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1.
Dig Dis Sci ; 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31485995

RESUMO

BACKGROUND AND AIMS: The use of anesthesia assistance (AA) for screening colonoscopy has been increasing substantially over the past decade, raising concerns about procedure safety and cost without demonstrating a proven improvement in overall quality indicators such as adenoma detection rate (ADR). The effect of AA on ADR has not been extensively studied among trainees learning colonoscopy. We aimed to determine whether type of sedation used during screening colonoscopy affects trainee ADR. METHODS: Using the electronic endoscopy databases of two hospitals in our medical center, we identified colonoscopies performed by 15 trainees from 2014 through 2018, including all screening examinations in which the cecum was reached. Multivariable logistic regression was used to determine factors associated with adenoma detection. RESULTS: We identified 1420 unique patients who underwent screening colonoscopy by a trainee meeting the inclusion criteria. Of these, 459 (32.3%) were performed with AA. Overall trainee ADR was 39.6%, with ADR increasing from 35.0% in year one of training to 42.8% in year three (p = 0.047). ADR for cases with AA was 37.9%, while ADR for conscious sedation cases was 32.0% (p = 0.374). Despite this 5.9% absolute difference, the use of AA was not associated with finding an adenoma on multivariable analysis when controlling for patient age, sex, smoking status, body mass index, trainee year of training, mean withdrawal time, supervising attending ADR, and bowel preparation quality (OR 0.85; 95% CI 0.67-1.09). CONCLUSIONS: Despite providing the ability to more consistently sedate patients, the use of AA did not affect trainee ADR. These results on trainee ADR and sedation type suggest that the overall lack of association between AA use and ADR is applicable to the trainee setting.

2.
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.

4.
Sci Immunol ; 3(30)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30578351

RESUMO

Hundreds of patients with autosomal recessive, complete IL-12p40 or IL-12Rß1 deficiency have been diagnosed over the last 20 years. They typically suffer from invasive mycobacteriosis and, occasionally, from mucocutaneous candidiasis. Susceptibility to these infections is thought to be due to impairments of IL-12-dependent IFN-γ immunity and IL-23-dependent IL-17A/IL-17F immunity, respectively. We report here patients with autosomal recessive, complete IL-12Rß2 or IL-23R deficiency, lacking responses to IL-12 or IL-23 only, all of whom, unexpectedly, display mycobacteriosis without candidiasis. We show that αß T, γδ T, B, NK, ILC1, and ILC2 cells from healthy donors preferentially produce IFN-γ in response to IL-12, whereas NKT cells and MAIT cells preferentially produce IFN-γ in response to IL-23. We also show that the development of IFN-γ-producing CD4+ T cells, including, in particular, mycobacterium-specific TH1* cells (CD45RA-CCR6+), is dependent on both IL-12 and IL-23. Last, we show that IL12RB1, IL12RB2, and IL23R have similar frequencies of deleterious variants in the general population. The comparative rarity of symptomatic patients with IL-12Rß2 or IL-23R deficiency, relative to IL-12Rß1 deficiency, is, therefore, due to lower clinical penetrance. There are fewer symptomatic IL-23R- and IL-12Rß2-deficient than IL-12Rß1-deficient patients, not because these genetic disorders are rarer, but because the isolated absence of IL-12 or IL-23 is, in part, compensated by the other cytokine for the production of IFN-γ, thereby providing some protection against mycobacteria. These experiments of nature show that human IL-12 and IL-23 are both required for optimal IFN-γ-dependent immunity to mycobacteria, both individually and much more so cooperatively.


Assuntos
Imunidade Inata/imunologia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-23/imunologia , Infecções por Micobactéria não Tuberculosa/imunologia , Mycobacterium/imunologia , Humanos , Interleucina-12/deficiência , Interleucina-12/genética , Interleucina-23/deficiência , Interleucina-23/genética , Linhagem
6.
Immunol Cell Biol ; 2018 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-30264912

RESUMO

Mendelian susceptibility to mycobacterial disease (MSMD) is caused by inborn errors of IFN-γ immunity. Since 1996, disease-causing mutations have been found in 11 genes, which, through allelic heterogeneity, underlie 21 different genetic disorders. We briefly review here progress in the study of molecular, cellular and clinical aspects of MSMD since the last comprehensive review published in 2014. Highlights include the discoveries of (1) a new genetic etiology, autosomal recessive signal peptide peptidase-like 2 A deficiency, (2) TYK2-deficient patients with a clinical phenotype of MSMD, (3) an allelic form of partial recessive IFN-γR2 deficiency, and (4) two forms of syndromic MSMD: RORγ/RORγT and JAK1 deficiencies. These recent findings illustrate how genetic and immunological studies of MSMD can shed a unique light onto the mechanisms of protective immunity to mycobacteria in humans.

7.
Nat Immunol ; 19(9): 973-985, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30127434

RESUMO

Human inborn errors of IFN-γ immunity underlie mycobacterial diseases. We describe patients with Mycobacterium bovis (BCG) disease who are homozygous for loss-of-function mutations of SPPL2A. This gene encodes a transmembrane protease that degrades the N-terminal fragment (NTF) of CD74 (HLA invariant chain) in antigen-presenting cells. The CD74 NTF therefore accumulates in the HLA class II+ myeloid and lymphoid cells of SPPL2a-deficient patients. This toxic fragment selectively depletes IL-12- and IL-23-producing CD1c+ conventional dendritic cells (cDC2s) and their circulating progenitors. Moreover, SPPL2a-deficient memory TH1* cells selectively fail to produce IFN-γ when stimulated with mycobacterial antigens in vitro. Finally, Sppl2a-/- mice lack cDC2s, have CD4+ T cells that produce small amounts of IFN-γ after BCG infection, and are highly susceptible to infection with BCG or Mycobacterium tuberculosis. These findings suggest that inherited SPPL2a deficiency in humans underlies mycobacterial disease by decreasing the numbers of cDC2s and impairing IFN-γ production by mycobacterium-specific memory TH1* cells.

8.
Hum Mol Genet ; 27(22): 3919-3935, 2018 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31222290

RESUMO

Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by clinical disease caused by weakly virulent mycobacteria, such as environmental mycobacteria and Bacillus Calmette-Guérin vaccines, in otherwise healthy individuals. All known genetic etiologies disrupt interferon (IFN)-γ immunity. Germline bi-allelic mutations of IFNGR2 can underlie partial or complete forms of IFN-γ receptor 2 (IFN-γR2) deficiency. Patients with partial IFN-γR2 deficiency express a dysfunctional molecule on the cell surface. We studied three patients with MSMD from two unrelated kindreds from Turkey (P1, P2) and India (P3), by whole-exome sequencing. P1 and P2 are homozygous for a mutation of the initiation codon(c.1A>G) of IFNGR2, whereas P3 is homozygous for a mutation of the second codon (c.4delC). Overexpressed mutant alleles produce small amounts of full-length IFN-γR2 resulting in an impaired, but not abolished, response to IFN-γ. Moreover, SV40-fibroblasts of P1 and P2 responded weakly to IFN-γ, and Epstein Barr virus-transformed B cells had a barely detectable response to IFN-γ. Studies in patients' primary T cells and monocyte-derived macrophages yielded similar results. The residual expression of IFN-γR2 protein of normal molecular weight and function is due to the initiation of translation between the second and ninth non-AUG codons. We thus describe mutations of the first and second codons of IFNGR2, which define a new form of partial recessive IFN-γR2 deficiency. Residual levels of IFN-γ signaling were very low, accounting for the more severe clinical phenotype of these patients with residual expression levels of normally functional surface receptors than of patients with partial recessive IFN-γR2 deficiency due to surface-expressed dysfunctional receptors, whose residual levels of IFN-γ signaling were higher.


Assuntos
Alelos , Códon de Iniciação , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Homozigoto , Infecções por Mycobacterium/genética , Receptores de Interferon/genética , Criança , Pré-Escolar , Feminino , Humanos , Índia , Lactente , Recém-Nascido , Masculino , Turquia , Sequenciamento Completo do Exoma
9.
J Allergy Clin Immunol ; 140(1): 232-241, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28011069

RESUMO

BACKGROUND: Germline heterozygous mutations in human signal transducer and activator of transcription 1 (STAT1) can cause loss of function (LOF), as in patients with Mendelian susceptibility to mycobacterial diseases, or gain of function (GOF), as in patients with chronic mucocutaneous candidiasis. LOF and GOF mutations are equally rare and can affect the same domains of STAT1, especially the coiled-coil domain (CCD) and DNA-binding domain (DBD). Moreover, 6% of patients with chronic mucocutaneous candidiasis with a GOF STAT1 mutation have mycobacterial disease, obscuring the functional significance of the identified STAT1 mutations. Current computational approaches, such as combined annotation-dependent depletion, do not distinguish LOF and GOF variants. OBJECTIVE: We estimated variations in the CCD/DBD of STAT1. METHODS: We mutagenized 342 individual wild-type amino acids in the CCD/DBD (45.6% of full-length STAT1) to alanine and tested the mutants for STAT1 transcriptional activity. RESULTS: Of these 342 mutants, 201 were neutral, 30 were LOF, and 111 were GOF mutations in a luciferase assay. This assay system correctly estimated all previously reported LOF mutations (100%) and slightly fewer GOF mutations (78.1%) in the CCD/DBD of STAT1. We found that GOF alanine mutants occurred at the interface of the antiparallel STAT1 dimer, suggesting that they destabilize this dimer. This assay also precisely predicted the effect of 2 hypomorphic and dominant negative mutations, E157K and G250E, in the CCD of STAT1 that we found in 2 unrelated patients with Mendelian susceptibility to mycobacterial diseases. CONCLUSION: The systematic alanine-scanning assay is a useful tool to estimate the GOF or LOF status and the effect of heterozygous missense mutations in STAT1 identified in patients with severe infectious diseases, including mycobacterial and fungal diseases.


Assuntos
Alanina/genética , Infecções por Mycobacterium/genética , Fator de Transcrição STAT1/genética , Bioensaio , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Mutagênese , Mutação , Domínios Proteicos
12.
Proc Natl Acad Sci U S A ; 112(44): 13615-20, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26483451

RESUMO

The protein-coding exome of a patient with a monogenic disease contains about 20,000 variants, only one or two of which are disease causing. We found that 58% of rare variants in the protein-coding exome of the general population are located in only 2% of the genes. Prompted by this observation, we aimed to develop a gene-level approach for predicting whether a given human protein-coding gene is likely to harbor disease-causing mutations. To this end, we derived the gene damage index (GDI): a genome-wide, gene-level metric of the mutational damage that has accumulated in the general population. We found that the GDI was correlated with selective evolutionary pressure, protein complexity, coding sequence length, and the number of paralogs. We compared GDI with the leading gene-level approaches, genic intolerance, and de novo excess, and demonstrated that GDI performed best for the detection of false positives (i.e., removing exome variants in genes irrelevant to disease), whereas genic intolerance and de novo excess performed better for the detection of true positives (i.e., assessing de novo mutations in genes likely to be disease causing). The GDI server, data, and software are freely available to noncommercial users from lab.rockefeller.edu/casanova/GDI.


Assuntos
Exoma , Doenças Genéticas Inatas/genética , Humanos , Curva ROC
13.
J Exp Med ; 212(10): 1641-62, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26304966

RESUMO

Autosomal recessive, complete TYK2 deficiency was previously described in a patient (P1) with intracellular bacterial and viral infections and features of hyper-IgE syndrome (HIES), including atopic dermatitis, high serum IgE levels, and staphylococcal abscesses. We identified seven other TYK2-deficient patients from five families and four different ethnic groups. These patients were homozygous for one of five null mutations, different from that seen in P1. They displayed mycobacterial and/or viral infections, but no HIES. All eight TYK2-deficient patients displayed impaired but not abolished cellular responses to (a) IL-12 and IFN-α/ß, accounting for mycobacterial and viral infections, respectively; (b) IL-23, with normal proportions of circulating IL-17(+) T cells, accounting for their apparent lack of mucocutaneous candidiasis; and (c) IL-10, with no overt clinical consequences, including a lack of inflammatory bowel disease. Cellular responses to IL-21, IL-27, IFN-γ, IL-28/29 (IFN-λ), and leukemia inhibitory factor (LIF) were normal. The leukocytes and fibroblasts of all seven newly identified TYK2-deficient patients, unlike those of P1, responded normally to IL-6, possibly accounting for the lack of HIES in these patients. The expression of exogenous wild-type TYK2 or the silencing of endogenous TYK2 did not rescue IL-6 hyporesponsiveness, suggesting that this phenotype was not a consequence of the TYK2 genotype. The core clinical phenotype of TYK2 deficiency is mycobacterial and/or viral infections, caused by impaired responses to IL-12 and IFN-α/ß. Moreover, impaired IL-6 responses and HIES do not appear to be intrinsic features of TYK2 deficiency in humans.


Assuntos
Síndrome de Job/etiologia , TYK2 Quinase/deficiência , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Interferon gama/metabolismo , Interleucina-10/farmacologia , Interleucina-12/metabolismo , Interleucina-12/farmacologia , Interleucina-23/farmacologia , Interleucina-6/farmacologia , Síndrome de Job/complicações , Síndrome de Job/genética , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Masculino , Mutação , Infecções por Mycobacterium/etiologia , Linfócitos T/metabolismo , Linfócitos T/patologia , TYK2 Quinase/genética , TYK2 Quinase/metabolismo , Viroses/etiologia , Adulto Jovem
14.
Biochem Biophys Res Commun ; 455(1-2): 90-7, 2014 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-25451272

RESUMO

We studied two patients from a nonconsanguineous family with life-long abnormal liver function, hepatomegaly and abnormal fatty acid profiles. Abnormal liver function, hypoglycemia and muscle weakness are observed in various genetic diseases, including medium-chain acyl-CoA dehydrogenase (MCAD) deficiency and glycogen storage diseases. The proband showed increased free fatty acids, mainly C8 and C10, resembling fatty acid oxidation disorder. However, no mutation was found in ACADM and ACADL gene. Sequencing of theamylo-alpha-1, 6-glucosidase, 4-alpha-glucanotransferase (AGL) gene showed that both patients were compound heterozygotes for c.118C > T (p.Gln40X) and c.753_756 del CAGA (p.Asp251Glufsx29), whereas their parents were each heterozygous for one of these mutations. The AGL protein was undetectable in EBV-B cells from the two patients. Transcriptome analysis demonstrated a significant different pattern of gene expression in both of patients' cells, including genes involving in the PPAR signaling pathway, fatty acid biosynthesis, lipid synthesis and visceral fat deposition and metabolic syndrome. This unique gene expression pattern is probably due to the absence of AGL, which potentially accounts for the observed clinical phenotypes of hyperlipidemia and hepatocyte steatosis in glycogen storage disease type IIIa.


Assuntos
Sistema da Enzima Desramificadora do Glicogênio/genética , Doença de Depósito de Glicogênio Tipo III/genética , Mutação , Acil-CoA Desidrogenase/deficiência , Adolescente , Células Cultivadas , Ácidos Graxos/biossíntese , Ácidos Graxos Insaturados/biossíntese , Expressão Gênica , Doença de Depósito de Glicogênio Tipo III/diagnóstico , Doença de Depósito de Glicogênio Tipo III/metabolismo , Humanos , Erros Inatos do Metabolismo Lipídico/diagnóstico , Masculino
15.
J Clin Immunol ; 34(8): 904-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25135595

RESUMO

Interferon-γ receptor 2 (IFN-γR2) deficiency is a rare primary immunodeficiency characterized by predisposition to infections with weakly virulent mycobacteria, such as environmental mycobacteria and BCG vaccines. We describe here two children with IFN-γR2 deficiency, from unrelated, consanguineous kindreds of Arab and Israeli descent. The first patient was a boy who died at the age of 4.5 years, from recurrent, disseminated disease caused by Mycobacterium simiae. His IFN-γR2 defect was autosomal recessive and complete. The second patient was a girl with multiple disseminated mycobacterial infections, including infection with M. simiae. She died at the age of 5 years, a short time after the transplantation of umbilical cord blood cells from an unrelated donor. Her IFN-γR2 defect was autosomal recessive and partial. Autosomal recessive IFN-γR2 deficiency is life-threatening, even in its partial form, and genetic diagnosis and familial counseling are therefore particularly important for this condition. These two cases are the first of IFN-γR2 deficiency associated with M. simiae infection to be described.


Assuntos
Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/genética , Infecções por Mycobacterium/complicações , Infecções por Mycobacterium/patologia , Receptores de Interferon/deficiência , Receptores de Interferon/genética , Pré-Escolar , Evolução Fatal , Feminino , Predisposição Genética para Doença , Humanos , Síndromes de Imunodeficiência/imunologia , Masculino , Infecções por Mycobacterium/imunologia , Infecções por Mycobacterium/mortalidade
16.
J Leukoc Biol ; 95(4): 667-76, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24343863

RESUMO

CMCD is a rare congenital disorder characterized by persistent or recurrent skin, nail, and mucosal membrane infections caused by Candida albicans. Heterozygous GOF STAT1 mutations have been shown to confer AD CMCD as a result of impaired dephosphorylation of STAT1. We aimed to identify and characterize STAT1 mutations in CMCD patients and to develop a simple diagnostic assay of CMCD. Genetic analysis of STAT1 was performed in patients and their relatives. The mutations identified were characterized by immunoblot and reporter assay using transient gene expression experiments. Patients' leukocytes are investigated by flow cytometry and immunoblot. Six GOF mutations were identified, three of which are reported for the first time, that affect the CCD and DBD of STAT1 in two sporadic and four multiplex cases in 10 CMCD patients from Japan. Two of the 10 patients presented with clinical symptoms atypical to CMCD, including other fungal and viral infections, and three patients developed bronchiectasis. Immunoblot analyses of patients' leukocytes showed abnormally high levels of pSTAT1 following IFN-γ stimulation. Based on this finding, we performed a flow cytometry-based functional analysis of STAT1 GOF alleles using IFN-γ stimulation and the tyrosine kinase inhibitor, staurosporine. The higher levels of pSTAT1 observed in primary CD14(+) cells from patients compared with control cells persisted and were amplified by the presence of staurosporine. We developed a flow cytometry-based STAT1 functional screening method that would greatly facilitate the diagnosis of CMCD patients with GOF STAT1 mutations.


Assuntos
Alelos , Candidíase Mucocutânea Crônica/genética , Mutação , Fator de Transcrição STAT1/genética , DNA/metabolismo , Citometria de Fluxo , Humanos , Receptores de Lipopolissacarídeos/análise , Fosforilação , Fator de Transcrição STAT1/metabolismo
17.
Blood ; 122(14): 2390-401, 2013 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-23963039

RESUMO

We report a molecular study of the two known patients with autosomal recessive, partial interferon-γ receptor (IFN-γR)2 deficiency (homozygous for mutations R114C and G227R), and three novel, unrelated children, homozygous for S124F (P1) and G141R (P2 and P3). IFN-γR2 levels on the surface of the three latter patients' cells are slightly lower than those on control cells. The patients' cells also display impaired, but not abolished, response to IFN-γ. Moreover, the R114C, S124F, G141R and G227R IFNGR2 hypomorphic alleles all encode misfolded proteins with abnormal N-glycosylation. The mutants are largely retained in the endoplasmic reticulum, although a small proportion reach and function at the cell surface. Strikingly, the IFN-γ response of the patients' cells is enhanced by chemical modifiers of N-glycosylation, as previously shown for patients with gain-of-glysosylation T168N and misfolding 382-387dup null mutations. All four in-frame IFNGR2 hypomorphic mutant alleles encoding surface-expressed receptors are thus deleterious by a mechanism involving abnormal N-glycosylation and misfolding of the IFN-γR2 protein. The diagnosis of partial IFN-γR2 deficiency is clinically useful, as affected patients should be treated with IFN-γ, [corrected] unlike patients with complete IFN-γR2 deficiency. Moreover, inhibitors of glycosylation might be beneficial in patients with complete or partial IFN-γR2 deficiency due to misfolding or gain-of-glycosylation receptors.


Assuntos
Deficiências na Proteostase/genética , Receptores de Interferon/deficiência , Receptores de Interferon/genética , Alcaloides/farmacologia , Sequência de Bases , Western Blotting , Criança , Inibidores Enzimáticos/farmacologia , Feminino , Citometria de Fluxo , Predisposição Genética para Doença/genética , Glicosilação/efeitos dos fármacos , Humanos , Masculino , Microscopia Confocal , Dados de Sequência Molecular , Mutação , Infecções por Mycobacterium/genética , Linhagem , Transfecção
18.
Gene ; 524(2): 401-2, 2013 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-23639962

RESUMO

We report here the case of a 32-year-old Chinese Han woman who presented with frequent severe abdominal pain, convulsion, numbness and confusion. She also had hypertension, hyponatremia, chronic renal failure, anemia and a high urinary δ-aminolevulinic acid concentration. We identified a heterozygous splicing mutation in intron 11 (IVS11-2A→G) of the porphobilinogen (PBG) deaminase gene (PBGD) in her genomic DNA. This mutation had previously been reported in a North American patient, but was absent from 50 healthy Chinese controls.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Hidroximetilbilano Sintase/genética , Mutação , Porfiria Aguda Intermitente/genética , Adulto , Feminino , Heterozigoto , Humanos , Hipertensão/patologia , Íntrons , Falência Renal Crônica/patologia , Sintase do Porfobilinogênio/urina , Porfiria Aguda Intermitente/patologia , Processamento de RNA , Recidiva
19.
PLoS One ; 8(3): e58286, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23472171

RESUMO

We report identical twins with intellectual disability, progressive spastic paraplegia and short stature, born to a consanguineous family. Intriguingly, both children presented with lymphadenitis caused by the live Bacillus Calmette-Guérin (BCG) vaccine. Two syndromes - hereditary spastic paraplegia (HSP) and mycobacterial disease - thus occurred simultaneously. Whole-exome sequencing (WES) revealed a homozygous nonsense mutation (p.R1105X) of the AP4E1 gene, which was confirmed by Sanger sequencing. The p.R1105X mutation has no effect on AP4E1 mRNA levels, but results in lower levels of AP-4ε protein and of the other components of the AP-4 complex, as shown by western blotting, immunoprecipitation and immunofluorescence. Thus, the C-terminal part of the AP-4ε subunit plays an important role in maintaining the integrity of the AP-4 complex. No abnormalities of the IL-12/IFN-γ axis or oxidative burst pathways were identified. In conclusion, we identified twins with autosomal recessive AP-4 deficiency associated with HSP and mycobacterial disease, suggesting that AP-4 may play important role in the neurological and immunological systems.


Assuntos
Complexo 4 de Proteínas Adaptadoras/genética , Complexo 4 de Proteínas Adaptadoras/fisiologia , Mutação , Infecções por Micobactéria não Tuberculosa/genética , Paraplegia Espástica Hereditária/genética , Consanguinidade , Análise Mutacional de DNA , Doenças em Gêmeos , Exoma , Feminino , Genes Recessivos , Predisposição Genética para Doença , Homozigoto , Humanos , Interferon gama/metabolismo , Masculino , Marrocos , Linhagem , Fenótipo
20.
Hum Mol Genet ; 22(4): 769-81, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23161749

RESUMO

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare syndrome, the known genetic etiologies of which impair the production of, or the response to interferon-gamma (IFN-γ). We report here a patient (P1) with MSMD whose cells display mildly impaired responses to IFN-γ, at levels, however, similar to those from MSMD patients with autosomal recessive (AR) partial IFN-γR2 or STAT1 deficiency. Whole-exome sequencing (WES) and Sanger sequencing revealed only one candidate variation for both MSMD-causing and IFN-γ-related genes. P1 carried a heterozygous frame-shift IFNGR2 mutation inherited from her father. We show that the mutant allele is intrinsically loss-of-function and not dominant-negative, suggesting haploinsufficiency at the IFNGR2 locus. We also show that Epstein-Barr virus transformed B lymphocyte cells from 10 heterozygous relatives of patients with AR complete IFN-γR2 deficiency respond poorly to IFN-γ, in some cases as poorly as the cells of P1. Naive CD4(+) T cells and memory IL-4-producing T cells from these individuals also responded poorly to IFN-γ, whereas monocytes and monocyte-derived macrophages (MDMs) did not. This is consistent with the lower levels of expression of IFN-γR2 in lymphoid than in myeloid cells. Overall, MSMD in this patient is probably due to autosomal dominant (AD) IFN-γR2 deficiency, resulting from haploinsufficiency, at least in lymphoid cells. The clinical penetrance of AD IFN-γR2 deficiency is incomplete, possibly due, at least partly, to the variability of cellular responses to IFN-γ in these individuals.


Assuntos
Haploinsuficiência , Infecções por Micobactéria não Tuberculosa/genética , Receptores de Interferon/genética , Adolescente , Linfócitos B/imunologia , Linfócitos B/metabolismo , Sequência de Bases , Estudos de Casos e Controles , Células Cultivadas , Feminino , Expressão Gênica , Genes Dominantes , Estudos de Associação Genética , Predisposição Genética para Doença , Heterozigoto , Humanos , Interferon gama/fisiologia , Infecções por Mycobacterium/genética , Análise de Sequência com Séries de Oligonucleotídeos , Linhagem , Fosforilação , Processamento de Proteína Pós-Traducional , Receptores de Interferon/deficiência , Análise de Sequência de DNA , Deleção de Sequência
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