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1.
Rev Med Liege ; 79(3): 175-180, 2024 Mar.
Article in French | MEDLINE | ID: mdl-38487912

ABSTRACT

It is estimated that in highly medicalised countries, median life expectancy for most newborns with cystic fibrosis now exceeds 70 years, approaching that of the general population. However, socio-economic disparities between countries continue to have a devastating impact on the prognosis of patients in Eastern Europe, Africa, India and South America. In Morocco, very limited genetic data suggest that the prevalence of this disease is at least of the same order as in Belgium. But as it is not really recognised by the national health system, patients are denied access even to symptomatic treatment. As a result, their outcome is tragic, similar to what it was 60 years ago in the most medicalised countries. A pilot project for a first paediatric reference centre in Casablanca is currently being set up. If properly resourced, this project can only be a success and should be the first step on the road towards cystic fibrosis care in this country. In a very humble way, several Belgian stakeholders are trying to support this project.


Dans les pays les plus médicalisés, l'espérance de vie médiane de la plupart des nouveau-nés atteints de mucoviscidose excède aujourd'hui 70 ans et se rapproche de celle de la population générale. Ailleurs, en Europe de l'Est comme en Afrique, en Inde ou en Amérique du Sud, les disparités socio-économiques des pays continuent à impacter très durement le pronostic des patients. Au Maroc, des données génétiques très fragmentaires suggèrent que la prévalence de la mucoviscidose est au moins du même ordre qu'en Belgique. Mais la maladie n'y est pas réellement reconnue par le système de santé, de telle sorte que même le traitement symptomatique reste inaccessible aux patients et leur pronostic est tragique, similaire à ce qu'il était il y a 60 ans dans les pays les plus médicalisés. À Casablanca, le projet pilote d'un premier Centre pédiatrique de Référence est en train de se mettre en place. S'il bénéficie d'un support adéquat, ce projet ne peut être qu'un succès et doit constituer un tout premier pas sur le chemin vers une prise en charge des patients dans ce pays. Très modestement, plusieurs intervenants belges tentent d'y apporter leur soutien.


Subject(s)
Cystic Fibrosis , Child , Humans , Infant, Newborn , Cystic Fibrosis/epidemiology , Cystic Fibrosis/therapy , Pilot Projects , Belgium/epidemiology
2.
J Exp Med ; 220(9)2023 09 04.
Article in English | MEDLINE | ID: mdl-37273177

ABSTRACT

Inborn errors of the NF-κB pathways underlie various clinical phenotypes in humans. Heterozygous germline loss-of-expression and loss-of-function mutations in RELA underlie RELA haploinsufficiency, which results in TNF-dependent chronic mucocutaneous ulceration and autoimmune hematological disorders. We here report six patients from five families with additional autoinflammatory and autoimmune manifestations. These patients are heterozygous for RELA mutations, all of which are in the 3' segment of the gene and create a premature stop codon. Truncated and loss-of-function RelA proteins are expressed in the patients' cells and exert a dominant-negative effect. Enhanced expression of TLR7 and MYD88 mRNA in plasmacytoid dendritic cells (pDCs) and non-pDC myeloid cells results in enhanced TLR7-driven secretion of type I/III interferons (IFNs) and interferon-stimulated gene expression in patient-derived leukocytes. Dominant-negative mutations in RELA thus underlie a novel form of type I interferonopathy with systemic autoinflammatory and autoimmune manifestations due to excessive IFN production, probably triggered by otherwise non-pathogenic TLR ligands.


Subject(s)
Autoimmunity , Interferon Type I , Transcription Factor RelA , Humans , Autoimmunity/genetics , Dendritic Cells , Interferon Type I/genetics , Interferon Type I/metabolism , NF-kappa B/metabolism , Toll-Like Receptor 7/genetics , Toll-Like Receptor 7/metabolism , Transcription Factor RelA/genetics , Transcription Factor RelA/metabolism
3.
J Exp Med ; 220(5)2023 05 01.
Article in English | MEDLINE | ID: mdl-36880831

ABSTRACT

X-linked recessive deficiency of TLR7, a MyD88- and IRAK-4-dependent endosomal ssRNA sensor, impairs SARS-CoV-2 recognition and type I IFN production in plasmacytoid dendritic cells (pDCs), thereby underlying hypoxemic COVID-19 pneumonia with high penetrance. We report 22 unvaccinated patients with autosomal recessive MyD88 or IRAK-4 deficiency infected with SARS-CoV-2 (mean age: 10.9 yr; 2 mo to 24 yr), originating from 17 kindreds from eight countries on three continents. 16 patients were hospitalized: six with moderate, four with severe, and six with critical pneumonia, one of whom died. The risk of hypoxemic pneumonia increased with age. The risk of invasive mechanical ventilation was also much greater than in age-matched controls from the general population (OR: 74.7, 95% CI: 26.8-207.8, P < 0.001). The patients' susceptibility to SARS-CoV-2 can be attributed to impaired TLR7-dependent type I IFN production by pDCs, which do not sense SARS-CoV-2 correctly. Patients with inherited MyD88 or IRAK-4 deficiency were long thought to be selectively vulnerable to pyogenic bacteria, but also have a high risk of hypoxemic COVID-19 pneumonia.


Subject(s)
COVID-19 , Myeloid Differentiation Factor 88 , Child , Humans , Adaptor Proteins, Signal Transducing , COVID-19/complications , Myeloid Differentiation Factor 88/genetics , SARS-CoV-2 , Toll-Like Receptor 7
4.
J Clin Invest ; 133(12)2023 06 15.
Article in English | MEDLINE | ID: mdl-36976641

ABSTRACT

STAT2 is a transcription factor activated by type I and III IFNs. We report 23 patients with loss-of-function variants causing autosomal recessive (AR) complete STAT2 deficiency. Both cells transfected with mutant STAT2 alleles and the patients' cells displayed impaired expression of IFN-stimulated genes and impaired control of in vitro viral infections. Clinical manifestations from early childhood onward included severe adverse reaction to live attenuated viral vaccines (LAV) and severe viral infections, particularly critical influenza pneumonia, critical COVID-19 pneumonia, and herpes simplex virus type 1 (HSV-1) encephalitis. The patients displayed various types of hyperinflammation, often triggered by viral infection or after LAV administration, which probably attested to unresolved viral infection in the absence of STAT2-dependent types I and III IFN immunity. Transcriptomic analysis revealed that circulating monocytes, neutrophils, and CD8+ memory T cells contributed to this inflammation. Several patients died from viral infection or heart failure during a febrile illness with no identified etiology. Notably, the highest mortality occurred during early childhood. These findings show that AR complete STAT2 deficiency underlay severe viral diseases and substantially impacts survival.


Subject(s)
COVID-19 , Encephalitis, Herpes Simplex , Influenza, Human , Pneumonia , Virus Diseases , Humans , Child, Preschool , Virus Diseases/genetics , Alleles , STAT1 Transcription Factor/genetics , STAT1 Transcription Factor/metabolism , STAT2 Transcription Factor/genetics
5.
J Allergy Clin Immunol Pract ; 11(1): 158-180.e11, 2023 01.
Article in English | MEDLINE | ID: mdl-36265766

ABSTRACT

Human inborn errors of immunity (IEI) are a group of 485 distinct genetic disorders affecting children and adults. Signs and symptoms of IEI are heterogeneous, and accurate diagnosis can be challenging and depends on the available human expertise and laboratory resources. The Middle East and North Africa (MENA) region has an increased prevalence of IEI because of the high rate of consanguinity with a predominance of autosomal recessive disorders. This area also exhibits more severe disease phenotypes compared with other regions, probably due to the delay in diagnosis. The MENA-IEI registry network has designed protocols and guidelines for the diagnosis and treatment of IEI, taking into consideration the variable regional expertise and resources. These guidelines are primarily meant to improve the care of patients within the region, but can also be followed in other regions with similar patient populations.


Subject(s)
Consanguinity , Adult , Child , Humans , Africa, Northern/epidemiology , Middle East/epidemiology , Phenotype , Registries
6.
J Clin Immunol ; 42(7): 1508-1520, 2022 10.
Article in English | MEDLINE | ID: mdl-36198931

ABSTRACT

The International Union of Immunological Societies (IUIS) expert committee (EC) on Inborn Errors of Immunity (IEI) reports here the 2022 updated phenotypic classification, which accompanies and complements the most-recent genotypic classification. This phenotypic classification is aimed for clinicians at the bedside and focuses on clinical features and laboratory phenotypes of specific IEI. In this classification, 485 IEI underlying phenotypes as diverse as infection, malignancy, allergy, auto-immunity and auto-inflammation are described, including 55 novel monogenic defects and 1 autoimmune phenocopy. Therefore, all 485 diseases of the genetic classification are presented in this paper in the form of colored tables with essential clinical or immunological phenotype entries.


Subject(s)
Hypersensitivity , Immunologic Deficiency Syndromes , Neoplasms , Humans , Immunologic Deficiency Syndromes/genetics , Phenotype , Genotype
7.
J Exp Med ; 219(10)2022 10 03.
Article in English | MEDLINE | ID: mdl-36094518

ABSTRACT

Human cells homozygous for rare loss-of-expression (LOE) TYK2 alleles have impaired, but not abolished, cellular responses to IFN-α/ß (underlying viral diseases in the patients) and to IL-12 and IL-23 (underlying mycobacterial diseases). Cells homozygous for the common P1104A TYK2 allele have selectively impaired responses to IL-23 (underlying isolated mycobacterial disease). We report three new forms of TYK2 deficiency in six patients from five families homozygous for rare TYK2 alleles (R864C, G996R, G634E, or G1010D) or compound heterozygous for P1104A and a rare allele (A928V). All these missense alleles encode detectable proteins. The R864C and G1010D alleles are hypomorphic and loss-of-function (LOF), respectively, across signaling pathways. By contrast, hypomorphic G996R, G634E, and A928V mutations selectively impair responses to IL-23, like P1104A. Impairment of the IL-23-dependent induction of IFN-γ is the only mechanism of mycobacterial disease common to patients with complete TYK2 deficiency with or without TYK2 expression, partial TYK2 deficiency across signaling pathways, or rare or common partial TYK2 deficiency specific for IL-23 signaling.


Subject(s)
Job Syndrome , TYK2 Kinase , Humans , Interferon-gamma/metabolism , Interleukin-23 , Job Syndrome/genetics , TYK2 Kinase/deficiency , TYK2 Kinase/genetics , TYK2 Kinase/metabolism
8.
Sci Immunol ; 7(73): eabq3277, 2022 07 22.
Article in English | MEDLINE | ID: mdl-35867801

ABSTRACT

High-level expression of the transcription factor T-bet characterizes a phenotypically distinct murine B cell population known as "age-associated B cells" (ABCs). T-bet-deficient mice have reduced ABCs and impaired humoral immunity. We describe a patient with inherited T-bet deficiency and largely normal humoral immunity including intact somatic hypermutation, affinity maturation and memory B cell formation in vivo, and B cell differentiation into Ig-producing plasmablasts in vitro. Nevertheless, the patient exhibited skewed class switching to IgG1, IgG4, and IgE, along with reduced IgG2, both in vivo and in vitro. Moreover, T-bet was required for the in vivo and in vitro development of a distinct subset of human B cells characterized by reduced expression of CD21 and the concomitantly high expression of CD19, CD20, CD11c, FCRL5, and T-bet, a phenotype that shares many features with murine ABCs. Mechanistically, human T-bet governed CD21loCD11chi B cell differentiation by controlling the chromatin accessibility of lineage-defining genes in these cells: FAS, IL21R, SEC61B, DUSP4, DAPP1, SOX5, CD79B, and CXCR4. Thus, human T-bet is largely redundant for long-lived protective humoral immunity but is essential for the development of a distinct subset of human CD11chiCD21lo B cells.


Subject(s)
B-Lymphocytes , Plasma Cells , Adaptor Proteins, Signal Transducing , Animals , CD11c Antigen/metabolism , Gene Expression Regulation , Humans , Immunoglobulin G , Lipoproteins/metabolism , Lymphocyte Activation , Mice
9.
J Clin Immunol ; 42(7): 1473-1507, 2022 10.
Article in English | MEDLINE | ID: mdl-35748970

ABSTRACT

We report the updated classification of inborn errors of immunity, compiled by the International Union of Immunological Societies Expert Committee. This report documents the key clinical and laboratory features of 55 novel monogenic gene defects, and 1 phenocopy due to autoantibodies, that have either been discovered since the previous update (published January 2020) or were characterized earlier but have since been confirmed or expanded in subsequent studies. While variants in additional genes associated with immune diseases have been reported in the literature, this update includes only those that the committee assessed that reached the necessary threshold to represent novel inborn errors of immunity. There are now a total of 485 inborn errors of immunity. These advances in discovering the genetic causes of human immune diseases continue to significantly further our understanding of molecular, cellular, and immunological mechanisms of disease pathogenesis, thereby simultaneously enhancing immunological knowledge and improving patient diagnosis and management. This report is designed to serve as a resource for immunologists and geneticists pursuing the molecular diagnosis of individuals with heritable immunological disorders and for the scientific dissection of cellular and molecular mechanisms underlying monogenic and related human immune diseases.


Subject(s)
Immune System Diseases , Immunologic Deficiency Syndromes , Humans , Immunologic Deficiency Syndromes/diagnosis , Phenotype , Research Report
10.
J Exp Med ; 219(4)2022 04 04.
Article in English | MEDLINE | ID: mdl-35258551

ABSTRACT

Human USP18 is an interferon (IFN)-stimulated gene product and a negative regulator of type I IFN (IFN-I) signaling. It also removes covalently linked ISG15 from proteins, in a process called deISGylation. In turn, ISG15 prevents USP18 from being degraded by the proteasome. Autosomal recessive complete USP18 deficiency is life-threatening in infancy owing to uncontrolled IFN-I-mediated autoinflammation. We report three Moroccan siblings with autoinflammation and mycobacterial disease who are homozygous for a new USP18 variant. We demonstrate that the mutant USP18 (p.I60N) is normally stabilized by ISG15 and efficient for deISGylation but interacts poorly with the receptor-anchoring STAT2 and is impaired in negative regulation of IFN-I signaling. We also show that IFN-γ-dependent induction of IL-12 and IL-23 is reduced owing to IFN-I-mediated impairment of myeloid cells to produce both cytokines. Thus, insufficient negative regulation of IFN-I signaling by USP18-I60N underlies a specific type I interferonopathy, which impairs IL-12 and IL-23 production by myeloid cells, thereby explaining predisposition to mycobacterial disease.


Subject(s)
Ubiquitin Thiolesterase , Ubiquitins , Cytokines/metabolism , Humans , Inflammation/genetics , Interleukin-12 , Interleukin-23 , Ubiquitin Thiolesterase/metabolism , Ubiquitins/genetics , Ubiquitins/metabolism
11.
J Exp Med ; 218(8)2021 08 02.
Article in English | MEDLINE | ID: mdl-34160550

ABSTRACT

We have described a child suffering from Mendelian susceptibility to mycobacterial disease (MSMD) due to autosomal recessive, complete T-bet deficiency, which impairs IFN-γ production by innate and innate-like adaptive, but not mycobacterial-reactive purely adaptive, lymphocytes. Here, we explore the persistent upper airway inflammation (UAI) and blood eosinophilia of this patient. Unlike wild-type (WT) T-bet, the mutant form of T-bet from this patient did not inhibit the production of Th2 cytokines, including IL-4, IL-5, IL-9, and IL-13, when overexpressed in T helper 2 (Th2) cells. Moreover, Herpesvirus saimiri-immortalized T cells from the patient produced abnormally large amounts of Th2 cytokines, and the patient had markedly high plasma IL-5 and IL-13 concentrations. Finally, the patient's CD4+ αß T cells produced most of the Th2 cytokines in response to chronic stimulation, regardless of their antigen specificities, a phenotype reversed by the expression of WT T-bet. T-bet deficiency thus underlies the excessive production of Th2 cytokines, particularly IL-5 and IL-13, by CD4+ αß T cells, causing blood eosinophilia and UAI. The MSMD of this patient results from defective IFN-γ production by innate and innate-like adaptive lymphocytes, whereas the UAI and eosinophilia result from excessive Th2 cytokine production by adaptive CD4+ αß T lymphocytes.


Subject(s)
Cytokines/metabolism , Pneumonia/immunology , T-Box Domain Proteins/deficiency , Th2 Cells/immunology , Animals , Cytokines/blood , Epigenesis, Genetic , Epitopes/immunology , Female , Humans , Immunologic Memory , Male , Mice, Inbred C57BL , Mutation/genetics , Pedigree , Receptors, Antigen, T-Cell, alpha-beta/metabolism , Respiratory Hypersensitivity/blood , Respiratory Hypersensitivity/immunology , Sequence Analysis, RNA , Single-Cell Analysis , T-Box Domain Proteins/genetics
12.
J Exp Med ; 218(8)2021 08 02.
Article in English | MEDLINE | ID: mdl-34137790

ABSTRACT

Most patients with autosomal dominant hyper-IgE syndrome (AD-HIES) carry rare heterozygous STAT3 variants. Only six of the 135 in-frame variants reported have been experimentally shown to be dominant negative (DN), and it has been recently suggested that eight out-of-frame variants operate by haploinsufficiency. We experimentally tested these 143 variants, 7 novel out-of-frame variants found in HIES patients, and other STAT3 variants from the general population. Strikingly, all 15 out-of-frame variants were DN via their encoded (1) truncated proteins, (2) neoproteins generated from a translation reinitiation codon, and (3) isoforms from alternative transcripts or a combination thereof. Moreover, 128 of the 135 in-frame variants (95%) were also DN. The patients carrying the seven non-DN STAT3 in-frame variants have not been studied for other genetic etiologies. Finally, none of the variants from the general population tested, including an out-of-frame variant, were DN. Overall, our findings show that heterozygous STAT3 variants, whether in or out of frame, underlie AD-HIES through negative dominance rather than haploinsufficiency.


Subject(s)
Genes, Dominant , Job Syndrome/genetics , Mutation/genetics , STAT3 Transcription Factor/genetics , Adolescent , Adult , Alleles , Alternative Splicing/genetics , Child , Child, Preschool , Codon, Nonsense/genetics , Evolution, Molecular , Family , Female , Frameshift Mutation/genetics , Genetics, Population , HEK293 Cells , Humans , Infant , Infant, Newborn , Male , Middle Aged , Pedigree , Protein Biosynthesis , RNA, Messenger/genetics , RNA, Messenger/metabolism
13.
J Clin Immunol ; 41(6): 1339-1351, 2021 08.
Article in English | MEDLINE | ID: mdl-34052995

ABSTRACT

BACKGROUND: Inborn errors of immunity (IEIs) are a heterogeneous group of genetic defects of immunity, which cause high rates of morbidity and mortality mainly among children due to infectious and non-infectious complications. The IEI burden has been critically underestimated in countries from middle- and low-income regions and the majority of patients with IEI in these regions lack a molecular diagnosis. METHODS: We analyzed the clinical, immunologic, and genetic data of IEI patients from 22 countries in the Middle East and North Africa (MENA) region. The data was collected from national registries and diverse databases such as the Asian Pacific Society for Immunodeficiencies (APSID) registry, African Society for Immunodeficiencies (ASID) registry, Jeffrey Modell Foundation (JMF) registry, J Project centers, and International Consortium on Immune Deficiency (ICID) centers. RESULTS: We identified 17,120 patients with IEI, among which females represented 39.4%. Parental consanguinity was present in 60.5% of cases and 27.3% of the patients were from families with a confirmed previous family history of IEI. The median age of patients at the onset of disease was 36 months and the median delay in diagnosis was 41 months. The rate of registered IEI patients ranges between 0.02 and 7.58 per 100,000 population, and the lowest rates were in countries with the highest rates of disability-adjusted life years (DALY) and death rates for children. Predominantly antibody deficiencies were the most frequent IEI entities diagnosed in 41.2% of the cohort. Among 5871 patients genetically evaluated, the diagnostic yield was 83% with the majority (65.2%) having autosomal recessive defects. The mortality rate was the highest in patients with non-syndromic combined immunodeficiency (51.7%, median age: 3.5 years) and particularly in patients with mutations in specific genes associated with this phenotype (RFXANK, RAG1, and IL2RG). CONCLUSIONS: This comprehensive registry highlights the importance of a detailed investigation of IEI patients in the MENA region. The high yield of genetic diagnosis of IEI in this region has important implications for prevention, prognosis, treatment, and resource allocation.


Subject(s)
Genetic Diseases, Inborn/epidemiology , Primary Immunodeficiency Diseases/epidemiology , Adolescent , Adult , Africa, Northern/epidemiology , Aged , Child , Consensus , Disability-Adjusted Life Years , Female , Humans , Male , Middle Aged , Middle East/epidemiology , Registries , Young Adult
14.
J Clin Immunol ; 41(3): 666-679, 2021 04.
Article in English | MEDLINE | ID: mdl-33598806

ABSTRACT

The most recent updated classification of inborn errors of immunity/primary immunodeficiencies, compiled by the International Union of Immunological Societies Expert Committee, was published in January 2020. Within days of completing this report, it was already out of date, evidenced by the frequent publication of genetic variants proposed to cause novel inborn errors of immunity. As the next formal report from the IUIS Expert Committee will not be published until 2022, we felt it important to provide the community with a brief update of recent contributions to the field of inborn errors of immunity. Herein, we highlight studies that have identified 26 additional monogenic gene defects that reach the threshold to represent novel causes of immune defects.


Subject(s)
Genetic Predisposition to Disease , Primary Immunodeficiency Diseases/epidemiology , Primary Immunodeficiency Diseases/genetics , Alleles , COVID-19/complications , COVID-19/epidemiology , COVID-19/virology , Diagnosis, Differential , Disease Management , Genetic Association Studies/methods , Genotype , Humans , Immunity/genetics , Inheritance Patterns , Phenotype , Primary Immunodeficiency Diseases/diagnosis , Public Health Surveillance , Risk Factors
15.
Cell ; 183(7): 1826-1847.e31, 2020 12 23.
Article in English | MEDLINE | ID: mdl-33296702

ABSTRACT

Inborn errors of human interferon gamma (IFN-γ) immunity underlie mycobacterial disease. We report a patient with mycobacterial disease due to inherited deficiency of the transcription factor T-bet. The patient has extremely low counts of circulating Mycobacterium-reactive natural killer (NK), invariant NKT (iNKT), mucosal-associated invariant T (MAIT), and Vδ2+ γδ T lymphocytes, and of Mycobacterium-non reactive classic TH1 lymphocytes, with the residual populations of these cells also producing abnormally small amounts of IFN-γ. Other lymphocyte subsets develop normally but produce low levels of IFN-γ, with the exception of CD8+ αß T and non-classic CD4+ αß TH1∗ lymphocytes, which produce IFN-γ normally in response to mycobacterial antigens. Human T-bet deficiency thus underlies mycobacterial disease by preventing the development of innate (NK) and innate-like adaptive lymphocytes (iNKT, MAIT, and Vδ2+ γδ T cells) and IFN-γ production by them, with mycobacterium-specific, IFN-γ-producing, purely adaptive CD8+ αß T, and CD4+ αß TH1∗ cells unable to compensate for this deficit.


Subject(s)
Adaptive Immunity , Immunity, Innate , Interferon-gamma/immunology , Mycobacterium/immunology , T-Box Domain Proteins/metabolism , Amino Acid Sequence , Base Sequence , Cell Lineage , Child, Preschool , Chromatin/metabolism , CpG Islands/genetics , DNA Methylation/genetics , Dendritic Cells/metabolism , Epigenesis, Genetic , Female , Homozygote , Humans , INDEL Mutation/genetics , Infant , Interferon-gamma/metabolism , Killer Cells, Natural/cytology , Killer Cells, Natural/metabolism , Loss of Function Mutation/genetics , Male , Mycobacterium Infections/genetics , Mycobacterium Infections/immunology , Mycobacterium Infections/microbiology , Pedigree , T-Box Domain Proteins/chemistry , T-Box Domain Proteins/deficiency , T-Box Domain Proteins/genetics , T-Lymphocytes, Helper-Inducer/immunology , Transcriptome/genetics
16.
J Exp Med ; 217(5)2020 05 04.
Article in English | MEDLINE | ID: mdl-32092142

ABSTRACT

Type I interferonopathies are monogenic disorders characterized by enhanced type I interferon (IFN-I) cytokine activity. Inherited USP18 and ISG15 deficiencies underlie type I interferonopathies by preventing the regulation of late responses to IFN-I. Specifically, USP18, being stabilized by ISG15, sterically hinders JAK1 from binding to the IFNAR2 subunit of the IFN-I receptor. We report an infant who died of autoinflammation due to a homozygous missense mutation (R148Q) in STAT2. The variant is a gain of function (GOF) for induction of the late, but not early, response to IFN-I. Surprisingly, the mutation does not enhance the intrinsic activity of the STAT2-containing transcriptional complex responsible for IFN-I-stimulated gene induction. Rather, the STAT2 R148Q variant is a GOF because it fails to appropriately traffic USP18 to IFNAR2, thereby preventing USP18 from negatively regulating responses to IFN-I. Homozygosity for STAT2 R148Q represents a novel molecular and clinical phenocopy of inherited USP18 deficiency, which, together with inherited ISG15 deficiency, defines a group of type I interferonopathies characterized by an impaired regulation of late cellular responses to IFN-I.


Subject(s)
Gain of Function Mutation/genetics , Interferon Type I/metabolism , STAT2 Transcription Factor/genetics , Ubiquitin Thiolesterase/deficiency , Amino Acid Sequence , Base Sequence , Cell Line , Female , Gene Expression Regulation , Homozygote , Humans , Infant, Newborn , Male , Pedigree , Phenotype , Protein Domains , STAT2 Transcription Factor/chemistry , Ubiquitin Thiolesterase/genetics , Exome Sequencing
17.
18.
J Clin Immunol ; 40(1): 66-81, 2020 01.
Article in English | MEDLINE | ID: mdl-32048120

ABSTRACT

Since 2013, the International Union of Immunological Societies (IUIS) expert committee (EC) on Inborn Errors of Immunity (IEI) has published an updated phenotypic classification of IEI, which accompanies and complements their genotypic classification into ten tables. This phenotypic classification is user-friendly and serves as a resource for clinicians at the bedside. There are now 430 single-gene IEI underlying phenotypes as diverse as infection, malignancy, allergy, autoimmunity, and autoinflammation. We herein report the 2019 phenotypic classification, including the 65 new conditions. The diagnostic algorithms are based on clinical and laboratory phenotypes for each of the ten broad categories of IEI.


Subject(s)
Immunity/genetics , Immunologic Deficiency Syndromes/genetics , Autoimmunity/genetics , Genotype , Hereditary Autoinflammatory Diseases/genetics , Humans , Hypersensitivity , Phenotype
19.
J Clin Immunol ; 40(1): 24-64, 2020 01.
Article in English | MEDLINE | ID: mdl-31953710

ABSTRACT

We report the updated classification of Inborn Errors of Immunity/Primary Immunodeficiencies, compiled by the International Union of Immunological Societies Expert Committee. This report documents the key clinical and laboratory features of 430 inborn errors of immunity, including 64 gene defects that have either been discovered in the past 2 years since the previous update (published January 2018) or were characterized earlier but have since been confirmed or expanded upon in subsequent studies. The application of next-generation sequencing continues to expedite the rapid identification of novel gene defects, rare or common; broaden the immunological and clinical phenotypes of conditions arising from known gene defects and even known variants; and implement gene-specific therapies. These advances are contributing to greater understanding of the molecular, cellular, and immunological mechanisms of disease, thereby enhancing immunological knowledge while improving the management of patients and their families. This report serves as a valuable resource for the molecular diagnosis of individuals with heritable immunological disorders and also for the scientific dissection of cellular and molecular mechanisms underlying inborn errors of immunity and related human diseases.

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