Orientador: Danilo Moretti Ferreira / Resumo: A síndrome de Williams-Beuren (SWB) é uma doença genética caracterizada por dismorfismos faciais, anomalias cardiovasculares, deficiência intelectual e perfil cognitivo típico. A SWB é causada por uma microdeleção hemizigótica da região cromossômica 7q11.23, de ~1,5Mb a 1,8Mb de genes de copias únicas e deleções maiores ou menores que esses limites são considerados deleções atípicas. O objetivo do trabalho foi detectar perdas ou ganhos de DNA por meio da técnica de MLPA na região crítica da SWB em pacientes com diagnóstico clínico estabelecido pela pontuação de escore da AAP, (2001) e com exame de FISH (-) realizado anteriormente pelo nosso grupo de pesquisa, e assim correlacionar os achados de perdas ou ganhos de DNA com os já descritos na literatura e correlaciona-los aos fenótipos/genótipo descritos em bancos de dados público como DVG, DECIPHER, UCSC Genome Browser dentre outros. Foram selecionados 30 indivíduos com hipótese diagnóstica de SWB e análise citogenética negativa para SWB estabelecida pela técnica da FISH. O diagnóstico clínico de SWB “clássica” foi estabelecido pelo escore da Academia Americana de Pediatria (2001). Foi realizada a extração de DNA das amostras e foi aplicada a técnica de MLPA com o kit SALSA P029 (MRC-Holland, Amsterdam, The Netherlands) com sondas específicas para os principais genes encontrados na região crítica da SWB. Nesta amostra predominou o sexo masculino (2M:1F) e a idade do 1° atendimento foi tardia (mediana 9,5 anos). A casuística ap... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Williams-Beuren Syndrome (WBS) is a genetic disorder characterized by facial dysmorphisms, cardiovascular anomalies, intellectual disability and typical cognitive profile. WBS is caused by a hemizygous microdeletion of the 7q11.23 chromosomal region, ~ 1.5Mb to 1.8Mb of single copy genes, and deletions larger or smaller than those limits are considered atypical deletions. The objective of this study was to detect DNA loss or gain by MLPA technique in the critical region of SWB in patients with clinical diagnosis established by AAP score (2001) and with FISH (-) examination previously performed by our search group, and thus correlate the findings of DNA loss or gain with those already described in the literature and correlate them with the phenotypes / genotype described in public databases such as DVG, DECIPHER, UCSC Genome Browser and others. Thirty individuals with diagnostic hypothesis of WBS and negative cytogenetic analysis for WBS established by the FISH technique were selected. The clinical diagnosis of “classic” WBS was established by the American Academy of Pediatrics score (2001). DNA extraction from the samples was performed and the MLPA technique was applied with the SALSA P029 kit (MRC-Holland, Amsterdam, The Netherlands) with probes specific for the major genes found in the critical region of the SWB. In this sample, the male gender predominated (2M: 1F) and the age of the first attendance was late (median 9.5 years). The sample presented the facial characterist... (Complete abstract click electronic access below) / Mestre

Submitted by admin tede (tede@pucgoias.edu.br) on 2016-09-13T13:52:57Z No. of bitstreams: 1 MARINA MACHADO SANTOS.pdf: 3084828 bytes, checksum: 7da6c5d67d268a88f71826629557e0c5 (MD5) / Made available in DSpace on 2016-09-13T13:52:58Z (GMT). No. of bitstreams: 1 MARINA MACHADO SANTOS.pdf: 3084828 bytes, checksum: 7da6c5d67d268a88f71826629557e0c5 (MD5) Previous issue date: 2016-05-16 / Chromosomal abnormalities cause specific and complex phenotypes due to imbalance in the normal dosage of genes located in a specific chromosomal segment. They account for 60% or even more of all the identifiable genetic syndromes. Williams-Beuren syndrome (WBS) is related to a group of multiple defects and intellectual disabilities, described independently by Williams et al. (1961) and Beuren et al. (1962). The WBS is a genetic disease characterized by a microdeletion of the 7q11.23 region, which delay the physical and intellectual development and it is associated with congenital cardiac abnormalities, facial dimorphism, mental retardation and occasionally infantile hypercalcemia.The existing phenotypic variation in this syndrome hinders clinical diagnosis.Through the development of new cytomolecular technologies and the increased number of studies regarding the clinical features of this syndrome, seeks a better understanding of the genotype-phenotype correlation in WBS. The present study reports some of these techniques used for the diagnosis of WBS, such as Karyotype, MLPA, PCR, with emphasis on FISH and CMA. Additionally, we described four patients who were referred to LaGene/SES and NPR/PUC by the public health service. Three of them had clinical suggestion of WBS and the fourth patient of ID. The confirmation was unsuccessful regarding the diagnostic through techniques of conventional cytogenetics for all of the patinets. FISH technique was useful in the diagnostic investigation of a patient while CMA was used to study the other 3 cases. Chromosomal microarray analysis detected long stretches of homozygosity of uncertain clinical significance at the Xq11.1q13.1 region and a microduplication at the 7q11.23 region, the latter is defined as a critical region of WBS. The study of genotype-phenotype correlation in WBS has been established for some genes detected by CMA. But other genes did not show a strong relation to the syndrome, thus requiring further investigation. / As anomalias cromossômicas causam fenótipos específicos e complexos resultantes de desequilíbrios na dose normal de genes localizados em um segmento cromossômico específico, sendo responsáveis por 60 % ou mais das síndromes genéticas identificáveis. A Síndrome de Williams-Beuren (SWB) caracteriza-se por anomalias múltiplas e deficiência intelectual, descrita independentemente por Williams et al. (1961) e por Beuren et al. (1962). A SWB consiste em uma doença genética causada pela microdeleção em 7q11.23, que ocasiona o atraso no desenvolvimento físico e intelectual associado com alterações cardíacas congênitas, dimorfismos faciais, retardo mental e ocasionalmente hipercalcemia infantil. A variação fenotípica existente nesta síndrome dificulta o seu diagnóstico clínico. Com o desenvolvimento de novas tecnologias citomoleculares e o aumento de estudos voltados para o conhecimento das características clínicas desta síndrome, busca-se explicar melhor a correlação genótipo-fenótipo na SWB. O presente estudo relata algumas técnicas utilizadas para o diagnóstico da SWB, como Cariótipo, MLPA e PCR, dando ênfase em FISH e CMA. Adicionalmente, são descritos quatro pacientes encaminhados ao LaGene/SES e NPR/PUC pelo serviço público de saúde, onde três destes pacientes apresentavam hipótese diagnóstica para a SWB e um paciente para a DI. Para os quatro pacientes não houve êxito no diagnóstico pela citogenética convencional. A técnica de FISH foi útil na elucidação diagnóstica para um paciente, enquanto que a CMA foi utilizada no estudo dos outros 3 casos. A análise cromossômica por microarranjo detectou longos trechos contínuos de homozigose de significado clínico incerto em Xq11.1q13.1 e um caso de microduplicação na região 7q11.23, que é definida como região crítica da SWB. O estudo da correlação genótipo-fenótipo na Síndrome de Williams-Beuren foi estabelecido para alguns dos genes detectados pelo CMA. Entretanto outros genes detectados não tiveram sua relação estabelecida, necessitando assim de estudos posteriores.

Le syndrome de Williams-Beuren (SWB} est une maladie génétique rare causée par une microdélétion de la région 7q11.23. A la suite de l'observation clinique d'une jeune fille atteinte du SWB ayant développé un lymphome de Burkitt à l'âge de 7 ans, nous nous sommes intéressé au lien génétique entre SWB et cancer. L'étude d'une série de cas de cancers survenus chez des enfants atteints de SWB a montré que les lymphomes non-hodgkiniens de type B étaient surreprésentés dans cette population puisque 73% des cancers chez les enfants atteints du SWB étaient des LNH-B. La région critique du SWB a été explorée par CGH-array et séquencage haut-débit dans les échantillons sains et tumoraux de 2 patients atteints de SWB. Aucune perte d'hétérozygotie de la région 7q11.23 n'a été trouvé. En outre, une délétion somatique de la région 7q11.23 a été identifiée dans un lymphome de Burkitt sporadique (Guenat D et al., J Hematol Oncol, 2014). Nous avons ensuite exploré les mécanismes de réponses aux dommages à l'ADN dans des lignées de fibroblastes primaires dérivées de patients atteints du SWB ainsi que dans des lignées 293T traitées avec des siRNA ciblant RFC2, BAZ1B et GTF2/, 3 gènes localisés en 7q11.23 et codant des protéines de réparation de l'ADN. Les cellules dérivées de patients SWB ont montré un défaut de signalisation dans les voies ATM/ATR-dépendantes en réponse aux dommages à l'ADN (Guenat D et al., DNA repair, article soumis). L'haploinsuffisance de la région 7q11.23 associée au SWB pourrait donc jouer un rôle dans la lymphomagenèse B par l'altération de voies de réponse aux dommages à l'ADN ATM/ATR-dépendantes. Cependant, ces résultats mériteraient d'être confirmés dans des modèles murins reproduisant le génotype complet du SWB. Enfin, des données épidémiologiques exhaustives sur l'incidence des pathologies tumorales chez les individus atteints du SWB sont indispensables pour affirmer qu'une prédisposition au cancer existe chez ces patients / Williams-Beuren syndrome (WBS) is a genetic disorder caused by a microdeletion at 7q11.23. The case of a young girl with WBS who developed a Burkitt lymphoma at the age of 7 leads us to explore the genetic link between WBS and cancer. The study of a series of cancers occurred in WBS patients during childhood have shown that B-cell non hodgkin lymphoma are over-represented in this population since 73% cancer cases in WBS were B-NHL. The critical region of WBS was explored by array-CGH and high-throughput sequencing in normal and tumor samples from WBS patients. No loss of heterozygosity at 7q11.23 was found. ln addition, a somatic deletion at 7q11.23 was observed in a sporadic case of Burkitt lymphoma (Guenat D et al., J Hematol Oncol, 2014). DNA damage response mechanisms were then explored in primary fibroblast cell lines derived from WBS patients as well as in 293T cell line treated with siRNA targeting RFC2, GTF2/ and BAZ1 B, 3 genes mapping at 7q11.23 that encode proteins involved in DNA damage response. WBS patients cell lines have shown a defect in ATM/ ATR-dependent DNA damage response pathways (Guenat D et al., DNA Repair, article submitted). Haploinsufficiency of the 7q11.23 region associated with WBS might play a role in B-cell lymphomagenesis through the alteration of ATM/ATR-dependent DNA damage response pathways. However, these results deserve to be confirmed in mouse models that reproduce the complete genotype of human WBS. Finally, strong epidemiological data would be required to confirm the predisposition to cancer in WBS patients.