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1.
Epilepsia ; 60(3): 406-418, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30682224

RESUMO

OBJECTIVE: To characterize the phenotypic spectrum associated with GNAO1 variants and establish genotype-protein structure-phenotype relationships. METHODS: We evaluated the phenotypes of 14 patients with GNAO1 variants, analyzed their variants for potential pathogenicity, and mapped them, along with those in the literature, on a three-dimensional structural protein model. RESULTS: The 14 patients in our cohort, including one sibling pair, had 13 distinct, heterozygous GNAO1 variants classified as pathogenic or likely pathogenic. We attributed the same variant in two siblings to parental mosaicism. Patients initially presented with seizures beginning in the first 3 months of life (8/14), developmental delay (4/14), hypotonia (1/14), or movement disorder (1/14). All patients had hypotonia and developmental delay ranging from mild to severe. Nine had epilepsy, and nine had movement disorders, including dystonia, ataxia, chorea, and dyskinesia. The 13 GNAO1 variants in our patients are predicted to result in amino acid substitutions or deletions in the GNAO1 guanosine triphosphate (GTP)-binding region, analogous to those in previous publications. Patients with variants affecting amino acids 207-221 had only movement disorder and hypotonia. Patients with variants affecting the C-terminal region had the mildest phenotypes. SIGNIFICANCE: GNAO1 encephalopathy most frequently presents with seizures beginning in the first 3 months of life. Concurrent movement disorders are also a prominent feature in the spectrum of GNAO1 encephalopathy. All variants affected the GTP-binding domain of GNAO1, highlighting the importance of this region for G-protein signaling and neurodevelopment.

2.
Clin Genet ; 95(4): 462-478, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30677142

RESUMO

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder characterized by intellectual disability, specific facial features, and marked autonomic nervous system dysfunction, especially with disturbances of regulating respiration and intestinal mobility. It is caused by variants in the transcription factor TCF4. Heterogeneity in the clinical and molecular diagnostic criteria and care practices has prompted a group of international experts to establish guidelines for diagnostics and care. For issues, for which there was limited information available in international literature, we collaborated with national support groups and the participants of a syndrome specific international conference to obtain further information. Here, we discuss the resultant consensus, including the clinical definition of PTHS and a molecular diagnostic pathway. Recommendations for managing particular health problems such as dysregulated respiration are provided. We emphasize the need for integration of care for physical and behavioral issues. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimization of diagnostics and care.

3.
Eur J Hum Genet ; 27(5): 738-746, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30679813

RESUMO

Determining pathogenicity of genomic variation identified by next-generation sequencing techniques can be supported by recurrent disruptive variants in the same gene in phenotypically similar individuals. However, interpretation of novel variants in a specific gene in individuals with mild-moderate intellectual disability (ID) without recognizable syndromic features can be challenging and reverse phenotyping is often required. We describe 24 individuals with a de novo disease-causing variant in, or partial deletion of, the F-box only protein 11 gene (FBXO11, also known as VIT1 and PRMT9). FBXO11 is part of the SCF (SKP1-cullin-F-box) complex, a multi-protein E3 ubiquitin-ligase complex catalyzing the ubiquitination of proteins destined for proteasomal degradation. Twenty-two variants were identified by next-generation sequencing, comprising 2 in-frame deletions, 11 missense variants, 1 canonical splice site variant, and 8 nonsense or frameshift variants leading to a truncated protein or degraded transcript. The remaining two variants were identified by array-comparative genomic hybridization and consisted of a partial deletion of FBXO11. All individuals had borderline to severe ID and behavioral problems (autism spectrum disorder, attention-deficit/hyperactivity disorder, anxiety, aggression) were observed in most of them. The most relevant common facial features included a thin upper lip and a broad prominent space between the paramedian peaks of the upper lip. Other features were hypotonia and hyperlaxity of the joints. We show that de novo variants in FBXO11 cause a syndromic form of ID. The current series show the power of reverse phenotyping in the interpretation of novel genetic variances in individuals who initially did not appear to have a clear recognizable phenotype.

4.
N Engl J Med ; 379(22): 2131-2139, 2018 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-30304647

RESUMO

BACKGROUND: Many patients remain without a diagnosis despite extensive medical evaluation. The Undiagnosed Diseases Network (UDN) was established to apply a multidisciplinary model in the evaluation of the most challenging cases and to identify the biologic characteristics of newly discovered diseases. The UDN, which is funded by the National Institutes of Health, was formed in 2014 as a network of seven clinical sites, two sequencing cores, and a coordinating center. Later, a central biorepository, a metabolomics core, and a model organisms screening center were added. METHODS: We evaluated patients who were referred to the UDN over a period of 20 months. The patients were required to have an undiagnosed condition despite thorough evaluation by a health care provider. We determined the rate of diagnosis among patients who subsequently had a complete evaluation, and we observed the effect of diagnosis on medical care. RESULTS: A total of 1519 patients (53% female) were referred to the UDN, of whom 601 (40%) were accepted for evaluation. Of the accepted patients, 192 (32%) had previously undergone exome sequencing. Symptoms were neurologic in 40% of the applicants, musculoskeletal in 10%, immunologic in 7%, gastrointestinal in 7%, and rheumatologic in 6%. Of the 382 patients who had a complete evaluation, 132 received a diagnosis, yielding a rate of diagnosis of 35%. A total of 15 diagnoses (11%) were made by clinical review alone, and 98 (74%) were made by exome or genome sequencing. Of the diagnoses, 21% led to recommendations regarding changes in therapy, 37% led to changes in diagnostic testing, and 36% led to variant-specific genetic counseling. We defined 31 new syndromes. CONCLUSIONS: The UDN established a diagnosis in 132 of the 382 patients who had a complete evaluation, yielding a rate of diagnosis of 35%. (Funded by the National Institutes of Health Common Fund.).

6.
NPJ Genom Med ; 3: 21, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30131872

RESUMO

Despite major progress in defining the genetic basis of Mendelian disorders, the molecular etiology of many cases remains unknown. Patients with these undiagnosed disorders often have complex presentations and require treatment by multiple health care specialists. Here, we describe an integrated clinical diagnostic and research program using whole-exome and whole-genome sequencing (WES/WGS) for Mendelian disease gene discovery. This program employs specific case ascertainment parameters, a WES/WGS computational analysis pipeline that is optimized for Mendelian disease gene discovery with variant callers tuned to specific inheritance modes, an interdisciplinary crowdsourcing strategy for genomic sequence analysis, matchmaking for additional cases, and integration of the findings regarding gene causality with the clinical management plan. The interdisciplinary gene discovery team includes clinical, computational, and experimental biomedical specialists who interact to identify the genetic etiology of the disease, and when so warranted, to devise improved or novel treatments for affected patients. This program effectively integrates the clinical and research missions of an academic medical center and affords both diagnostic and therapeutic options for patients suffering from genetic disease. It may therefore be germane to other academic medical institutions engaged in implementing genomic medicine programs.

7.
J Exp Med ; 215(8): 2211-2226, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30045946

RESUMO

Tle/Groucho proteins are transcriptional corepressors interacting with Tcf/Lef and Runx transcription factors, but their physiological roles in T cell development remain unknown. Conditional targeting of Tle1, Tle3 and Tle4 revealed gene dose-dependent requirements for Tle proteins in CD8+ lineage cells. Upon ablating all three Tle proteins, generation of CD8+ T cells was greatly diminished, largely owing to redirection of MHC-I-selected thymocytes to CD4+ lineage; the remaining CD8-positive T cells showed aberrant up-regulation of CD4+ lineage-associated genes including Cd4, Thpok, St8sia6, and Foxp3 Mechanistically, Tle3 bound to Runx-occupied Thpok silencer, in post-selection double-positive thymocytes to prevent excessive ThPOK induction and in mature CD8+ T cells to silence Thpok expression. Tle3 also bound to Tcf1-occupied sites in a few CD4+ lineage-associated genes, including Cd4 silencer and St8sia6 introns, to repress their expression in mature CD8+ T cells. These findings indicate that Tle corepressors are differentially partitioned to Runx and Tcf/Lef complexes to instruct CD8+ lineage choice and cooperatively establish CD8+ T cell identity, respectively.

8.
Am J Hum Genet ; 102(5): 995-1007, 2018 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-29656858

RESUMO

Developmental and epileptic encephalopathies (DEEs) represent a large clinical and genetic heterogeneous group of neurodevelopmental diseases. The identification of pathogenic genetic variants in DEEs remains crucial for deciphering this complex group and for accurately caring for affected individuals (clinical diagnosis, genetic counseling, impacting medical, precision therapy, clinical trials, etc.). Whole-exome sequencing and intensive data sharing identified a recurrent de novo PACS2 heterozygous missense variant in 14 unrelated individuals. Their phenotype was characterized by epilepsy, global developmental delay with or without autism, common cerebellar dysgenesis, and facial dysmorphism. Mixed focal and generalized epilepsy occurred in the neonatal period, controlled with difficulty in the first year, but many improved in early childhood. PACS2 is an important PACS1 paralog and encodes a multifunctional sorting protein involved in nuclear gene expression and pathway traffic regulation. Both proteins harbor cargo(furin)-binding regions (FBRs) that bind cargo proteins, sorting adaptors, and cellular kinase. Compared to the defined PACS1 recurrent variant series, individuals with PACS2 variant have more consistently neonatal/early-infantile-onset epilepsy that can be challenging to control. Cerebellar abnormalities may be similar but PACS2 individuals exhibit a pattern of clear dysgenesis ranging from mild to severe. Functional studies demonstrated that the PACS2 recurrent variant reduces the ability of the predicted autoregulatory domain to modulate the interaction between the PACS2 FBR and client proteins, which may disturb cellular function. These findings support the causality of this recurrent de novo PACS2 heterozygous missense in DEEs with facial dysmorphim and cerebellar dysgenesis.

9.
J Neurogenet ; 31(1-2): 30-36, 2017 Mar - Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28460589

RESUMO

Pathogenic missense and truncating variants in the GABRG2 gene cause a spectrum of epilepsies, from Dravet syndrome to milder simple febrile seizures. In most cases, pathogenic missense variants in the GABRG2 gene segregate with a febrile seizure phenotype. In this case series, we report a recurrent, de novo missense variant (c0.316 G > A; p.A106T) in the GABRG2 gene that was identified in five unrelated individuals. These patients were described to have a more severe phenotype than previously reported for GABRG2 missense variants. Common features include variable early-onset seizures, significant motor and speech delays, intellectual disability, hypotonia, movement disorder, dysmorphic features and vision/ocular issues. Our report further explores a recurrent pathogenic missense variant within the GABRG2 variant family and broadens the spectrum of associated phenotypes for GABRG2-associated disorders.


Assuntos
Anormalidades Múltiplas/patologia , Mutação de Sentido Incorreto , Receptores de GABA-A/genética , Índice de Gravidade de Doença , Anormalidades Múltiplas/genética , Adolescente , Criança , Epilepsia/genética , Epilepsia/patologia , Feminino , Humanos , Lactente , Deficiência Intelectual/genética , Deficiência Intelectual/patologia , Masculino , Transtornos Motores/genética , Transtornos Motores/patologia , Transtornos dos Movimentos/genética , Transtornos dos Movimentos/patologia , Hipotonia Muscular/genética , Hipotonia Muscular/patologia , Linhagem , Fenótipo , Distúrbios da Fala/genética , Distúrbios da Fala/patologia
10.
J Med Genet ; 54(2): 84-86, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27389779

RESUMO

BACKGROUND: The causes of intellectual disability (ID) are diverse and de novo mutations are increasingly recognised to account for a significant proportion of ID. METHODS AND RESULTS: In this study, we performed whole exome sequencing on a large cohort of patients with ID or neurodevelopmental delay and identified four novel de novo predicted deleterious missense variants in HECW2 in six probands with ID/developmental delay and hypotonia. Other common features include seizures, strabismus, nystagmus, cortical visual impairment and dysmorphic facial features. HECW2 is an ubiquitin ligase that stabilises p73, a crucial mediator of neurodevelopment and neurogenesis. CONCLUSION: This study implicates pathogenic genetic variants in HECW2 as potential causes of neurodevelopmental disorders in humans.


Assuntos
Deficiência Intelectual/genética , Hipotonia Muscular/genética , Transtornos do Neurodesenvolvimento/genética , Proteína Tumoral p73/genética , Ubiquitina-Proteína Ligases/genética , Criança , Pré-Escolar , Exoma/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Deficiência Intelectual/patologia , Masculino , Hipotonia Muscular/patologia , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/patologia
12.
Leuk Res ; 48: 46-56, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27486062

RESUMO

The presence of AML1-ETO (RUNX1-CBF2T1), a fusion oncoprotein resulting from a t(8;21) chromosomal translocation, has been implicated as a necessary but insufficient event in the development of a subset of acute myeloid leukemias (AML). While AML1-ETO prolongs survival and inhibits differentiation of hematopoietic stem cells (HSC), other contributory events are needed for cell proliferation and leukemogenesis. We have postulated that specific tumor suppressor genes keep the leukemic potential of AML1-ETO in check. In studying del(9q), one of the most common concomitant chromosomal abnormalities with t(8;21), we identified the loss of an apparent tumor suppressor, TLE4, that appears to cooperate with AML1-ETO to confer a leukemic phenotype. This study sought to identify the molecular basis of this cooperation. We show that the loss of TLE4 confers proliferative advantage to leukemic cells, simultaneous with an upregulation of a pro- inflammatory signature mediated through aberrant increases in Wnt signaling activity. We further demonstrate that inhibition of cyclooxygenase (COX) activity partly reverses the pro-leukemic phenotype due to TLE4 knockdown, pointing towards a novel therapeutic approach for myeloid leukemia.


Assuntos
Inflamação , Leucemia Mieloide/patologia , Proteínas Nucleares/fisiologia , Proteínas Repressoras/fisiologia , Proteínas Wnt/fisiologia , Deleção Cromossômica , Cromossomos Humanos Par 9 , Inibidores de Ciclo-Oxigenase/farmacologia , Deleção de Genes , Regulação Leucêmica da Expressão Gênica , Genes Supressores de Tumor , Humanos , Leucemia Mieloide/genética , Proteínas Nucleares/genética , Proteínas Repressoras/genética , Células Tumorais Cultivadas , Proteínas Supressoras de Tumor
13.
J Mol Diagn ; 18(5): 697-706, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27471182

RESUMO

Next-generation sequencing has evolved technically and economically into the method of choice for interrogating the genome in cancer and inherited disorders. The introduction of procedural code sets for whole-exome and genome sequencing is a milestone toward financially sustainable clinical implementation; however, achieving reimbursement is currently a major challenge. As part of a prospective quality-improvement initiative to implement the new code sets, we adopted Agile, a development methodology originally devised in software development. We implemented eight functionally distinct modules (request review, cost estimation, preauthorization, accessioning, prebilling, testing, reporting, and reimbursement consultation) and obtained feedback via an anonymous survey. We managed 50 clinical requests (January to June 2015). The fraction of pursued-to-requested cases (n = 15/50; utilization management fraction, 0.3) aimed for a high rate of preauthorizations. In 13 of 15 patients the insurance plan required preauthorization, which we obtained in 70% and ultimately achieved reimbursement in 50%. Interoperability enabled assessment of 12 different combinations of modules that underline the importance of an adaptive workflow and policy tailoring to achieve higher yields of reimbursement. The survey confirmed a positive attitude toward self-organizing teams. We acknowledge the individuals and their interactions and termed the infrastructure: human pipeline. Nontechnical barriers currently are limiting the scope and availability of clinical genomic sequencing. The presented human pipeline is one approach toward long-term financial sustainability of clinical genomics.


Assuntos
Assistência à Saúde , Genômica , Informática Médica/métodos , Software , Assistência à Saúde/economia , Assistência à Saúde/métodos , Assistência à Saúde/organização & administração , Exoma , Genômica/economia , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Informática Médica/economia , Encaminhamento e Consulta , Mecanismo de Reembolso , Pesquisa , Inquéritos e Questionários , Fluxo de Trabalho , Recursos Humanos
14.
J Child Neurol ; 31(9): 1127-37, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27095821

RESUMO

Mutations in mitochondrial aminoacyl-tRNA synthetases are an increasingly recognized cause of human diseases, often arising in individuals with compound heterozygous mutations and presenting with system-specific phenotypes, frequently neurologic. FARS2 encodes mitochondrial phenylalanyl transfer ribonucleic acid (RNA) synthetase (mtPheRS), perturbations of which have been reported in 6 cases of an infantile, lethal disease with refractory epilepsy and progressive myoclonus. Here the authors report the case of juvenile onset refractory epilepsy and progressive myoclonus with compound heterozygous FARS2 mutations. The authors describe the clinical course over 6 years of care at their institution and diagnostic studies including electroencephalogram (EEG), brain magnetic resonance imaging (MRI), serum and cerebrospinal fluid analyses, skeletal muscle biopsy histology, and autopsy gross and histologic findings, which include features shared with Alpers-Huttenlocher syndrome, Leigh syndrome, and a previously published case of FARS2 mutation associated infantile onset disease. The authors also present structure-guided analysis of the relevant mutations based on published mitochondrial phenylalanyl transfer RNA synthetase and related protein crystal structures as well as biochemical analysis of the corresponding recombinant mutant proteins.


Assuntos
Epilepsia Resistente a Medicamentos/genética , Epilepsias Mioclônicas/genética , Heterozigoto , Proteínas Mitocondriais/genética , Mutação , Fenilalanina-tRNA Ligase/genética , Adolescente , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/patologia , Epilepsia Resistente a Medicamentos/fisiopatologia , Epilepsias Mioclônicas/diagnóstico por imagem , Epilepsias Mioclônicas/patologia , Epilepsias Mioclônicas/fisiopatologia , Evolução Fatal , Feminino , Humanos , Fenótipo
15.
Psychiatr Genet ; 26(3): 101-8, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27010919

RESUMO

Despite the recent acceleration in the discovery of genetic risk factors for intellectual disability (ID), the genetic etiology of ID is unknown in approximately half of cases and remains a major frontier of genetics in medicine and psychiatry. The distinction between syndromal and nonsyndromal forms of ID is of great clinical importance, but the boundary between these clinical entities is difficult to ascertain for many genes of interest. ID is more common in men than in women, but the genetic explanation of this sex asymmetry is incompletely understood. This Review systematically examines the reported cases of X-linked ID caused by de novo loss-of-function mutations in the gene IQSEC2. This gene is largely known as a cause of X-linked nonsyndromal ID in male patients. However, depending on the severity of the mutation, the phenotypic spectrum of IQSEC2-related ID can range from the classic X-linked nonsyndromal form of the disease to a severe syndrome that has been reported in the context of de novo mutations only, in both male and female patients. Bioinformatics analysis suggests that truncation of the longer of the two protein isoforms of the gene can be sufficient to lead to the syndrome, which may be caused by the disruption of cell signaling and signal transduction pathways. The clinical features of the syndrome converge on a pattern of global developmental delay, deficits in social communication, stereotypical hand movements, and hypotonia. In addition, many if not all of these patients have seizures, microcephaly, and language regression in addition to delay. We argue that it is clinically appropriate to test for IQSEC2 mutations in male and female patients with this symptom profile but without a known genetic mutation.


Assuntos
Doenças Genéticas Ligadas ao Cromossomo X/genética , Fatores de Troca do Nucleotídeo Guanina/genética , Deficiência Intelectual/genética , Criança , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/fisiopatologia , Doenças Genéticas Ligadas ao Cromossomo X/psicologia , Humanos , Deficiência Intelectual/fisiopatologia , Deficiência Intelectual/psicologia , Masculino , Mutação
16.
Proc Natl Acad Sci U S A ; 113(7): 1871-6, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26831087

RESUMO

Tle1 (transducin-like enhancer of split 1) is a corepressor that interacts with a variety of DNA-binding transcription factors and has been implicated in many cellular functions; however, physiological studies are limited. Tle1-deficient (Tle1(Δ/Δ)) mice, although grossly normal at birth, exhibit skin defects, lung hypoplasia, severe runting, poor body condition, and early mortality. Tle1(Δ/Δ) mice display a chronic inflammatory phenotype with increased expression of inflammatory cytokines and chemokines in the skin, lung, and intestine and increased circulatory IL-6 and G-CSF, along with a hematopoietic shift toward granulocyte macrophage progenitor and myeloid cells. Tle1(Δ/Δ) macrophages produce increased inflammatory cytokines in response to Toll-like receptor (TLR) agonists and lipopolysaccharides (LPS), and Tle1(Δ/Δ) mice display an enhanced inflammatory response to ear skin 12-O-tetradecanoylphorbol-13-acetate treatment. Loss of Tle1 not only results in increased phosphorylation and activation of proinflammatory NF-κB but also results in decreased Hes1 (hairy and enhancer of split-1), a negative regulator of inflammation in macrophages. Furthermore, Tle1(Δ/Δ) mice exhibit accelerated growth of B6-F10 melanoma xenografts. Our work provides the first in vivo evidence, to our knowledge, that TLE1 is a major counterregulator of inflammation with potential roles in a variety of inflammatory diseases and in cancer progression.


Assuntos
Proteínas Correpressoras/fisiologia , Genes Supressores de Tumor , Inflamação/fisiopatologia , NF-kappa B/metabolismo , Animais , Proteínas Correpressoras/genética , Inflamação/metabolismo , Camundongos , Camundongos Transgênicos
17.
J Pers Med ; 6(1)2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26751479

RESUMO

The era of personalized medicine has arrived, and with it a need for leaders in this discipline. This generation of trainees requires a cadre of new skill sets to lead the implementation of personalized medicine into mainstream healthcare. Traditional training programs no longer provide trainees with all the skills they will need to optimize implementation of this revolution now underway in medicine. Today's trainees must manage clinical teams, act as clinical and molecular diagnostic consultants, train other healthcare professionals, teach future generations, and be knowledgeable about clinical trials to facilitate genomic-based therapies. To prepare trainees for the transition to junior faculty positions, contemporary genomic training programs must emphasize the development of these management, teaching, and clinical skills.

18.
Genet Med ; 17(4): 253-261, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25412400

RESUMO

PURPOSE: Next-generation sequencing-based methods are being adopted broadly for genetic diagnostic testing, but the performance characteristics of these techniques with regard to test accuracy and reproducibility have not been fully defined. METHODS: We developed a targeted enrichment and next-generation sequencing approach for genetic diagnostic testing of patients with inherited eye disorders, including inherited retinal degenerations, optic atrophy, and glaucoma. In preparation for providing this genetic eye disease (GEDi) test on a CLIA-certified basis, we performed experiments to measure the sensitivity, specificity, and reproducibility, as well as the clinical sensitivity, of the test. RESULTS: The GEDi test is highly reproducible and accurate, with sensitivity and specificity of 97.9 and 100%, respectively, for single-nucleotide variant detection. The sensitivity for variant detection was notably better than the 88.3% achieved by whole-exome sequencing using the same metrics, because of better coverage of targeted genes in the GEDi test as compared with a commercially available exome capture set. Prospective testing of 192 patients with inherited retinal degenerations indicated that the clinical sensitivity of the GEDi test is high, with a diagnostic rate of 51%. CONCLUSION: Based on quantified performance metrics, the data suggest that selective targeted enrichment is preferable to whole-exome sequencing for genetic diagnostic testing.


Assuntos
Oftalmopatias/diagnóstico , Oftalmopatias/genética , Testes Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Exoma/genética , Oftalmopatias/patologia , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
PLoS One ; 9(8): e105557, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25153823

RESUMO

Hematopoiesis is a complex process that relies on various cell types, signaling pathways, transcription factors and a specific niche. The integration of these various components is of critical importance to normal blood development, as deregulation of these may lead to bone marrow failure or malignancy. Tle4, a transcriptional corepressor, acts as a tumor suppressor gene in a subset of acute myeloid leukemia, yet little is known about its function in normal and malignant hematopoiesis or in mammalian development. We report here that Tle4 knockout mice are runted and die at around four weeks with defects in bone development and BM aplasia. By two weeks of age, Tle4 knockout mice exhibit leukocytopenia, B cell lymphopenia, and significant reductions in hematopoietic stem and progenitor cells. Tle4 deficient hematopoietic stem cells are intrinsically defective in B lymphopoiesis and exhaust upon stress, such as serial transplantation. In the absence of Tle4 there is a profound decrease in bone mineralization. In addition, Tle4 knockout stromal cells are defective at maintaining wild-type hematopoietic stem cell function in vitro. In summary, we illustrate a novel and essential role for Tle4 in the extrinsic and intrinsic regulation of hematopoiesis and in bone development.


Assuntos
Desenvolvimento Ósseo/genética , Hematopoese/genética , Células-Tronco Hematopoéticas/metabolismo , Proteínas Repressoras/genética , Células Estromais/metabolismo , Animais , Células da Medula Óssea/metabolismo , Camundongos , Camundongos Knockout , Proteínas Repressoras/metabolismo
20.
Blood ; 121(24): 4906-16, 2013 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-23645839

RESUMO

Developing novel therapies that suppress self-renewal of leukemia stem cells may reduce the likelihood of relapses and extend long-term survival of patients with acute myelogenous leukemia (AML). AML1-ETO (AE) is an oncogene that plays an important role in inducing self-renewal of hematopoietic stem/progenitor cells (HSPCs), leading to the development of leukemia stem cells. Previously, using a zebrafish model of AE and a whole-organism chemical suppressor screen, we have discovered that AE induces specific hematopoietic phenotypes in embryonic zebrafish through a cyclooxygenase (COX)-2 and ß-catenin-dependent pathway. Here, we show that AE also induces expression of the Cox-2 gene and activates ß-catenin in mouse bone marrow cells. Inhibition of COX suppresses ß-catenin activation and serial replating of AE(+) mouse HSPCs. Genetic knockdown of ß-catenin also abrogates the clonogenic growth of AE(+) mouse HSPCs and human leukemia cells. In addition, treatment with nimesulide, a COX-2 selective inhibitor, dramatically suppresses xenograft tumor formation and inhibits in vivo progression of human leukemia cells. In summary, our data indicate an important role of a COX/ß-catenin-dependent signaling pathway in tumor initiation, growth, and self-renewal, and in providing the rationale for testing potential benefits from common COX inhibitors as a part of AML treatments.


Assuntos
Proliferação de Células , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Ciclo-Oxigenase 2/biossíntese , Células-Tronco Hematopoéticas/metabolismo , Leucemia Mieloide Aguda/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Transdução de Sinais , beta Catenina/metabolismo , Animais , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Ciclo-Oxigenase 2/genética , Inibidores de Ciclo-Oxigenase/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica/genética , Células-Tronco Hematopoéticas/patologia , Humanos , Células K562 , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos , Camundongos Transgênicos , Transplante de Neoplasias , Células-Tronco Neoplásicas/patologia , Proteínas de Fusão Oncogênica/genética , Proteína 1 Parceira de Translocação de RUNX1 , Sulfonamidas/farmacologia , Transplante Heterólogo , Peixe-Zebra , beta Catenina/genética
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