Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Wiskott-Aldrich syndrome protein (WASP) is an important regulator of the actin cytoskeleton that is required for many haematopoietic and immune cell functions, including effective migration, phagocytosis and immune synapse formation. Loss of WASP activity leads to Wiskott-Aldrich syndrome, an X-linked disease that is associated with defects in a broad range of cellular processes, resulting in complex immunodeficiency, autoimmunity and microthrombocytopenia. Intriguingly, gain of function mutations cause a separate disease that is mainly characterized by neutropenia. Here, we describe recent insights into the cellular mechanisms of these two related, but distinct, human diseases and discuss their wider implications for haematopoiesis, immune function and autoimmunity.
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PMID:WASP: a key immunological multitasker. 2018 58

Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive primary immunodeficiency characterised by immune dysregulation, microthrombocytopaenia, eczema and lymphoid malignancies. Mutations in the WAS gene can lead to distinct syndrome variations which largely, although not exclusively, depend upon the mutation. Premature termination and deletions abrogate Wiskott-Aldrich syndrome protein (WASp) expression and lead to severe disease (WAS). Missense mutations usually result in reduced protein expression and the phenotypically milder X-linked thrombocytopenia (XLT) or attenuated WAS [1-3]. More recently however novel activating mutations have been described that give rise to X-linked neutropenia (XLN), a third syndrome defined by neutropenia with variable myelodysplasia [4-6]. WASP is key in transducing signals from the cell surface to the actin cytoskeleton, and a lack of WASp results in cytoskeletal defects that compromise multiple aspects of normal cellular activity including proliferation, phagocytosis, immune synapse formation, adhesion and directed migration.
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PMID:The Wiskott-Aldrich syndrome: The actin cytoskeleton and immune cell function. 2117 75

Severe congenital neutropenia (SCN) is a rare primary immunodeficiency. Different genes are found to be associated with SCN, including ELA2, HAX1, WAS, GFI1, G-CSFR. Also, recently G6PC3 as a rare gene in SCN has been reported. Patients with G6PC3 often have cardiac and/or urogenital malformations. Two patients with persistent severe neutropenia, recurrent infections and maturation arrest at promyelocyte-myelocyte stage in their bone marrow were assessed in this study. Both patients showed structural heart disease and one of them also showed urogenital anomaly. Sequence analyses of G6PC3 in 2 patients revealed two different homozygous mutations, one in exon 6 (Asn 313 fs), and the other in exon 3 (Ser 139 Met), the latter is a new mutation which has not been reported in previous studies. It can be concluded that G6PC3 is one of the responsible gene for SCN in Iranian patients. Based on the results, a new mutation in G6PC3 observed in one patient.
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PMID:Two cases of syndromic neutropenia with a report of novel mutation in G6PC3. 2189 29

OVER THE PAST DECADE, ENORMOUS PROGRESS HAS BEEN MADE IN THE UNDERSTANDING OF SEVERE CONGENITAL NEUTROPENIA (SCN), BY IDENTIFICATION OF SEVERAL CAUSAL GENE MUTATIONS: in ELANE, GFI1, HAX1, WAS and G3PC3. SCN is a preleukemic condition, independent of the genetic subtype. Acquired CSF3R mutations are specific for SCN and are strongly associated with malignant progression. In this review, we describe the known genetic subtypes of SCN, their molecular basis and clinical presentation and summarize the available evidence on CSF3R mutations and monosomy 7 in malignant conversion.
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PMID:Severe congenital neutropenia, a genetically heterogeneous disease group with an increased risk of AML/MDS. 2205 85

Wiskott-Aldrich Syndrome (WAS) is a severe X-linked Primary Immunodeficiency that affects 1-10 out of 1 million male individuals. WAS is caused by mutations in the WAS Protein (WASP) expressing gene that leads to the absent or reduced expression of the protein. WASP is a cytoplasmic protein that regulates the formation of actin filaments in hematopoietic cells. WASP deficiency causes many immune cell defects both in humans and in the WAS murine model, the Was(-/-) mouse. Both cellular and humoral immune defects in WAS patients contribute to the onset of severe clinical manifestations, in particular microthrombocytopenia, eczema, recurrent infections, and a high susceptibility to develop autoimmunity and malignancies. Autoimmune diseases affect from 22 to 72% of WAS patients and the most common manifestation is autoimmune hemolytic anemia, followed by vasculitis, arthritis, neutropenia, inflammatory bowel disease, and IgA nephropathy. Many groups have widely explored immune cell functionality in WAS partially explaining how cellular defects may lead to pathology. However, the mechanisms underlying the occurrence of autoimmune manifestations have not been clearly described yet. In the present review, we report the most recent progresses in the study of immune cell function in WAS that have started to unveil the mechanisms contributing to autoimmune complications in WAS patients.
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PMID:Autoimmunity in wiskott-Aldrich syndrome: an unsolved enigma. 2282 11

Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive disease characterized by eczema, thrombocytopenia and immune deficiency. WAS gene mutations impair WAS protein function which cause WAS. The WAS-related disorders of X-linked thrombocytopenia (XLT) and X-linked congenital neutropenia (XLN) may have similar but less severe symptoms those are also caused by mutations of the same gene. We present two cases of WAS in neonates with WAS gene mutations. Early genetic diagnosis can help to the treatment and prevention this disease.
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PMID:Two cases of Wiskott-Aldrich syndrome in neonates due to gene mutations. 2330 16

Severe congenital neutropenia (SCN) is a rare primary immunodeficiency disease. Different genes are found to be associated with SCN, including ELA2, HAX1, WAS, GFI1, G-CSFR and G6PC3. The aim of this study was to find different gene mutations responsible for SCN in Iranian patients. Twenty-seven patients with SCN referred to Immunology, Asthma and Allergy Research Institute during a five year priod 5 years (May 2007 and May 2012), were included in this study. Neutropenia related exons and flanking regions of ELA2, HAX1, WAS, GFI1, G-CSFR and G6PC3 were amplified by PCR and the sequences were analyzed. The results showed different mutations including 4 ELANE mutations, 11 HAX1 mutations and 2 G6PC3 mutations. None of the patients had GFI1 mutation and also one mutation was found in G-CSFR in a patient with ELANE mutation. Ten patients had unknown genetic diagnosis which was compatible with other studies. According to these results, most of the patients showed HAX1 mutations and this finding which significantly differed from other reports, might be related to differences in Iranian ethnicity and also in high rate of consanguineous marriages in Iran.
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PMID:Different pattern of gene mutations in Iranian patients with severe congenital neutropenia (including 2 new mutations). 2345 84

Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by microthrombocytopenia, eczema, recurrent infections, and an increased incidence of autoimmunity and malignancies. The disease is caused by mutations in the WAS gene expressed exclusively in hematopoietic cells. WAS protein (WASp) is a multidomain protein that exists in complex with several partners that play important roles in its function. WASp belongs to a family of proteins that relay signals from the surface of the cell to the actin cytoskeleton. Mutations in the WAS gene have various effects on the level of WASp, which, in turn, correlates with the severity of the disease. In addition to WAS, mutations in the WAS gene can result in the mild variant X-linked thrombocytopenia, or in X-linked neutropenia, characterized by neutropenia with myelodysplasia. The absence of functional WASp leads to a severe clinical phenotype that can result in death if not diagnosed and treated early in life. The treatment of choice with the best outcome is hematopoietic stem cell transplantation, preferably from a matched related donor.
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PMID:Wiskott-Aldrich syndrome: a comprehensive review. 2352 2

Wiskott-Aldrich syndrome (WAS) and X-linked neutropenia (XLN) are immunodeficiencies in which the function of several haematopoietic cell lineages is perturbed as a result of mutations in the actin regulator WASp. From in vitro cell biology experiments, and biochemical and structural approaches, we know much about the functional domains of WASp and how WASp might regulate the dynamic actin cytoskeleton downstream of activators such as Cdc42, but in vivo experiments are much more challenging. In patients, there is a correlation between clinical disease and genotype, with severe reductions in WASp expression or function associating with complex multilineage immunodeficiency, whereas specific mutations that cause constitutive activation of WASp result in congenital neutropenia. Here, we take advantage of the genetic tractability and translucency of zebrafish larvae to first characterise how a null mutant in zfWASp influences the behaviour of neutrophils and macrophages in response to tissue damage and to clearance of infections. We then use this mutant background to study how leukocyte lineage-specific transgenic replacement with human WASp variants (including normal wild type and point mutations that either fail to bind Cdc42 or cannot be phosphorylated, and a constitutively active mutant equivalent to that seen in XLN patients) alter the capacity for generation of neutrophils, their chemotactic response to wounds and the phagocytic clearance capacity of macrophages. This model provides a unique insight into WASp-related immunodeficiency at both a cellular and whole organism level.
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PMID:Modelling of human Wiskott-Aldrich syndrome protein mutants in zebrafish larvae using in vivo live imaging. 2386 79

Mutations in the gene encoding the Wiskott-Aldrich syndrome protein (WASP) are responsible for Wiskott-Aldrich syndrome and WASP is a major actin regulator in the cytoplasm. Although rare gain-of-function mutations in the WASP gene are known to result in X-linked neutropenia (XLN), the molecular pathogenesis of XLN is not fully understood. In this study, we showed that all reported constitutively activating mutants (L270P, S272P and I294T) of WASP were hyperphosphorylated by Src family tyrosine kinases and demonstrated higher actin polymerization activities compared with wild-type (WT) WASP. Further analysis showed a tendency of activating WASP mutants to localize in the nucleus compared with WT or the Y291F mutant of WASP. In addition, we found that WASP could form a complex with nuclear RNA-binding protein, 54 kDa (p54nrb) and RNA polymerase II (RNAP II). ChIP assays revealed that WASP associated with DNA, although the affinity was relatively weaker than RNAP II. To determine whether gene transcription was affected by WASP mutation in myeloid cells, we performed microarray analysis and found different expression profiles between WT and L270P WASP-transfected K562 cells. Among the genes affected, granulocyte colony-stimulating factor receptor, Runx1, and protein tyrosine phosphatase receptor c were included. ChIP on chip analysis of genomic DNA showed WT and L270P WASP had a highly similar DNA-binding pattern but differed in binding affinity at the same locus. Therefore, our results suggest that the open conformation of WASP regulates its nuclear localization and plays requisite roles in regulating gene transcription that would contribute to the outcome in the nucleus of myeloid cells.
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PMID:The open conformation of WASP regulates its nuclear localization and gene transcription in myeloid cells. 2440 8


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