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Ferreira CS, Francisco Junior RDS, Gerber AL, Guimarães APDC, de Carvalho FAA, Dos Reis BCS, Pinto-Mariz F, de Souza MS, de Vasconcelos ZFM, Goudouris ES, Vasconcelos ATR. Genetic screening in a Brazilian cohort with inborn errors of immunity. BMC Genom Data 2023; 24:47. [PMID: 37592284 PMCID: PMC10433585 DOI: 10.1186/s12863-023-01148-z] [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: 11/25/2022] [Accepted: 08/07/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND Inherited genetic defects in immune system-related genes can result in Inborn Errors of Immunity (IEI), also known as Primary Immunodeficiencies (PID). Diagnosis of IEI disorders is challenging due to overlapping clinical manifestations. Accurate identification of disease-causing germline variants is crucial for appropriate treatment, prognosis, and genetic counseling. However, genetic sequencing is challenging in low-income countries like Brazil. This study aimed to perform genetic screening on patients treated within Brazil's public Unified Health System to identify candidate genetic variants associated with the patient's phenotype. METHODS Thirteen singleton unrelated patients from three hospitals in Rio de Janeiro were enrolled in this study. Genomic DNA was extracted from the peripheral blood lymphocytes of each patient, and whole exome sequencing (WES) analyses were conducted using Illumina NextSeq. Germline genetic variants in IEI-related genes were prioritized using a computational framework considering their molecular consequence in coding regions; minor allele frequency ≤ 0.01; pathogenicity classification based on American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG/AMP) guidelines gathered from the VarSome clinical database; and IEI-related phenotype using the Franklin tool. The genes classification into IEI categories follows internationally recognized guidelines informed by the International Union of Immunological Societies Expert Committee. Additional methods for confirmation of the variant included Sanger sequencing, phasing analysis, and splice site prediction. RESULTS A total of 16 disease-causing variants in nine genes, encompassing six different IEI categories, were identified. X-Linked Agammaglobulinemia, caused by BTK variations, emerged as the most prevalent IEI disorder in the cohort. However, pathogenic and likely pathogenic variants were also reported in other known IEI-related genes, namely CD40LG, CARD11, WAS, CYBB, C6, and LRBA. Interestingly, two patients with suspected IEI exhibited pathogenic variants in non-IEI-related genes, ABCA12 and SLC25A13, potentially explaining their phenotypes. CONCLUSIONS Genetic screening through WES enabled the detection of potentially harmful variants associated with IEI disorders. These findings contribute to a better understanding of patients' clinical manifestations by elucidating the genetic basis underlying their phenotypes.
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Affiliation(s)
- Cristina Santos Ferreira
- Bioinformatics Laboratory-LABINFO, National Laboratory of Scientific Computation LNCC/MCTIC, Av. Getúlio Vargas, 333, Quitandinha CEP: 25651-075, Petrópolis, Rio de Janeiro, Brazil
| | - Ronaldo da Silva Francisco Junior
- Bioinformatics Laboratory-LABINFO, National Laboratory of Scientific Computation LNCC/MCTIC, Av. Getúlio Vargas, 333, Quitandinha CEP: 25651-075, Petrópolis, Rio de Janeiro, Brazil
| | - Alexandra Lehmkuhl Gerber
- Bioinformatics Laboratory-LABINFO, National Laboratory of Scientific Computation LNCC/MCTIC, Av. Getúlio Vargas, 333, Quitandinha CEP: 25651-075, Petrópolis, Rio de Janeiro, Brazil
| | - Ana Paula de Campos Guimarães
- Bioinformatics Laboratory-LABINFO, National Laboratory of Scientific Computation LNCC/MCTIC, Av. Getúlio Vargas, 333, Quitandinha CEP: 25651-075, Petrópolis, Rio de Janeiro, Brazil
| | - Flavia Amendola Anisio de Carvalho
- Allergy and Immunology Service of Institute of Women, Children and Adolescents' Health Fernandes Figueira (IFF/FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | - Bárbara Carvalho Santos Dos Reis
- Allergy and Immunology Service of Institute of Women, Children and Adolescents' Health Fernandes Figueira (IFF/FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | - Fernanda Pinto-Mariz
- Allergy and Immunology Service of the Martagão Gesteira Institute for Childcare and Pediatrics (IPPMG) - Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Monica Soares de Souza
- Allergy and Immunology Sector of the Pediatric Service of the Federal Hospital of Rio de Janeiro State (HFSE) - Ministry of Health, Rio de Janeiro, RJ, Brazil
| | - Zilton Farias Meira de Vasconcelos
- Laboratory of High Complexity of the Institute of Women, Children and Adolescents' Health Fernandes Figueira (IFF/FIOCRUZ), Rio de Janeiro, RJ, Brazil
| | - Ekaterini Simões Goudouris
- Allergy and Immunology Service of the Martagão Gesteira Institute for Childcare and Pediatrics (IPPMG) - Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Ana Tereza Ribeiro Vasconcelos
- Bioinformatics Laboratory-LABINFO, National Laboratory of Scientific Computation LNCC/MCTIC, Av. Getúlio Vargas, 333, Quitandinha CEP: 25651-075, Petrópolis, Rio de Janeiro, Brazil.
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Kato M, Kudo Y, Hatase M, Tsuchida N, Takeyama S, Sugiyama T, Fujimura M, Yabe I, Tsujimoto H, Fukumori Y, Inoue N, Atsumi T. Moyamoya Disease Associated with a Deficiency of Complement Component 6. J Stroke Cerebrovasc Dis 2022; 31:106601. [PMID: 35717718 DOI: 10.1016/j.jstrokecerebrovasdis.2022.106601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 05/21/2022] [Accepted: 06/09/2022] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES Complement component 6 (C6) deficiency is a very rare genetic defect that leads to significantly diminished synthesis, secretion, or function of C6. In the current report, we demonstrate a previously undescribed, homozygous missense mutation in exon 17 of the C6 gene (c.2545A>G p.Arg849Gly) in a 35-year-old Japanese woman with moyamoya disease and extremely low levels of CH50 (<7.0 U/mL). MATERIALS AND METHODS The complement gene analysis using hybridization capture-based next generation sequencing was performed. CH50 was determined in patient's plasma mixed with plasma from a healthy donor or purified human C6 protein. Western blot was performed on patient's plasma using polyclonal antibodies against C6, with healthy donor's plasma and purified human C6 protein as positive controls while C6-depleted human serum as a negative control. The carriage of ring finger protein 213 variant (c.14576G>A p.Arg4859Lys), a susceptibility gene for moyamoya disease, was examined by direct sequencing. RESULTS CH50 mixing test clearly showed a deficiency pattern, being rescued by addition of only 1% healthy donor's plasma or 1 μg/mL purified human C6 protein (1/50-1/100 of physiological concentration). Western blot revealed the absence of C6 protein in the patient's plasma, confirming a quantitative deficiency of C6. The ring finger protein 213 variant was not detected. CONCLUSIONS Our data implies that unrecognized complement deficiencies would be harbored in cerebrovascular diseases with unknown etiologies.
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Affiliation(s)
- Masaru Kato
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N14W5, Kita-Ku, Sapporo 060-8648, Japan.
| | - Yuki Kudo
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N14W5, Kita-Ku, Sapporo 060-8648, Japan
| | - Masanao Hatase
- Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, N14W5, Kita-Ku, Sapporo 060-8648, Japan
| | - Naohisa Tsuchida
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N14W5, Kita-Ku, Sapporo 060-8648, Japan
| | - Shuhei Takeyama
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N14W5, Kita-Ku, Sapporo 060-8648, Japan
| | - Taku Sugiyama
- Department of Neurosurgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15W7, Kita-Ku, Sapporo 060-8648, Japan
| | - Miki Fujimura
- Department of Neurosurgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N15W7, Kita-Ku, Sapporo 060-8648, Japan
| | - Ichiro Yabe
- The Division of Clinical Genetics, Hokkaido University Hospital, N14W5, Kita-Ku, Sapporo 060-8638, Japan
| | - Hiroshi Tsujimoto
- Department of Molecular Genetics, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan
| | - Yasuo Fukumori
- Department of Molecular Genetics, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan
| | - Norimitsu Inoue
- Department of Molecular Genetics, Wakayama Medical University, Kimiidera 811-1, Wakayama 641-8509, Japan
| | - Tatsuya Atsumi
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N14W5, Kita-Ku, Sapporo 060-8648, Japan
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Massri M, Foco L, Würzner R. Comprehensive Update and Revision of Nomenclature on Complement C6 and C7 Variants. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:2597-2612. [PMID: 35867677 DOI: 10.4049/jimmunol.2200045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 04/11/2022] [Indexed: 06/15/2023]
Abstract
Complement genes encompass a wide array of variants, giving rise to numerous protein isoforms that have often been shown to exhibit clinical significance. Given that these variants have been discovered over a span of 50 y, one challenging consequence is the inconsistency in the terminology used to classify them. This issue is prominently evident in the nomenclature used for complement C6 and C7 variants, for which we observed a great discrepancy between previously published works and variants described in current genome browsers. This report discusses the causes for the discrepancies in C6 and C7 nomenclature and seeks to establish a classification system that would unify existing and future variants. The inconsistency in the methods used to annotate amino acids and the modifications pinpointed in the C6 and C7 primers are some of the factors that contribute greatly to the discrepancy in the nomenclature. Several variants that were classified incorrectly are highlighted in this report, and we showcase first-hand how a unified classification system is important to match previous with current genetic information. Ultimately, we hope that the proposed classification system of nomenclature becomes an incentive for studies on complement variants and their physiological and/or pathological effects.
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Affiliation(s)
- Mariam Massri
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria; and
| | - Luisa Foco
- Institute for Biomedicine (affiliated with the University of Lübeck), Eurac Research, Bolzano, Italy
| | - Reinhard Würzner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria; and
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Li PH, Wong WW, Leung EN, Lau CS, Au E. Novel pathogenic mutations identified in the first Chinese pedigree of complete C6 deficiency. Clin Transl Immunology 2020; 9:e1148. [PMID: 32670577 PMCID: PMC7343556 DOI: 10.1002/cti2.1148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 01/25/2023] Open
Abstract
Objectives Complete C6 deficiency (C6Q0) is a rare primary immunodeficiency leading to increased susceptibility to recurrent Neisseria infections. Patients with C6Q0 have mostly been reported in individuals of African ancestry previously, but never in Chinese. We identify the first Chinese patients with C6Q0 through family screening of an index case presenting with recurrent Neisseria meningitis with septicaemia and performed extensive clinical, serological and genetic investigations. Methods Two variants in C6 were identified by next‐generation sequencing and confirmed by Sanger sequencing in an index case of C6Q0. Immunological investigations, complement haemolytic assays (CH50/AH50), C6 gene sequencing and quantification of serum C6 levels were performed for all available members of his nonconsanguineous family. Results Three C6Q0 patients were identified with near‐absent C6 levels, absent CH50/AH50 activity and compound heterozygous for two nonsense mutations in the C6 gene: NM_000065.4:c.1786C>T (p.Arg596Ter) and NM_000065.4:c.1816C>T (p.Arg606Ter). Neither mutations have been reported to be pathogenic previously. Two other family members who were heterozygous for either p.Arg596Ter or and p.Arg606Ter had intermediate C6 levels but preserved CH50/AH50 activity. These two loss‐of‐function mutations showed a strong genotype–phenotype correlation in C6 levels. Conclusions We report on two compound heterozygous mutations in C6, p.Arg596Ter and p.Arg606Ter inherited in three patients of the first recorded Chinese pedigree of C6Q0. Neither mutations had been reported to be pathogenic previously. We demonstrate that heterozygous family members with subtotal C6 levels had preserved complement haemolytic function and demonstrate a threshold effect of C6 protein level.
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Affiliation(s)
- Philip H Li
- Division of Rheumatology & Clinical Immunology Department of Medicine Queen Mary Hospital The University of Hong Kong Hong Kong
| | - William Wy Wong
- Division of Clinical Immunology Department of Pathology Queen Mary Hospital Hong Kong
| | - Evelyn Ny Leung
- Division of Clinical Immunology Department of Pathology Queen Mary Hospital Hong Kong
| | - Chak-Sing Lau
- Division of Rheumatology & Clinical Immunology Department of Medicine Queen Mary Hospital The University of Hong Kong Hong Kong
| | - Elaine Au
- Division of Clinical Immunology Department of Pathology Queen Mary Hospital Hong Kong
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5
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Díaz-Rodríguez SM, López-López D, Herrero-Turrión MJ, Gómez-Nieto R, Canal-Alonso A, Lopéz DE. Inferior Colliculus Transcriptome After Status Epilepticus in the Genetically Audiogenic Seizure-Prone Hamster GASH/Sal. Front Neurosci 2020; 14:508. [PMID: 32528245 PMCID: PMC7264424 DOI: 10.3389/fnins.2020.00508] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 04/22/2020] [Indexed: 01/31/2023] Open
Abstract
The Genetic Audiogenic Seizure Hamster from Salamanca (GASH/Sal), an animal model of reflex epilepsy, exhibits generalized tonic–clonic seizures in response to loud sound with the epileptogenic focus localized in the inferior colliculus (IC). Ictal events in seizure-prone strains cause gene deregulation in the epileptogenic focus, which can provide insights into the epileptogenic mechanisms. Thus, the present study aimed to determine the expression profile of key genes in the IC of the GASH/Sal after the status epilepticus. For such purpose, we used RNA-Seq to perform a comparative study between the IC transcriptome of GASH/Sal and that of control hamsters both subjected to loud sound stimulation. After filtering for normalization and gene selection, a total of 36 genes were declared differentially expressed from the RNA-seq analysis in the IC. A set of differentially expressed genes were validated by RT-qPCR showing significant differentially expression between GASH/Sal hamsters and Syrian control hamsters. The confirmed differentially expressed genes were classified on ontological categories associated with epileptogenic events similar to those produced by generalized tonic seizures in humans. Subsequently, based on the result of metabolomics, we found the interleukin-4 and 13-signaling, and nucleoside transport as presumably altered routes in the GASH/Sal model. This research suggests that seizures in GASH/Sal hamsters are generated by multiple molecular substrates, which activate biological processes, molecular processes, cellular components and metabolic pathways associated with epileptogenic events similar to those produced by tonic seizures in humans. Therefore, our study supports the use of the GASH/Sal as a valuable animal model for epilepsy research, toward establishing correlations with human epilepsy and searching new biomarkers of epileptogenesis.
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Affiliation(s)
- Sandra M Díaz-Rodríguez
- Institute of Neurosciences of Castilla y León, University of Salamanca, Salamanca, Spain.,Institute of Biomedical Research of Salamanca, University of Salamanca, Salamanca, Spain.,Department of Cellular Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - Daniel López-López
- Institute of Neurosciences of Castilla y León, University of Salamanca, Salamanca, Spain
| | - Manuel J Herrero-Turrión
- Institute of Neurosciences of Castilla y León, University of Salamanca, Salamanca, Spain.,Institute of Biomedical Research of Salamanca, University of Salamanca, Salamanca, Spain.,Neurological Tissue Bank INCYL (BTN-INCYL), Salamanca, Spain
| | - Ricardo Gómez-Nieto
- Institute of Neurosciences of Castilla y León, University of Salamanca, Salamanca, Spain.,Institute of Biomedical Research of Salamanca, University of Salamanca, Salamanca, Spain.,Department of Cellular Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - Angel Canal-Alonso
- Institute of Biomedical Research of Salamanca, University of Salamanca, Salamanca, Spain.,BISITE Research Group, University of Salamanca, Salamanca, Spain
| | - Dolores E Lopéz
- Institute of Neurosciences of Castilla y León, University of Salamanca, Salamanca, Spain.,Institute of Biomedical Research of Salamanca, University of Salamanca, Salamanca, Spain.,Department of Cellular Biology and Pathology, University of Salamanca, Salamanca, Spain
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El Sissy C, Rosain J, Vieira-Martins P, Bordereau P, Gruber A, Devriese M, de Pontual L, Taha MK, Fieschi C, Picard C, Frémeaux-Bacchi V. Clinical and Genetic Spectrum of a Large Cohort With Total and Sub-total Complement Deficiencies. Front Immunol 2019; 10:1936. [PMID: 31440263 PMCID: PMC6694794 DOI: 10.3389/fimmu.2019.01936] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 07/30/2019] [Indexed: 01/11/2023] Open
Abstract
The complement system is crucial for defense against pathogens and the removal of dying cells or immune complexes. Thus, clinical indications for possible complete complement deficiencies include, among others, recurrent mild or serious bacterial infections as well as autoimmune diseases (AID). The diagnostic approach includes functional activity measurements of the classical (CH50) and alternative pathway (AP50) and the determination of the C3 and C4 levels, followed by the quantitative analysis of individual components or regulators. When biochemical analysis reveals the causal abnormality of the complement deficiency (CD), molecular mechanisms remains frequently undetermined. Here, using direct sequencing analysis of the coding region we report the pathogenic variants spectrum that underlie the total or subtotal complement deficiency in 212 patients. We identified 107 different hemizygous, homozygous, or compound heterozygous pathogenic variants in 14 complement genes [C1Qβ (n = 1), C1r (n = 3), C1s (n = 2), C2 (n = 12), C3 (n = 5), C5 (n = 12), C6 (n = 9), C7 (n = 17), C8 β (n = 7), C9 (n = 3), CFH (n = 7), CFI (n = 18), CFP (n = 10), CFD (n = 2)]. Molecular analysis identified 17 recurrent pathogenic variants in 6 genes (C2, CFH, C5, C6, C7, and C8). More than half of the pathogenic variants identified in unrelated patients were also found in healthy controls from the same geographic area. Our study confirms the strong association of meningococcal infections with terminal pathway deficiency and highlights the risk of pneumococcal and auto-immune diseases in the classical and alternative pathways. Results from this large genetic investigation provide evidence of a restricted number of molecular mechanisms leading to complement deficiency and describe the clinical potential adverse events of anti-complement therapy.
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Affiliation(s)
- Carine El Sissy
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire d'Immunologie, Hôpital Européen Georges-Pompidou, Paris, France
| | - Jérémie Rosain
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire d'Immunologie, Hôpital Européen Georges-Pompidou, Paris, France
| | - Paula Vieira-Martins
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire d'Immunologie, Hôpital Européen Georges-Pompidou, Paris, France
| | - Pauline Bordereau
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire d'Immunologie, Hôpital Européen Georges-Pompidou, Paris, France
| | - Aurélia Gruber
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire d'Immunologie, Hôpital Européen Georges-Pompidou, Paris, France
| | - Magali Devriese
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire d'Immunologie, Hôpital Européen Georges-Pompidou, Paris, France
| | - Loïc de Pontual
- Pediatrics Department, Jean Verdier Hospital, Assistance Publique des Hôpitaux de Paris, Paris 13 University, Bondy, France
| | - Muhamed-Kheir Taha
- Invasive Bacterial Infection and National Reference Center for Meningococci, Pasteur Institut, Paris, France
| | - Claire Fieschi
- Department of Clinical Immunology, Hôpital Saint-Louis, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France.,Inserm U1126, Centre Hayem, Hôpital Saint-Louis, Paris, France
| | - Capucine Picard
- Paris University, INSERM UMR1163, Imagine Institute, Paris, France.,Study Center for Primary Immunodeficiencies (AP-HP), Hôpital Necker-Enfants maladies Hospital, Paris, France
| | - Véronique Frémeaux-Bacchi
- Assistance Publique - Hôpitaux de Paris (AP-HP), Laboratoire d'Immunologie, Hôpital Européen Georges-Pompidou, Paris, France.,Centre de Recherche des Cordeliers, INSERM, Sorbonne Université, USPC, Université Paris Descartes, Complement and Diseases Team, Paris, France
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7
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Rosain J, Hong E, Fieschi C, Martins PV, El Sissy C, Deghmane AE, Ouachée M, Thomas C, Launay D, de Pontual L, Suarez F, Moshous D, Picard C, Taha MK, Frémeaux-Bacchi V. Strains Responsible for Invasive Meningococcal Disease in Patients With Terminal Complement Pathway Deficiencies. J Infect Dis 2017; 215:1331-1338. [DOI: 10.1093/infdis/jix143] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 03/23/2017] [Indexed: 12/17/2022] Open
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8
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Complement component C6 deficiency in a Spanish family: implications for clinical and molecular diagnosis. Gene 2013; 521:204-6. [PMID: 23537992 DOI: 10.1016/j.gene.2013.03.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 03/07/2013] [Indexed: 11/24/2022]
Abstract
Complement component C6 deficiency is a genetic disease presenting as increased susceptibility to invasive Neisseria meningitidis infections. This disorder has rarely been diagnosed in the Spanish population. In this work we report the immunochemical and molecular characterization of complement C6 deficiency in a Spanish patient showing no detectable functional activity of either the classical or alternative complement pathways and reporting a history of several episodes of meningococcal meningitis. The levels of individual complement components C3, C4, C5, C7, C8 and C9 were within the normal range. However, C6 level was low in the patient's serum as measured by radial immunodiffusion. Exon-specific polymerase chain reaction and sequencing of the C6 gene revealed a previously described homozygous single base deletion in exon 6 (c.821delA), leading to a shift in the reading frame that caused the generation of a downstream stop codon, which, in turn, provoked the truncation of the C6 protein (p.Gln274fs). To our knowledge, this is the first report on the c.821delA mutation in the Spanish population, which has previously only been identified in individuals of African ancestry. Characterization of this mutation was thought interesting in order to elucidate its source and help understand the molecular basis of this uncommon deficiency in our population. Moreover, this report highlights the importance of complement screening in cases of repeated meningococcal infections in order to establish its involvement and to consider adequate clinical recommendations such as prophylactic antibiotics or meningococcal vaccines and, subsequently, for genetic counselling.
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9
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Kuijpers TW, Nguyen M, Hopman CTP, Nieuwenhuys E, Dewald G, Lankester AC, Roos A, van der Ende A, Fijen C, de Boer M. Complement factor 7 gene mutations in relation to meningococcal infection and clinical recurrence of meningococcal disease. Mol Immunol 2010; 47:671-7. [DOI: 10.1016/j.molimm.2009.10.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 10/16/2009] [Accepted: 10/25/2009] [Indexed: 11/26/2022]
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10
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Welch TR, Blystone LW. Renal disease associated with inherited disorders of the complement system. Pediatr Nephrol 2009; 24:1439-44. [PMID: 18958500 DOI: 10.1007/s00467-008-1027-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 09/23/2008] [Accepted: 09/24/2008] [Indexed: 12/25/2022]
Abstract
The human complement system is vital for host defense and plays a role in a number of inflammatory disorders. Inherited deficiency or dysfunction of most of the individual complement components occurs uncommonly. The phenotype displayed by such patients varies with the specific component deficiency and ranges from recurrent infections to autoimmune diseases. Most of the latter are associated with glomerulonephritis. The onset of severe lupus erythematosus in a young child, with prominent cutaneous and renal manifestations, especially if a similar disorder is present in another family member, is a clue to the presence of a complement component deficiency. The distinguishing of acquired deficiencies from inherited deficiencies in complement components is sometimes difficult and may require sophisticated laboratory testing.
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Affiliation(s)
- Thomas R Welch
- Department of Pediatrics, State University of New York, Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA.
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11
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Botto M, Kirschfink M, Macor P, Pickering MC, Würzner R, Tedesco F. Complement in human diseases: Lessons from complement deficiencies. Mol Immunol 2009; 46:2774-83. [PMID: 19481265 DOI: 10.1016/j.molimm.2009.04.029] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Accepted: 04/28/2009] [Indexed: 01/22/2023]
Abstract
Complement deficient cases reported in the second half of the last century have been of great help in defining the role of complement in host defence. Surveys of the deficient individuals have been instrumental in the recognition of the clinical consequences of the deficiencies. This review focuses on the analysis of the diseases associated with the deficiencies of the various components and regulators of the complement system and their therapeutic implications. The diagnostic approach leading to the identification of the deficiency is discussed here as a multistep process that starts with the screening assays and proceeds in specialized laboratories with the characterization of the defect at the molecular level. The organization of a registry of complement deficiencies is presented as a means to collect the cases identified in and outside Europe with the aim to promote joint projects on treatment and prevention of diseases associated with defective complement function.
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12
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Mejri K, Mbarek H, Kallel-Sellami M, Petit-Teixeira E, Zerzeri Y, Abida O, Zitouni M, Ben Ayed M, Mokni M, Fezza B, Turki H, Tron F, Gilbert D, Masmoudi H, Prum B, Cornelis F, Makni S. TRAF1/C5 polymorphism is not associated with pemphigus. Br J Dermatol 2009; 160:1348-50. [PMID: 19416238 DOI: 10.1111/j.1365-2133.2009.09136.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kallel-Sellami M, Baili-Klila L, Zerzeri Y, Laadhar L, Blouin J, Abdelmalek R, Fremeaux-Bacchi V, Zitouni M, Makni S. Hereditary Complement Deficiency and Lupus: Report of Four Tunisian Cases. Ann N Y Acad Sci 2007; 1108:197-202. [PMID: 17893986 DOI: 10.1196/annals.1422.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of the study was to assess the clinical and immunological profile of lupus erythematosus (LE) patients with inherited complement deficiency (ICD). A laboratory-based study was conducted in which all LE patients with hypocomplementemia were included. ICD was assessed by hemolytic and antigenic assays. Type I C2 deficiency was assessed by polymerase chain reaction (PCR). ICD was diagnosed in four cases. In three systemic LE patients, ICD were: homozygous C2 deficiency in the first case, heterozygous C2 deficiency in the second, and homozygous C1q deficiency in the third case. In a discoid LE patient, a combined homozygous C2 and C6 deficiency was diagnosed. Almost all of our patients presented the classical clinical and immunological features of LE associated with ICD. Severe lupus with renal involvement and recurrent infections was present in half of the patients suggesting that these patients are prone to a serious management.
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Rameix-Welti MA, Régnier CH, Bienaimé F, Blouin J, Schifferli J, Fridman WH, Sautès-Fridman C, Frémeaux-Bacchi V. Hereditary complement C7 deficiency in nine families: Subtotal C7 deficiency revisited. Eur J Immunol 2007; 37:1377-85. [PMID: 17407100 DOI: 10.1002/eji.200636812] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Deficiencies in terminal complement components, including the component C7, are uncommon and associated with an increased risk of recurrent systemic neisserial infection. A total of 22 molecular defects have been reported in the C7 gene with both complete (C7Q0) and subtotal (C7SD) C7 deficiencies. In this study we report the molecular basis of nine new cases of C7 deficiencies that were characterized by exon-specific sequence analysis. Seven different C7 gene mutations were identified corresponding to small deletions (n=2), splice site changes (n=1) and single base pair substitutions leading to nonsense (n=1) or missense (n=3) mutations. Altogether, three changes of the C7 gene (G357R, R499S and 5' splice donor site of intron 16) account for half of the molecular defects which emphasize that a restricted number of molecular abnormalities are involved in this deficiency. We identified two patients with combined C7Q0/C7SD(R499S) and established the C7SD(R499S) frequency at about 1% in normal Caucasian population. We demonstrated that C7(R499S) mutant protein is retained in the endoplasmic reticulum whereas the wild-type C7 is located in the Golgi apparatus. Our results provide evidence that R499S represents a loss-of-function polymorphism of C7 due to a defective folding of the protein.
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Affiliation(s)
- Marie-Anne Rameix-Welti
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service d'Immunologie Biologique, Paris, France
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Parham KL, Roberts A, Thomas A, Würzner R, Henderson HE, Potter PC, Morgan BP, Orren A. Prevalence of mutations leading to complete C6 deficiency (C6Q0) in the Western Cape, South Africa and detection of novel mutations leading to C6Q0 in an Irish family. Mol Immunol 2007; 44:2756-60. [PMID: 17257682 DOI: 10.1016/j.molimm.2006.11.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 11/06/2006] [Accepted: 11/06/2006] [Indexed: 11/27/2022]
Abstract
Complement component C6 is one of five terminal complement components incorporated into the membrane attack complex. Complete deficiency of C6 (C6Q0) leads to an increased susceptibility to Neisseria meningitidis infections, and affected individuals typically present with recurrent meningococcal disease. There is a relatively high prevalence of C6Q0 in the Western Cape, South Africa and three frameshift mutations have previously been described to be responsible for C6Q0 in this area-879delG, 1195delC, and 1936delG (current nomenclature). We have now genotyped a further nine genetically independent individuals with C6Q0, confirming previous reports that the most common defect in the Western Cape is 879delG. Moreover, we report the first identification of the 878delA mutation within the Western Cape, which has previously only been reported in individuals of African descent living in the United States or Europe. We also investigated the genotype of an Irish C6Q0 individual and her sibling, and report two previously undescribed mutations. One mutation alters a tyrosine codon to a stop codon within exon 10. The second mutation is within the 5' donor splice site of intron 3, and would, in all probability, disrupt splicing. These two mutations were shown to segregate independently. We also discuss the nomenclature for reporting C6 and C7 gene mutations, as the current nomenclature does not follow the recognised guidelines.
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Affiliation(s)
- Kelly L Parham
- Department of Medical Biochemistry, Cardiff University and University Hospital of Wales, Heath Park, Cardiff CF14 4XW, United Kingdom.
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16
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Abstract
The complement system, composed of several plasma and membrane proteins, is an integral part of the innate immune system and plays a role in inflammatory response, destruction of infectious agents, elimination of immune complexes, and control of the specific (adaptive) immune response. Hereditary deficiencies of complement components are relatively rare and associated with susceptibility to a wide variety of clinical diseases. Complement components may be target of antibodies (anti-C1q, factor H, C3 alternative convertase, or C3NeF autoantibodies or anti-C1 inhibitor antibodies) that lead to acquired deficiencies. Testing the complement system is especially necessary in patients with autoimmune diseases, some kidney diseases, recurrent infections (especially meningococcal), and angioedema. Precise clinical descriptions of the phenotypes associated with these deficiencies and their molecular diagnosis are necessary to improve our understanding of the role that the complement system plays in the physiopathological mechanisms of these diseases and to propose the most specific treatment for them.
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Soejima M, Tachida H, Tsuneoka M, Takenaka O, Kimura H, Koda Y. Nucleotide Sequence Analyses of Human Complement 6 (C6) Gene Suggest Balancing Selection. Ann Hum Genet 2005. [DOI: 10.1046/j.1469-1809.2005.00165.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Rameix-Welti MA, Chedani H, Blouin J, Alonso JM, Fridman WH, Fremeaux-Bacchi V. [Neisseria meningitidis infection. Clinical criteria orienting towards a deficiency in the proteins of the complement]. Presse Med 2005; 34:425-30. [PMID: 15902872 DOI: 10.1016/s0755-4982(05)83936-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE Complement protein deficiency of the classical pathway or in proteins of the alternate pathway is rare but considerably increase the risk of infection with Neisseria meningitidis. The aim of this study was to determine the clinical criteria of the group at risk. METHODS Retrospective study of the clinical and biological data of patients exhibiting complement protein deficiency associated with one or several N. meningitidis infections. RESULTS Forty cases were studied, including 35 classical pathway protein deficiencies, with a predominance of C7 deficiency, 3 properdin deficiencies and 2 acquired C3 deficiencies. More than 60% of the patients exhibited recurrent N. meningitidis infections. Serogroups of rare strains were isolated in 50% of cases. Properdin deficiency was associated with a fulminating form in 2 cases out of 3. The age at onset of the first manifestations varied from 2 months to 32 years. CONCLUSION A deficiency must be systematically searched for in all patients presenting with a N. meningitidis infection before the age of 6 months or after the age of 5 years. Identification of deficient patients permits the proposal of family screening and appropriate prophylaxis, including preventive vaccination.
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Affiliation(s)
- M A Rameix-Welti
- Service d'immunologie biologique, Hôpital européen Georges Pompidou, Paris
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Würzner R. Deficiencies of the complement MAC II gene cluster (C6, C7, C9): is subtotal C6 deficiency of particular evolutionary benefit? Clin Exp Immunol 2003; 133:156-9. [PMID: 12869019 PMCID: PMC1808758 DOI: 10.1046/j.1365-2249.2003.02230.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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