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1.
Proc Natl Acad Sci U S A ; 116(33): 16463-16472, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31346092

RESUMO

Heterozygous in-frame mutations in coding regions of human STAT3 underlie the only known autosomal dominant form of hyper IgE syndrome (AD HIES). About 5% of familial cases remain unexplained. The mutant proteins are loss-of-function and dominant-negative when tested following overproduction in recipient cells. However, the production of mutant proteins has not been detected and quantified in the cells of heterozygous patients. We report a deep intronic heterozygous STAT3 mutation, c.1282-89C>T, in 7 relatives with AD HIES. This mutation creates a new exon in the STAT3 complementary DNA, which, when overexpressed, generates a mutant STAT3 protein (D427ins17) that is loss-of-function and dominant-negative in terms of tyrosine phosphorylation, DNA binding, and transcriptional activity. In immortalized B cells from these patients, the D427ins17 protein was 2 kDa larger and 4-fold less abundant than wild-type STAT3, on mass spectrometry. The patients' primary B and T lymphocytes responded poorly to STAT3-dependent cytokines. These findings are reminiscent of the impaired responses of leukocytes from other patients with AD HIES due to typical STAT3 coding mutations, providing further evidence for the dominance of the mutant intronic allele. These findings highlight the importance of sequencing STAT3 introns in patients with HIES without candidate variants in coding regions and essential splice sites. They also show that AD HIES-causing STAT3 mutant alleles can be dominant-negative even if the encoded protein is produced in significantly smaller amounts than wild-type STAT3.

2.
J Clin Immunol ; 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29995221

RESUMO

PURPOSE: Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Autosomal recessive complete IL-12Rß1 deficiency is the most frequent genetic etiology of MSMD. Only two of the 84 known mutations are copy number variations (CNVs), identified in two of the 213 IL-12Rß1-deficient patients and two of the 164 kindreds reported. These two CNVs are large deletions found in the heterozygous or homozygous state. We searched for novel families with IL-12Rß1 deficiency due to CNVs. METHODS: We studied six MSMD patients from five unrelated kindreds displaying adverse reactions to BCG vaccination. Three of the patients also presented systemic salmonellosis, two had mucocutaneous candidiasis, and one had disseminated histoplasmosis. We searched for CNVs and other variations by IL12RB1-targeted next-generation sequencing (NGS). RESULTS: We identified six new IL-12Rß1-deficient patients with a complete loss of IL-12Rß1 expression on phytohemagglutinin-activated T cells and/or EBV-transformed B cells. The cells of these patients did not respond to IL-12 and IL-23. Five different CNVs encompassing IL12RB1 (four deletions and one duplication) were identified in these patients by NGS coverage analysis, either in the homozygous state (n = 1) or in trans (n = 4) with a single-nucleotide variation (n = 3) or a small indel (n = 1). Seven of the nine mutations are novel. Interestingly, four of the five CNVs were predicted to be driven by nearby Alu elements, as well as the two previously reported large deletions. The IL12RB1 locus is actually enriched in Alu elements (44.7%), when compared with the rest of the genome (10.5%). CONCLUSION: The IL12RB1 locus is Alu-enriched and therefore prone to rearrangements at various positions. CNVs should be considered in the genetic diagnosis of IL-12Rß1 deficiency.

3.
Hum Mutat ; 38(10): 1355-1359, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28585352

RESUMO

Griscelli syndrome type 2 (GS2) is a rare and often fatal autosomal recessive, hyperinflammatory disorder. It is associated with hypopigmentation of the skin and the hair, resulting in the characteristic pigment accumulation and clumping in the hair shaft. Loss-of-function mutations in RAB27A, resulting from point mutations, short indel, or large deletions, account for all the cases reported to date. However, several GS2 cases originating from Saudi Arabia lack a genetic diagnosis. Here, we report on a new RAB27A genetic anomaly observed in seven Saudi Arabia families that had remained negative after extensive molecular genomic DNA testing. Linkage analysis and targeted sequencing of the RAB27A genomic region in several of these patients led to the identification of a common homozygous tandem duplication of 38 kb affecting exon 2-5 and resulting in a premature stop codon. The pathogenic effect of this duplication was confirmed by a cDNA analysis and functional assays. The identification of microhomology flanking the breakpoint site suggests a possible underlying mechanism.


Assuntos
Hipopigmentação/diagnóstico , Hipopigmentação/genética , Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/genética , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/genética , Piebaldismo/diagnóstico , Piebaldismo/genética , Proteínas rab27 de Ligação ao GTP/genética , Códon sem Sentido , Consanguinidade , Éxons/genética , Feminino , Duplicação Gênica/genética , Ligação Genética , Cabelo/patologia , Homozigoto , Humanos , Hipopigmentação/metabolismo , Hipopigmentação/patologia , Síndromes de Imunodeficiência/patologia , Linfo-Histiocitose Hemofagocítica/patologia , Masculino , Mutação/genética , Linhagem , Piebaldismo/patologia , Arábia Saudita , Deleção de Sequência , Pigmentação da Pele/genética , Linfócitos T Citotóxicos/patologia
5.
Medicine (Baltimore) ; 91(4): e1-19, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22751495

RESUMO

Autosomal dominant deficiency of signal transducer and activator of transcription 3 (STAT3) is the main genetic etiology of hyper-immunoglobulin (Ig) E syndrome. We documented the molecular, cellular, and clinical features of 60 patients with heterozygous STAT3 mutations from 47 kindreds followed in France. We identified 11 known and 13 new mutations of STAT3. Low levels of interleukin (IL)-6-dependent phosphorylation and nuclear translocation (or accumulation) of STAT3 were observed in Epstein-Barr virus-transformed B lymphocytes (EBV-B cells) from all STAT3-deficient patients tested. The immunologic phenotype was characterized by high serum IgE levels (96% of the patients), memory B-cell lymphopenia (94.5%), and hypereosinophilia (80%). A low proportion of IL-17A-producing circulating T cells was found in 14 of the 15 patients tested. Mucocutaneous infections were the most frequent, typically caused by Staphylococcus aureus (all patients) and Candida albicans (85%). Up to 90% of the patients had pneumonia, mostly caused by Staph. aureus (31%) or Streptococcus pneumoniae (30%). Recurrent pneumonia was associated with secondary bronchiectasis and pneumatocele (67%), as well as secondary aspergillosis (22%). Up to 92% of the patients had dermatitis and connective tissue abnormalities, with facial dysmorphism (95%), retention of decidual teeth (65%), osteopenia (50%), and hyperextensibility (50%). Four patients developed non-Hodgkin lymphoma. The clinical outcome was favorable, with 56 patients, including 43 adults, still alive at the end of study (mean age, 21 yr; range, 1 mo to 46 yr). Only 4 patients died, 3 from severe bacterial infection (aged 1, 15, and 29 yr, respectively). Antibiotic prophylaxis (90% of patients), antifungal prophylaxis (50%), and IgG infusions (53%) improved patient health, as demonstrated by the large decrease in pneumonia recurrence. Overall, the prognosis of STAT3 deficiency may be considered good, provided that multiple prophylactic measures, including IgG infusions, are implemented.


Assuntos
Hospedeiro Imunocomprometido/genética , Síndrome de Job/epidemiologia , Síndrome de Job/genética , Fator de Transcrição STAT3/deficiência , Fator de Transcrição STAT3/genética , Adolescente , Adulto , Distribuição por Idade , Criança , Pré-Escolar , Estudos Transversais , Análise Mutacional de DNA , Bases de Dados Factuais , Eczema/epidemiologia , Eczema/etiologia , Feminino , França/epidemiologia , Predisposição Genética para Doença/epidemiologia , Heterozigoto , Humanos , Incidência , Lactente , Recém-Nascido , Síndrome de Job/complicações , Síndrome de Job/imunologia , Masculino , Pessoa de Meia-Idade , Fosforilação , Pneumonia Bacteriana/epidemiologia , Pneumonia Bacteriana/etiologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/etiologia , Medição de Risco , Índice de Gravidade de Doença , Distribuição por Sexo , Transdução de Sinais , Dermatopatias Bacterianas/epidemiologia , Dermatopatias Bacterianas/etiologia , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/etiologia , Análise de Sobrevida , Adulto Jovem
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