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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Entwicklung und Implementierung von Auswertungswerkzeugen für Hochdurchsatz-DNA-Kopienzahl-Analysen und deren Anwendung auf Lymphomdaten

Kreuz, Markus 23 March 2015 (has links) (PDF)
Aberrationen in der DNA-Kopienzahl sind häufige genetische Veränderungen bei malignen Lymphomerkrankungen. Zugewinne sowie Deletionen stellen dabei Mechanismen zur Onkogen-Aktivierung sowie Tumorsuppressorgen-Inaktivierung dar und tragen somit zur Pathogenese der Erkrankung bei. Array-CGH und SNP-Array sind Messplattformen, die die genomweite Bestimmung von Kopienzahlaberrationen in einem Experiment ermöglichen. Die bei der Analyse entstehenden Datensätze sind komplex und erfordern automatische Methoden zur Unterstützung der Analyse und Interpretation der Messergebnisse. In dieser Promotionsarbeit wurden Methoden entwickelt, welche die Analyse von Array-CGH- und SNP-Array-Messungen ermöglichen. Diese Methoden wurden für die Auswertung umfangreicher Datensätze von malignen Non-Hodgkin-Lymphomen verwendet. Dabei wurden Lymphome der Entitäten Burkitt-Lymphom, diffus großzelliges B-Zell-Lymphom, Mantelzelllymphom, primäres ZNS-Lymphom und peripheres T-Zell-Lymphom – nicht anderweitig spezifiziert – analysiert. Für die untersuchten Lymphom-Entitäten konnten hierbei zahlreiche neue rekurrente Kopienzahlaberrationen sowie uniparentale Disomien gezeigt werden, die neue Einblicke in die Pathogenese der jeweiligen Erkrankungen erlauben. Darüber hinaus erfolgte ein Vergleich beider Messplattformen anhand eines Datensatzes mit gepaarten Array-CGH- und SNP-Array-Daten. Für die eingesetzten Plattformen (2800k-BAC-Array vs. Affymetrix 250k-Sty-SNP-Array) konnte eine circa zwölffach höhere effektive Auflösung der SNP-Array-Plattform gezeigt werden. Die wesentlichen Ergebnisse dieser Arbeit sind in sieben Publikationen eingeflossen.
32

Déficience intellectuelle : identification de nouveaux gènes par une approche multicentrique / Intellectual diability : discovery of new genes by a multicentre approach

Piard, Juliette 07 May 2018 (has links)
La déficience intellectuelle (DI) touche 1 à 3% de la population générale avec un excès de sujets de sexe masculin. Cette affection est caractérisée par une extrême hétérogénéité clinique et génétique rendant son élucidation complexe. La révolution technologique des outils permettant l’analyse du génome intervenue depuis les années 2000 avec l’analyse chromosomique sur microréseau et singulièrement depuis 2010 avec les applications du séquençage à haut débit a considérablement facilité l’identification de nouveaux gènes. Nous avons tiré avantage de ce phénomène pour identifier trois affections neurologiques à caractère familial Nous avons procédé selon une méthodologie structurée pour conduire, grâce à la mise en place d’un réseau de collaborations, à la découverte ou à la confirmation de l’existence de nouvelles formes de DI. 1.Séquençage de l'exome couplé à la recherche de variations du nombre de copies 2. Mise à jour d’une altération de séquence génique potentiellement causale retrouvée chez le cas index et chez les autres sujets atteints de la famille 3.Extension des résultats à d’autres familles par la constitution d’une cohorte de réplication 4.Élaboration d’une série d’études fonctionnelles venant conforter l’hypothèse de causalité par la création d’un modèle animal et/ou la réalisation d’études biochimiques spécifiquesL’application de cette méthodologie nous a permis de conduire à terme trois projets : L’individualisation d’une forme syndromique de DI récessive autosomique associée à une malformation du rachis cervical et liée aux mutations bi-alléliques de CDK10. La caractérisation d’une encéphalopathie récessive autosomique létale associée à une hypertonie sévère et à une arthrogrypose distale liée aux mutations bi-alléliques d’ATAD1. L’implication de FRMPD4 dans une nouvelle forme de DI non syndromique liée à l’X / Intellectual disability (ID) impacts 1 to 3% of the general population with an excess of affected males. This condition is characterized by an extreme clinical and genetic heterogeneity making the deciphering of its causes more complex. The technological revolution that took place in the study of the genome over the last two decades has provided a useful tool for identification of new genetic entities. This is particularly true for chromosomal micro-array analysis since early 2000s and for next generation sequencing since 2011. We took advantage of this by identifying the molecular basis of three singular conditions. We applied a structured methodology and created a network of collaborations to define or confirm these new ID syndromes. 1. Whole exome sequencing alongside with array-CGH 2.Identification of a candidate gene sequence alteration in the index case and other affected patients of the family 3.Constitution and study of a replication cohort 4.Biochemical studies and/or animal models in order to support the assumption of causalityBased on this research strategy, we were able to complete the following projects : Discovery of a syndromic form of autosomal recessive ID associated with cervical spine defects due to bi-allelic CDK10 mutations. Identification of an ATAD1-related profound and lethal autosomal recessive encephalopathy with stiffness and distal arthrogryposis. Characterization of a FRMPD4-related X-linked non-syndromic ID
33

Estudo de genes candidatos aos Transtornos do Espectro Autista / Study of candidate genes to Autism Spectrum Disorders

Cintia Marques Ribeiro 07 June 2013 (has links)
Os transtornos do espectro autista (TEA) são condições neuropsiquiátricas caracterizadas por padrões comportamentais estereotipados, ausência ou limitação de comunicação verbal e de interação social recíproca. Diversos estudos têm mostrado que esses transtornos possuem etiologia genética complexa e heterogênea, o que dificulta a identificação dos fatores causais. Estima-se que cerca de 70% dos casos de TEA são idiopáticos. Portanto, com o objetivo de identificar mecanismos etiológicos associados aos TEA, utilizamos as seguintes estratégias: customização de uma lâmina de microarray CGH que possibilite a detecção não só de grandes CNVs, mas também de alterações menores do que 10 kbp, em exons e regiões UTR de genes potencialmente candidatos; a comparação entre os tipos de rearranjos detectados em pacientes sindrômicos e em não sindrômicos e, ainda, a investigação mais detalhada de uma família com indivíduos portadores de transtorno autista e síndrome de Asperger. Foram avaliados 103 portadores de TEA não sindrômicos e 18 sindrômicos, sendo as taxas de detecção de alterações potencialmente patogênicas, respectivamente, de 11,6% e 38,9%. Dentre as alterações detectadas 44,4% são menores do que 10 Kbp. Portanto, a estratégia de usar uma lâmina customizada, com alta densidade de sondas complementares aos exons e regiões não codificantes de genes potencialmente envolvidos na etiologia dos TEA, capaz de detectar tanto alterações grandes quanto pequenas, parece ser relevante na tentativa de elucidar o maior número de casos possíveis e melhor compreender esses transtornos. Além disso, essa lâmina também pode ser utilizada como uma ferramenta para auxiliar o diagnóstico clínico e o aconselhamento genético com um custo mais acessível em comparação a outras comerciais ou ao sequenciamento de última geração. Cerca de 33,3% das CNVs observadas afetam região UTR, sugerindo que mutações nessas regiões podem explicar uma proporção significativa dos casos nos quais não são detectadas alterações através de outros testes genômicos, visto que a maioria desses ainda não exploram adequadamente regiões não codificantes. Entre os pacientes autistas não sindrômicos verificou-se que a maioria dos genes afetados por CNVs estão envolvidos em duas principais funções biológicas - sinapses glutamatérgicas e orientação axonal, sugerindo que TEA não sindrômico pode ser causado por disfunção em genes diferentes envolvidos em processos fisiológicos comuns. Diferente do que observamos entre pacientes não sindrômicos, detectamos mais de uma alteração em um mesmo indivíduo ou alterações que englobam mais de um gene entre os pacientes sindrômicos, reforçando o modelo oligogênico para alguns casos de TEA. Por fim, os dados obtidos no estudo da família com portadores de síndrome de Asperger e transtorno autista sugere que a gravidade do quadro clínico possa estar relacionada ao número de mutações e possivelmente por duas mutações diferentes em ambos os alelos de um mesmo gene. Nossos resultados, além de apoiar o envolvimento dos genes MDGA2, FHIT, HTR2A, SHANK2, GRIA3, ZNF778, PRKCα, CDH15, DIAPH3, GCH1, GRM5, MARK1, SLC17A6, IMMP2L, BZRAP1, SYNGAP1, ANK3, MAP1A, GABRR2 e LAMC3 nos TEA também sugere novos genes candidatos: LRRC7, LRRIQ3, CADPS1, NUFIP, SEMA3A, SNAP29, MBD2, GAD2, DGKH e PARD3 / The autism spectrum disorders (ASD) are neuropsychiatric conditions typically characterized by social deficits, communication difficulties, stereotyped or repetitive behaviors and interests. Several studies have shown that these disorders have a complex and heterogeneous genetic etiology, which makes difficult to identify the causal factors. Approximately 70% of cases are idiopathic. In order to identify etiological mechanisms associated with ASD, we have used the following strategies: customized a microarray CGH platform that allows detection not only of large CNVs, but also alterations smaller than 10 kbp in exons and UTR regions of potential candidate genes, the comparison between the types of rearrangements detected in syndromic and non-syndromic patients and further, more detailed investigation of a family segregating both autistic disorder and Asperger syndrome. We evaluated 103 nonsyndromic and 18 syndromic patients by the custom-designed array and the detection rate of possibly pathogenic alterations were, respectively, 11.6% and 38.9%. Among these CNVs, 44.4% are smaller than 10 kbp. Therefore, the strategy of using a custom-designed array, enriched with probes targeted to genes potentially involved in the ASD etiology and able to detect both large and small CNVs, seems to be relevant in an attempt to elucidate the largest number of cases and to better understand these disorders. Furthermore, this platform can also be used as a tool to support the clinical diagnosis and genetic counseling with a more affordable cost compared to conventional other or next-generation sequencing. Approximately 33.3% of the observed CNVs affect UTR region, suggesting that mutations in non-coding regions might explain a significant proportion of ASD cases negative for most genomic screenings, which still do not explore adequately these regions. Among nonsyndromic autistic patients we found that most of the genes affected by CNVs are involved in two main biological functions - glutamatergic synapses and axonal guidance, suggesting that nonsyndromic ASD can be caused by dysfunction in different genes of a few common physiological processes. In contrast to our findings in nonsyndromic patients, we detected more than one alteration in a single individual or alterations that involve more than one gene among the syndromic patients, reinforcing the oligogenic model for some cases of ASD. Finally, the data obtained in the study of the family segregating both Asperger syndrome and autistic disorder suggests that the severity of ASD seems to be modulated by the number of hits and possibly by hits in both alleles of the same gene. Our results support the involvement of genes MDGA2, FHIT, HTR2A, SHANK2, GRIA3, ZNF778, PRKCα, CDH15, DIAPH3, GCH1, GRM5, MARK1, SLC17A6, IMMP2L, BZRAP1, SYNGAP1, ANK3, MAP1A, GABRR2 and LAMC3 in ASD etiology and also suggests new candidates: LRRC7, LRRIQ3, CADPS1, NUFIP, SEMA3A, SNAP29, MBD2, GAD2, DGKH and PARD3
34

Variations structurales du génome et pathologies humaines : recherche de nouveaux marqueurs génétiques impliqués dans les ischémies cérébrales du sujet jeune / Human genome variations ans disorders : identification of new genetic susceptibility loci in young ischemic strokes

Redon, Sylvia 02 July 2012 (has links)
Ce travail de thèse a permis, dans un premier temps, de mettre en évidence de nouveaux grandsréarrangements dans trois pathologies étudiées au laboratoire : la mucoviscidose, la pancréatitechronique et l’hémochromatose. En particulier, ces travaux ont permis de trouver de nouveaux CNVs(Copy Number Variations) pathologiques dans le gène CFTR (Cystic Fibrosis Transmembraneconductance Regulator), de mieux comprendre les mécanismes d’un remaniement complexe dansPRSS1 (Protease Serine 1) et d’aider à caractériser finement un réarrangement dans HFE(Hemochromatosis). Ces études ont donc servi de preuve de concept pour l’utilisation de puces à ADN àl’échelle d’un gène et dans des zones difficiles car riches en séquences répétées.Dans un second temps, la recherche de facteurs de susceptibilité génétiques aux infarctus cérébraux(AICs) du sujet jeune a été réalisée chez 168 cas et 200 témoins âgés de moins de 40 ans. Dans notrepopulation, l’hypertension, les migraines, le tabac, et la prise de stupéfiants sont des facteurs de risqueimportants, multipliant respectivement par 35, 3,8, 4 et 2,8 le risque d’AIC. Notre étude pangénomiquepar CGH-array (Comparative Genomic Hybridization-array) a mis en évidence 98 régionspolymorphiques dans le génome humain. Parmi elles, la délétion d’une partie du gène NOTCH2, pourraitjouer un rôle protecteur dans la survenue des AICs (OR=0,11 [0,01-0,87] ; p=0,013) mais qui ne dépassepas le seuil fixé par la correction de Bonferroni). Ce travail a également mis en évidence environ 400CNVs rares, dont deux récurrents chez les cas, l'un portant les gènes CRELD2 (cysteine-rich with EGFlikedomains 2) et AGL12 (asparagine-linked glycosylation 12, alpha-1, 6-mannosyltransferase) (p=0,02)et le deuxième situé en 5’ du gène VBP1 (von Hippel-Lindau binding protein 1) (p=0,04). Enfin, uneapproche gènes candidats a été effectuée sur les gènes NOTCH2 et ALOX5AP (5-lipoxygenaseactivating protein) sans donner de résultats significatifs. Ceci a également été réalisé sur les mutationsprincipales de trois gènes de la coagulation (Facteur II, Facteur V Leiden et MTHFR). Une associationsignificative a été mise en évidence entre la C677T du gène MTHFR (5,10-methyltetrahydrofolate) et lesinfarctus cérébraux du sujet jeune (OR=2,39, p=0,02 pour le génotype TT). Ce travail de thèse a permisde confirmer l’existence de facteurs de risque environnementaux et génétiques déjà connus mais surtoutd’émettre de nouvelles hypothèses génétiques dans la survenue des AICs du sujet jeune. / The use of locus-specific array-CGH (Comparative Genomic Hybridization) has allowed us to detect largerearrangements in three pathologies of our laboratory: cystic fibrosis, chronic pancreatitis andhemochromatosis. We successfully observed new pathological CNV (Copy Number Variations) in theCFTR (Cystic Fibrosis Transmembrane conductance Regulator) gene and characterized complex eventsin PRSS1 (Protease Serine 1) and HFE (Hemochromatosis) genes, showing that the use of thistechnique is possible even in regions with high sequence homologies.We also confirmed that hypertension, migraine, tobacco and drugs are high significant risk factors forischemic strokes (IS) in young population (under 40 years) (OR=35, 3.8, 4 and 2.8, respectively). Then,we tried to identify new genetic susceptibility loci using a pangenomic approach. Among the 98 copynumber polymorphisms (CNP) observed, an interstitial NOTCH2 deletion is candidate for a protective rolein IS (OR=0.11 [0.01-0.87] ; p=0.013 before Bonferonni correction). We also observed approximately 400uncommon CNV, two of them being particularly reccurent in patients: a 22q13.31 duplication containingCRELD2 (cysteine-rich with EGF-like domains 2) and AGL12 (asparagine-linked glycosylation 12, alpha-1, 6-mannosyltransferase) genes (p=0.02) and a Xq28 deletion localised in the 5’ region of the VBP1 (vonHippel-Lindau binding protein 1) gene (p=0.04). We also applied a candidate-gene approach onNOTCH2, ALOX5AP (5-lipoxygenase activating protein) and coagulation genes (Factor II, Factor VLeiden and MTHFR). A significant association was found for the C677T in the MTHFR gene (5,10-methyltetrahydrofolate) and young ischemic strokes (OR=2.39, p=0.02 for TT genotype). In conclusion,this study confirmed the implication of environmental and genetic factors in ischemic strokes before 40years and suggests new genetic risk factors for IS.
35

Etude clinique et génétique de l’albinisme oculocutané : développement d’outils de diagnostic moléculaire et recherche de nouveaux gènes / Clinical and molecular study of oculocutaneous albinism : development of molecular diagnosis tools and search for new genes

Morice-Picard, Fanny 11 December 2013 (has links)
Notre travail s’est intéressé à l’albinisme oculocutané en étudiant ses aspects clinico- moléculaires. Malgré l’analyse approfondie des gènes connus d’albinisme oculocutané, 15 % des patients restent sans mutation identifiée indiquant que les mutations sont situées dans des régions géniques non analysées par les techniques classiques de diagnostic moléculaire, ou qu’il existe d’autres gènes d’albinisme oculocutané. Nous avons établi une base de données clinico- biologiques décrivant les caractéristiques de plus de 400 patients analysés. Des outils de diagnostic moléculaire ont été développés à la recherche de mutations situées dans les introns et les régions régulatrices et de réarrangements géniques. Différentes stratégies ont également été utilisées pour rechercher des gènes candidats. La puce à façon a permis l’identification de grands réarrangements dans les gènes TYR, OCA2 et SLC45A2 et un réarrangement complexe du gène OCA2 chez 2 patients non apparentés. L'analyse de gènes candidats nous a permis d'identifier, chez 5 patients non apparentés présentant un albinisme oculocutané non syndromique, des mutations dans le gène SLC24A5, très récemment associé à l’AOC6. Le séquençage d’exome de 6 patients a mis en évidence des gènes candidats pour lesquels des analyses complémentaires sont poursuivies afin de confirmer leur implication dans la pathogenèse de l’AOC.Les résultats de ce travail permettent de redéfinir les aspects cliniques et moléculaires de l’AOC, d’identifier de nouveaux mécanismes moléculaires à l’origine de l’AOC ainsi que des gènes candidats dont la fonction dans le développement pigmentaire reste à élucider. L’identification de nouveaux gènes impliqués dans l’AOC pourrait permettre de mieux comprendre et de mieux prendre en charge les patients avec un AOC. / Our work focused on oculocutaneous albinism (OCA) by studying its clinical and molecular aspects. Despite a thorough analysis of the known genes involved in oculocutaneous albinism, 15% of patients remain without diagnostic at the molecular level indicating that mutations are located in unexplored regions and are undetected by standard techniques or that other genes are involved in albinism. We established a clinicomolecular database describing more than 400 patients and developped molecular tools in order to improve molecular diagnostic including a custom high resolution array-CGH dedicated to the four OCA genes (TYR, OCA2, TYRP1 and SLC45A2). We also used different strategies to identify new genes. Array-CGH allows us to detect large deletion in TYR, OCA2 and SLC45A2 and a complexe rearrangement in OCA2 in 2 unrelated patients. We identified, in 5 patients presenting with a non syndromic OCA, mutations in SLC24A5, recently associated with OCA6. Exome sequencing of 6 different patients allows us to identify candidate genes, for which further studies are required to confirm their involvement in OCA pathogenesis. The results of this work allowed us to delineate clinical and genetics aspects of more than 400 OCA patients and to identify new molecular mechanisms leading to OCA and candidates genes for which exact nature of their functions has to be understood. Giving the complexity of pigmentary system development and its regulation, identification of new genes leading to OCA could help to better understand OCA and take care of patients
36

InDels e CNVs pequenas em pacientes com Transtorno do Espectro Autista / InDels and small CNVs in patients whit Autism Spectrum Disorder

Silva, Isabela Mayá Wayhs 05 April 2017 (has links)
O Transtorno do Espectro Autista (TEA) é uma doença do neurodesenvolvimento. É caracterizado por déficits significativos e persistentes na comunicação e na interação social e por padrões restritos e repetitivos de comportamento, interesses ou atividades. O TEA é considerado uma doença comum, afetando 1 a cada 68 crianças e com uma proporção de 4,2 meninos afetados para cada menina (.A etiologia do autismo apresenta um forte componente genético. Neste contexto, as metodologias genômicas de larga escala (Sequenciamento de nova geração, microarray) contribuíram para o conhecimento sobre a genética do TEA. No entanto, em aproximadamente 70% dos pacientes, o transtorno permanece com etiologia não identificada. Com base nisso, para o presente trabalho, elaborou-se a hipótese de que pequenas CNVs (entre 1 e 50 Kb), que se encontram abaixo da resolução da maioria dos microarrays comerciais, e cuja detecção ainda apresenta limitações para a sua detecção através de sequenciamento de nova geração, poderiam contribuir para o fenótipo em uma proporção significativa dos casos. Como primeira etapa para abordar essa questão, realizou-se a metodologia de aCGH customizado 60K cobrindo um total de 269 genes candidatos ao TEA, a fim de selecionar CNVs potencialmente patogênicas entre 98 pacientes brasileiros com TEA idiopático. Com esta triagem inicial, a prevalência de CNVs potencialmente patogênicas obtida foi de 9%, com 20% delas caracterizadas como pequenas. A análise subsequente foi realizada com a metodologia de aCGH customizado 180K, o qual cobriu um total de 1527 genes candidatos ao TEA. Um total de 63 pacientes com autismo foram analisados com este novo array. A partir destas hibridações, a prevalência de CNVs potencialmente patogênicas obtida foi de 12,7%, com 62,5 % delas classificadas como pequenas. Esta taxa de detecção é bastante expressiva, particularmente se considerarmos que a amostra de pacientes utilizada foi submetida a uma pré-triagem, com a finalidade de excluir os pacientes com as CNVs mais prevalentes no TEA, nas regiões 15q11-q13, 16p11.2 e 22q13.3. A última abordagem utilizada neste trabalho foi comparar a detecção de CNVs pela metodologia de aCGH, referência padrão ouro para detecção de CNVs, com a de sequenciamento de nova geração (NGS). Os dados de 9 pacientes obtidos por NGS foram analisados através dos softwares NextGene e XHMM. Os softwares, no entanto, apresentaram resultados discrepantes entre si e pouca sobreposição com os dados de aCGH 180K, de 38,9% e 50%, considerando o NextGene e o XHMM respectivamente. Os resultados obtidos sugerem que o aCGH customizado é promissor para a detecção de CNVs pequenas e que essas, por sua vez, podem contribuir para o risco de TEA em pelo menos 6,3 %, dos casos / Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder. It is characterized by significant and persistent deficits in communication and social interaction, and by restricted and repetitive patterns of behavior, interests or activities. ASD is considered a common disease, affecting 1 in 68 children and a proportion of 4.2 boys affected for each girl.The etiology of autism has a strong genetic component. In this context, genomic methodologies of high-throughput (new generation sequencing, microarray) contributed to the knowledge about the genetics of ASD. However, in approximately 70% of patients with ASD, the disorder remains with unidentified etiology. Therefore, foi this work, it was hypothesized that small CNVs (between 1 and 50 Kb), which are below the resolution of most commercial microarrays and and whose detection still has limitations for its detection detection through NGS, could contribute to the phenotype in a proportion of cases. As a first step to address this hypothesis, it was performed the methodology of custom aCGH 60K, covering a total of 269 ASD candidate genes, in order to select potentially pathogenic CNVs among 98 Brazilian patients with idiopathic ASD. With this initial screening, the prevalence of potentially pathogenic CNVs obtained was 9%, with 20% of them characterized as small. The subsequent analysis was performed using the 180K custom aCGH methodology, which covered a total of 1527 TEA candidate genes. A total of 63 patients with autism were analyzed with this new array. From these hybridizations, the prevalence of potentially pathogenic CNVs obtained was 12.7%, with 62.5% of them classified as small. This detection rate is quite significant, particularly considering that the sample of patients used was pre-screened, in order to exclude patients with the most prevalent CNVs in ASD in the regions 15q11-q13, 16p11.2 and 22q13.3. The last approach used in this work was to compare the detection of CNVs by the methodology of aCGH, gold standard reference for CNVs detection, with the next generation sequencing (NGS).Data from 9 patients obtained by NGS were analyzed using NextGene and XHMM software. The softwares, however, presented discrepant results among themselves and little overlap with the data of aCGH 180K, of 38.9% and 50%, considering NextGene and XHMM respectively. These results suggest that the customized aCGH represents a promising approach for the detection of small CNVs and that these, in turn, can contribute to the risk of ASD in at least 6,3 % of cases
37

Identification de gènes responsables d'épilepsies de l'enfant / Identification of genes implicated in childhood epilepsies

Dimassi, Sarra 10 July 2017 (has links)
L'épilepsie est une affection neurologique chronique qui se définit par la répétition de crises épileptiques, signe de l'hyperactivité paroxystique d'un groupe de neurones corticaux. Ces dernières années, plusieurs gènes responsables d'épilepsies monogéniques ont été mis en évidence. Notre travail avait pour objectif l'identification d'anomalies génétiques responsables ou favorisants certaines formes d'épilepsies de l'enfant. Ce travail est composé de quatre études complémentaires. La première était l'exploration pangénomique d'une cohorte de 47 patients porteurs d'épilepsie à paroxysme rolandique (EPR) par CGH array, à la recherche de variations de nombre de copies (CNV) récurrentes. Nous avons ainsi pu mettre en évidence plusieurs CNVs emportant des gènes impliqués dans l'épilepsie, dont PRRT2 et GRIN2A. La deuxième reposait sur la même approche appliquée à une cohorte de 8 patients tunisiens présentant des spasmes infantiles. Elle a permis d'identifier une délétion 9q34.3 emportant le gène EHMT1, responsable du syndrome de Kleefstra et une duplication 15q13.1, région impliquée dans des troubles du neurodéveloppement. Pour la troisième étude, nous avons comparé deux techniques de capture pour séquençage à haut débit d'un panel de gènes impliqués dans les épilepsies de l'enfant, à partir des échantillons de 24 patients épileptiques. Cette approche nous a permis de mettre au point un logiciel d'analyse de couverture, que nous avons nommé DeCovA. Lors de la dernière étude, nous avons appliqué une stratégie de séquençage d'exome en trio pour explorer 10 patients porteurs des spasmes infantiles. Nous avons ainsi pu mettre en évidence des variants pathogènes de novo chez quatre patients,impliquant les gènes KCNQ2, SCN1A, NR2F1 et ALG13. Nos résultats confirment ainsi la place importante de la génétique et l'intérêt majeur des nouvelles technologies dans l'exploration étiologique des épilepsies de l'enfant / Epilepsy is a chronic neurological disorder characterized by repeated epileptic seizures, a sign of cortical neurons paroxysmal hyperactivity. In recent years, several monogenic genes involved in epilepsy have been identified. The aim of our work is to identify new genetic abnormalities responsible for childhood epilepsies. This work is divided into four complementary studies. First, we searched copy number variation (CNV) by pangenomic exploration of a cohort of 47 patients with Rolandic epilepsy (RE) using CGH array. We identified several CNVs carrying genes involved in epilepsy, including PRRT2 and GRIN2A (genes). Secondly, the same approach was applied to a cohort of 8 Tunisian patients with infantile spasms. It allowed the identification of a 9q34.3 deletion includingEHMT1, implicated in Kleefstra syndrome and a 15q13.1 duplication, known to be involved in neurodevelopment disorders. For the third study, we compared two library-building methods for a gene-targeted panel for the diagnosis of Monogenic childhood epilepsies, in a cohort of 24 epileptic patients. This approach allowed us to develop a coverage analysis software, which we named DeCovA. In the last study, we used a trio-based exome-sequencing approach to look for de novo mutations in 10 patients with infantile spasms. We found de novo pathogenic variants in four patients, involving KCNQ2, SCN1A, NR2F1, and ALG13. Our results confirm the increasing role of genetics and the major interest of new technologies in the etiological exploration of childhood epilepsy
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Copy number variations (CNVs) in Brazilian patients with autism spectrum disorder (ASD) / Variações no número de cópias (CNVs) em pacientes brasileiros com transtorno do espectro autista (TEA)

Costa, Claudia Ismania Samogy 18 July 2018 (has links)
Autism Spectrum Disorder (ASD) is a heterogeneous group of neurodevelopmental disorders that affects about 1% of the worldwide population and has a strong genetic component. Stereotyped behavior and restricted interests, as well as problems of social interaction and communication characterize ASD. Moreover, in 10% of cases, ASD occurs as a secondary condition in addition to a syndrome, such as Phelan-McDermid syndrome (PMS), which is associated with a great clinical variability. Among genetic factors, copy number variations (CNVs) are one of the most important. However, the clinical significance of many CNVs remains nuclear and there is an underrepresentation of small CNVs associated with ASD in the literature. In this context, this project aimed to 1) characterize large and small CNVs in Brazilian patients with ASD using an array-CGH previously customized in our laboratory. 2) Clinically and genetically describe a cohort of Brazilian patients with PMS, as well as to determine the frequency of this syndrome among Brazilian patients with ASD and other neurodevelopmental disorders. In result, we 1) further validated the customized array-CGH, 2) provided additional evidence of association with ASD for 27 candidate genes, 3) described 15 CNVs never reported in the literature in association with this disorder, 4) presented evidence that around 70% of CNVs found in our cohort are not polymorphism of our population and 5) reinforced the idea of shared molecular pathways among different neurodevelopmental disorders. In addition, we described for the first time a Brazilian cohort of patients with PMS and contributed to the molecular and clinical characterization of this syndrome. We also provided additional evidence of genotype-phenotype association with regard to the presence of renal problems and speech status in patients with PMS and estimated the frequency of this syndrome among Brazilian patients with ASD and intellectual disability (syndromic or not). With these results, we hope to contribute to better understand the ASD and PMS etiology, especially in our population / O Transtorno do Espectro Autista (TEA) corresponde ao um grupo heterogêneo de alterações no neurodesenvolvimento que afeta cerca de 1% da população mundial e apresenta um forte componente genético. O TEA é caracterizado pela presença de comportamento estereotipado e interesses restritos, além de problemas de interação social e comunicação. Além disso, em 10% dos casos, o TEA ocorre como uma condição secundária somada a uma síndrome. Um exemplo é a síndrome de Phelan-McDermid (PMS), associada a uma grande variabilidade clínica. Dentre os fatores genéticos, as variações no número de cópias (CNVs) são um dos mais importantes. No entanto, o significado clínico de muitas CNVs permanece incerto, além de haver juma sub-representação de CNVs pequenas associadas ao TEA na literatura. Dentro deste contexto, este projeto teve como objetivos 1) caracterizar CNVs grandes e pequenas em pacientes brasileiros com TEA utilizando uma lâmina de array-CGH previamente customizada no Laboratório de Genética do Desenvolvimento - USP. 2) descrever clínica e geneticamente uma casuística de pacientes brasileiros com PMS, bem como determinar a frequência desta síndrome em pacientes com TEA e com outras alterações de neurodesenvolvimento. Como resultados, nós 1) validamos a lâmina customizada, 2) fornecemos evidencia adicional de associação com o TEA para 27 genes, 3) descrevemos 15 CNVs nunca reportadas em associação com o transtorno 4) apresentamos evidências de que cerca de 70% das CNVs encontradas em nossa coorte não são polimorfismo de nossa população e 5) reforçamos a ideia de vias moleculares compartilhadas entre diferentes alterações do neurodesenvolvimento. Além disso, descrevemos pela primeira vez uma casuística brasileira de pacientes com PMS e contribuímos para a síndrome. Fornecemos evidência adicional de associação genótipo-fenótipo no que diz respeito à presença de problemas renais e status de fala em pacientes com PMS e estimamos a frequência da síndrome entre pacientes brasileiros com TEA e com deficiência intelectual (sindrômica ou não). Com estes resultados, esperamos ter contribuído para o entendimento da etiologia tanto do TEA, quanto da PMS, sobretudo na nossa população
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Apport de l'analyse chromosomique sur différents microréseaux d'ADN dans l'identification de nouvelles mutations et la caractérisation de gènes candidats impliqués dans la déficience intellectuelle / Contribution of chromosome analysis on different DNA Micro-Arrays in the identification of novel mutations and characterization of candidate genes involved in intellectual disability

Huynh, Minh Tuan 15 November 2013 (has links)
Anomalies de structure du génome et Déficience Intellectuelle : Recherche des gènes candidats de Déficience intellectuelle en utilisant l'analyse chromosomique sur microréseau d'ADN pangénomique 180K et l'analyse chromosomique sur microréseau d'ADN de haute résolution 1M ciblée des gènes candidats de Déficience intellectuelle. L'analyse chromosomique sur microréseau d'ADN (ACM) de haute résolution est une innovation technologique puissante afin de détecter les aberrations chromosomiques concernant les variations du nombre de copies. En utilisant l'ACM 180K, l'ACM 1M et la PCR quantitative, nous avons identifié les 5 variations du nombre de copies (CNV) intragéniques pathogènes de novo impliquant les gènes : RUNX1T1, KIAA1468, FABP7, ZEB2 (syndrome de Mowat-Wilson) et ANKRD11 (syndrome de KBG). Les 5 patients ayant une DI et une dysmorphie faciale. L'ACM 180K a révélé une délétion d'une taille de 92 kb emportant le gène KIAA1468 candidat pour le syndrome de West chez un enfant de 3 ans présentant une DI sévère et une encéphalopathie épileptique infantile précoce. Le criblage des mutations du gène KIAA1468 a été réalisé chez 35 patients atteints de syndrome de West. Un variant intronique c.2761-7 T>C et un variant faux-sens hérité de la mère c.3547 G>A avec signification clinque inconnue ont été identifiés. En utilisant des approches par l'ACM 1M de haute résolution chez 45 patients atteints de DI idiopathique modérée à sévère, un seul CNV causal a été identifié, une délétion intragénique d'une taille de 28.37 kb du gène ZEB2. Notre étude confirme une fréquence très faible des délétions/duplications intragéniques avec la détection d'une seule aberration chromosomique (1/45). En conclusion, si la fréquence des mutations ponctuelles est élevée, nous avons également souligné l'application de la technique de séquençage à haut débit avec un rendement diagnostique jusqu'à 45%-55% des cas de DI sévère idiopathique chez lesquels aucun CNV n'a été détecté sur ACM / Chromosomal structural abnormalities and Intellectual Disability : In search of intellectual disability candidate genes by using pangenomic comparative genomic hybridization 180 K and high resolution comparative genomic hybridization 1M targeting intellectual disability candidate gene.High resolution microarray-based comparative genomic hybridization (a-CGH) has been a powerful technical innovation in order to detect submicroscopic chromosomal aberrations related to copy number variations. By using a-CGH 180K, 1M high resolution a-CGH and quantitative PCR, we have identified 5 pathogenic intragenic copy number variations (CNVs) de novo : RUNX1T1, KIAA1468, FABP7, ZEB2 (Mowat-Wilson syndrome) and ANKRD11 (KBG syndrome). All five patients had intellectual disability (ID) and facial dysmorphism. Interestingly, a-CGH 180K has revealed a 92 kb deletion of a candidate gene KIAA1468 for West syndrome in a 3 year-old boy with severe ID and early infantile epileptic encephalopathy. Mutational screening for candidate gene KIAA1468 was performed in 35 patients with West syndrome. An intronic variant c.2761-7 T>C and a non synonymous maternally inherited variant c.3547 G>A with unknown clinical significance were identified. By using 1M high-resolution a-CGH approach in 45 patients presenting moderate to severe idiopathic ID, only one causal CNV was identified, a 28.37 kb intragenic ZEB2 deletion. Our study has confirmed the low frequency of intragenic deletion/duplication with the detection of only one chromosomal aberration (1/45). In conclusion, providing that the high frequency of intragenic point mutation, we also stressed the application of next-generation sequencing technology with 45-55% diagnostic yield in patients with idiopathic severe ID in case of no apparent CNV(s) on high-resolution a-CGH
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Charakterisierung chromosomaler Imbalancen in Adenokarzinomen der Lunge mit Hilfe der Comparativen genomischen Hybridisierung (CGH)

Goeze, Almut 30 October 2000 (has links)
Das Adenokarzinom ist weltweit das häufigste nicht-kleinzellige Lungenkarzinom mit ansteigender Inzidenz insbesondere bei Frauen. Zur genetischen Analyse dieses Tumortyps haben wir 60 Fälle mittels der Comparativen Genomische Hybridisierung (CGH) untersucht, dabei wurden 60 Primärtumoren und von 10 Fällen zusätzlich 23 Metastasen (pro Primärtumor max. 4 korrespondierende Metastasen) analysiert. Bei den 60 Primärtumoren wurden folgende Veränderungen in über 50% der Fälle beobachtet: Deletionen auf den Chromosomen 3p, 4p, 4q, 5q, 6q, 8p, 9p, 9q, 13q, 15q und 18q sowie Überrepräsentationen auf den Chromosomen 1q, 5p, 8q, 11q. 17q. 19q und 20q. Häufigste Veränderung war die Überrepräsentation auf Chromosom 1q22-q23 (73,3%), gefolgt von Überrepräsentationen auf den Chromosomen 20q11.2-q13.2 (66,7%) und 8q23-q24.1 (61,7%) und Deletionen auf 3p22-p21 (61,7% ), 4q26-q28 (63,3%), 6q16 (60,0%), 6q22 (60,0%), 9p13-p21 (63,3%), 13q21 (68,3%) und 13q31 (68,3%). Beim statistischen Vergleich mittels c2-Test von 24 nicht-metastasierten Primärtumoren mit der Gruppe von 23 metastasierten Primärtumoren und 10 Metastasen waren folgende Veränderungen statistisch signifikant mit Metastasierung verbunden: Deletionen von 3p22-p25, 4p13-p15.1 und 17p12-p13 sowie Überrepräsentationen von 1q21, 11q12-13, 14q11.1-q13, 15q24 und 20q12-13.1. Statistisch signifikant häufiger mit dem nicht-metastasierten Phänotyp assoziiert waren dagegen folgende Veränderungen: Deletion von 19p13.1-p13.3 und Überrepräsentationen von 3p12-p14 , 4q26-q28 und 5p14. Die Analyse der Primärtumoren und ihrer korrespondierenden Metastasen konnten in jedem Fall einen klonalen Zusammenhang aufzeigen. Zusammenfassend sind Adenokarzinome der Lunge durch wiederkehrende Muster chromosomaler Veränderungen charakterisiert, die eine Korrelation zwischen Tumor-Genotyp und -Phänotyp ermöglichen. / Adenocarcinomas are the most common non small cell lung carcinomas worldwide with increasing incidence especially in women. For the genetic analysis of this tumor type we screened 60 primary tumors and additionally 23 metastases from 10 cases (4 corresponding metastases per primary tumor as maximum) by Comparative Genomic Hybridization (CGH). The following alterations were found in over 50% of the 60 primary tumors: Deletions on chromosomes 3p, 4p, 4q, 5q, 6q, 8p, 9p, 9q, 13q, 15q, and 18q as well as overrepresentations on chromosomes 1q, 5p, 8q, 11q. 17q. 19q und 20q. The most frequent alteration was the overrepresentation on chromosome 1q22-q23 (73,3%), followed by overrepresentations on chromosomes 20q11.2-q13.2 (66,7%), and 8q23-q24.1 (61,7%), and deletions on 3p22-p21 (61,7% ), 4q26-q28 (63,3%), 6q16 (60,0%), 6q22 (60,0%), 9p13-p21 (63,3%), 13q21 (68,3%), and 13q31 (68,3%). At the comparison between 24 non metastasizing primary tumors versus 23 metastasizing tumors and 10 metastases the following changes were statistically significant (c2 test) associated with the metastasizing phenotype: deletions on chromosomes 3p22-p25, 4p13-p15.1, and 17p12-p13, as well as overrepresentations on 1q21, 11q12-13, 14q11.1-q13, 15q24, and 20q12-13.1 whereas the deletion on chromosome 19p13.1-p13.3 and overrepresentations on chromosomes 3p12-p14 , 4q26-q28, and 5p14 were associated with the non metastasizing phenotype. A clonal relationship could be shown in every case with primary tumor and corresponding metastases. In summary, adenocarcinomas of the lung are characterized by recurrent patterns of chromosomal imbalances allowing a correlation between tumor genotype and tumor phenotype.

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