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Thompson MD, Knaus A. Rare Genetic Developmental Disabilities: Mabry Syndrome (MIM 239300) Index Cases and Glycophosphatidylinositol (GPI) Disorders. Genes (Basel) 2024; 15:619. [PMID: 38790248 PMCID: PMC11121671 DOI: 10.3390/genes15050619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 05/26/2024] Open
Abstract
The case report by Mabry et al. (1970) of a family with four children with elevated tissue non-specific alkaline phosphatase, seizures and profound developmental disability, became the basis for phenotyping children with the features that became known as Mabry syndrome. Aside from improvements in the services available to patients and families, however, the diagnosis and treatment of this, and many other developmental disabilities, did not change significantly until the advent of massively parallel sequencing. As more patients with features of the Mabry syndrome were identified, exome and genome sequencing were used to identify the glycophosphatidylinositol (GPI) biosynthesis disorders (GPIBDs) as a group of congenital disorders of glycosylation (CDG). Biallelic variants of the phosphatidylinositol glycan (PIG) biosynthesis, type V (PIGV) gene identified in Mabry syndrome became evidence of the first in a phenotypic series that is numbered HPMRS1-6 in the order of discovery. HPMRS1 [MIM: 239300] is the phenotype resulting from inheritance of biallelic PIGV variants. Similarly, HPMRS2 (MIM 614749), HPMRS5 (MIM 616025) and HPMRS6 (MIM 616809) result from disruption of the PIGO, PIGW and PIGY genes expressed in the endoplasmic reticulum. By contrast, HPMRS3 (MIM 614207) and HPMRS4 (MIM 615716) result from disruption of post attachment to proteins PGAP2 (HPMRS3) and PGAP3 (HPMRS4). The GPI biosynthesis disorders (GPIBDs) are currently numbered GPIBD1-21. Working with Dr. Mabry, in 2020, we were able to use improved laboratory diagnostics to complete the molecular diagnosis of patients he had originally described in 1970. We identified biallelic variants of the PGAP2 gene in the first reported HPMRS patients. We discuss the longevity of the Mabry syndrome index patients in the context of the utility of pyridoxine treatment of seizures and evidence for putative glycolipid storage in patients with HPMRS3. From the perspective of the laboratory innovations made that enabled the identification of the HPMRS phenotype in Dr. Mabry's patients, the need for treatment innovations that will benefit patients and families affected by developmental disabilities is clear.
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Affiliation(s)
- Miles D. Thompson
- Krembil Brain Institute, Toronto Western Hospital, 399 Bathurst Street, Toronto, ON M5T 2S8, Canada
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, University of Bonn, 53127 Bonn, Germany;
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Fang Z, Hu C, Zhou S, Yu L. PIGW-related glycosylphosphatidylinositol deficiency: A case report and literature review. Neurol Sci 2024; 45:2253-2260. [PMID: 38055078 DOI: 10.1007/s10072-023-07225-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023]
Abstract
INTRODUCTION PIGW-related glycosylphosphatidylinositol deficiency is a rare disease that manifests heterogeneous clinical phenotypes. METHODS We describe a patient with PIGW deficiency and summarize the clinical characteristics of the case. In addition, we conducted a literature review of previously reported patients with pathogenic variants of PIGW. RESULTS A Chinese girl presented with refractory epilepsy, severe intellectual disability, recurrent respiratory infections, and hyperphosphatasia. Seizures worsened during fever and infections, making her more susceptible to epileptic status. She was found to carry a heterozygous variant of PIGW and a deletion of chromosome 17q12 containing PIGW. Only six patients with homozygous or compound heterozygous pathogenic variants of PIGW have been identified in the literature thus far. Epileptic seizures were reported in all patients, and the most common types of seizures were epileptic spasms. Distinctive facial and physical features and recurrent respiratory infections are common in these patients with developmental delays. Serum alkaline phosphatase (ALP) levels were elevated in four of the six patients. CONCLUSIONS PIGW-related glycosylphosphatidylinositol deficiency is characterized by developmental delay, epilepsy, distinctive facial features, and multiple organ anomalies. Genetic testing is an important method for diagnosing this disease, and flow cytometry and serum ALP level detection are crucial complements for genetic testing.
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Affiliation(s)
- Zhixu Fang
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Chaoping Hu
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Shuizhen Zhou
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China
| | - Lifei Yu
- Department of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, No. 399, Wanyuan Road, Minhang District, Shanghai, 201102, China.
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Torres-Valdetano Á, Vallejo-Ruiz V, Milflores-Flores L, Martínez-Morales P. Role of PIGM and PIGX in glycosylphosphatidylinositol biosynthesis and human health (Review). Biomed Rep 2024; 20:57. [PMID: 38414627 PMCID: PMC10895387 DOI: 10.3892/br.2024.1746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/09/2024] [Indexed: 02/29/2024] Open
Abstract
Glycosylphosphatidylinositol-glycan (GPI) is an anchor to specific cell surface proteins known as GPI-anchored proteins (APs) that are localized in lipid rafts and may act as cell co-receptors, enzymes and adhesion molecules. The present review investigated the significance of GPI biosynthesis class phosphatidylinositol-glycan (PIG)M and PIGX in GPI synthesis and their implications in human health conditions. PIGM encodes GPI-mannosyltransferase I (MT-I) enzyme that adds the first mannose to the GPI core structure. PIGX encodes the regulatory subunit of GPI-MT-I. The present review summarizes characteristics of the coding sequences of PIGM and PIGX, and their expression in humans, as well as the relevance of GPI-MT-I and the regulatory subunit in maintaining the presence of GPI-APs on the cell surface and their secretion. In addition, the association of PIGM mutations with paroxysmal nocturnal hemoglobinuria and certain types of GPI-deficiency disease and the altered expression of PIGM and PIGX in cancer were also reviewed. In addition, their interaction with other proteins was described, suggesting a complex role in cell biology. PIGM and PIGX are critical genes for GPI synthesis. Understanding gene and protein regulation may provide valuable insights into the role of GPI-APs in cellular processes.
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Affiliation(s)
- Ángeles Torres-Valdetano
- Faculty of Biological Science, Building BIO 1 University City, Autonomous University of Puebla, Puebla 72570, Mexico
| | - Verónica Vallejo-Ruiz
- Mexican Social Security Institute, East Biomedical Research Center, Puebla 74360, Mexico
| | - Lorena Milflores-Flores
- Faculty of Biological Science, Building BIO 1 University City, Autonomous University of Puebla, Puebla 72570, Mexico
| | - Patricia Martínez-Morales
- National Council of Humanities, Sciences and Technologies, East Biomedical Research Center, Puebla 74360, Mexico
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4
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陈 秋, 张 朕, 卢 一, 袁孙 碧, 李 冀. [Glycosylphosphatidylinositol biosynthesis deficiency 15 caused by GPAA1 gene mutation: a rare disease study]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2023; 25:1276-1281. [PMID: 38112147 PMCID: PMC10731960 DOI: 10.7499/j.issn.1008-8830.2307114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/06/2023] [Indexed: 12/20/2023]
Abstract
A boy, aged 6 years, attended the hospital due to global developmental delay for 6 years and recurrent fever and convulsions for 5 years. The boy was found to have delayed mental and motor development at the age of 3 months and experienced recurrent fever and convulsions since the age of 1 year, with intermittent canker sores and purulent tonsillitis. During the fever period, blood tests showed elevated white blood cell count, C-reactive protein, and erythrocyte sedimentation rate, which returned to normal after the fever subsides. Electroencephalography showed epilepsy, and genetic testing showed compound heterozygous mutations in the GPAA1 gene. The boy was finally diagnosed with glycosylphosphatidylinositol biosynthesis deficiency 15 (GPIBD15) and periodic fever. The patient did not respond well to antiepileptic treatment, but showed successful fever control with glucocorticoid therapy. This article reports the first case of GPIBD15 caused by GPAA1 gene mutation in China and summarizes the genetic features, clinical features, diagnosis, and treatment of this disease, which provides a reference for the early diagnosis and treatment of GPIBD15.
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Liu D, Paladino S, Zurzolo C, Lebreton S. Calcium-binding Cab45 regulates the polarized apical secretion of soluble proteins in epithelial cells. Mol Biol Cell 2023; 34:br12. [PMID: 37163315 PMCID: PMC10398874 DOI: 10.1091/mbc.e22-12-0549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/12/2023] [Accepted: 05/02/2023] [Indexed: 05/11/2023] Open
Abstract
Protein secretion is essential for epithelial tissue homoeostasis and therefore has to be tightly regulated. However, while the mechanisms regulating polarized protein sorting and trafficking have been widely studied in the past decade, those governing polarized secretion remain elusive. The calcium manganese pump SPCA1 and the calcium-binding protein Cab45 were recently shown to regulate the secretion of a subset of soluble cargoes in nonpolarized HeLa cells. Interestingly, we demonstrated that in polarized epithelial cells calcium levels in the trans-Golgi network (TGN), controlled by SPCA1, and Cab45 are critical for the apical sorting of glycosylphosphatidylinositol-anchored proteins (GPI-APs), a class of integral membrane proteins containing a soluble protein attached to the membrane by the GPI anchor, prompting us to investigate the mechanism regulating the polarized secretion of soluble cargoes. By reducing Cab45 expression level or overexpressing an inactive mutant of SPCA1, we found that Cab45 and calcium levels in the TGN drive the polarized apical secretion of a secretory form of placental alkaline phosphatase, exogenously expressed, and the endogenous soluble protein clusterin/Gp80 in Madin-Darby canine kidney (MDCK) cells. These data highlight the critical role of a calcium-dependent Cab45 mechanism regulating apical exocytosis in polarized MDCK cells.
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Affiliation(s)
- Dandan Liu
- Unité de Trafic Membranaire et Pathogenèse, Institut Pasteur, 75015 Paris, France
| | - Simona Paladino
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Chiara Zurzolo
- Unité de Trafic Membranaire et Pathogenèse, Institut Pasteur, 75015 Paris, France
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, 80131 Naples, Italy
| | - Stéphanie Lebreton
- Unité de Trafic Membranaire et Pathogenèse, Institut Pasteur, 75015 Paris, France
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Messina M, Manea E, Cullup T, Tuschl K, Batzios S. Hyperphosphatasia with mental retardation syndrome 3: Cerebrospinal fluid abnormalities and correction with pyridoxine and Folinic acid. JIMD Rep 2023; 64:42-52. [PMID: 36636587 PMCID: PMC9830023 DOI: 10.1002/jmd2.12347] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/16/2022] [Accepted: 10/25/2022] [Indexed: 11/24/2022] Open
Abstract
Glycosylphosphatidylinositol anchored proteins (GPI-APs) represent a class of molecules attached to the external leaflet of the plasma membrane by the GPI anchor where they play important roles in numerous cellular processes including neurogenesis, cell adhesion, immune response and signalling. Within the group of GPI anchor defects, six present with the clinical phenotype of Hyperphosphatasia with Mental Retardation Syndrome (HPMRS, Mabry Syndrome) characterized by moderate to severe intellectual disability, dysmorphic features, hypotonia, seizures and persistent hyperphosphatasia. We report the case of a 5-year-old female with global developmental delay associated with precocious puberty and persistently raised plasma alkaline phosphatase. Targeted next generation sequencing analysis of the HPMRS genes identified novel compound heterozygous variants in the PGAP2 gene (c.103del p.(Leu35Serfs*90)and c.134A > Gp.(His45Arg)) consistent with the diagnosis of HPMRS type 3. Cerebrospinal fluid (CSF) neurotransmitter analysis showed low levels of pyridoxal phosphate and 5-methyltetrahydrofolate and raised homovanillic acid. Supplementation with pyridoxine and folinic acid led to normalization of biochemical abnormalities. The patient continues to make developmental progress with significant improvement in speech and fine motor skills. Our reported case expands the clinical spectrum of HPMRS3 in which multisystem involvement is being increasingly recognized. Furthermore, it shows that miss-targeting GPI-APs and the effect on normal cellular function could provide a physiopathologic explanation for the CSF biochemical abnormalities with management implications for a group of disorders that currently has no treatment that can lead possibly to improved clinical outcomes.
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Affiliation(s)
- Martina Messina
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
| | - Emanuela Manea
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
| | - Thomas Cullup
- North Thames Genomic Laboratory HubGreat Ormond Street Hospital for ChildrenLondonUK
| | - Karin Tuschl
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
- University College London Great Ormond Street Institute for ChildrenLondonUK
| | - Spyros Batzios
- Metabolic Medicine DepartmentGreat Ormond Street Hospital for ChildrenLondonUK
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Wagatsuma T, Shimotsuma K, Sogo A, Sato R, Kubo N, Ueda S, Uchida Y, Kinoshita M, Kambe T. Zinc transport via ZNT5-6 and ZNT7 is critical for cell surface glycosylphosphatidylinositol-anchored protein expression. J Biol Chem 2022; 298:102011. [PMID: 35525268 PMCID: PMC9168625 DOI: 10.1016/j.jbc.2022.102011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/20/2022] [Accepted: 04/27/2022] [Indexed: 11/25/2022] Open
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins play crucial roles in various enzyme activities, cell signaling and adhesion, and immune responses. While the molecular mechanism underlying GPI-anchored protein biosynthesis has been well studied, the role of zinc transport in this process has not yet been elucidated. Zn transporter (ZNT) proteins mobilize cytosolic zinc to the extracellular space and to intracellular compartments. Here, we report that the early secretory pathway ZNTs (ZNT5–ZNT6 heterodimers [ZNT5-6] and ZNT7–ZNT7 homodimers [ZNT7]), which supply zinc to the lumen of the early secretory pathway compartments are essential for GPI-anchored protein expression on the cell surface. We show, using overexpression and gene disruption/re-expression strategies in cultured human cells, that loss of ZNT5-6 and ZNT7 zinc transport functions results in significant reduction in GPI-anchored protein levels similar to that in mutant cells lacking phosphatidylinositol glycan anchor biosynthesis (PIG) genes. Furthermore, medaka fish with disrupted Znt5 and Znt7 genes show touch-insensitive phenotypes similar to zebrafish Pig mutants. These findings provide a previously unappreciated insight into the regulation of GPI-anchored protein expression and protein quality control in the early secretory pathway.
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Affiliation(s)
- Takumi Wagatsuma
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Keiko Shimotsuma
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Akiko Sogo
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Risa Sato
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578 Sendai, Japan
| | - Naoya Kubo
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Sachiko Ueda
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Yasuo Uchida
- Division of Membrane Transport and Drug Targeting, Graduate School of Pharmaceutical Sciences, Tohoku University, 980-8578 Sendai, Japan
| | - Masato Kinoshita
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Taiho Kambe
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan.
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8
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Salian S, Guo XY, Murakami Y, Kinoshita T, Kaur P, Shukla A, Girisha KM, Fujita M, Campeau PM. C18orf32 loss-of-function is associated with a neurodevelopmental disorder with hypotonia and contractures. Hum Genet 2022; 141:1423-1429. [PMID: 35107634 DOI: 10.1007/s00439-022-02433-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/07/2022] [Indexed: 11/04/2022]
Abstract
Glycosylphosphatidylinositol (GPI) functions to anchor certain proteins to the cell surface. Although defects in GPI biosynthesis can result in a wide range of phenotypes, most affected patients present with neurological abnormalities and their diseases are grouped as inherited-GPI deficiency disorders. We present two siblings with global developmental delay, brain anomalies, hypotonia, and contractures. Exome sequencing revealed a homozygous variant, NM_001035005.4:c.90dupC (p.Phe31Leufs*3) in C18orf32, a gene not previously associated with any disease in humans. The encoded protein is known to be important for GPI-inositol deacylation. Knockout of C18orf32 in HEK293 cells followed by a transfection rescue assay revealed that the PIPLC (Phosphatidylinositol-Specific Phospholipase C) sensitivity of GPI-APs (GPI-anchored proteins) was restored only by the wild type and not the mutant C18orf32. Immunofluorescence revealed that the mutant C18orf32 was localized to the endoplasmic reticulum and was also found as aggregates in the nucleus. In conclusion, we identified a pathogenic variant in C18orf32 as the cause of a novel autosomal recessive neurodevelopmental disorder with hypotonia and contractures. Our results demonstrate the importance of C18orf32 in the biosynthesis of GPI-anchors, the molecular impact of the variant on the protein function, and add a novel candidate gene to the existing repertoire of genes implicated in neurodevelopmental disorders.
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Affiliation(s)
- Smrithi Salian
- Department of Pediatrics, CHU Sainte Justine Research Center, University of Montreal, Côte-Sainte-Catherine, Montreal, QC, 3175H3T 1C5, Canada
| | - Xin-Yu Guo
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Parneet Kaur
- Kasturba Medical College - Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Anju Shukla
- Kasturba Medical College - Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Katta M Girisha
- Kasturba Medical College - Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Morihisa Fujita
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, Jiangsu, China
| | - Philippe M Campeau
- Department of Pediatrics, CHU Sainte Justine Research Center, University of Montreal, Côte-Sainte-Catherine, Montreal, QC, 3175H3T 1C5, Canada.
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Hirata T, Kobayashi A, Furuse T, Yamada I, Tamura M, Tomita H, Tokoro Y, Ninomiya A, Fujihara Y, Ikawa M, Maeda Y, Murakami Y, Kizuka Y, Kinoshita T. Loss of the N-acetylgalactosamine side chain of the GPI-anchor impairs bone formation and brain functions and accelerates the prion disease pathology. J Biol Chem 2022; 298:101720. [PMID: 35151686 PMCID: PMC8913354 DOI: 10.1016/j.jbc.2022.101720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 01/28/2022] [Accepted: 01/29/2022] [Indexed: 02/07/2023] Open
Abstract
Glycosylphosphatidylinositol (GPI) is a posttranslational glycolipid modification of proteins that anchors proteins in lipid rafts on the cell surface. Although some GPI-anchored proteins (GPI-APs), including the prion protein PrPC, have a glycan side chain composed of N-acetylgalactosamine (GalNAc)−galactose−sialic acid on the core structure of GPI glycolipid, in vivo functions of this GPI-GalNAc side chain are largely unresolved. Here, we investigated the physiological and pathological roles of the GPI-GalNAc side chain in vivo by knocking out its initiation enzyme, PGAP4, in mice. We show that Pgap4 mRNA is highly expressed in the brain, particularly in neurons, and mass spectrometry analysis confirmed the loss of the GalNAc side chain in PrPC GPI in PGAP4-KO mouse brains. Furthermore, PGAP4-KO mice exhibited various phenotypes, including an elevated blood alkaline phosphatase level, impaired bone formation, decreased locomotor activity, and impaired memory, despite normal expression levels and lipid raft association of various GPI-APs. Thus, we conclude that the GPI-GalNAc side chain is required for in vivo functions of GPI-APs in mammals, especially in bone and the brain. Moreover, PGAP4-KO mice were more vulnerable to prion diseases and died earlier after intracerebral inoculation of the pathogenic prion strains than wildtype mice, highlighting the protective roles of the GalNAc side chain against prion diseases.
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Affiliation(s)
- Tetsuya Hirata
- Institute for Glyco-core Research (iGCORE), Gifu University, Gifu, Japan
| | - Atsushi Kobayashi
- Laboratory of Comparative Pathology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Tamio Furuse
- Technology and Development Team for Mouse Phenotype Analysis, RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Ikuko Yamada
- Technology and Development Team for Mouse Phenotype Analysis, RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Masaru Tamura
- Technology and Development Team for Mouse Phenotype Analysis, RIKEN BioResource Research Center, Tsukuba, Ibaraki, Japan
| | - Hiroyuki Tomita
- Department of Tumor Pathology, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Yuko Tokoro
- Institute for Glyco-core Research (iGCORE), Gifu University, Gifu, Japan
| | - Akinori Ninomiya
- Core Instrumentation Facility, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Yoshitaka Fujihara
- Department of Experimental Genome Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Masahito Ikawa
- Department of Experimental Genome Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Yusuke Maeda
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan; WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Yoshiko Murakami
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan; WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Yasuhiko Kizuka
- Institute for Glyco-core Research (iGCORE), Gifu University, Gifu, Japan.
| | - Taroh Kinoshita
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan; WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.
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Paprocka J, Hutny M, Hofman J, Tokarska A, Kłaniewska M, Szczałuba K, Stembalska A, Jezela-Stanek A, Śmigiel R. Spectrum of Neurological Symptoms in Glycosylphosphatidylinositol Biosynthesis Defects: Systematic Review. Front Neurol 2022; 12:758899. [PMID: 35058872 PMCID: PMC8763846 DOI: 10.3389/fneur.2021.758899] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Mutations of genes involved in the synthesis of glycosylphosphatidylinositol and glycosylphosphatidylinositol-anchored proteins lead to rare syndromes called glycosylphosphatidylinositol-anchored proteins biosynthesis defects. Alterations of their structure and function in these disorders impair often fundamental processes in cells, resulting in severe clinical image. This study aimed to provide a systematic review of GPIBD cases reports published in English-language literature. Methods: The browsing of open-access databases (PubMed, PubMed Central. and Medline) was conducted, followed by statistical analysis of gathered information concerning neurological symptomatology. The inclusion criteria were: studies on humans, age at onset (<18 y.o.), and report of GPIBD cases with adequate data on the genetic background and symptomatology. Exclusion criteria were: publication type (manuscripts, personal communication, review articles); reports of cases of GPI biosynthesis genes mutations in terms of other disorders; reports of GPIBD cases concentrating on non-neurological symptoms; or articles concentrating solely on the genetic issues of GPI biosynthesis. Risk of bias was assessed using Joanna Brigs Institute Critical Appraisal Checklists. Data synthesis was conducted using STATISTICA 13.3.721.1 (StatSoft Polska Sp. z.o.o.). Used tests were chi-square, Fisher's exact test (for differences in phenotype), and Mann-Whitney U test (for differences in onset of developmental delay). Results: Browsing returned a total of 973 articles which, after ruling out the repetitions and assessing the inclusion and exclusion criteria, led to final inclusion of 77 articles (337 GPIBD cases) in the analysis. The main outcomes were prevalence of neurological symptoms, onset and semiology of seizures and their response to treatment, and onset of developmental delay. Based on this data a synthesis of phenotypical differences between the groups of GPIBD cases and the general GPIBD cases population was made. Discussion: A synthetical analysis of neurological components in clinical image of GPIBD patients was presented. It highlights the main features of these disorders, which might be useful in clinical practice for consideration in differential diagnosis with children presenting with early-onset seizures and developmental delay. The limitation of this review is the scarcity of the specific data in some reports, concerning the semiology and onset of two main features of GPIBD.
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Affiliation(s)
- Justyna Paprocka
- Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Michał Hutny
- Students' Scientific Society, Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Jagoda Hofman
- Students' Scientific Society, Department of Pediatric Neurology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Katowice, Poland
| | - Agnieszka Tokarska
- Department of Pediatrics and Developmental Age Neurology, Upper Silesian Child Health Centre, Katowice, Poland
| | | | - Krzysztof Szczałuba
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | | | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, Warsaw, Poland
| | - Robert Śmigiel
- Department of Pediatrics, Medical University of Wroclaw, Wroclaw, Poland
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Palagano E, Gordon CT, Uva P, Strina D, Dimartino C, Villa A, Amiel J, Guion-Almeida ML, Vendramini-Pittoli S, Kokitsu-Nakata NM, Zechi-Ceide RM, Sobacchi C. A novel intronic variant in PIGB in Acrofrontofacionasal dysostosis type 1 patients expands the spectrum of phenotypes associated with GPI biosynthesis defects. Bone 2021; 153:116152. [PMID: 34400385 DOI: 10.1016/j.bone.2021.116152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 11/15/2022]
Abstract
Acrofrontofacionasal dysostosis type 1 (AFFND1) is an extremely rare disorder characterized by several dysmorphic features, skeletal abnormalities and intellectual disability, and described only in seven patients in the literature. A biallelic variant in the Neuroblastoma Amplified Sequence (NBAS) gene was recently identified in two Indian patients with AFFND1. Here we report genetic investigation of AFFND1 in the originally described Brazilian families and the identification of an extremely rare, recessively-inherited, intronic variant in the Phosphatidylinositol Glycan class B (PIGB) gene NC_000015.10 (NM_004855.4): c.795-19T > G) in the affected individuals. The PIGB gene encodes an enzyme involved in the biosynthesis of the glycosylphosphatidylinositol (GPI) anchor, which is required for the post-translational modification of a large variety of proteins, enabling their correct cellular localization and function. Recessive variants in PIGB have previously been reported in individuals with a neurodevelopmental syndrome having partial overlap with AFFND1. In vitro assays demonstrated that the intronic variant leads to exon skipping, suggesting the Brazilian AFFND1 patients may be null for PIGB, in agreement with their severe clinical phenotype. These data increase the number of pathogenic variants in the PIGB gene, place AFFND1 among GPI deficiencies and extend the spectrum of phenotypes associated with GPI biosynthesis defects.
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Affiliation(s)
- Eleonora Palagano
- CNR-IRGB, Milan Unit, Milan, Italy; IRCCS Humanitas Research Hospital, Rozzano (MI), Italy
| | | | - Paolo Uva
- IRCCS G. Gaslini, Genoa, Italy; Italian Institute of Technology, Genoa, Italy
| | - Dario Strina
- CNR-IRGB, Milan Unit, Milan, Italy; IRCCS Humanitas Research Hospital, Rozzano (MI), Italy
| | | | - Anna Villa
- CNR-IRGB, Milan Unit, Milan, Italy; San Raffaele Telethon Institute for Gene Therapy SR-Tiget, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Jeanne Amiel
- INSERM UMR1163, Institut Imagine, Université de Paris, Paris, France; Service de Génétique, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
| | - Maria L Guion-Almeida
- Department of Clinical Genetics, Hospital for Rehabilitation of Craniofacial Anomalies (HRCA), University of São Paulo, Bauru, Brazil
| | - Siulan Vendramini-Pittoli
- Department of Clinical Genetics, Hospital for Rehabilitation of Craniofacial Anomalies (HRCA), University of São Paulo, Bauru, Brazil
| | - Nancy M Kokitsu-Nakata
- Department of Clinical Genetics, Hospital for Rehabilitation of Craniofacial Anomalies (HRCA), University of São Paulo, Bauru, Brazil
| | - Roseli M Zechi-Ceide
- Department of Clinical Genetics, Hospital for Rehabilitation of Craniofacial Anomalies (HRCA), University of São Paulo, Bauru, Brazil
| | - Cristina Sobacchi
- CNR-IRGB, Milan Unit, Milan, Italy; IRCCS Humanitas Research Hospital, Rozzano (MI), Italy.
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12
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Castle AMR, Salian S, Bassan H, Sofrin-Drucker E, Cusmai R, Herman KC, Heron D, Keren B, Johnstone DL, Mears W, Morlot S, Nguyen TTM, Rock R, Stolerman E, Russo J, Burns WB, Jones JR, Serpieri V, Wallaschek H, Zanni G, Dyment DA, Campeau PM. Expanding the Phenotypic Spectrum of GPI Anchoring Deficiency Due to Biallelic Variants in GPAA1. NEUROLOGY-GENETICS 2021; 7:e631. [PMID: 34703884 PMCID: PMC8532669 DOI: 10.1212/nxg.0000000000000631] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 08/09/2021] [Indexed: 11/15/2022]
Abstract
Background and Objectives To expand the clinical knowledge of GPAA1-related glycosylphosphatidylinositol (GPI) deficiency. Methods An international case series of 7 patients with biallelic GPAA1 variants were identified. Clinical, biochemical, and neuroimaging data were collected for comparison. Where possible, GPI-anchored proteins were assessed using flow cytometry. Results Ten novel variants were identified in 7 patients. Flow cytometry samples of 3 available patients confirmed deficiency of several GPI-anchored proteins on leukocytes. Extensive phenotypic information was available for each patient. The majority experienced developmental delay, seizures, and hypotonia. Neuroimaging revealed cerebellar anomalies in the majority of the patients. Alkaline phosphatase was within the normal range in 5 individuals and low in 1 individual, as has been noted in other transamidase defects. We notably describe individuals either less affected or older than the ones published previously. Discussion Clinical features of the cases reported broaden the spectrum of the known phenotype of GPAA1-related GPI deficiency, while outlining the importance of using functional studies such as flow cytometry to aid in variant classification.
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Affiliation(s)
- Alison M R Castle
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Smrithi Salian
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Haim Bassan
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Efrat Sofrin-Drucker
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Raffaella Cusmai
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Kristin C Herman
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Delphine Heron
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Boris Keren
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Devon L Johnstone
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Wendy Mears
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Susanne Morlot
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Thi Tuyet Mai Nguyen
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Rachel Rock
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Elliot Stolerman
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Julia Russo
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - William Boyce Burns
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Julie R Jones
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Valentina Serpieri
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Hannah Wallaschek
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Ginevra Zanni
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - David A Dyment
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
| | - Philippe M Campeau
- Department of Genetics (A.M.R.C., D.A.D.), Children's Hospital of Eastern Ontario, Ottawa; CHU Sainte Justine Research Centre (S.S., T.T.M.N., P.M.C.), Université de Montréal, Quebec, Canada; Pediatric Neurology & Development Center (H.B.), Shamir (Assaf Harofeh) Medical Center, Zerifin, Tel Aviv University; Pediatric Genetics Clinic (E.S.-D.), Schneider Children's Medical Centre, Petach Tikya, Tel Aviv University, Israel; Unit of Neurophysiology, Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; Section of Medical Genomics (K.C.H.), Medical Investigation of Neurodevelopmental Disorders Institute, University of California, Davis, Sacramento; APHP (B.K.), Département de Génétique, Groupe Hospitalier Pitié Salpêtrière, Paris, France; APHP Sorbonne-Université (D.H.), UF Génétique Médicale, Hôpitaux Pitié-Salpêtrière et Trousseau, Centre de Référence "déficiences intellectuelles de causes rares", Paris, France; Children's Hospital of Eastern Ontario Research Institute (D.L.J., W. M., D.A.D.), Ottawa, Canada; Department of Human Genetics (S.M., H.W.), Hannover Medical School, Germany; Biochemical Diseases (R.R.), BC Children's Hospital, Vancouver, British Columbia, Canada; Greenwood Genetic Center (E.S., J.R., W.B.B., J.R.J.), SC; Department of Molecular Medicine (V.S.), University of Pavia; Neurogenetics Research Center (V.S.), IRCCS Mondino Foundation, Pavia; Unit of Neuromuscular and Neurodegenerative Disorders (G.Z.), Department of Neurosciences, IRCCS, Bambino Gesù Research Hospital, Rome, Italy; and Medical Genetics Division (P.M.C.), Department of Pediatrics, Sainte-Justine University Hospital Centre, Montreal, Quebec, Canada
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13
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Zanni G, D'Abrusco F, Nicita F, Cascioli S, Tosi M, Corrente F, Serpieri V, Ciccone R, Motta M, Vasco G, Carsetti R, Valente EM, Bertini E. PIGQ-Related Glycophosphatidylinositol Deficiency Associated with Nonprogressive Congenital Ataxia. THE CEREBELLUM 2021; 21:525-530. [PMID: 34089469 DOI: 10.1007/s12311-021-01288-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/26/2021] [Indexed: 10/21/2022]
Abstract
The glycophosphatidylinositol (GPI) anchor pathway plays an essential role in posttranslational modification of proteins to facilitate proper membrane anchoring and trafficking to lipid rafts, which is critical for many cell functions, including embryogenesis and neurogenesis. GPI biosynthesis is a multi-step process requiring the activity of over 25 distinct genes, most of them belonging to the phosphatidylinositol glycan (PIG) family and associated with rare neurodevelopmental disorders. PIGQ encodes the phosphatidylinositol glycan class Q protein and is part of the GPI-N-acetylglucosaminyltransferase complex that initiates GPI biosynthesis from phosphatidylinositol (PI) and N-acetylglucosamine (GlcNAc) on the cytoplasmic side of the endoplasmic reticulum (ER). Pathogenic variants in the PIGQ gene have been previously reported in 10 patients with congenital hypotonia, early-infantile epileptic encephalopathy, and premature death occurring in more than half cases. We detected a novel homozygous variant in PIGQ (NM_004204.5: c.1631dupA; p.Tyr544fs*79) by WES trio-analysis of a male patient with a neurodevelopmental disorder characterized by nonprogressive congenital ataxia, intellectual disability, generalized epilepsy, and cerebellar atrophy. Flow cytometry confirmed deficiency of several GPI-anchored proteins on leukocytes (CD14, FLAER). Clinical features of this case broaden the phenotypic spectrum of PIGQ-related GPI deficiency, outlining the importance of glycophosphatidylinositol (GPI) anchor pathway in the pathogenesis of cerebellar ataxia.
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Affiliation(s)
- G Zanni
- Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
| | - F D'Abrusco
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - F Nicita
- Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - S Cascioli
- Unit of Diagnostic Immunology, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - M Tosi
- Child Neurology and Psychiatry Unit, University Hospital of Rome Tor Vergata, Rome, Italy
| | - F Corrente
- Unit of Diagnostic Immunology, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - V Serpieri
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy
| | - R Ciccone
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - M Motta
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - G Vasco
- Unit of Neurorehabilitation, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - R Carsetti
- Unit of Diagnostic Immunology, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - E M Valente
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.,Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy
| | - E Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
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14
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Tanigawa J, Nabatame S, Tominaga K, Nishimura Y, Maegaki Y, Kinosita T, Murakami Y, Ozono K. High-dose pyridoxine treatment for inherited glycosylphosphatidylinositol deficiency. Brain Dev 2021; 43:680-687. [PMID: 33824024 DOI: 10.1016/j.braindev.2021.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/21/2021] [Accepted: 02/28/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE We aimed to assess the efficacy and safety of high-dose pyridoxine treatment for seizures and its effects on development in patients with inherited glycosylphosphatidylinositol deficiencies (IGDs). METHODS In this prospective open-label multicenter pilot study, we enrolled patients diagnosed with IGDs using flow cytometry and/or genetic tests. The patients received oral pyridoxine (20-30 mg/kg/day) for 1 year, in addition to previous treatment. RESULTS All nine enrolled patients (mean age: 66.3 ± 44.3 months) exhibited marked decreases in levels of CD16, a glycosylphosphatidylinositol-anchored protein, on blood granulocytes. The underlying genetic causes of IGDs were PIGO, PIGL, and unknown gene mutations in two, two, and five patients, respectively. Six patients experienced seizures, while all patients presented with developmental delay (mean developmental age: 11.1 ± 8.1 months). Seizure frequencies were markedly (>50%) and drastically (>90%) reduced in three and one patients who experienced seizures, respectively. None of the patients presented with seizure exacerbation. Eight of nine patients exhibited modest improvements in development (P = 0.14). No adverse events were observed except for mild transient diarrhea in one patient. CONCLUSION One year of daily high-dose pyridoxine treatment was effective in the treatment of seizures in more than half of our patients with IGDs and modestly improved development in the majority of them. Moreover, such treatment was reasonably safe. These findings indicate that high-dose pyridoxine treatment may be effective against seizures in patients with IGDs, although further studies are required to confirm our findings. (University Hospital Medical Information Network Clinical Trials Registry [UMIN-CTR] number: UMIN000024185.).
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Affiliation(s)
- Junpei Tanigawa
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shin Nabatame
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Koji Tominaga
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Division of Developmental Neuroscience, United Graduate School of Child Development, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoko Nishimura
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan
| | - Yoshihiro Maegaki
- Division of Child Neurology, Institute of Neurological Sciences, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504, Japan
| | - Taroh Kinosita
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka Suita, Osaka 565-0871, Japan
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases and World Premier International Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka Suita, Osaka 565-0871, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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15
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Packer RA, Wachowiak I, Thomovsky SA, Berg J, Vasquez L, O'Brien DP. Phenotypic characterization of PIGN-associated paroxysmal dyskinesia in Soft-coated wheaten terriers and preliminary response to acetazolamide therapy. Vet J 2021; 269:105606. [PMID: 33593494 DOI: 10.1016/j.tvjl.2021.105606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 10/22/2022]
Abstract
A hereditary movement disorder in Soft coated wheaten terriers (SCWT) has been associated with a mutation in PIGN which encodes an enzyme involved in synthesis of glycosylphosphatidylinositol (GPI). The objective of this study was to describe and classify the clinical phenotype and assess therapeutic response. Twenty-five SCWT and related dogs homozygous for PIGN:c.398C>T with paroxysmal dyskinesia were available for inclusion. Medical records and video recordings of 17 dogs were evaluated in a retrospective case series. Affected dogs had episodes of involuntary, hyperkinetic movements and dystonia. Median age of onset was 2.5 years. A typical episode consisted of rapid, irregular hyperflexion and extension of the pelvic limbs with some degree of truncal dystonia. A mild episode consisted of spontaneous flexion of one pelvic limb while walking which could resemble a lameness. Episodes lasted several minutes to several hours and occurred up to 10 times/day or more. They were not associated with exercise or fasting but were sometimes triggered by excitement or stress. Acetazolamide therapy improved nine of 11 dogs, in seven cases abolishing episodes. Five of 17 dogs treated with other agents had mild improvement with clonazepam (n = 2), levetiracetam (n = 1), or phenobarbital (n = 2). Paroxysmal dyskinesias must be differentiated from seizure disorders since they often respond to different therapies. The SCWT phenotype consisted predominantly of hyperkinesia, and can respond dramatically to acetazolamide. GPI anchors proteins to the cell surface including carbonic anhydrase IV which modulates synaptic pH in the brain. Altered activity of this enzyme may be the target of acetazolamide therapy.
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Affiliation(s)
- R A Packer
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
| | - I Wachowiak
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - S A Thomovsky
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, Indiana, USA
| | - J Berg
- Animal Specialty Center, Yonkers, New York, USA
| | - L Vasquez
- Gulf Coast Veterinary Neurology and Neurosurgery, Houston, Texas, USA
| | - D P O'Brien
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, USA
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16
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Tremblay-Laganière C, Kaiyrzhanov R, Maroofian R, Nguyen TTM, Salayev K, Chilton IT, Chung WK, Madden JA, Phornphutkul C, Agrawal PB, Houlden H, Campeau PM. PIGH deficiency can be associated with severe neurodevelopmental and skeletal manifestations. Clin Genet 2020; 99:313-317. [PMID: 33156547 PMCID: PMC7839508 DOI: 10.1111/cge.13877] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/27/2020] [Accepted: 11/02/2020] [Indexed: 01/10/2023]
Abstract
Phosphatidylinositol Glycan Anchor Biosynthesis class H (PIGH) is an essential player in the glycosylphosphatidylinositol (GPI) synthesis, an anchor for numerous cell membrane-bound proteins. PIGH deficiency is a newly described and rare disorder associated with developmental delay, seizures and behavioral difficulties. Herein, we report three new unrelated families with two different bi-allelic PIGH variants, including one new variant p.(Arg163Trp) which seems associated with a more severe phenotype. The common clinical features in all affected individuals are developmental delay/intellectual disability and hypotonia. Variable clinical features include seizures, autism spectrum disorder, apraxia, severe language delay, dysarthria, feeding difficulties, facial dysmorphisms, microcephaly, strabismus, and musculoskeletal anomalies. The two siblings homozygous for the p.(Arg163Trp) variant have severe symptoms including profound psychomotor retardation, intractable seizures, multiple bone fractures, scoliosis, loss of independent ambulation, and delayed myelination on brain MRI. Serum iron levels were significantly elevated in one individual. All tested individuals with PIGH deficiency had normal alkaline phosphatase and CD16, a GPI-anchored protein (GPI-AP), was found to be decreased by 60% on granulocytes from one individual. This study expands the PIGH deficiency phenotype range toward the severe end of the spectrum with the identification of a novel pathogenic variant.
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Affiliation(s)
| | - Rauan Kaiyrzhanov
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Reza Maroofian
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | | | - Kamran Salayev
- Department of Neurology, Azerbaijan Medical University, Baku, Azerbaijan
| | - Ilana T Chilton
- Departments of Pediatrics, Columbia University Irving Medical Center, New York, NY, USA
| | - Wendy K Chung
- Departments of Pediatrics, Columbia University Irving Medical Center, New York, NY, USA.,Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Jill A Madden
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA
| | - Chanika Phornphutkul
- Departments of Pediatric and Pathology, The Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Pankaj B Agrawal
- Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA, USA.,Division of Newborn Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
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Johnstone DL, Nguyen TTM, Zambonin J, Kernohan KD, St‐Denis A, Baratang NV, Hartley T, Geraghty MT, Richer J, Majewski J, Bareke E, Guerin A, Pendziwiat M, Pena LDM, Braakman HMH, Gripp KW, Edmondson AC, He M, Spillmann RC, Eklund EA, Bayat A, McMillan HJ, Boycott KM, Campeau PM. Early infantile epileptic encephalopathy due to biallelic pathogenic variants in PIGQ: Report of seven new subjects and review of the literature. J Inherit Metab Dis 2020; 43:1321-1332. [PMID: 32588908 PMCID: PMC7689772 DOI: 10.1002/jimd.12278] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 06/21/2020] [Accepted: 06/23/2020] [Indexed: 01/18/2023]
Abstract
We investigated seven children from six families to expand the phenotypic spectrum associated with an early infantile epileptic encephalopathy caused by biallelic pathogenic variants in the phosphatidylinositol glycan anchor biosynthesis class Q (PIGQ) gene. The affected children were all identified by clinical or research exome sequencing. Clinical data, including EEGs and MRIs, was comprehensively reviewed and flow cytometry and transfection experiments were performed to investigate PIGQ function. Pathogenic biallelic PIGQ variants were associated with increased mortality. Epileptic seizures, axial hypotonia, developmental delay and multiple congenital anomalies were consistently observed. Seizure onset occurred between 2.5 months and 7 months of age and varied from treatable seizures to recurrent episodes of status epilepticus. Gastrointestinal issues were common and severe, two affected individuals had midgut volvulus requiring surgical correction. Cardiac anomalies including arrythmias were observed. Flow cytometry using granulocytes and fibroblasts from affected individuals showed reduced expression of glycosylphosphatidylinositol (GPI)-anchored proteins. Transfection of wildtype PIGQ cDNA into patient fibroblasts rescued this phenotype. We expand the phenotypic spectrum of PIGQ-related disease and provide the first functional evidence in human cells of defective GPI-anchoring due to pathogenic variants in PIGQ.
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Affiliation(s)
- Devon L. Johnstone
- Children's Hospital of Eastern Ontario Research InstituteOttawaOntarioCanada
| | | | - Jessica Zambonin
- Children's Hospital of Eastern Ontario Research InstituteOttawaOntarioCanada
- Department of GeneticsChildren's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Kristin D. Kernohan
- Children's Hospital of Eastern Ontario Research InstituteOttawaOntarioCanada
- Division of Metabolics and Newborn Screening, Department of PediatricsChildren's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Anik St‐Denis
- Research Center, CHU Sainte JustineUniversity of MontrealMontrealQuebecCanada
| | - Nissan V. Baratang
- Research Center, CHU Sainte JustineUniversity of MontrealMontrealQuebecCanada
| | - Taila Hartley
- Children's Hospital of Eastern Ontario Research InstituteOttawaOntarioCanada
| | - Michael T. Geraghty
- Division of Metabolics and Newborn Screening, Department of PediatricsChildren's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Julie Richer
- Department of GeneticsChildren's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Jacek Majewski
- Department of Human GeneticsMcGill UniversityMontrealQuebecCanada
- McGill University and Genome Quebec Innovation CentreMontrealQuebecCanada
| | - Eric Bareke
- Department of Human GeneticsMcGill UniversityMontrealQuebecCanada
- McGill University and Genome Quebec Innovation CentreMontrealQuebecCanada
| | - Andrea Guerin
- Division of Medical Genetics, Department of PediatricsQueen's UniversityKingstonOntarioCanada
| | - Manuela Pendziwiat
- Department of NeuropediatricsChristian‐Albrechts‐University of KielKielGermany
| | - Loren D. M. Pena
- Division of Human GeneticsCincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
- Department of PediatricsUniversity of Cincinnati College of MedicineCincinnatiOhioUSA
| | - Hilde M. H. Braakman
- Department of NeurologyAcademic Center for Epileptology Kempenhaeghe & Maastricht University Medical CenterHeezeThe Netherlands
- Department of Pediatric Neurology, Amalia Children's HospitalRadboud University Medical Center & Donders Institute for Brain, Cognition and Behaviour, Radboud UniversityNijmegenThe Netherlands
| | - Karen W. Gripp
- Division of Medical GeneticsA. I. DuPont Hospital for Children/NemoursWilmingtonDelawareUSA
| | - Andrew C. Edmondson
- Department of Pediatrics, Division of Human GeneticsChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | - Miao He
- Department of Pathology and Laboratory MedicineChildren's Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
| | - Rebecca C. Spillmann
- Division of Medical Genetics, Department of PediatricsDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Erik A. Eklund
- Department of Pediatric Neurology, Region Skåne and Clinical SciencesLund University Skåne University Hospital (SUS)LundSweden
| | - Allan Bayat
- Department of Genetics and Personalized MedicineDanish Epilepsy CentreDianalundDenmark
- Institute for Regional Health Services ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Hugh J. McMillan
- Division of Neurology, Department of PediatricsChildren's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Kym M. Boycott
- Children's Hospital of Eastern Ontario Research InstituteOttawaOntarioCanada
- Department of GeneticsChildren's Hospital of Eastern OntarioOttawaOntarioCanada
| | - Philippe M. Campeau
- Research Center, CHU Sainte JustineUniversity of MontrealMontrealQuebecCanada
- Department of Pediatrics, Sainte‐Justine HospitalUniversity of MontrealMontrealQuebecCanada
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18
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Höchsmann B, Murakami Y, Osato M, Knaus A, Kawamoto M, Inoue N, Hirata T, Murata S, Anliker M, Eggermann T, Jäger M, Floettmann R, Höllein A, Murase S, Ueda Y, Nishimura JI, Kanakura Y, Kohara N, Schrezenmeier H, Krawitz PM, Kinoshita T. Complement and inflammasome overactivation mediates paroxysmal nocturnal hemoglobinuria with autoinflammation. J Clin Invest 2020; 129:5123-5136. [PMID: 31430258 DOI: 10.1172/jci123501] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 08/16/2019] [Indexed: 12/16/2022] Open
Abstract
Patients with paroxysmal nocturnal hemoglobinuria (PNH) have a clonal population of blood cells deficient in glycosylphosphatidylinositol-anchored (GPI-anchored) proteins, resulting from a mutation in the X-linked gene PIGA. Here we report on a set of patients in whom PNH results instead from biallelic mutation of PIGT on chromosome 20. These PIGT-PNH patients have clinically typical PNH, but they have in addition prominent autoinflammatory features, including recurrent attacks of aseptic meningitis. In all these patients we find a germ-line point mutation in one PIGT allele, whereas the other PIGT allele is removed by somatic deletion of a 20q region comprising maternally imprinted genes implicated in myeloproliferative syndromes. Unlike in PIGA-PNH cells, GPI is synthesized in PIGT-PNH cells and, since its attachment to proteins is blocked, free GPI is expressed on the cell surface. From studies of patients' leukocytes and of PIGT-KO THP-1 cells we show that, through increased IL-1β secretion, activation of the lectin pathway of complement and generation of C5b-9 complexes, free GPI is the agent of autoinflammation. Eculizumab treatment abrogates not only intravascular hemolysis, but also autoinflammation. Thus, PIGT-PNH differs from PIGA-PNH both in the mechanism of clonal expansion and in clinical manifestations.
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Affiliation(s)
- Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Transfusion Service and University Hospital Ulm, Ulm, Germany
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases and.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Makiko Osato
- Research Institute for Microbial Diseases and.,Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Michi Kawamoto
- Department of Neurology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Norimitsu Inoue
- Department of Tumor Immunology, Osaka International Cancer Institute, Osaka, Japan
| | | | - Shogo Murata
- Research Institute for Microbial Diseases and.,Department of Hematology/Oncology, Wakayama Medical University, Wakayama, Japan
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany
| | - Thomas Eggermann
- Institute for Human Genetics,Medical Faculty, RWTH University Aachen, Aachen, Germany
| | - Marten Jäger
- Department of Medical Genetics, Charite Hospital, University of Berlin, Berlin, Germany
| | - Ricarda Floettmann
- Department of Medical Genetics, Charite Hospital, University of Berlin, Berlin, Germany
| | | | - Sho Murase
- Department of Neurology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yasutaka Ueda
- Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Jun-Ichi Nishimura
- Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Yuzuru Kanakura
- Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Nobuo Kohara
- Department of Neurology, Kobe City Medical Center General Hospital, Kobe, Japan
| | | | - Peter M Krawitz
- Institute for Genomic Statistics and Bioinformatics, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases and.,WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
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19
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Effects of a Sudden Drop in Salinity on Scapharca subcrenata Antioxidant Defenses and Metabolism Determined Using LC-MS Non-targeted Metabolomics. Sci Rep 2020; 10:7324. [PMID: 32355228 PMCID: PMC7192903 DOI: 10.1038/s41598-020-63293-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 03/27/2020] [Indexed: 11/08/2022] Open
Abstract
In this experiment, the effects of a sudden drop in salinity on the antioxidant defense system and related gene expression of the ark shell Scapharca subcrenata were examined. The sudden drop in seawater salinity after a rainstorm was simulated, and subsequently differentially expressed metabolic markers were identified by LC-MS non-targeted metabolomics. When the salinity dropped to 14‰ (S14), the total anti-oxidant content, activity of Na+/K+-ATPase, superoxide dismutase (SOD), and catalase (CAT), content of malondialdehyde, and expression levels of Mn-SOD, CAT, and C-type lectin of S. subcrenata were significantly higher than in groups with salinity of 22‰ (S22) or 30‰ (S30) (P < 0.05). The activity of glutathione peroxidase (GPx), the content of reduced glutathione, and the expression levels of GPx were not significantly different between S14 and S22, but the values in each group were significantly higher than those in S30 (P < 0.05). Using the metabolomics technique, 361, 271, and 264 metabolites with significant differences were identified from S22 vs. S14, S30 vs. S14, and S30 vs. S22, respectively. The drop in salinity was accompanied by up-regulation of phosphatidylcholine (PC) (20:4 (5Z, 8Z, 11Z, 14Z)/P-18: 1 (11Z)), PC (16:0/22: 6 (4Z, 7Z, 10Z, 13Z, 16Z, 19Z)), phosphatidylethanolamine (PE) (18:4 (6Z, 9Z, 12Z, 15Z)/24:1 (15Z)), phosphatidylinositol (PI) (20:1 (11Z)/0:0), phalluside-1, C16 sphinganine, and LacCer (d18:0/14:0) and by significant down-regulation of PI-Cer (d18:1/14:0) and PE (14:0/16:1(9Z). The results of this study illustrate how these nine metabolites can be used as metabolic markers for the response of S. subcrenata to a sudden drop in salinity. They also provide the theoretical groundwork for selection of bottom areas with salinity that is optimal for release and proliferation of S. subcrenata, which is needed to restore the declining populations of this species.
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20
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Analyzing clinical and genetic characteristics of a cohort with multiple congenital anomalies-hypotonia-seizures syndrome (MCAHS). Orphanet J Rare Dis 2020; 15:78. [PMID: 32220244 PMCID: PMC7099766 DOI: 10.1186/s13023-020-01365-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/18/2020] [Indexed: 12/28/2022] Open
Abstract
Objective To summarize and extend the phenotypic characterization of Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome, and to discuss genotype-phenotype correlations. Methods Collecting clinical information of 17 patients with pathogenic variants in PIGN, PIGA, and PIGT. Genetic studies were performed on all patients. Results There were 7 patients with 15 PIGN mutations (one patient carrying 3 mutations), 8 patients with 8 PIGA mutations, and 2 patients with 5 PIGT mutations (one patient carrying 3 mutations). All patients had epilepsy and developmental delay, with 71% of them showed hypotonia. And among these patients’ various seizure types, the focal seizure was the most common one. Eighty-two percent patients showed a significant relationship between seizures and fever. Serum ALP was elevated in one patient with PIGN mutations and in two patients with PIGA mutations. Brain MRI showed enlarged subarachnoid space in 56% of patients. Some other different characteristics had also been found in our patients: First, atypical absence seizures presented in three patients with PIGN mutations; Second, diffuse slow waves mixed with focal or multifocal discharges of interictal EEG in 88% cases with PIGA-deficient; Third, phenotypes of seven out of eight patients with PIGA mutations were difficult to be classified as severe or less severe group; Last, mild neurological symptoms and developmental status rather than severe conditions occurred in one patient with PIGT mutations. Conclusion With epilepsy, developmental delay, and/or hypotonia as common features, the knowledge of MCAHS in terms of phenotype and genotype has been expanded. In cases with PIGN-deficient, we expanded the types of atypical absence seizures, and described one patient with elevated serum ALP. Focal seizures with diffuse slow waves mixed with focal or multifocal discharges on EEG rather than infantile spasms with hypsarrhythmia, which as previously reported were often seen in our patients with PIGA mutations. The classifications of phenotypes caused by PIGA mutations should be more continuous than discrete. The mild phenotype of one patient with PIGT mutations expanded the clinical presentation of MCAHS3.
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21
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Froukh T, Nafie O, Al Hait SAS, Laugwitz L, Sommerfeld J, Sturm M, Baraghiti A, Issa T, Al-Nazer A, Koch PA, Hanselmann J, Kootz B, Bauer P, Al-Ameri W, Abou Jamra R, Alfrook AJ, Hamadallah M, Sofan L, Riess A, Haack TB, Riess O, Buchert R. Genetic basis of neurodevelopmental disorders in 103 Jordanian families. Clin Genet 2020; 97:621-627. [PMID: 32056211 DOI: 10.1111/cge.13720] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/15/2020] [Accepted: 02/05/2020] [Indexed: 10/25/2022]
Abstract
We recruited 103 families from Jordan with neurodevelopmental disorders (NDD) and patterns of inheritance mostly suggestive of autosomal recessive inheritance. In each family, we investigated at least one affected individual using exome sequencing and an in-house diagnostic variant interpretation pipeline including a search for copy number variation. This approach led us to identify the likely molecular defect in established disease genes in 37 families. We could identify 25 pathogenic nonsense and 11 missense variants as well as 3 pathogenic copy number variants and 1 repeat expansion. Notably, 11 of the disease-causal variants occurred de novo. In addition, we prioritized a homozygous frameshift variant in PUS3 in two sisters with intellectual disability. To our knowledge, PUS3 has been postulated only recently as a candidate disease gene for intellectual disability in a single family with three affected siblings. Our findings provide additional evidence to establish loss of PUS3 function as a cause of intellectual disability.
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Affiliation(s)
- Tawfiq Froukh
- Department of Biotechnology and Genetic Engineering, Philadelphia University, Amman, Jordan
| | - Omar Nafie
- Faculty of Medicine, Mutah University, Alkarak, Jordan
| | | | - Lucia Laugwitz
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Julia Sommerfeld
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Marc Sturm
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Aya Baraghiti
- Department of Biotechnology and Genetic Engineering, Philadelphia University, Amman, Jordan
| | - Tala Issa
- Department of Biotechnology and Genetic Engineering, Philadelphia University, Amman, Jordan
| | - Anis Al-Nazer
- Department of Biotechnology and Genetic Engineering, Philadelphia University, Amman, Jordan
| | - Philipp A Koch
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Johannes Hanselmann
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Beate Kootz
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | | | - Rami Abou Jamra
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig, Germany
| | | | | | - Linda Sofan
- Department of Biotechnology and Genetic Engineering, Philadelphia University, Amman, Jordan
| | - Angelika Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Rebecca Buchert
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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22
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Neuhofer CM, Funke R, Wilken B, Knaus A, Altmüller J, Nürnberg P, Li Y, Wollnik B, Burfeind P, Pauli S. A Novel Mutation in PIGA Associated with Multiple Congenital Anomalies-Hypotonia-Seizure Syndrome 2 (MCAHS2) in a Boy with a Combination of Severe Epilepsy and Gingival Hyperplasia. Mol Syndromol 2020; 11:30-37. [PMID: 32256299 DOI: 10.1159/000505797] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/03/2019] [Indexed: 01/25/2023] Open
Abstract
Multiple congenital anomalies-hypotonia-seizures syndrome 2 (MCAHS2) is a rare disease caused by mutations in the X chromosomal PIGA gene. Clinically it is characterized by early-onset epilepsy, hypotonia, dysmorphic features, and variable congenital anomalies. PIGA codes for the phosphatidylinositol glycan-class A protein, which forms a subunit of an enzymatic complex involved in glycophosphatidylinositol (GPI) biosynthesis. We present a new case of MCAHS2 and perform a comprehensive review of the available literature to delineate the phenotypical traits associated with germline PIGA mutations. Furthermore, we provide functional evidence of pathogenicity of the novel missense mutation, c.154C>T; (p.His52Tyr), in the PIGA gene causative of MCAHS2 in our patient. By flow cytometry, we observed reduced expression of GPI-anchored surface proteins in patient granulocytes compared to control samples, proving GPI-biogenesis impairment. The patient's severe epilepsy with several daily attacks was refractory to treatment, but the frequency of seizures reduced temporarily under triple therapy with perampanel, rufinamide and vigabatrin. Our study delineates the known MCAHS2 phenotype and discusses challenges of diagnosis and clinical management in this complex, rare disease. Furthermore, we present a novel mutation with functional evidence of pathogenicity.
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Affiliation(s)
- Christiane M Neuhofer
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Rudolf Funke
- Department of Pediatric Neurology, Klinikum Kassel, Kassel, Germany
| | - Bernd Wilken
- Department of Pediatric Neurology, Klinikum Kassel, Kassel, Germany
| | - Alexej Knaus
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), University of Köln, Köln, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), University of Köln, Köln, Germany
| | - Yun Li
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Peter Burfeind
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Silke Pauli
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
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23
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Müller WE, Schröder HC, Wang X. Inorganic Polyphosphates As Storage for and Generator of Metabolic Energy in the Extracellular Matrix. Chem Rev 2019; 119:12337-12374. [PMID: 31738523 PMCID: PMC6935868 DOI: 10.1021/acs.chemrev.9b00460] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Indexed: 12/14/2022]
Abstract
Inorganic polyphosphates (polyP) consist of linear chains of orthophosphate residues, linked by high-energy phosphoanhydride bonds. They are evolutionarily old biopolymers that are present from bacteria to man. No other molecule concentrates as much (bio)chemically usable energy as polyP. However, the function and metabolism of this long-neglected polymer are scarcely known, especially in higher eukaryotes. In recent years, interest in polyP experienced a renaissance, beginning with the discovery of polyP as phosphate source in bone mineralization. Later, two discoveries placed polyP into the focus of regenerative medicine applications. First, polyP shows morphogenetic activity, i.e., induces cell differentiation via gene induction, and, second, acts as an energy storage and donor in the extracellular space. Studies on acidocalcisomes and mitochondria provided first insights into the enzymatic basis of eukaryotic polyP formation. In addition, a concerted action of alkaline phosphatase and adenylate kinase proved crucial for ADP/ATP generation from polyP. PolyP added extracellularly to mammalian cells resulted in a 3-fold increase of ATP. The importance and mechanism of this phosphotransfer reaction for energy-consuming processes in the extracellular matrix are discussed. This review aims to give a critical overview about the formation and function of this unique polymer that is capable of storing (bio)chemically useful energy.
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Affiliation(s)
- Werner E.G. Müller
- ERC Advanced Investigator
Grant Research
Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - Heinz C. Schröder
- ERC Advanced Investigator
Grant Research
Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator
Grant Research
Group at the Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, Duesbergweg 6, D-55128 Mainz, Germany
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24
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Tian X, Chen Y, Nakamura J. Development of a novel PIG-A gene mutation assay based on a GPI-anchored fluorescent protein sensor. Genes Environ 2019; 41:21. [PMID: 31867084 PMCID: PMC6902599 DOI: 10.1186/s41021-019-0135-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 11/14/2019] [Indexed: 11/19/2022] Open
Abstract
Background Accumulation of somatic mutations caused by both endogenous and exogenous exposures is a high risk for human health, in particular, cancer. Efficient detection of somatic mutations is crucial for risk assessment of different types of exposures. Due to its requirement in the process of attaching glycosylphatidylinositol- (GPI-) anchored proteins to the cell surface, the PIG-A gene located on the X-chromosome is used in both in vivo and in vitro mutation assays. Loss-of-function mutations in PIG-A lead to the elimination of GPI-anchored proteins such that they can no longer be detected on the cell surface by antibodies. Historically, mutation assays based on the PIG-A gene rely on the staining of these cell-surface proteins by antibodies; however, as with any antibody-based assay, there are major limitations, especially in terms of variability and lack of specific antibodies. Results In the current study, we developed a modified PIG-A mutation assay that uses the expression of GPI-anchored fluorescent proteins (henceforth referred to as a GPI-sensor), whereby the presence of fluorescence on the cell membrane is dependent on the expression of wild-type PIG-A. Using our modified PIG-A mutation assay, we have achieved complete separation of wild type cells and spontaneously mutated cells, in which the presence of PIG-A mutations has been confirmed via proaerolysin resistance and gene sequencing. Conclusion This study establishes a novel PIG-A mutation assay using GPI-anchored fluorescent protein expression that eliminates the need for antibody-based staining. This GPI-sensor PIG-A mutation assay should be widely applicable for accurate and efficient testing of genotoxicity for use in many mammalian and vertebrate cells.
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Affiliation(s)
- Xu Tian
- 1Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC USA
| | - Youjun Chen
- 2Department of Neurology, UNC Neuroscience center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina USA
| | - Jun Nakamura
- 1Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC USA.,3Laboratory of Laboratory Animal Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, Izumisano, Osaka, Japan
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25
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Pode-Shakked B, Heimer G, Vilboux T, Marek-Yagel D, Ben-Zeev B, Davids M, Ferreira CR, Philosoph AM, Veber A, Pode-Shakked N, Kenet G, Soudack M, Hoffmann C, Vernitsky H, Safaniev M, Lodzki M, Lahad A, Shouval DS, Levinkopf D, Weiss B, Barg AA, Daka A, Amariglio N, Malicdan MCV, Gahl WA, Anikster Y. Cerebral and portal vein thrombosis, macrocephaly and atypical absence seizures in Glycosylphosphatidyl inositol deficiency due to a PIGM promoter mutation. Mol Genet Metab 2019; 128:151-161. [PMID: 31445883 PMCID: PMC10569059 DOI: 10.1016/j.ymgme.2019.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 10/26/2022]
Abstract
Defects of the glycosylphosphatidylinositol (GPI) biosynthesis pathway constitute an emerging subgroup of congenital disorders of glycosylation with heterogeneous phenotypes. A mutation in the promoter of PIGM, resulting in a syndrome with portal vein thrombosis and persistent absence seizures, was previously described in three patients. We now report four additional patients in two unrelated families, with further clinical, biochemical and molecular delineation of this unique entity. We also describe the first prenatal diagnosis of PIGM deficiency, allowing characterization of the natural history of the disease from birth. The patients described herein expand the phenotypic spectrum of PIGM deficiency to include macrocephaly and infantile-onset cerebrovascular thrombotic events. Finally, we offer insights regarding targeted treatment of this rare disorder with sodium phenylbutyrate.
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Affiliation(s)
- Ben Pode-Shakked
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Gali Heimer
- Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Thierry Vilboux
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; Inova Functional Laboratory, Inova Health System, Fairfax, Virginia, USA
| | - Dina Marek-Yagel
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Wohl Institute for Translational Medicine, Sheba Medical Center, Israel
| | - Bruria Ben-Zeev
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Pediatric Neurology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; The Wohl Institute for Translational Medicine, Sheba Medical Center, Israel
| | - Mariska Davids
- NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA
| | - Carlos R Ferreira
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amit Mary Philosoph
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Alvit Veber
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Naomi Pode-Shakked
- Talpiot Medical Leadership Program, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Gili Kenet
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Israeli National Hemophilia Center and Thrombosis Unit, Sheba Medical Center, Tel-Hashomer, Israel
| | - Michalle Soudack
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Pediatric Imaging Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Chen Hoffmann
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Radiology, Sheba Medical Center, Tel-Hashomer, Israel
| | - Helly Vernitsky
- Hematology Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - Marina Safaniev
- Hematology Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - Maya Lodzki
- Pharmaceutical Services, Sheba Medical Center, Tel-Hashomer, Israel
| | - Avishay Lahad
- NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Dror S Shouval
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Division of Pediatric Gastroenterology, Hepatology and Nutrition, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Dana Levinkopf
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Batia Weiss
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Division of Pediatric Gastroenterology, Hepatology and Nutrition, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Assaf Arie Barg
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Israeli National Hemophilia Center and Thrombosis Unit, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ayman Daka
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Department of Pediatrics, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel
| | - Ninette Amariglio
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Hematology Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - May Christine V Malicdan
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA
| | - William A Gahl
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA; NIH Undiagnosed Diseases Program, NIH, National Human Genome Research Institute, Bethesda, MD, USA.
| | - Yair Anikster
- Metabolic Disease Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel; The Wohl Institute for Translational Medicine, Sheba Medical Center, Israel.
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26
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Murakami Y, Nguyen TTM, Baratang N, Raju PK, Knaus A, Ellard S, Jones G, Lace B, Rousseau J, Ajeawung NF, Kamei A, Minase G, Akasaka M, Araya N, Koshimizu E, van den Ende J, Erger F, Altmüller J, Krumina Z, Strautmanis J, Inashkina I, Stavusis J, El-Gharbawy A, Sebastian J, Puri RD, Kulshrestha S, Verma IC, Maier EM, Haack TB, Israni A, Baptista J, Gunning A, Rosenfeld JA, Liu P, Joosten M, Rocha ME, Hashem MO, Aldhalaan HM, Alkuraya FS, Miyatake S, Matsumoto N, Krawitz PM, Rossignol E, Kinoshita T, Campeau PM. Mutations in PIGB Cause an Inherited GPI Biosynthesis Defect with an Axonal Neuropathy and Metabolic Abnormality in Severe Cases. Am J Hum Genet 2019; 105:384-394. [PMID: 31256876 PMCID: PMC6698938 DOI: 10.1016/j.ajhg.2019.05.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/28/2019] [Indexed: 11/15/2022] Open
Abstract
Proteins anchored to the cell surface via glycosylphosphatidylinositol (GPI) play various key roles in the human body, particularly in development and neurogenesis. As such, many developmental disorders are caused by mutations in genes involved in the GPI biosynthesis and remodeling pathway. We describe ten unrelated families with bi-allelic mutations in PIGB, a gene that encodes phosphatidylinositol glycan class B, which transfers the third mannose to the GPI. Ten different PIGB variants were found in these individuals. Flow cytometric analysis of blood cells and fibroblasts from the affected individuals showed decreased cell surface presence of GPI-anchored proteins. Most of the affected individuals have global developmental and/or intellectual delay, all had seizures, two had polymicrogyria, and four had a peripheral neuropathy. Eight children passed away before four years old. Two of them had a clinical diagnosis of DOORS syndrome (deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures), a condition that includes sensorineural deafness, shortened terminal phalanges with small finger and toenails, intellectual disability, and seizures; this condition overlaps with the severe phenotypes associated with inherited GPI deficiency. Most individuals tested showed elevated alkaline phosphatase, which is a characteristic of the inherited GPI deficiency but not DOORS syndrome. It is notable that two severely affected individuals showed 2-oxoglutaric aciduria, which can be seen in DOORS syndrome, suggesting that severe cases of inherited GPI deficiency and DOORS syndrome might share some molecular pathway disruptions.
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Affiliation(s)
- Yoshiko Murakami
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Thi Tuyet Mai Nguyen
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Nissan Baratang
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Praveen K Raju
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Alexej Knaus
- Insitute for Genomic Statistics and Bioinformatics, University Hospital Bonn, 53127 Bonn, Germany
| | - Sian Ellard
- Royal Devon and Exeter NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Gabriela Jones
- Clinical Genetics Department, Nottingham University Hospitals NHS Trust, Nottingham NGS 1PB, UK
| | - Baiba Lace
- Centre Hospitalier Universitaire de Québec, 2705 Boulevard Laurier, Ville de Québec, QC G1V 4G2, Canada
| | - Justine Rousseau
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Norbert Fonya Ajeawung
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Atsushi Kamei
- Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Iwate 020-8505, Japan
| | - Gaku Minase
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | - Manami Akasaka
- Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Iwate 020-8505, Japan
| | - Nami Araya
- Department of Pediatrics, School of Medicine, Iwate Medical University, Morioka, Iwate 020-8505, Japan
| | - Eriko Koshimizu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | | | - Florian Erger
- Institute of Human Genetics, University Hospital of Cologne, and Center for Molecular Medicine, University of Cologne, 50931 Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Zita Krumina
- Deparment of Biology and Microbiology, Riga Stradinš University, Riga, LV-1029, Latvia
| | | | - Inna Inashkina
- Latvian Biomedical Research and Study Centre, Ratsupites Str. 1 k-1, Riga LV-1067, Latvia
| | - Janis Stavusis
- Latvian Biomedical Research and Study Centre, Ratsupites Str. 1 k-1, Riga LV-1067, Latvia
| | - Areeg El-Gharbawy
- Department of Medical Genetics, Children's Hospital of Pittsburgh of University Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Jessica Sebastian
- Department of Medical Genetics, Children's Hospital of Pittsburgh of University Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
| | - Ratna Dua Puri
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi 110060, India
| | - Samarth Kulshrestha
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi 110060, India
| | - Ishwar C Verma
- Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, New Delhi 110060, India
| | - Esther M Maier
- Department of Inborn Errors of Metabolism, Dr. von Hauner Children's Hospital, 80337 Munich, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72074 Tübingen, Germany; Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany
| | - Anil Israni
- Department of Paediatric Neurology, Leicester Royal Infirmary, Leicester LE1 5WW, UK
| | - Julia Baptista
- Royal Devon and Exeter NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Adam Gunning
- Royal Devon and Exeter NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Marieke Joosten
- Dept of Clinical Genetics, Erasmus MC, PO Box 2040, 3000 CA Rotterdam, the Netherlands
| | | | - Mais O Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Hesham M Aldhalaan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
| | - Satoko Miyatake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan
| | - Peter M Krawitz
- Insitute for Genomic Statistics and Bioinformatics, University Hospital Bonn, 53127 Bonn, Germany
| | - Elsa Rossignol
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada; Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia; Department of Neurosciences, Centre Hospitalier Universitaire Sainte-Justine and University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Taroh Kinoshita
- Yabumoto Department of Intractable Disease Research, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.
| | - Philippe M Campeau
- Centre Hospitalier Universitaire Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada; Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine and University of Montreal, Montreal, QC H3T 1C5, Canada.
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27
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Stability of the transamidase complex catalyzing GPI anchoring of proteins. Biochem Biophys Res Commun 2019; 512:584-590. [DOI: 10.1016/j.bbrc.2019.03.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 03/17/2019] [Indexed: 11/18/2022]
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28
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Fu L, Liu Y, Chen Y, Yuan Y, Wei W. Mutations in the PIGW gene associated with hyperphosphatasia and mental retardation syndrome: a case report. BMC Pediatr 2019; 19:68. [PMID: 30813920 PMCID: PMC6394075 DOI: 10.1186/s12887-019-1440-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 02/20/2019] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Mutations in the PIGV, PIGO, PIGL, PIGY, PGAP2, PGAP3, and PIGW genes have recently been reported to cause hyperphosphatasia accompanied by mental retardation syndrome (HPMRS); the latter is an autosomal-recessive neurological disorder typically characterised by recurrent seizures, intellectual disability, and distinct facial features. Here, we report an extremely rare case of a Chinese boy with compound heterozygous PIGW mutations who suffers from severe pneumonia, mental retardation, and epilepsy. CASE PRESENTATION A 70-day-old boy presented with fever and cough over 20 days in duration at the time of admission. At the age of 6 months, unusual facial features were apparent, and seizures were clinically observed, accompanied by obvious cognitive delay. Next-generation sequencing identified novel PIGW c.178G > A and c.462A > T mutations, confirmed by Sanger sequencing. CONCLUSIONS Mutations in the PIGW gene in infants can cause various symptoms and multiple anomalies. Next-generation sequencing efficiently detects such mutations. The compound PIGW mutations that we describe expand the genotype/phenotype spectrum of HPMRS and may aid in clinical treatment.
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Affiliation(s)
- Li'na Fu
- Department of Pediatrics, Affiliated Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Yan Liu
- Department of Pediatrics, Affiliated Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, 430000, China.
| | - Yu Chen
- Department of Pediatrics, Affiliated Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Yi Yuan
- Department of Pediatrics, Affiliated Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Wuhan, 430000, China
| | - Wei Wei
- Kangso Medical Inspection, Beijing, China
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Abstract
The pathophysiology of the neuromuscular manifestations of hypophosphatasia (HPP) remains unknown. Pyridoxine-sensitive seizures characterize severe forms of infantile HPP. Young children and infants affected with severe forms of HPP, but also adults often present with myopathy characterized by hypotonia or muscle weakness. Chronic pain, of unclear mechanism is also often present. Tissue-non-specific alkaline phosphatase (Alkaline Phosphatase-Liver/Bone/Kidney [ALPL]) is expressed in brain neuronal cell and in muscle cells during development and adulthood. The knockout of the ALPL impacts neuronal functions in animal models. This may occur through metabolic anomalies involving gamma-aminobutyric acid (GABA) and other neurotransmitters via the metabolism of pyridoxal phosphate (vitamin B6) and phosphoethanolamine. In this context, a greater understanding of the neuromuscular pathophysiology of HPP is critical to assess the potential impact of new therapies.
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30
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Müller GA. The release of glycosylphosphatidylinositol-anchored proteins from the cell surface. Arch Biochem Biophys 2018; 656:1-18. [DOI: 10.1016/j.abb.2018.08.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/07/2018] [Accepted: 08/14/2018] [Indexed: 12/15/2022]
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Bellai‐Dussault K, Nguyen TTM, Baratang NV, Jimenez‐Cruz DA, Campeau PM. Clinical variability in inherited glycosylphosphatidylinositol deficiency disorders. Clin Genet 2018; 95:112-121. [DOI: 10.1111/cge.13425] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Kara Bellai‐Dussault
- Medical Genetics DivisionChildren's Hospital of Eastern Ontario Ottawa ON Canada
| | | | - Nissan V. Baratang
- CHU Sainte‐Justine Research CenterUniversity of Montreal Montreal QC Canada
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Foskett GK, Engleman E, Klotz J, Choi O, Tolentino L, Kochhar A, Yang QZ, Stevenson DA. Use of Flow Cytometry for Diagnosis of Epilepsy Associated With Homozygous PIGW Variants. Pediatr Neurol 2018; 85:67-70. [PMID: 30078644 DOI: 10.1016/j.pediatrneurol.2018.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 05/20/2018] [Indexed: 10/14/2022]
Abstract
BACKGROUND Biallelic variants in PIGW have been suggested to cause infantile spasms and hyperphosphatasia. PIGW encodes for a protein involved in the third step of glycosylphosphatidylinositol (GPI) synthesis. GPI anchored proteins are increasingly recognized as important structures for cellular interactions and neuronal development. METHODS Molecular testing of PIGW was performed followed by fluorescence activating cell sorting analysis of granulocytes, lymphocytes, and monocytes, and compared to controls. FINDINGS An infant was homozygous for variants in PIGW (c.199C>G; p.Pro67Ala) with an associated phenotype of infantile spasms, myoclonic seizures, cortical visual impairment, developmental delay, and minor dysmorphic features. Alkaline phosphatase levels ranged from normal to mildly elevated. Flow cytometric studies showed significantly decreased expression of important GPIs, providing functional evidence of pathogenicity. CONCLUSION Our data provide further evidence of a novel autosomal recessive PIGW-related epilepsy disorder. Flow cytometry provided functional evidence of the pathogenicity of homozygous variants of uncertain significance in PIGW, and supports the use of flow cytometry as a functional tool to demonstrate decreased surface expression of GPI anchored proteins in individuals with variants of unknown significance.
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Affiliation(s)
| | - Edgar Engleman
- Stanford Blood Center, Stanford University, Stanford, California
| | - Jenna Klotz
- Department of Neurology, Stanford University, Stanford, California
| | - Okmi Choi
- Stanford Blood Center, Stanford University, Stanford, California
| | - Lorna Tolentino
- Stanford Blood Center, Stanford University, Stanford, California
| | - Aaina Kochhar
- Division of Medical Genetics, Stanford University, Stanford, California; Valley Children's Healthcare, Madera, California
| | - Qian Zhou Yang
- Department of Neurology, Stanford University, Stanford, California
| | - David A Stevenson
- Division of Medical Genetics, Stanford University, Stanford, California.
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33
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Manea E. A step closer in defining glycosylphosphatidylinositol anchored proteins role in health and glycosylation disorders. Mol Genet Metab Rep 2018; 16:67-75. [PMID: 30094187 PMCID: PMC6080220 DOI: 10.1016/j.ymgmr.2018.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 07/21/2018] [Accepted: 07/21/2018] [Indexed: 12/18/2022] Open
Abstract
Glycosylphosphatidylinositol anchored proteins (GPI-APs) represent a class of soluble proteins attached to the external leaflet of the plasma membrane by a post-translation modification, the GPI anchor. The 28 genes currently involved in the synthesis and remodelling of the GPI anchor add to the ever-growing class of congenital glycosylation disorders. Recent advances in next generation sequencing technology have led to the discovery of Mabry disease and CHIME syndrome genetic aetiology. Moreover, with each described mutation known phenotypes expand and new ones emerge without clear genotype-phenotype correlation. A protein database search was made for human GPI-APs with defined pathology to help building-up a physio-pathological mechanism from a clinical perspective. GPI-APs function in vitamin-B6 and folate transport, nucleotide metabolism and lipid homeostasis. Defining GPI-APs role in disease bears significant clinical implications.
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34
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Kinoshita T. Congenital Defects in the Expression of the Glycosylphosphatidylinositol-Anchored Complement Regulatory Proteins CD59 and Decay-Accelerating Factor. Semin Hematol 2018; 55:136-140. [DOI: 10.1053/j.seminhematol.2018.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/10/2018] [Indexed: 12/29/2022]
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Ceroni JR, Yamamoto GL, Honjo RS, Kim CA, Passos-Bueno MR, Bertola DR. Large deletion in PIGL: a common mutational mechanism in CHIME syndrome? Genet Mol Biol 2018; 41:85-91. [PMID: 29473937 PMCID: PMC5901507 DOI: 10.1590/1678-4685-gmb-2017-0172] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 10/17/2017] [Indexed: 11/26/2022] Open
Abstract
CHIME syndrome is an extremely rare autosomal recessive multisystemic disorder
caused by mutations in PIGL. PIGL is an endoplasmic reticulum
localized enzyme that catalyzes the second step of glycosylphosphatidylinositol
(GPI) biosynthesis, which plays a role in the anchorage of cell-surface proteins
including receptors, enzymes, and adhesion molecules. Germline mutations in
other members of GPI and Post GPI Attachment to Proteins (PGAP) family genes
have been described and constitute a group of diseases within the congenital
disorders of glycosylation. Patients in this group often present alkaline
phosphatase serum levels abnormalities and neurological symptoms. We report a
CHIME syndrome patient who harbors a missense mutation c.500T > C
(p.Leu167Pro) and a large deletion involving the 5’ untranslated region and part
of exon 1 of PIGL. In CHIME syndrome, a recurrent missense
mutation c.500T > C (p.Leu167Pro) is found in the majority of patients,
associated with a null mutation in the other allele, including an
overrepresentation of large deletions. The latter are not detected by the
standard analysis in sequencing techniques, including next-generation
sequencing. Thus, in individuals with a clinical diagnosis of CHIME syndrome in
which only one mutation is found, an active search for a large deletion should
be sought.
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Affiliation(s)
- José Rm Ceroni
- Genetics Unit, Instituto da Criança do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Guilherme L Yamamoto
- Genetics Unit, Instituto da Criança do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.,Centro de Pesquisa sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Rachel S Honjo
- Genetics Unit, Instituto da Criança do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Chong A Kim
- Genetics Unit, Instituto da Criança do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Maria R Passos-Bueno
- Centro de Pesquisa sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Débora R Bertola
- Genetics Unit, Instituto da Criança do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.,Centro de Pesquisa sobre o Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
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Altassan R, Fox S, Poulin C, Buhas D. Hyperphosphatasia with mental retardation syndrome, expanded phenotype of PIGL related disorders. Mol Genet Metab Rep 2018; 15:46-49. [PMID: 30023290 PMCID: PMC6047459 DOI: 10.1016/j.ymgmr.2018.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 12/20/2022] Open
Abstract
Hypomorphic mutations in six different genes involved in the glycosylphosphatidylinositol (GPI) biogenesis pathway are linked to Mabry syndrome (hyperphosphatasia with mental retardation syndrome, HPMRS). This report on the third affected family with a HPMRS phenotype caused by mutations in PIGL, confirming the seventh GPI biogenesis gene linked to HPMRS. Two siblings presented with the main features of HPMRS; developmental delay, cognitive impairment, seizure disorder, skeletal deformities, and high alkaline phosphatase. We identified two heterozygous mutations in the PIGL gene (P.Trp20Ter and p.Arg88Cys). PIGL mutations have been linked to another distinctive neuroectodermal disorder: CHIME syndrome. The clinical picture of our patients expands the spectrum of PIGL-related phenotypes.
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Key Words
- ALP, alkaline phosphatase
- CHIME syndrome
- CHIME, ocular colobomas, heart defect, ichthyosis, mental retardation, and abnormal ears or epilepsy
- CSS, Coffin-Siris syndrome
- GPI biogenesis
- GPI, glycosylphosphatidylinositol
- HPMRS, hyperphosphatasia with mental retardation syndrome
- Hyperphosphatasia mental retardation syndrome (HPMRS)
- Mabry syndrome
- PIGL gene
- PIGL, phosphatidylinositol glycan anchor biosynthesis class L
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Affiliation(s)
- Ruqaiah Altassan
- Department of Medical Genetics, Montreal Children's Hospital, McGill University Health Center, Montreal, Quebec, Canada
| | - Stephanie Fox
- Department of Medical Genetics, Montreal Children's Hospital, McGill University Health Center, Montreal, Quebec, Canada
| | - Chantal Poulin
- Department of Pediatric, Division of Neurology, Montreal Children's Hospital, McGill University Health Center, Montreal, Quebec, Canada
| | - Daniela Buhas
- Department of Medical Genetics, Montreal Children's Hospital, McGill University Health Center, Montreal, Quebec, Canada.,Department of Human Genetics, McGill University, Montreal, Quebec, Canada
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37
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Knaus A, Pantel JT, Pendziwiat M, Hajjir N, Zhao M, Hsieh TC, Schubach M, Gurovich Y, Fleischer N, Jäger M, Köhler S, Muhle H, Korff C, Møller RS, Bayat A, Calvas P, Chassaing N, Warren H, Skinner S, Louie R, Evers C, Bohn M, Christen HJ, van den Born M, Obersztyn E, Charzewska A, Endziniene M, Kortüm F, Brown N, Robinson PN, Schelhaas HJ, Weber Y, Helbig I, Mundlos S, Horn D, Krawitz PM. Characterization of glycosylphosphatidylinositol biosynthesis defects by clinical features, flow cytometry, and automated image analysis. Genome Med 2018; 10:3. [PMID: 29310717 PMCID: PMC5759841 DOI: 10.1186/s13073-017-0510-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 12/11/2017] [Indexed: 12/17/2022] Open
Abstract
Background Glycosylphosphatidylinositol biosynthesis defects (GPIBDs) cause a group of phenotypically overlapping recessive syndromes with intellectual disability, for which pathogenic mutations have been described in 16 genes of the corresponding molecular pathway. An elevated serum activity of alkaline phosphatase (AP), a GPI-linked enzyme, has been used to assign GPIBDs to the phenotypic series of hyperphosphatasia with mental retardation syndrome (HPMRS) and to distinguish them from another subset of GPIBDs, termed multiple congenital anomalies hypotonia seizures syndrome (MCAHS). However, the increasing number of individuals with a GPIBD shows that hyperphosphatasia is a variable feature that is not ideal for a clinical classification. Methods We studied the discriminatory power of multiple GPI-linked substrates that were assessed by flow cytometry in blood cells and fibroblasts of 39 and 14 individuals with a GPIBD, respectively. On the phenotypic level, we evaluated the frequency of occurrence of clinical symptoms and analyzed the performance of computer-assisted image analysis of the facial gestalt in 91 individuals. Results We found that certain malformations such as Morbus Hirschsprung and diaphragmatic defects are more likely to be associated with particular gene defects (PIGV, PGAP3, PIGN). However, especially at the severe end of the clinical spectrum of HPMRS, there is a high phenotypic overlap with MCAHS. Elevation of AP has also been documented in some of the individuals with MCAHS, namely those with PIGA mutations. Although the impairment of GPI-linked substrates is supposed to play the key role in the pathophysiology of GPIBDs, we could not observe gene-specific profiles for flow cytometric markers or a correlation between their cell surface levels and the severity of the phenotype. In contrast, it was facial recognition software that achieved the highest accuracy in predicting the disease-causing gene in a GPIBD. Conclusions Due to the overlapping clinical spectrum of both HPMRS and MCAHS in the majority of affected individuals, the elevation of AP and the reduced surface levels of GPI-linked markers in both groups, a common classification as GPIBDs is recommended. The effectiveness of computer-assisted gestalt analysis for the correct gene inference in a GPIBD and probably beyond is remarkable and illustrates how the information contained in human faces is pivotal in the delineation of genetic entities. Electronic supplementary material The online version of this article (doi:10.1186/s13073-017-0510-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alexej Knaus
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany.,Berlin-Brandenburg School for Regenerative Therapies, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany
| | - Jean Tori Pantel
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Manuela Pendziwiat
- Department of Neuropediatrics, University Medical Center Schleswig Holstein, 24105, Kiel, Germany
| | - Nurulhuda Hajjir
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Max Zhao
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Tzung-Chien Hsieh
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany
| | - Max Schubach
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), 10178, Berlin, Germany
| | | | | | - Marten Jäger
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), 10178, Berlin, Germany
| | - Sebastian Köhler
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany
| | - Hiltrud Muhle
- Department of Neuropediatrics, University Medical Center Schleswig Holstein, 24105, Kiel, Germany
| | - Christian Korff
- Unité de Neuropédiatrie, Université de Genève, CH-1211, Genève, Switzerland
| | - Rikke S Møller
- Danish Epilepsy Centre, DK-4293, Dianalund, Denmark.,Institute for Regional Health Services Research, University of Southern Denmark, DK-5000, Odense, Denmark
| | - Allan Bayat
- Department of Pediatrics, University Hospital of Hvidovre, 2650, Hvicovre, Denmark
| | - Patrick Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU, 31059, Toulouse, France
| | - Nicolas Chassaing
- Service de Génétique Médicale, Hôpital Purpan, CHU, 31059, Toulouse, France
| | | | | | | | - Christina Evers
- Genetische Poliklinik, Universitätsklinik Heidelberg, 69120, Heidelberg, Germany
| | - Marc Bohn
- St. Bernward Krankenhaus, 31134, Hildesheim, Germany
| | - Hans-Jürgen Christen
- Kinderkrankenhaus auf der Bult, Hannoversche Kinderheilanstalt, 30173, Hannover, Germany
| | | | - Ewa Obersztyn
- Institute of Mother and Child Department of Molecular Genetics, 01-211, Warsaw, Poland
| | - Agnieszka Charzewska
- Institute of Mother and Child Department of Molecular Genetics, 01-211, Warsaw, Poland
| | - Milda Endziniene
- Neurology Department, Lithuanian University of Health Sciences, 50009, Kaunas, Lithuania
| | - Fanny Kortüm
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Natasha Brown
- Victorian Clinical Genetics Services, Royal Children's Hospital, MCRI, Parkville, Australia.,Department of Clinical Genetics, Austin Health, Heidelberg, Australia
| | - Peter N Robinson
- The Jackson Laboratory for Genomic Medicine, 06032, Farmington, USA
| | - Helenius J Schelhaas
- Departement of Neurology, Academic Center for Epileptology, 5590, Heeze, The Netherlands
| | - Yvonne Weber
- Department of Neurology and Epileptology and Hertie Institute for Clinical Brain Research, University Tübingen, 72076, Tübingen, Germany
| | - Ingo Helbig
- Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany.,Pediatric Neurology, Children's Hospital of Philadelphia, 3401, Philadelphia, USA
| | - Stefan Mundlos
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.,Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany
| | - Denise Horn
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany.
| | - Peter M Krawitz
- Institut für Medizinische Genetik und Humangenetik, Charité Universitätsmedizin Berlin, 13353, Berlin, Germany. .,Max Planck Institute for Molecular Genetics, 14195, Berlin, Germany. .,Institute for Genomic Statistics and Bioinformatics, University Hospital Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53127, Bonn, Germany.
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38
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Mutations in GPAA1, Encoding a GPI Transamidase Complex Protein, Cause Developmental Delay, Epilepsy, Cerebellar Atrophy, and Osteopenia. Am J Hum Genet 2017; 101:856-865. [PMID: 29100095 DOI: 10.1016/j.ajhg.2017.09.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 09/21/2017] [Indexed: 11/21/2022] Open
Abstract
Approximately one in every 200 mammalian proteins is anchored to the cell membrane through a glycosylphosphatidylinositol (GPI) anchor. These proteins play important roles notably in neurological development and function. To date, more than 20 genes have been implicated in the biogenesis of GPI-anchored proteins. GPAA1 (glycosylphosphatidylinositol anchor attachment 1) is an essential component of the transamidase complex along with PIGK, PIGS, PIGT, and PIGU (phosphatidylinositol-glycan biosynthesis classes K, S, T, and U, respectively). This complex orchestrates the attachment of the GPI anchor to the C terminus of precursor proteins in the endoplasmic reticulum. Here, we report bi-allelic mutations in GPAA1 in ten individuals from five families. Using whole-exome sequencing, we identified two frameshift mutations (c.981_993del [p.Gln327Hisfs∗102] and c.920delG [p.Gly307Alafs∗11]), one intronic splicing mutation (c.1164+5C>T), and six missense mutations (c.152C>T [p.Ser51Leu], c.160_161delinsAA [p.Ala54Asn], c.527G>C [p.Trp176Ser], c.869T>C [p.Leu290Pro], c.872T>C [p.Leu291Pro], and c.1165G>C [p.Ala389Pro]). Most individuals presented with global developmental delay, hypotonia, early-onset seizures, cerebellar atrophy, and osteopenia. The splicing mutation was found to decrease GPAA1 mRNA. Moreover, flow-cytometry analysis of five available individual samples showed that several GPI-anchored proteins had decreased cell-surface abundance in leukocytes (FLAER, CD16, and CD59) or fibroblasts (CD73 and CD109). Transduction of fibroblasts with a lentivirus encoding the wild-type protein partially rescued the deficiency of GPI-anchored proteins. These findings highlight the role of the transamidase complex in the development and function of the cerebellum and the skeletal system.
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39
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Zhao JJ, Halvardson J, Knaus A, Georgii-Hemming P, Baeck P, Krawitz PM, Thuresson AC, Feuk L. Reduced cell surface levels of GPI-linked markers in a new case with PIGG loss of function. Hum Mutat 2017; 38:1394-1401. [PMID: 28581210 PMCID: PMC6180480 DOI: 10.1002/humu.23268] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 05/03/2017] [Accepted: 05/21/2017] [Indexed: 12/28/2022]
Abstract
Glycosylphosphatidylinositol (GPI) is a glycolipid that tethers more than 150 different proteins to the cell surface. Aberrations in biosynthesis of GPI anchors cause congenital disorders of glycosylation with clinical features including intellectual disability (ID), seizures, and facial dysmorphism. Here, we present two siblings with ID, cerebellar hypoplasia, cerebellar ataxia, early‐onset seizures, and minor facial dysmorphology. Using exome sequencing, we identified a homozygous nonsense variant (NM_001127178.1:c.1640G>A, p.Trp547*) in the gene Phosphatidylinositol Glycan Anchor Biosynthesis, Class G (PIGG) in both the patients. Variants in several other GPI anchor synthesis genes lead to a reduced expression of GPI‐anchored proteins (GPI‐APs) that can be measured by flow cytometry. No significant differences in GPI‐APs could be detected in patient granulocytes, consistent with recent findings. However, fibroblasts showed a reduced global level of GPI anchors and of specific GPI‐linked markers. These findings suggest that fibroblasts might be more sensitive to pathogenic variants in GPI synthesis pathway and are well suited to screen for GPI‐anchor deficiencies. Based on genetic and functional evidence, we confirm that pathogenic variants in PIGG cause an ID syndrome, and we find that loss of function of PIGG is associated with GPI deficiency.
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Affiliation(s)
- Jin James Zhao
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Jonatan Halvardson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Alexej Knaus
- Institute for Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany.,Berlin-Brandenburg School for Regenerative Therapies (BSRT), Charitè Universitätsmedizin Berlin, Berlin, Germany
| | - Patrik Georgii-Hemming
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institute, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Peter Baeck
- Childrens Clinic, County Hospital, Kalmar, Sweden
| | - Peter M Krawitz
- Institute for Medical Genetics and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Ann-Charlotte Thuresson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Clinical Genetics, Uppsala University Hospital, Uppsala, Sweden
| | - Lars Feuk
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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Abstract
Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal haematopoietic stem cell (HSC) disease that presents with haemolytic anaemia, thrombosis and smooth muscle dystonias, as well as bone marrow failure in some cases. PNH is caused by somatic mutations in PIGA (which encodes phosphatidylinositol N-acetylglucosaminyltransferase subunit A) in one or more HSC clones. The gene product of PIGA is required for the biosynthesis of glycosylphosphatidylinositol (GPI) anchors; thus, PIGA mutations lead to a deficiency of GPI-anchored proteins, such as complement decay-accelerating factor (also known as CD55) and CD59 glycoprotein (CD59), which are both complement inhibitors. Clinical manifestations of PNH occur when a HSC clone carrying somatic PIGA mutations acquires a growth advantage and differentiates, generating mature blood cells that are deficient of GPI-anchored proteins. The loss of CD55 and CD59 renders PNH erythrocytes susceptible to intravascular haemolysis, which can lead to thrombosis and to much of the morbidity and mortality of PNH. The accumulation of anaphylatoxins (such as C5a) from complement activation might also have a role. The natural history of PNH is highly variable, ranging from quiescent to life-threatening. Therapeutic strategies include terminal complement blockade and bone marrow transplantation. Eculizumab, a monoclonal antibody complement inhibitor, is highly effective and the only licensed therapy for PNH.
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Affiliation(s)
- Anita Hill
- Department of Haematology, St. James' University Hospital, Leeds, UK
| | - Amy E DeZern
- Division of Hematology, Johns Hopkins Department of Medicine, Johns Hopkins University, Ross Research Building, Room 1025, 720 Rutland Avenue, Baltimore, Maryland 21205, USA
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA
| | - Taroh Kinoshita
- Laboratory of Immunoglycobiology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
- Department of Immunoregulation Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Robert A Brodsky
- Division of Hematology, Johns Hopkins Department of Medicine, Johns Hopkins University, Ross Research Building, Room 1025, 720 Rutland Avenue, Baltimore, Maryland 21205, USA
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA
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41
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Tanigawa J, Mimatsu H, Mizuno S, Okamoto N, Fukushi D, Tominaga K, Kidokoro H, Muramatsu Y, Nishi E, Nakamura S, Motooka D, Nomura N, Hayasaka K, Niihori T, Aoki Y, Nabatame S, Hayakawa M, Natsume J, Ozono K, Kinoshita T, Wakamatsu N, Murakami Y. Phenotype-genotype correlations of PIGO deficiency with variable phenotypes from infantile lethality to mild learning difficulties. Hum Mutat 2017; 38:805-815. [PMID: 28337824 DOI: 10.1002/humu.23219] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/15/2017] [Accepted: 03/19/2017] [Indexed: 01/23/2023]
Abstract
Inherited GPI (glycosylphosphatidylinositol) deficiencies (IGDs), a recently defined group of diseases, show a broad spectrum of symptoms. Hyperphosphatasia mental retardation syndrome, also known as Mabry syndrome, is a type of IGDs. There are at least 26 genes involved in the biosynthesis and transport of GPI-anchored proteins; however, IGDs constitute a rare group of diseases, and correlations between the spectrum of symptoms and affected genes or the type of mutations have not been shown. Here, we report four newly identified and five previously described Japanese families with PIGO (phosphatidylinositol glycan anchor biosynthesis class O) deficiency. We show how the clinical severity of IGDs correlates with flow cytometric analysis of blood, functional analysis using a PIGO-deficient cell line, and the degree of hyperphosphatasia. The flow cytometric analysis and hyperphosphatasia are useful for IGD diagnosis, but the expression level of GPI-anchored proteins and the degree of hyperphosphatasia do not correlate, although functional studies do, with clinical severity. Compared with PIGA (phosphatidylinositol glycan anchor biosynthesis class A) deficiency, PIGO deficiency shows characteristic features, such as Hirschsprung disease, brachytelephalangy, and hyperphosphatasia. This report shows the precise spectrum of symptoms according to the severity of mutations and compares symptoms between different types of IGD.
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Affiliation(s)
- Junpei Tanigawa
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Haruka Mimatsu
- Division of Neonatology Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Seiji Mizuno
- Department of Pediatrics, Central Hospital, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Osaka, Japan
| | - Daisuke Fukushi
- Department of Genetics, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Koji Tominaga
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.,Department of Child Development, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Hiroyuki Kidokoro
- Department of Pediatrics, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Yukako Muramatsu
- Division of Neonatology Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Eriko Nishi
- Department of Pediatrics, Central Hospital, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Shota Nakamura
- Department of Infection Metagenomics, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Daisuke Motooka
- Department of Infection Metagenomics, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Noriko Nomura
- Department of Genetics, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Kiyoshi Hayasaka
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Yamagata, Japan
| | - Tetsuya Niihori
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai, Miyagi, Japan
| | - Shin Nabatame
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Masahiro Hayakawa
- Division of Neonatology Center for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Jun Natsume
- Department of Developmental Disability Medicine and Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Taroh Kinoshita
- Department of Immunoregulation, Research Institute for Microbial Diseases Osaka University, Suita, Osaka, Japan
| | - Nobuaki Wakamatsu
- Department of Genetics, Institute for Developmental Research, Aichi Human Service Center, Kasugai, Aichi, Japan
| | - Yoshiko Murakami
- Department of Immunoregulation, Research Institute for Microbial Diseases Osaka University, Suita, Osaka, Japan
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42
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Xue J, Li H, Zhang Y, Yang Z. Clinical and genetic analysis of two Chinese infants with Mabry syndrome. Brain Dev 2016; 38:807-18. [PMID: 27177984 DOI: 10.1016/j.braindev.2016.04.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 04/05/2016] [Accepted: 04/12/2016] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Hyperphosphatasia mental retardation syndrome (Mabry syndrome) is an autosomal recessive disorder. We aim to analyze two Chinese patients diagnosed as Mabry syndrome. METHODS The clinical manifestations, diagnosis and treatment were observed in two patients. Genetic analysis including PIGV and PIGO was examined. RESULTS Two patients were diagnosed as Mabry syndrome clinically and genetically. Developmental delay, hyperphosphatasia and seizures were presented in both of them. Typical facial dysmorphism and hypoplastic terminal phalanges were only found in one. Some novel presentations including congenital laryngeal cartilage softening, inguinal hernia, broken palmprint, optic atrophy and skeleton dysplasia such as carpal age delay and metaphysis anomalies were observed in two patients. Molecular genetic analysis revealed compound heterozygous mutations of PIGV or PIGO in our patients, including c.615C>G (p.Asn205Lys) and c.854A>G (p.Tyr285Cys) of PIGV in patient 1, and c.458T>C (p.Phe153Ser) and c.1355_1356del (p.Ala452Glyfs*52) of PIGO in patient 2. Additionally, a heterozygous c.2926G>A (Asp976Asn) of PCDH19 was identified in patient with PIGV mutations, the causative gene of Epilepsy and mental retardation limited to females (EFMR). CONCLUSION To our best knowledge, this is the first time to report Chinese patients diagnosed as Mabry syndrome. For the PCDH19 mutation in our patient carrying PIGV mutations, due to lacking characteristics of EFMR and the ambiguity results in pathogenicity analysis, we were not sure how much pathogenic role PCDH19 mutation shared with PIGV mutations in this disease. The novel mutations of PIGV and PIGO, and novel clinical manifestations reported here might expand the genotype and phenotype spectrum of Mabry syndrome.
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Affiliation(s)
- Jiao Xue
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Hui Li
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Yuehua Zhang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China.
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43
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Hogrebe M, Murakami Y, Wild M, Ahlmann M, Biskup S, Hörtnagel K, Grüneberg M, Reunert J, Linden T, Kinoshita T, Marquardt T. A novel mutation in PIGW causes glycosylphosphatidylinositol deficiency without hyperphosphatasia. Am J Med Genet A 2016; 170:3319-3322. [PMID: 27626616 DOI: 10.1002/ajmg.a.37950] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 08/15/2016] [Indexed: 01/02/2023]
Abstract
In recent years, many mutations have been identified that affect the biosynthesis of the glycosylphosphatidylinositol anchor, a biomolecule that attaches surface molecules to cell membranes. Here, we present two second-degree cousins with unexplained patterns of seizures. Next-generation sequencing identified the homozygous c.460A>G; p.(R154G) PIGW mutation in both patients. Transfection of the mutated allele into Pigw-defective CHO cells indicated impaired enzymatic activity of the mutated PIGW product. Alkaline phosphatase did not exceed the upper normal range and flow cytometry of CD16, CD24, and CD66c on granulocytes showed subtle changes of the cellular expression of the glycosylphosphatidylinositol-anchored proteins. The patients' phenotype is therefore remarkably different from the phenotype of the only other described individual with PIGW mutations. Patients might therefore be missed when relying on traditional flow cytometry of glycosylphosphatidylinositol-anchored proteins only and we suggest that glycosylphosphatidylinositol-deficiency should be considered even with patients not showing the typical clinical phenotypes. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Max Hogrebe
- Universitätsklinikum Münster, Klinik für Kinder- und Jugendmedizin, Albert-Schweitzer-Campus 1, Münster, Germany
| | - Yoshiko Murakami
- Department of Immunoregulation, Research Institute for Microbial Diseases and Laboratory of Immunoglycobiology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Martin Wild
- Max Planck Institute for Molecular Biomedicine, Muenster, Germany
| | - Martina Ahlmann
- Universitätsklinikum Münster, Pädiatrische Hämatologie und Onkologie, Albert-Schweitzer-Campus 1, Münster, Germany
| | | | | | - Marianne Grüneberg
- Universitätsklinikum Münster, Klinik für Kinder- und Jugendmedizin, Albert-Schweitzer-Campus 1, Münster, Germany
| | - Janine Reunert
- Universitätsklinikum Münster, Klinik für Kinder- und Jugendmedizin, Albert-Schweitzer-Campus 1, Münster, Germany
| | - Tobias Linden
- Kinderklinik Oldenburg, Klinik für Neuropädiatrie und angeborene Stoffwechselerkrankungen, Oldenburg, Germany
| | - Taroh Kinoshita
- Department of Immunoregulation, Research Institute for Microbial Diseases and Laboratory of Immunoglycobiology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Thorsten Marquardt
- Universitätsklinikum Münster, Klinik für Kinder- und Jugendmedizin, Albert-Schweitzer-Campus 1, Münster, Germany
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The Fibrinolytic System in the Interstitial Space. Protein Sci 2016. [DOI: 10.1201/9781315374307-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kettwig M, Elpeleg O, Wegener E, Dreha-Kulaczewski S, Henneke M, Gärtner J, Huppke P. Compound heterozygous variants in PGAP1 causing severe psychomotor retardation, brain atrophy, recurrent apneas and delayed myelination: a case report and literature review. BMC Neurol 2016; 16:74. [PMID: 27206732 PMCID: PMC4875637 DOI: 10.1186/s12883-016-0602-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 05/12/2016] [Indexed: 11/25/2022] Open
Abstract
Background Mutations in proteins involved in the glycosylphosphatidylinositol anchor biosynthesis and remodeling pathway are associated with autosomal recessive forms of intellectual disability. Recently mutations in the PGAP1 gene that codes for PGAP1, a protein localized in the endoplasmic reticulum responsible for the first step of the remodeling of glycosylphosphatidylinositol was linked to a disorder characterized by psychomotor retardation and facial dysmorphism. Whole exome sequencing (WES) was performed in siblings with severely delayed myelination and psychomotor retardation. Mutations in PGAP1 were confirmed by Sanger sequencing and RNA analysis. A literature search was performed to describe the emerging phenotype of PGAP1 related disease. Case presentation WES resulted in the detection of two novel compound heterozygous mutations in PGAP1, one base pair insertion leading to a frame shift c.334_335InsA (p.A112fs) and a splice site mutation leading to exon skipping c.G1173C (p.L391L). A symptom not described in PGAP1 related disorder before but prominent in the siblings were recurrent apnea especially during sleep that persisted at least until age 2 years. Sequential cerebral MRI at age one and two year(s) respectively revealed frontal accentuated brain atrophy and significantly delayed myelination. Conclusion We report siblings with two novel mutations in PGAP1. Other that the common symptoms related to PGAP1 mutations including non-progressive psychomotor retardation, neonatal feeding problems, microcephaly and brain atrophy these patients displayed severely delayed myelination and recurrent apneas thereby widing the clinical spectrum associated with such mutations. Electronic supplementary material The online version of this article (doi:10.1186/s12883-016-0602-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Matthias Kettwig
- Department of Pediatrics and Pediatric Neurology, University Medical Center, Georg August University, 37075, Göttingen, Germany.
| | - Orly Elpeleg
- Monique and Jacques Roboh Department of Genetic Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Eike Wegener
- Department of Pediatrics and Pediatric Neurology, University Medical Center, Georg August University, 37075, Göttingen, Germany
| | - Steffi Dreha-Kulaczewski
- Department of Pediatrics and Pediatric Neurology, University Medical Center, Georg August University, 37075, Göttingen, Germany
| | - Marco Henneke
- Department of Pediatrics and Pediatric Neurology, University Medical Center, Georg August University, 37075, Göttingen, Germany
| | - Jutta Gärtner
- Department of Pediatrics and Pediatric Neurology, University Medical Center, Georg August University, 37075, Göttingen, Germany
| | - Peter Huppke
- Department of Pediatrics and Pediatric Neurology, University Medical Center, Georg August University, 37075, Göttingen, Germany
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Abstract
Hypophosphatasia (HPP) is due to deficient activity of the tissue-nonspecific isoenzyme of alkaline phosphatase (TNAP). This enzyme cleaves extracellular substrates inorganic pyrophosphates (PPi), pyridoxal-5'-phosphate (PLP), phosphoethanolamine (PEA) and nucleotides, and probably other substrates not yet identified. During the last 15 years the role of TNAP in mineralization, and to a less degree in brain, has been investigated, providing hypotheses and explanations for both bone and neuronal HPP phenotypes. ALPL, the gene encoding TNAP, is subject to many mutations, mostly missense mutations. A few number of mutations are recurrently found and may be quite frequent in particular populations. This reflects founder effects. The great variety of mutations results in a great number of compound heterozygous genotypes and in highly variable clinical expressivity. A good correlation was observed between the severity of the disease and in vitro enzymatic activity of the mutant protein measured after site-directed mutagenesis. Many missense mutations found in severe hypophosphatasia produced a mutant protein that failed to reach the cell membrane , was accumulated in the cis-Golgi and was subsequently degraded in the proteasome. Missense mutations located in the catalytic site or in the homodimer interface were often shown by site-directed mutagenesis to have a dominant negative effect. Currently molecular diagnosis of HPP is based on the sequencing of the coding sequence of ALPL that allows detection of approximately 95 % of mutations in severe cases. In addition, other genes, especially genes encoding proteins involved in the regulation of extracellular PPi concentration, could modify the phenotype (modifier genes).
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Kinoshita T, Fujita M. Biosynthesis of GPI-anchored proteins: special emphasis on GPI lipid remodeling. J Lipid Res 2015; 57:6-24. [PMID: 26563290 DOI: 10.1194/jlr.r063313] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Indexed: 02/06/2023] Open
Abstract
Glycosylphosphatidylinositols (GPIs) act as membrane anchors of many eukaryotic cell surface proteins. GPIs in various organisms have a common backbone consisting of ethanolamine phosphate (EtNP), three mannoses (Mans), one non-N-acetylated glucosamine, and inositol phospholipid, whose structure is EtNP-6Manα-2Manα-6Manα-4GlNα-6myoinositol-P-lipid. The lipid part is either phosphatidylinositol of diacyl or 1-alkyl-2-acyl form, or inositol phosphoceramide. GPIs are attached to proteins via an amide bond between the C-terminal carboxyl group and an amino group of EtNP. Fatty chains of inositol phospholipids are inserted into the outer leaflet of the plasma membrane. More than 150 different human proteins are GPI anchored, whose functions include enzymes, adhesion molecules, receptors, protease inhibitors, transcytotic transporters, and complement regulators. GPI modification imparts proteins with unique characteristics, such as association with membrane microdomains or rafts, transient homodimerization, release from the membrane by cleavage in the GPI moiety, and apical sorting in polarized cells. GPI anchoring is essential for mammalian embryogenesis, development, neurogenesis, fertilization, and immune system. Mutations in genes involved in remodeling of the GPI lipid moiety cause human diseases characterized by neurological abnormalities. Yeast Saccharomyces cerevisiae has >60 GPI-anchored proteins (GPI-APs). GPI is essential for growth of yeast. In this review, we discuss biosynthesis of GPI-APs in mammalian cells and yeast with emphasis on the lipid moiety.
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Affiliation(s)
- Taroh Kinoshita
- WPI Immunology Frontier Research Center and Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
| | - Morihisa Fujita
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China
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48
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Loss of function of PGAP1 as a cause of severe encephalopathy identified by Whole Exome Sequencing: Lessons of the bioinformatics pipeline. Mol Cell Probes 2015; 29:323-9. [DOI: 10.1016/j.mcp.2015.05.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/21/2015] [Accepted: 05/22/2015] [Indexed: 11/18/2022]
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Carmean V, Yonkers MA, Tellez MB, Willer JR, Willer GB, Gregg RG, Geisler R, Neuhauss SC, Ribera AB. pigk Mutation underlies macho behavior and affects Rohon-Beard cell excitability. J Neurophysiol 2015; 114:1146-57. [PMID: 26133798 DOI: 10.1152/jn.00355.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/25/2015] [Indexed: 12/20/2022] Open
Abstract
The study of touch-evoked behavior allows investigation of both the cells and circuits that generate a response to tactile stimulation. We investigate a touch-insensitive zebrafish mutant, macho (maco), previously shown to have reduced sodium current amplitude and lack of action potential firing in sensory neurons. In the genomes of mutant but not wild-type embryos, we identify a mutation in the pigk gene. The encoded protein, PigK, functions in attachment of glycophosphatidylinositol anchors to precursor proteins. In wild-type embryos, pigk mRNA is present at times when mutant embryos display behavioral phenotypes. Consistent with the predicted loss of function induced by the mutation, knock-down of PigK phenocopies maco touch insensitivity and leads to reduced sodium current (INa) amplitudes in sensory neurons. We further test whether the genetic defect in pigk underlies the maco phenotype by overexpressing wild-type pigk in mutant embryos. We find that ubiquitous expression of wild-type pigk rescues the touch response in maco mutants. In addition, for maco mutants, expression of wild-type pigk restricted to sensory neurons rescues sodium current amplitudes and action potential firing in sensory neurons. However, expression of wild-type pigk limited to sensory cells of mutant embryos does not allow rescue of the behavioral touch response. Our results demonstrate an essential role for pigk in generation of the touch response beyond that required for maintenance of proper INa density and action potential firing in sensory neurons.
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Affiliation(s)
- V Carmean
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado; Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - M A Yonkers
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado; Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - M B Tellez
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - J R Willer
- Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky; Zebrafish Mutant Mapping Facility, University of Louisville, Louisville, Kentucky; and
| | - G B Willer
- Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky; Zebrafish Mutant Mapping Facility, University of Louisville, Louisville, Kentucky; and
| | - R G Gregg
- Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky; Zebrafish Mutant Mapping Facility, University of Louisville, Louisville, Kentucky; and
| | - R Geisler
- Max-Planck-Institut für Entwicklungsbiologie, Tübingen, Germany
| | - S C Neuhauss
- Max-Planck-Institut für Entwicklungsbiologie, Tübingen, Germany
| | - A B Ribera
- Neuroscience Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado; Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, Colorado;
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50
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Bosch DGM, Boonstra FN, Kinoshita T, Jhangiani S, de Ligt J, Cremers FPM, Lupski JR, Murakami Y, de Vries BBA. Cerebral visual impairment and intellectual disability caused by PGAP1 variants. Eur J Hum Genet 2015; 23:1689-93. [PMID: 25804403 DOI: 10.1038/ejhg.2015.42] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/05/2014] [Accepted: 02/06/2015] [Indexed: 11/09/2022] Open
Abstract
Homozygous variants in PGAP1 (post-GPI attachment to proteins 1) have recently been identified in two families with developmental delay, seizures and/or spasticity. PGAP1 is a member of the glycosylphosphatidylinositol anchor biosynthesis and remodeling pathway and defects in this pathway are a subclass of congenital disorders of glycosylation. Here we performed whole-exome sequencing in an individual with cerebral visual impairment (CVI), intellectual disability (ID), and factor XII deficiency and revealed compound heterozygous variants in PGAP1, c.274_276del (p.(Pro92del)) and c.921_925del (p.(Lys308Asnfs*25)). Subsequently, PGAP1-deficient Chinese hamster ovary (CHO)-cell lines were transfected with either mutant or wild-type constructs and their sensitivity to phosphatidylinositol-specific phospholipase C (PI-PLC) treatment was measured. The mutant constructs could not rescue the PGAP1-deficient CHO cell lines resistance to PI-PLC treatment. In addition, lymphoblastoid cell lines (LCLs) of the affected individual showed no sensitivity to PI-PLC treatment, whereas the LCLs of the heterozygous carrier parents were partially resistant. In conclusion, we report novel PGAP1 variants in a boy with CVI and ID and a proven functional loss of PGAP1 and show, to our knowledge, for the first time this genetic association with CVI.
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Affiliation(s)
- Daniëlle G M Bosch
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Bartiméus, Institute for the Visually Impaired, Zeist, The Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - F Nienke Boonstra
- Bartiméus, Institute for the Visually Impaired, Zeist, The Netherlands.,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases and WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Shalini Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA
| | - Joep de Ligt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - James R Lupski
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Texas Children's Hospital, Houston, TX, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Yoshiko Murakami
- Research Institute for Microbial Diseases and WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Bert B A de Vries
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands.,Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
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