations and an unaffected sibling with tall stature carried the heterozygous mutation in SEC23A only. Mutations in SEC23A are responsible for craniolenticosultura dysplasia (CLSD). CLSD patients are short, have late-closing fontanels, and have reduced procollagen (pro-COL1A1) secretion because of abnormal pro-COL1A1 retention in the endoplasmic reticulum (ER). The mutation we identified in MAN1B1 was previously associated with reduced MAN1B1 protein and congenital disorders of glycosylation (CDG). CDG patients are also short, are obese, and have abnormal glycan remodeling. Molecular analysis of fibroblasts from the family revealed normal levels of SEC23A in all cells and reduced levels of MAN1B1 in cells with heterozygous or homozygous mutations in SEC23A and MAN1B1. Secretion of pro-COL1A1 was increased in fibroblasts from the siblings and patients, and pro-COL1A1 was retained in Golgi of heterozygous and homozygous mutant cells, although intracellular pro-COL1A1 was increased in patient fibroblasts only. We postulate that increased pro-COL1A1 secretion is responsible for tall stature in these patients and an unaffected sibling, and not previously discovered in patients with mutations in either SEC23A or MAN1B1. The patients in this study share biochemical and cellular characteristics consistent with mutations in MAN1B1 and SEC23A, indicating a digenic disease.
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Affiliation(s)
- Swati Gupta
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Somayyeh Fahiminiya
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Tracy Wang
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Laura Dempsey Nunez
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada;; Department of Pediatrics, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - William T Gibson
- Department of Medical Genetics, Child and Family Research Institute, Vancouver, British Columbia V6H 3V4, Canada
| | - Brian Gilfix
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - John J M Bergeron
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Loydie A Jerome-Majewska
- Department of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada;; Department of Pediatrics, McGill University, Montreal, Quebec H4A 3J1, Canada;; Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
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Esmaeeli-Nieh S, Fenckova M, Porter IM, Motazacker MM, Nijhof B, Castells-Nobau A, Asztalos Z, Weißmann R, Behjati F, Tzschach A, Felbor U, Scherthan H, Sayfati SM, Ropers HH, Kahrizi K, Najmabadi H, Swedlow JR, Schenck A, Kuss AW. BOD1 Is Required for Cognitive Function in Humans and Drosophila. PLoS Genet 2016; 12:e1006022. [PMID: 27166630 PMCID: PMC4864283 DOI: 10.1371/journal.pgen.1006022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 04/08/2016] [Indexed: 11/19/2022] Open
Abstract
Here we report a stop-mutation in the BOD1 (Biorientation Defective 1) gene, which co-segregates with intellectual disability in a large consanguineous family, where individuals that are homozygous for the mutation have no detectable BOD1 mRNA or protein. The BOD1 protein is required for proper chromosome segregation, regulating phosphorylation of PLK1 substrates by modulating Protein Phosphatase 2A (PP2A) activity during mitosis. We report that fibroblast cell lines derived from homozygous BOD1 mutation carriers show aberrant localisation of the cell cycle kinase PLK1 and its phosphatase PP2A at mitotic kinetochores. However, in contrast to the mitotic arrest observed in BOD1-siRNA treated HeLa cells, patient-derived cells progressed through mitosis with no apparent segregation defects but at an accelerated rate compared to controls. The relatively normal cell cycle progression observed in cultured cells is in line with the absence of gross structural brain abnormalities in the affected individuals. Moreover, we found that in normal adult brain tissues BOD1 expression is maintained at considerable levels, in contrast to PLK1 expression, and provide evidence for synaptic localization of Bod1 in murine neurons. These observations suggest that BOD1 plays a cell cycle-independent role in the nervous system. To address this possibility, we established two Drosophila models, where neuron-specific knockdown of BOD1 caused pronounced learning deficits and significant abnormalities in synapse morphology. Together our results reveal novel postmitotic functions of BOD1 as well as pathogenic mechanisms that strongly support a causative role of BOD1 deficiency in the aetiology of intellectual disability. Moreover, by demonstrating its requirement for cognitive function in humans and Drosophila we provide evidence for a conserved role of BOD1 in the development and maintenance of cognitive features.
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Affiliation(s)
- Sahar Esmaeeli-Nieh
- Department for Human Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Michaela Fenckova
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, Netherlands
| | - Iain M. Porter
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - M. Mahdi Motazacker
- Department for Human Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Bonnie Nijhof
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, Netherlands
| | - Anna Castells-Nobau
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, Netherlands
| | - Zoltan Asztalos
- Department Genetics, Aktogen Limited, University of Cambridge, Cambridge, United Kingdom
- Aktogen Hungary Ltd., Bay Zoltán Nonprofit Ltd., Institute for Biotechnology, Szeged, Hungary
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Robert Weißmann
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Farkhondeh Behjati
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Andreas Tzschach
- Department for Human Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Ute Felbor
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Harry Scherthan
- Department for Human Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
- Institut für Radiobiologie der Bundeswehr in Verbindung mit der Universität Ulm, München, Germany
| | - Seyed Morteza Sayfati
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - H. Hilger. Ropers
- Department for Human Genetics, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Kimia Kahrizi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hossein Najmabadi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Jason R. Swedlow
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, Netherlands
| | - Andreas W. Kuss
- Department of Human Genetics, University Medicine Greifswald and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
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Jaeken J, Lefeber DJ, Matthijs G. Clinical utility gene card for: MAN1B1 defective congenital disorder of glycosylation. Eur J Hum Genet 2015; 24:ejhg2015248. [PMID: 26577042 DOI: 10.1038/ejhg.2015.248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/06/2015] [Accepted: 10/21/2015] [Indexed: 02/03/2023] Open
Affiliation(s)
- Jaak Jaeken
- Centre for Metabolic Disease, University Hospital Gasthuisberg, Leuven, Belgium
| | - Dirk J Lefeber
- Department of Neurology, Translational Metabolic Laboratory, Radboudumc, Nijmegen, The Netherlands
| | - Gert Matthijs
- Centre for Human Genetics, KULeuven, Leuven, Belgium
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Rafiullah R, Aslamkhan M, Paramasivam N, Thiel C, Mustafa G, Wiemann S, Schlesner M, Wade RC, Rappold GA, Berkel S. Homozygous missense mutation in the LMAN2L gene segregates with intellectual disability in a large consanguineous Pakistani family. J Med Genet 2015; 53:138-44. [PMID: 26566883 DOI: 10.1136/jmedgenet-2015-103179] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/22/2015] [Indexed: 01/22/2023]
Abstract
BACKGROUND Intellectual disability (ID) is a neurodevelopmental disorder affecting 1%-3% of the population worldwide. It is characterised by high phenotypic and genetic heterogeneity and in most cases the underlying cause of the disorder is unknown. In our study we investigated a large consanguineous family from Baluchistan, Pakistan, comprising seven affected individuals with a severe form of autosomal recessive ID (ARID) and epilepsy, to elucidate a putative genetic cause. METHODS AND RESULTS Whole exome sequencing (WES) of a trio, including a child with ID and epilepsy and its healthy parents that were part of this large family, revealed a homozygous missense variant p.R53Q in the lectin mannose-binding 2-like (LMAN2L) gene. This homozygous variant was co-segregating in the family with the phenotype of severe ID and infantile epilepsy; unaffected family members were heterozygous variant carriers. The variant was predicted to be pathogenic by five different in silico programmes and further three-dimensional structure modelling of the protein suggests that variant p.R53Q may impair protein-protein interaction. LMAN2L (OMIM: 609552) encodes for the lectin, mannose-binding 2-like protein which is a cargo receptor in the endoplasmic reticulum important for glycoprotein transport. Genome-wide association studies have identified an association of LMAN2L to different neuropsychiatric disorders. CONCLUSION This is the first report linking LMAN2L to a phenotype of severe ARID and seizures, indicating that the deleterious homozygous p.R53Q variant very likely causes the disorder.
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Affiliation(s)
- Rafiullah Rafiullah
- Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany Department of Human Genetics and Molecular Biology, University of Health Sciences Lahore, Lahore, Pakistan
| | - Muhammad Aslamkhan
- Department of Human Genetics and Molecular Biology, University of Health Sciences Lahore, Lahore, Pakistan
| | - Nagarajan Paramasivam
- Division of Theoretical Bioinformatics (B080), German Cancer Research Center (DKFZ), Heidelberg, Germany Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Christian Thiel
- Department I, Center for Child and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Ghulam Mustafa
- Molecular and Cellular Modeling (MCM) Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany Center for Molecular Biology, DKFZ-ZMBH Alliance, Heidelberg University, Heidelberg, Germany
| | - Stefan Wiemann
- Genomics and Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Rebecca C Wade
- Molecular and Cellular Modeling (MCM) Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany Center for Molecular Biology, DKFZ-ZMBH Alliance, Heidelberg University, Heidelberg, Germany
| | - Gudrun A Rappold
- Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany
| | - Simone Berkel
- Department of Human Molecular Genetics, Heidelberg University Hospital, Heidelberg, Germany
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Saldova R, Stöckmann H, O’Flaherty R, Lefeber DJ, Jaeken J, Rudd PM. N-Glycosylation of Serum IgG and Total Glycoproteins in MAN1B1 Deficiency. J Proteome Res 2015; 14:4402-12. [DOI: 10.1021/acs.jproteome.5b00709] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Radka Saldova
- NIBRT
GlycoScience Group, National Institute for Bioprocessing Research and Training, Fosters Avenue, Mount Merrion, Blackrock, Dublin 4, Ireland
| | - Henning Stöckmann
- NIBRT
GlycoScience Group, National Institute for Bioprocessing Research and Training, Fosters Avenue, Mount Merrion, Blackrock, Dublin 4, Ireland
| | - Roisin O’Flaherty
- NIBRT
GlycoScience Group, National Institute for Bioprocessing Research and Training, Fosters Avenue, Mount Merrion, Blackrock, Dublin 4, Ireland
| | - Dirk J. Lefeber
- Department
of Neurology, Translational Metabolic Laboratory, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Jaak Jaeken
- Centre
for Metabolic Diseases, University Hospital Gasthuisberg, Leuven, Belgium
| | - Pauline M. Rudd
- NIBRT
GlycoScience Group, National Institute for Bioprocessing Research and Training, Fosters Avenue, Mount Merrion, Blackrock, Dublin 4, Ireland
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Zhou T, Frabutt DA, Moremen KW, Zheng YH. ERManI (Endoplasmic Reticulum Class I α-Mannosidase) Is Required for HIV-1 Envelope Glycoprotein Degradation via Endoplasmic Reticulum-associated Protein Degradation Pathway. J Biol Chem 2015. [PMID: 26205822 DOI: 10.1074/jbc.m115.675207] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previously, we reported that the mitochondrial translocator protein (TSPO) induces HIV-1 envelope (Env) degradation via the endoplasmic reticulum (ER)-associated protein degradation (ERAD) pathway, but the mechanism was not clear. Here we investigated how the four ER-associated glycoside hydrolase family 47 (GH47) α-mannosidases, ERManI, and ER-degradation enhancing α-mannosidase-like (EDEM) proteins 1, 2, and 3, are involved in the Env degradation process. Ectopic expression of these four α-mannosidases uncovers that only ERManI inhibits HIV-1 Env expression in a dose-dependent manner. In addition, genetic knock-out of the ERManI gene MAN1B1 using CRISPR/Cas9 technology disrupts the TSPO-mediated Env degradation. Biochemical studies show that HIV-1 Env interacts with ERManI, and between the ERManI cytoplasmic, transmembrane, lumenal stem, and lumenal catalytic domains, the catalytic domain plays a critical role in the Env-ERManI interaction. In addition, functional studies show that inactivation of the catalytic sites by site-directed mutagenesis disrupts the ERManI activity. These studies identify ERManI as a critical GH47 α-mannosidase in the ER-associated protein degradation pathway that initiates the Env degradation and suggests that its catalytic domain and enzymatic activity play an important role in this process.
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Affiliation(s)
- Tao Zhou
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, 150001, China, BEACON Center for the Study of Evolution in Action and Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824
| | - Dylan A Frabutt
- BEACON Center for the Study of Evolution in Action and Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824
| | - Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602, and
| | - Yong-Hui Zheng
- From the Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Harbin, 150001, China, BEACON Center for the Study of Evolution in Action and Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824
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Hu H, Wienker TF, Musante L, Kalscheuer VM, Kahrizi K, Najmabadi H, Ropers HH. Integrated sequence analysis pipeline provides one-stop solution for identifying disease-causing mutations. Hum Mutat 2015; 35:1427-35. [PMID: 25219469 DOI: 10.1002/humu.22695] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 08/28/2014] [Indexed: 12/23/2022]
Abstract
Next-generation sequencing has greatly accelerated the search for disease-causing defects, but even for experts the data analysis can be a major challenge. To facilitate the data processing in a clinical setting, we have developed a novel medical resequencing analysis pipeline (MERAP). MERAP assesses the quality of sequencing, and has optimized capacity for calling variants, including single-nucleotide variants, insertions and deletions, copy-number variation, and other structural variants. MERAP identifies polymorphic and known causal variants by filtering against public domain databases, and flags nonsynonymous and splice-site changes. MERAP uses a logistic model to estimate the causal likelihood of a given missense variant. MERAP considers the relevant information such as phenotype and interaction with known disease-causing genes. MERAP compares favorably with GATK, one of the widely used tools, because of its higher sensitivity for detecting indels, its easy installation, and its economical use of computational resources. Upon testing more than 1,200 individuals with mutations in known and novel disease genes, MERAP proved highly reliable, as illustrated here for five families with disease-causing variants. We believe that the clinical implementation of MERAP will expedite the diagnostic process of many disease-causing defects.
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Affiliation(s)
- Hao Hu
- Max-Planck Institute for Molecular Genetics, Berlin, Germany
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33
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Benyair R, Ogen-Shtern N, Lederkremer GZ. Glycan regulation of ER-associated degradation through compartmentalization. Semin Cell Dev Biol 2015; 41:99-109. [DOI: 10.1016/j.semcdb.2014.11.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 11/13/2014] [Accepted: 11/14/2014] [Indexed: 12/20/2022]
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Hoffjan S, Epplen JT, Reis A, Abou Jamra R. MAN1B1 Mutation Leads to a Recognizable Phenotype: A Case Report and Future Prospects. Mol Syndromol 2015; 6:58-62. [PMID: 26279649 DOI: 10.1159/000371399] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2014] [Indexed: 01/23/2023] Open
Abstract
Intellectual disability (ID) is one of the most common reasons for referral to genetic counseling. Nevertheless, in over 50% of the cases no diagnosis can be made. Here, we present how exome sequencing in combination with medical genetics evaluation led to the identification of a known pathogenic homozygous mutation in MAN1B1 in a consanguineous Turkish family. The phenotype comprised mild ID, truncal obesity and facial dysmorphism, comparable to that of the patients in the 3 recent publications on mutations in this gene. Clinically, the majority of patients in the literature showed congenital disorder of glycosylation syndrome type 2. In this study, we summarize the current knowledge about MAN1B1 mutations from the literature as well as databases and suggest that exome sequencing should be implemented in a larger scale in routine diagnostics, since autosomal recessive ID has proven to be extremely heterogeneous. Even syndromic patterns may only become recognizable retrospectively.
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Affiliation(s)
- Sabine Hoffjan
- Department of Human Genetics, Ruhr-University, Bochum, Friedrich-Alexander-University, Erlangen-Nuremberg, Germany
| | - Jörg T Epplen
- Department of Human Genetics, Ruhr-University, Bochum, Friedrich-Alexander-University, Erlangen-Nuremberg, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-University, Erlangen-Nuremberg, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, Friedrich-Alexander-University, Erlangen-Nuremberg, Germany
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Homozygosity mapping of autosomal recessive intellectual disability loci in 11 consanguineous Pakistani families. Acta Neuropsychiatr 2015; 27:38-47. [PMID: 25434728 DOI: 10.1017/neu.2014.37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Autosomal recessive intellectual disability (ID) is genetically heterogeneous and most of the genes causing it remain undiscovered. OBJECTIVE We have ascertained 11 consanguineous families multiplex for IDs in order to identify new loci for autosomal recessive genes for non-syndromic ID, or to aid pinpointing mutations in known causative gene/loci. Methodology Microarray genotyping (Affymatrix 250K) was performed to identify homozygosity-by-descent (HBD) in all affected families. RESULTS Analysis of genotypes revealed 45 potential HBD regions across the families, although these may be rationalised down to 39. Two families share an overlapping HBD region on 7q11.21. In one family, X-linkage also looks plausible, and a new ID gene near the centromere may be a likely cause. In one family, no HBD region was found, and thus we exclude autosomal recessive mutation as the likely cause in this family. Copy-number variation (CNV) was also performed and revealed no CNVs, homozygous or heterozygous, segregating with the phenotype. CONCLUSION The homozygous loci identified in this study might harbour candidate genes for ID in these studied families. Therefore, we are proceeding with next-generation sequencing analysis of the families, using whole-exome approaches, and anticipate that this will identify the causative gene/mutation within the identified HBD regions for many of the families studied here.
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Ferris SP, Kodali VK, Kaufman RJ. Glycoprotein folding and quality-control mechanisms in protein-folding diseases. Dis Model Mech 2015; 7:331-41. [PMID: 24609034 PMCID: PMC3944493 DOI: 10.1242/dmm.014589] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Biosynthesis of proteins – from translation to folding to export – encompasses a complex set of events that are exquisitely regulated and scrutinized to ensure the functional quality of the end products. Cells have evolved to capitalize on multiple post-translational modifications in addition to primary structure to indicate the folding status of nascent polypeptides to the chaperones and other proteins that assist in their folding and export. These modifications can also, in the case of irreversibly misfolded candidates, signal the need for dislocation and degradation. The current Review focuses on the glycoprotein quality-control (GQC) system that utilizes protein N-glycosylation and N-glycan trimming to direct nascent glycopolypeptides through the folding, export and dislocation pathways in the endoplasmic reticulum (ER). A diverse set of pathological conditions rooted in defective as well as over-vigilant ER quality-control systems have been identified, underlining its importance in human health and disease. We describe the GQC pathways and highlight disease and animal models that have been instrumental in clarifying our current understanding of these processes.
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Affiliation(s)
- Sean P Ferris
- Department of Biological Chemistry and Medical Scientist Training Program, University of Michigan, Ann Arbor, MI 48109, USA
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37
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Makrythanasis P, Nelis M, Santoni FA, Guipponi M, Vannier A, Béna F, Gimelli S, Stathaki E, Temtamy S, Mégarbané A, Masri A, Aglan MS, Zaki MS, Bottani A, Fokstuen S, Gwanmesia L, Aliferis K, Bustamante Eduardo M, Stamoulis G, Psoni S, Kitsiou-Tzeli S, Fryssira H, Kanavakis E, Al-Allawi N, Sefiani A, Al Hait S, Elalaoui SC, Jalkh N, Al-Gazali L, Al-Jasmi F, Bouhamed HC, Abdalla E, Cooper DN, Hamamy H, Antonarakis SE. Diagnostic exome sequencing to elucidate the genetic basis of likely recessive disorders in consanguineous families. Hum Mutat 2014; 35:1203-10. [PMID: 25044680 DOI: 10.1002/humu.22617] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 06/30/2014] [Indexed: 01/19/2023]
Abstract
Rare, atypical, and undiagnosed autosomal-recessive disorders frequently occur in the offspring of consanguineous couples. Current routine diagnostic genetic tests fail to establish a diagnosis in many cases. We employed exome sequencing to identify the underlying molecular defects in patients with unresolved but putatively autosomal-recessive disorders in consanguineous families and postulated that the pathogenic variants would reside within homozygous regions. Fifty consanguineous families participated in the study, with a wide spectrum of clinical phenotypes suggestive of autosomal-recessive inheritance, but with no definitive molecular diagnosis. DNA samples from the patient(s), unaffected sibling(s), and the parents were genotyped with a 720K SNP array. Exome sequencing and array CGH (comparative genomic hybridization) were then performed on one affected individual per family. High-confidence pathogenic variants were found in homozygosity in known disease-causing genes in 18 families (36%) (one by array CGH and 17 by exome sequencing), accounting for the clinical phenotype in whole or in part. In the remainder of the families, no causative variant in a known pathogenic gene was identified. Our study shows that exome sequencing, in addition to being a powerful diagnostic tool, promises to rapidly expand our knowledge of rare genetic Mendelian disorders and can be used to establish more detailed causative links between mutant genotypes and clinical phenotypes.
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Affiliation(s)
- Periklis Makrythanasis
- Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland; Service of Genetic Medicine, University Hospitals of Geneva, Geneva, Switzerland
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Scott K, Gadomski T, Kozicz T, Morava E. Congenital disorders of glycosylation: new defects and still counting. J Inherit Metab Dis 2014; 37:609-17. [PMID: 24831587 PMCID: PMC4141334 DOI: 10.1007/s10545-014-9720-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 04/16/2014] [Accepted: 04/22/2014] [Indexed: 12/11/2022]
Abstract
Almost 50 inborn errors of metabolism have been described due to congenital defects in N-linked glycosylation. These phenotypically diverse disorders typically present as clinical syndromes, affecting multiple systems including the central nervous system, muscle function, transport, regulation, immunity, endocrine system, and coagulation. An increasing number of disorders have been discovered using novel techniques that combine glycobiology with next-generation sequencing or use tandem mass spectrometry in combination with molecular gene-hunting techniques. The number of "classic" congenital disorders of glycosylation (CDGs) due to N-linked glycosylation defects is still rising. Eight novel CDGs affecting N-linked glycans were discovered in 2013 alone. Newly discovered genes teach us about the significance of glycosylation in cell-cell interaction, signaling, organ development, cell survival, and mosaicism, in addition to the consequences of abnormal glycosylation for muscle function. We have learned how important glycosylation is in posttranslational modification and how glycosylation defects can imitate recognizable, previously described phenotypes. In many CDG subtypes, patients unexpectedly presented with long-term survival, whereas some others presented with nonsyndromic intellectual disability. In this review, recently discovered N-linked CDGs are described, with a focus on clinical presentations and therapeutic ideas. A diagnostic approach in unsolved N-linked CDG cases with abnormal transferrin screening results is also suggested.
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Affiliation(s)
- Kyle Scott
- Hayward Genetics Center, Tulane University School of Medicine, 1430 Tulane Ave, New Orleans, LA, 70112, USA
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Enns GM, Shashi V, Bainbridge M, Gambello MJ, Zahir FR, Bast T, Crimian R, Schoch K, Platt J, Cox R, Bernstein JA, Scavina M, Walter RS, Bibb A, Jones M, Hegde M, Graham BH, Need AC, Oviedo A, Schaaf CP, Boyle S, Butte AJ, Chen R, Chen R, Clark MJ, Haraksingh R, Cowan TM, He P, Langlois S, Zoghbi HY, Snyder M, Gibbs RA, Freeze HH, Goldstein DB. Mutations in NGLY1 cause an inherited disorder of the endoplasmic reticulum-associated degradation pathway. Genet Med 2014; 16:751-8. [PMID: 24651605 DOI: 10.1038/gim.2014.22] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 02/09/2014] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The endoplasmic reticulum-associated degradation pathway is responsible for the translocation of misfolded proteins across the endoplasmic reticulum membrane into the cytosol for subsequent degradation by the proteasome. To define the phenotype associated with a novel inherited disorder of cytosolic endoplasmic reticulum-associated degradation pathway dysfunction, we studied a series of eight patients with deficiency of N-glycanase 1. METHODS Whole-genome, whole-exome, or standard Sanger sequencing techniques were employed. Retrospective chart reviews were performed in order to obtain clinical data. RESULTS All patients had global developmental delay, a movement disorder, and hypotonia. Other common findings included hypolacrima or alacrima (7/8), elevated liver transaminases (6/7), microcephaly (6/8), diminished reflexes (6/8), hepatocyte cytoplasmic storage material or vacuolization (5/6), and seizures (4/8). The nonsense mutation c.1201A>T (p.R401X) was the most common deleterious allele. CONCLUSION NGLY1 deficiency is a novel autosomal recessive disorder of the endoplasmic reticulum-associated degradation pathway associated with neurological dysfunction, abnormal tear production, and liver disease. The majority of patients detected to date carry a specific nonsense mutation that appears to be associated with severe disease. The phenotypic spectrum is likely to enlarge as cases with a broader range of mutations are detected.
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Affiliation(s)
- Gregory M Enns
- Department of Pediatrics, Division of Medical Genetics, Lucile Packard Children's Hospital, Stanford University, Stanford, California, USA
| | - Vandana Shashi
- Department of Pediatrics, Division of Medical Genetics, Duke University, Durham, North Carolina, USA
| | - Matthew Bainbridge
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Michael J Gambello
- Department of Human Genetics, Division of Medical Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Farah R Zahir
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Rebecca Crimian
- Department of Pediatrics, Division of Medical Genetics, Duke University, Durham, North Carolina, USA
| | - Kelly Schoch
- Department of Pediatrics, Division of Medical Genetics, Duke University, Durham, North Carolina, USA
| | - Julia Platt
- Department of Pediatrics, Division of Medical Genetics, Lucile Packard Children's Hospital, Stanford University, Stanford, California, USA
| | - Rachel Cox
- Department of Pediatrics, Division of Medical Genetics, Lucile Packard Children's Hospital, Stanford University, Stanford, California, USA
| | - Jonathan A Bernstein
- Department of Pediatrics, Division of Medical Genetics, Lucile Packard Children's Hospital, Stanford University, Stanford, California, USA
| | - Mena Scavina
- Division of Pediatric Neurology, Department of Pediatrics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware, USA
| | - Rhonda S Walter
- Division of Developmental Medicine, Department of Pediatrics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, Delaware, USA
| | - Audrey Bibb
- Department of Human Genetics, Division of Medical Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Melanie Jones
- Department of Human Genetics, Division of Medical Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Madhuri Hegde
- Department of Human Genetics, Division of Medical Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Brett H Graham
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Anna C Need
- Department of Medicine, Imperial College, London, UK
| | - Angelica Oviedo
- Department of Pathology and Laboratory Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Christian P Schaaf
- 1] Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA [2] Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
| | - Sean Boyle
- Department of Genetics, Stanford University, Stanford, California, USA
| | - Atul J Butte
- Department of Genetics, Stanford University, Stanford, California, USA
| | - Rui Chen
- Department of Genetics, Stanford University School of Medicine, Stanford, California, USA
| | - Rong Chen
- Department of Genetics, Stanford University, Stanford, California, USA
| | - Michael J Clark
- Department of Genetics, Stanford University, Stanford, California, USA
| | - Rajini Haraksingh
- Department of Genetics, Stanford University, Stanford, California, USA
| | | | - Tina M Cowan
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Ping He
- Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | - Sylvie Langlois
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Huda Y Zoghbi
- 1] Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA [2] Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA [3] Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, USA
| | - Michael Snyder
- Department of Genetics, Stanford University, Stanford, California, USA
| | - Richard A Gibbs
- 1] Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA [2] Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
| | - Hudson H Freeze
- Sanford-Burnham Medical Research Institute, La Jolla, California, USA
| | - David B Goldstein
- 1] Center for Human Genome Variation and Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA [2] Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, North Carolina, USA
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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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41
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Iannotti MJ, Figard L, Sokac AM, Sifers RN. A Golgi-localized mannosidase (MAN1B1) plays a non-enzymatic gatekeeper role in protein biosynthetic quality control. J Biol Chem 2014; 289:11844-11858. [PMID: 24627495 DOI: 10.1074/jbc.m114.552091] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Conformation-based disorders are manifested at the level of protein structure, necessitating an accurate understanding of how misfolded proteins are processed by the cellular proteostasis network. Asparagine-linked glycosylation plays important roles for protein quality control within the secretory pathway. The suspected role for the MAN1B1 gene product MAN1B1, also known as ER mannosidase I, is to function within the ER similar to the yeast ortholog Mns1p, which removes a terminal mannose unit to initiate a glycan-based ER-associated degradation (ERAD) signal. However, we recently discovered that MAN1B1 localizes to the Golgi complex in human cells and uncovered its participation in ERAD substrate retention, retrieval to the ER, and subsequent degradation from this organelle. The objective of the current study was to further characterize the contribution of MAN1B1 as part of a Golgi-based quality control network. Multiple lines of experimental evidence support a model in which neither the mannosidase activity nor catalytic domain is essential for the retention or degradation of the misfolded ERAD substrate Null Hong Kong. Instead, a highly conserved, vertebrate-specific non-enzymatic decapeptide sequence in the luminal stem domain plays a significant role in controlling the fate of overexpressed Null Hong Kong. Together, these findings define a new functional paradigm in which Golgi-localized MAN1B1 can play a mannosidase-independent gatekeeper role in the proteostasis network of higher eukaryotes.
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Affiliation(s)
- Michael J Iannotti
- Interdepartmental Program in Cell and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030; Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas 77030
| | - Lauren Figard
- Interdepartmental Program in Cell and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Anna M Sokac
- Interdepartmental Program in Cell and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Richard N Sifers
- Interdepartmental Program in Cell and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030; Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas 77030; Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030.
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Van Scherpenzeel M, Timal S, Rymen D, Hoischen A, Wuhrer M, Hipgrave-Ederveen A, Grunewald S, Peanne R, Saada A, Edvardson S, Grønborg S, Ruijter G, Kattentidt-Mouravieva A, Brum JM, Freckmann ML, Tomkins S, Jalan A, Prochazkova D, Ondruskova N, Hansikova H, Willemsen MA, Hensbergen PJ, Matthijs G, Wevers RA, Veltman JA, Morava E, Lefeber DJ. Diagnostic serum glycosylation profile in patients with intellectual disability as a result of MAN1B1 deficiency. ACTA ACUST UNITED AC 2014; 137:1030-8. [PMID: 24566669 DOI: 10.1093/brain/awu019] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Congenital disorders of glycosylation comprise a group of genetic defects with a high frequency of intellectual disability, caused by deficient glycosylation of proteins and lipids. The molecular basis of the majority of the congenital disorders of glycosylation type I subtypes, localized in the cytosol and endoplasmic reticulum, has been solved. However, elucidation of causative genes for defective Golgi glycosylation (congenital disorders of glycosylation type II) remains challenging because of a lack of sufficiently specific diagnostic serum methods. In a single patient with intellectual disability, whole-exome sequencing revealed MAN1B1 as congenital disorder of glycosylation type II candidate gene. A novel mass spectrometry method was applied for high-resolution glycoprofiling of intact plasma transferrin. A highly characteristic glycosylation signature was observed with hybrid type N-glycans, in agreement with deficient mannosidase activity. The speed and robustness of the method allowed subsequent screening in a cohort of 100 patients with congenital disorder of glycosylation type II, which revealed the characteristic glycosylation profile of MAN1B1-congenital disorder of glycosylation in 11 additional patients. Abnormal hybrid type N-glycans were also observed in the glycoprofiles of total serum proteins, of enriched immunoglobulins and of alpha1-antitrypsin in variable amounts. Sanger sequencing revealed MAN1B1 mutations in all patients, including severe truncating mutations and amino acid substitutions in the alpha-mannosidase catalytic site. Clinically, this group of patients was characterized by intellectual disability and delayed motor and speech development. In addition, variable dysmorphic features were noted, with truncal obesity and macrocephaly in ∼65% of patients. In summary, MAN1B1 deficiency appeared to be a frequent cause in our cohort of patients with unsolved congenital disorder of glycosylation type II. Our method for analysis of intact transferrin provides a rapid test to detect MAN1B1-deficient patients within congenital disorder of glycosylation type II cohorts and can be used as efficient diagnostic method to identify MAN1B1-deficient patients in intellectual disability cohorts. In addition, it provides a functional confirmation of MAN1B1 mutations as identified by next-generation sequencing in individuals with intellectual disability.
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Affiliation(s)
- Monique Van Scherpenzeel
- 1 Laboratory of Genetic, Endocrine and Metabolic Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands
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43
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Wolthuis DFGJ, Janssen MC, Cassiman D, Lefeber DJ, Morava E, Morava-Kozicz E. Defining the phenotype and diagnostic considerations in adults with congenital disorders of N-linked glycosylation. Expert Rev Mol Diagn 2014; 14:217-24. [PMID: 24524732 DOI: 10.1586/14737159.2014.890052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Congenital disorders of N-glycosylation (CDG) form a rapidly growing group of more than 20 inborn errors of metabolism. Most patients are identified at the pediatric age with multisystem disease. There is no systematic review on the long-term outcome and clinical presentation in adult patients. Here, we review the adult phenotype in 78 CDG patients diagnosed with 18 different forms of N-glycosylation defects. Characteristics include intellectual disability, speech disorder and abnormal gait. After puberty, symptoms might remain non-progressive and patients may lead a socially functional life. Thrombosis and progressive symptoms, such as peripheral neuropathy, scoliosis and visual demise are specifically common in PMM2-CDG. Especially in adult patients, diagnostic glycosylation screening can be mildly abnormal or near-normal, hampering diagnosis. Features of adult CDG patients significantly differ from the pediatric phenotype. Non-syndromal intellectual disability, or congenital malformations in different types of CDG and decreasing sensitivity of screening might be responsible for the CDG cases remaining undiagnosed until adulthood.
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Affiliation(s)
- David F G J Wolthuis
- Hayward Genetics Center, Tulane University Medical School, New Orleans, LA, 70112, USA
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44
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Aikawa JI, Takeda Y, Matsuo I, Ito Y. Trimming of glucosylated N-glycans by human ER α1,2-mannosidase I. ACTA ACUST UNITED AC 2014; 155:375-84. [DOI: 10.1093/jb/mvu008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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45
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The α-endomannosidase gene (MANEA) is associated with panic disorder and social anxiety disorder. Transl Psychiatry 2014; 4:e353. [PMID: 24473444 PMCID: PMC3905232 DOI: 10.1038/tp.2013.122] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 11/21/2013] [Accepted: 11/25/2013] [Indexed: 01/28/2023] Open
Abstract
Unbiased genome-wide approaches can provide novel insights into the biological pathways that are important for human behavior and psychiatric disorder risk. The association of α-endomannosidase gene (MANEA) variants and cocaine-induced paranoia (CIP) was initially described in a study that used a whole-genome approach. Behavioral effects have been reported for other mannosidase genes, but MANEA function in humans and the clinical potential of the previous findings remain unclear. We hypothesized that MANEA would be associated with psychiatric phenotypes unrelated to cocaine use. We used a multi-stage association study approach starting with four psychiatric disorders to show an association between a MANEA single-nucleotide polymorphism (SNP; rs1133503) and anxiety disorders. In the first study of 2073 European American (EA) and 2459 African American subjects mostly with comorbid drug or alcohol dependence, we observed an association in EAs of rs1133503 with panic disorder (PD) (191 PD cases, odds ratio (OR)=1.7 (95% confidence interval (CI): 1.22-2.41), P=0.002). We replicated this finding in an independent sample of 142 PD cases (OR =1.53 (95% CI: 1.00-2.31), P=0.043) and extended it in an independent sample of 131 generalized social anxiety disorder cases (OR=2.15 (95% CI: 1.27-3.64), P=0.004). MANEA alleles and genotypes were also associated with gene expression differences in whole blood cells. Using publically available data, we observed a consistent effect on expression in brain tissue. We conclude that pathways involving α-endomannosidase warrant further investigation in relation to anxiety disorders.
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46
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Rymen D, Peanne R, Millón MB, Race V, Sturiale L, Garozzo D, Mills P, Clayton P, Asteggiano CG, Quelhas D, Cansu A, Martins E, Nassogne MC, Gonçalves-Rocha M, Topaloglu H, Jaeken J, Foulquier F, Matthijs G. MAN1B1 deficiency: an unexpected CDG-II. PLoS Genet 2013; 9:e1003989. [PMID: 24348268 PMCID: PMC3861123 DOI: 10.1371/journal.pgen.1003989] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Accepted: 10/09/2013] [Indexed: 11/18/2022] Open
Abstract
Congenital disorders of glycosylation (CDG) are a group of rare metabolic diseases, due to impaired protein and lipid glycosylation. In the present study, exome sequencing was used to identify MAN1B1 as the culprit gene in an unsolved CDG-II patient. Subsequently, 6 additional cases with MAN1B1-CDG were found. All individuals presented slight facial dysmorphism, psychomotor retardation and truncal obesity. Generally, MAN1B1 is believed to be an ER resident alpha-1,2-mannosidase acting as a key factor in glycoprotein quality control by targeting misfolded proteins for ER-associated degradation (ERAD). However, recent studies indicated a Golgi localization of the endogenous MAN1B1, suggesting a more complex role for MAN1B1 in quality control. We were able to confirm that MAN1B1 is indeed localized to the Golgi complex instead of the ER. Furthermore, we observed an altered Golgi morphology in all patients' cells, with marked dilatation and fragmentation. We hypothesize that part of the phenotype is associated to this Golgi disruption. In conclusion, we linked mutations in MAN1B1 to a Golgi glycosylation disorder. Additionally, our results support the recent findings on MAN1B1 localization. However, more work is needed to pinpoint the exact function of MAN1B1 in glycoprotein quality control, and to understand the pathophysiology of its deficiency. Glycosylation concerns the synthesis of sugar chains, their addition onto proteins and/or lipids, and their subsequent modifications. The resulting glycoproteins serve many critical roles in metabolism. The importance of this pathway is illustrated by a group of diseases called Congenital Disorders of Glycosylation (CDG). To date, over 60 distinct disorders have been described. In the present study, we demonstrated that mutations in MAN1B1, a gene formerly linked to non-syndromic intellectual disability, cause CDG. We described 7 patients with similar clinical features (developmental delay, intellectual disability, facial dysmorphism and obesity), defining MAN1B1-CDG as a syndrome. Furthermore, we confirmed that the MAN1B1 protein is localized into the Golgi apparatus instead of the endoplasmic reticulum, where it was assumed to reside for many years. Moreover, we showed that mutations in MAN1B1 lead to alterations of the Golgi structure.
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Affiliation(s)
- Daisy Rymen
- Center for Human Genetics, University of Leuven, Leuven, Belgium
- Center for Metabolic Diseases, University Hospital Gasthuisberg, Leuven, Belgium
| | - Romain Peanne
- Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - María B. Millón
- Centro de Estudio Metabalopatías Congénitas, Faculdad de Ciencias Médicas, Universidad Nacional de Córdoba, Hospital de Niños de la Santísima Trinidad, Córdoba, Argentina
| | - Valérie Race
- Center for Human Genetics, University of Leuven, Leuven, Belgium
| | - Luisa Sturiale
- Institute of Chemistry and Technology of Polymers, CNR, Catania, Italy
| | - Domenico Garozzo
- Institute of Chemistry and Technology of Polymers, CNR, Catania, Italy
| | - Philippa Mills
- Clinical & Molecular Genetics Unit, Institute of Child Health, University College and Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom
| | - Peter Clayton
- Clinical & Molecular Genetics Unit, Institute of Child Health, University College and Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom
| | - Carla G. Asteggiano
- Centro de Estudio Metabalopatías Congénitas, Faculdad de Ciencias Médicas, Universidad Nacional de Córdoba, Hospital de Niños de la Santísima Trinidad, Córdoba, Argentina
| | - Dulce Quelhas
- Unidade de Genética Médica, Departamento de Genética Humana, Centro de Genética Médica - Dr. Jacinto Magalhães - INSA, IP. Porto, Portugal
| | - Ali Cansu
- Gazi University Faculty of Medicine, Department of Paediatric Neurology, Besevler/Ankara, Turkey
| | - Esmeralda Martins
- Unidade de Doenças Metabólicas, Hospital de Crianças Maria Pia, Porto, Portugal
| | - Marie-Cécile Nassogne
- Université Catholique de Louvain, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Miguel Gonçalves-Rocha
- Unidade de Genética Médica, Departamento de Genética Humana, Centro de Genética Médica - Dr. Jacinto Magalhães - INSA, IP. Porto, Portugal
| | - Haluk Topaloglu
- Department of Child Neurology, Hacettepe University Children's Hospital, Ankara, Turkey
| | - Jaak Jaeken
- Center for Metabolic Diseases, University Hospital Gasthuisberg, Leuven, Belgium
| | - François Foulquier
- Structural and Functional Glycobiology Unit, UMR CNRS/USTL 8576, IFR 147, University of Lille 1, Villeneuve d'Ascq, France
| | - Gert Matthijs
- Center for Human Genetics, University of Leuven, Leuven, Belgium
- * E-mail:
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47
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Genetics of recessive cognitive disorders. Trends Genet 2013; 30:32-9. [PMID: 24176302 DOI: 10.1016/j.tig.2013.09.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 09/11/2013] [Accepted: 09/20/2013] [Indexed: 01/23/2023]
Abstract
Most severe forms of intellectual disability (ID) have specific genetic causes. Numerous X chromosome gene defects and disease-causing copy-number variants have been linked to ID and related disorders, and recent studies have revealed that sporadic cases are often due to dominant de novo mutations with low recurrence risk. For autosomal recessive ID (ARID) the recurrence risk is high and, in populations with frequent parental consanguinity, ARID is the most common form of ID. Even so, its elucidation has lagged behind. Here we review recent progress in this field, show that ARID is not rare even in outbred Western populations, and discuss the prospects for improving its diagnosis and prevention.
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48
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Carss K, Stevens E, Foley A, Cirak S, Riemersma M, Torelli S, Hoischen A, Willer T, van Scherpenzeel M, Moore S, Messina S, Bertini E, Bönnemann C, Abdenur J, Grosmann C, Kesari A, Punetha J, Quinlivan R, Waddell L, Young H, Wraige E, Yau S, Brodd L, Feng L, Sewry C, MacArthur D, North K, Hoffman E, Stemple D, Hurles M, van Bokhoven H, Campbell K, Lefeber D, Lin YY, Muntoni F, Muntoni F. Mutations in GDP-mannose pyrophosphorylase B cause congenital and limb-girdle muscular dystrophies associated with hypoglycosylation of α-dystroglycan. Am J Hum Genet 2013; 93:29-41. [PMID: 23768512 DOI: 10.1016/j.ajhg.2013.05.009] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/08/2013] [Accepted: 05/14/2013] [Indexed: 12/26/2022] Open
Abstract
Congenital muscular dystrophies with hypoglycosylation of α-dystroglycan (α-DG) are a heterogeneous group of disorders often associated with brain and eye defects in addition to muscular dystrophy. Causative variants in 14 genes thought to be involved in the glycosylation of α-DG have been identified thus far. Allelic mutations in these genes might also cause milder limb-girdle muscular dystrophy phenotypes. Using a combination of exome and Sanger sequencing in eight unrelated individuals, we present evidence that mutations in guanosine diphosphate mannose (GDP-mannose) pyrophosphorylase B (GMPPB) can result in muscular dystrophy variants with hypoglycosylated α-DG. GMPPB catalyzes the formation of GDP-mannose from GTP and mannose-1-phosphate. GDP-mannose is required for O-mannosylation of proteins, including α-DG, and it is the substrate of cytosolic mannosyltransferases. We found reduced α-DG glycosylation in the muscle biopsies of affected individuals and in available fibroblasts. Overexpression of wild-type GMPPB in fibroblasts from an affected individual partially restored glycosylation of α-DG. Whereas wild-type GMPPB localized to the cytoplasm, five of the identified missense mutations caused formation of aggregates in the cytoplasm or near membrane protrusions. Additionally, knockdown of the GMPPB ortholog in zebrafish caused structural muscle defects with decreased motility, eye abnormalities, and reduced glycosylation of α-DG. Together, these data indicate that GMPPB mutations are responsible for congenital and limb-girdle muscular dystrophies with hypoglycosylation of α-DG.
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Croes K, De Coster S, De Galan S, Morrens B, Loots I, Van de Mieroop E, Nelen V, Sioen I, Bruckers L, Nawrot T, Colles A, Den Hond E, Schoeters G, van Larebeke N, Baeyens W, Gao Y. Health effects in the Flemish population in relation to low levels of mercury exposure: from organ to transcriptome level. Int J Hyg Environ Health 2013; 217:239-47. [PMID: 23920476 DOI: 10.1016/j.ijheh.2013.06.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 04/29/2013] [Accepted: 06/04/2013] [Indexed: 11/30/2022]
Abstract
Due to possible health risks, quantification of mercury accumulation in humans was included in the Flemish biomonitoring programmes FLEHS I (2002-2006) and FLEHS II (2007-2011). The general objective of FLEHS I was to assess regional exposure levels in order to link possible differences in these internal exposure levels to different types of local environmental pressure. Therefore, Hg and MMHg (methylmercury) were only measured in pooled blood samples per region and per age class. In FLEHS II, mercury concentrations were measured in hair of each participant. About 200 adolescents and 250 mothers (reference group) and two times 200 adolescents (2 hotspots) were screened. The main objectives of the FLEHS II study were: (1) to determine reference levels of mercury in hair for Flanders; (2) to assess relations between mercury exposure and possible sources like fish consumption; (3) to assess dose-effect relations between mercury exposure and health effect markers. The results showed that mercury concentrations in the Flemish population were rather low compared to other studies. Mercury levels in the Flemish populations were strongly related to the age of the participants and consumption of fish. Significant negative associations were observed between mercury in hair and asthma, having received breast feeding as a newborn, age at menarche in girls, allergy for animals and free testosterone levels. Significant correlations were also observed between mercury in hair and genes JAK2, ARID4A, Hist1HA4L (boys) and HLAdrb5, PIAS2, MANN1B1, GIT and ABCA1 (girls).
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Affiliation(s)
- Kim Croes
- Free University of Brussels (VUB), Department of Analytical and Environmental Chemistry (ANCH), Pleinlaan 2, 1050 Brussels, Belgium
| | - Sam De Coster
- Ghent University Hospital, Study Centre for Carcinogenesis and Primary Prevention of Cancer, De Pintelaan 185, 9000 Ghent, Belgium
| | - Sandra De Galan
- Free University of Brussels (VUB), Department of Analytical and Environmental Chemistry (ANCH), Pleinlaan 2, 1050 Brussels, Belgium
| | - Bert Morrens
- University of Antwerp, Faculty of Political and Social Sciences, Department of Sociology, Sint Jacobstraat 2, 2000 Antwerp, Belgium
| | - Ilse Loots
- University of Antwerp, Faculty of Political and Social Sciences, Department of Sociology, Sint Jacobstraat 2, 2000 Antwerp, Belgium
| | - Els Van de Mieroop
- Provincial Institute for Hygiene, Kronenburgstraat 45, 2000 Antwerp, Belgium
| | - Vera Nelen
- Provincial Institute for Hygiene, Kronenburgstraat 45, 2000 Antwerp, Belgium
| | - Isabelle Sioen
- Ghent University, Department of Public Health, UZ-2 Blok A, De Pintelaan 185, 9000 Ghent, Belgium; Research Foundation - Flanders, Egmontstraat 5, 1000 Brussels, Belgium
| | - Liesbeth Bruckers
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Martelarenlaan 42, 3500 Hasselt, Belgium
| | - Tim Nawrot
- School of Public Health, Occupational & Environmental Medicine, K.U. Leuven, Herestraat 49 (O&N 706), 3000 Leuven, Belgium; Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium
| | - Ann Colles
- Flemish Institute for Technological Research (VITO), Environmental Health and Risk, Boeretang 200, 2400 Mol, Belgium
| | - Elly Den Hond
- Flemish Institute for Technological Research (VITO), Environmental Health and Risk, Boeretang 200, 2400 Mol, Belgium
| | - Greet Schoeters
- Flemish Institute for Technological Research (VITO), Environmental Health and Risk, Boeretang 200, 2400 Mol, Belgium
| | - Nicolas van Larebeke
- Ghent University Hospital, Study Centre for Carcinogenesis and Primary Prevention of Cancer, De Pintelaan 185, 9000 Ghent, Belgium
| | - Willy Baeyens
- Free University of Brussels (VUB), Department of Analytical and Environmental Chemistry (ANCH), Pleinlaan 2, 1050 Brussels, Belgium
| | - Yue Gao
- Free University of Brussels (VUB), Department of Analytical and Environmental Chemistry (ANCH), Pleinlaan 2, 1050 Brussels, Belgium.
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50
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Elfrink HL, Zwart R, Baas F, Scheper W. Inhibition of endoplasmic reticulum associated degradation reduces endoplasmic reticulum stress and alters lysosomal morphology and distribution. Mol Cells 2013; 35:291-7. [PMID: 23515578 PMCID: PMC3887885 DOI: 10.1007/s10059-013-2286-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 02/06/2013] [Accepted: 02/13/2013] [Indexed: 12/11/2022] Open
Abstract
Disturbances in proteostasis are observed in many neurodegenerative diseases. This leads to activation of protein quality control to restore proteostasis, with a key role for the removal of aberrant proteins by proteolysis. The unfolded protein response (UPR) is a protein quality control mechanism of the endoplasmic reticulum (ER) that is activated in several neurodegenerative diseases. Recently we showed that the major proteolytic pathway during UPR activation is via the autophagy/lysosomal system. Here we investigate UPR induction if the other major proteolytic pathway of the ER -ER associated degradation (ERAD)-is inhibited. Surprisingly, impairment of ERAD results in decreased UPR activation and protects against ER stress toxicity. Autophagy induction is not affected under these conditions, however, a striking relocalization of the lysosomes is observed. Our data suggest that a protective UPR-modulating mechanism is activated if ERAD is inhibited, which involves lysosomes. Our data provide insight in the cross-talk between proteolytic pathways involved in ER proteostasis. This has implications for neurodegenerative diseases like Alzheimer's disease where disturbed ER proteostasis and proteolytic impairment are early phenomena in the pathology.
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Affiliation(s)
- Hyung Lim Elfrink
- Department of Genome Analysis, Academic Medical Center, Amsterdam,
the Netherlands
| | - Rob Zwart
- Department of Genome Analysis, Academic Medical Center, Amsterdam,
the Netherlands
| | - Frank Baas
- Department of Genome Analysis, Academic Medical Center, Amsterdam,
the Netherlands
- Department of Neurology, Academic Medical Center, Amsterdam,
the Netherlands
| | - Wiep Scheper
- Department of Genome Analysis, Academic Medical Center, Amsterdam,
the Netherlands
- Department of Neurology, Academic Medical Center, Amsterdam,
the Netherlands
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