Orientador: Vera Lúcia Gil da Silva Lopes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T02:52:06Z (GMT). No. of bitstreams: 1 Sgardioli_IlariaCristina_M.pdf: 3234786 bytes, checksum: cb2f0f67f9d7df7814742dbf6ed4fb44 (MD5) Previous issue date: 2011 / Resumo: A Síndrome Velocardiofacial (SVCF), uma das formas do espectro da Síndrome de deleção 22q11.2, possui incidência de 1/4.000 a 1/6.000 nascimentos. Embora a microdeleção em 22q11.2 seja a principal causa da síndrome, cerca de 10 a 20% dos pacientes com características clínicas da SVCF não a apresentam. Em alguns indivíduos com características clinicas da SVCF e sem microdeleção em 22q11.2, foram encontradas outras aberrações cromossômicas e mutações no gene TBX1. Existem evidências em modelos animais que aventam a associação de alterações no gene FGF8 ao fenótipo da SVCF em humanos. No entanto, até o momento, o gene FGF8 ainda não havia sido estudado em pacientes com SVCF sem microdeleção. Os objetivos deste trabalho foram: 1 - investigar as causas genéticas em pacientes com suspeita clínica da SVCF por meio de cariótipo e triagem de microdeleções, utilizando a técnica de MLPA e FISH; 2 - verificar a presença de alterações nas seqüências codificantes dos genes TBX1 e FGF8 em pacientes sem deleção 22q11.2. Foram incluídos 109 indivíduos com suspeita clínica de SVCF avaliados clinicamente por médico geneticista e os métodos utilizados foram: cariótipo com bandas G; MLPA, FISH; seqüenciamento direto das regiões codificantes dos genes TBX1 e FGF8 e SNP-array. Dos 101 casos em que o exame de cariótipo foi realizado, quatro apresentaram aberrações cromossômicas não relacionadas à SVCF, sendo que em duas foi possível a confirmação dos resultados por SNP-array. Realizou-se MLPA de 106 casos, sendo que 29 foram positivos para a deleção. Dos casos negativos, selecionou-se 31 indivíduos após reavaliação clínico-dismorfológica com a hipótese clínica mantida e foi realizado seqüenciamento das regiões codificantes dos genes TBX1 e FGF8. No gene TBX1 foram encontradas variações normais na seqüência e no gene FGF8 não foram detectadas alterações, com exceção dos exons 1 e 2, em que não foi possível análise por problemas técnicos. O exame de cariótipo contribuiu na investigação inicial e permitiu concluir a investigação por outras técnicas. O MLPA se mostrou eficiente para a investigação diagnóstica da deleção 22q11.2, identificando, também, outras alterações; FISH confirmou 82,1% dos resultados obtidos por MLPA. Não foram identificadas alterações patogênicas nas regiões codificantes dos genes TBX1 e em 90% das regiões codificantes do gene FGF8 / Abstract: Velocardiofacial Syndrome (SVCF), one of the forms of the 22q11.2 Microdeletion Syndrome spectrum, has an incidence of 1/4.000 to 1/6.000 births. Although the 22q11.2 microdeletion is the main cause of the syndrome, approximately 10 to 20% of the patients with clinical features of SVCF don't present it. In a few individuals with SVCF clinical features and without 22q11.2 microdeletion other chromosomal aberrations and changes in TBX1 gene were found. There is evidence in animal models that suggests the associated changes in FGF8 gene in humans. However, the FGF8 gene had not been studied in patients with SVCF without microdeletion yet. The purpose of this work was: 1 - To investigate the genetic causes in patients with clinical suspicion of SVCF through the karyotype and microdeletion screening using MLPA and FISH techniques; 2 - To check the presence of changes in coding sequences of the TBX1 gene and FGF8 gene in patients without 22q11.2 deletion. 109 individuals with clinical suspicion of SVCF and clinically evaluated by a clinical geneticist were included, and the following methods were used: karyotype with GTG banding, MLPA, FISH, direct sequencing of coding regions of TBX1 and FGF8 gene and SNP-array. Four out of 102 cases in which the tests of karyotype were performed presented chromosomal aberrations not related to SVCF, two of them confirmed by SNP-array. The MLPA of 106 cases was performed, 29 of them positive to deletion. 31 individuals were selected among negative cases, after clinical reevaluation based on the same clinical hypothesis maintained, and direct sequencing of coding regions of TBX1 and FGF8 gene were performed. Normal variations in sequence were found in TBX1 gene and alterations were not detected in FGF8 gene except for 1 and 2 exons because of technical problems. The karyotype test contributed in the first investigation and permitted us to conclude the investigation by means of other techniques. The MLPA proved to be effective for the diagnostic investigation of 22q11.2 deletion, identifying other alterations as well; FISH confirmed 82,1% results obtained by MLPA. Pathogenic alterations in coding regions of TBX1 gene and in 90% of the coding regions of FGF8 gene were not identified / Mestrado / Ciencias Biomedicas / Mestre em Ciências Médicas

Orientadores: Vera Lúcia Gil da Silva Lopes, Milena Simioni / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-27T18:40:32Z (GMT). No. of bitstreams: 1 Molck_MiriamCoelho_D.pdf: 5956023 bytes, checksum: 07a0d65667a7a002b0e8ad7a872c0d31 (MD5) Previous issue date: 2015 / Resumo: A Síndrome Velocardiofacial (SVCF) tem prevalência de ~1:4.000 nascimentos e apresenta espectro fenotípico variável, incluindo defeitos cardíacos congênitos (DCC). Microdeleções de ~3 Mb em 22q11.2 representam a principal causa, entretanto deleções atípicas nesta região têm sido relatadas, assim como fenótipos similares associados a variações no número de cópias do DNA (Copy number variations, CNVs) em outras regiões cromossômicas. Esta proposta objetiva mapear os pontos de quebra da região 22q11.2 e investigar CNVs em outras regiões do genoma em pacientes com a deleção 22q11.2 confirmada previamente (Grupo I) e investigar CNVs no genoma de pacientes sem a deleção 22q11.2 (Grupo II). Foram investigados 108 pacientes (30 do Grupo I e 78 do Grupo II) com suspeita clínica da SVCF e DCC por Hibridação Genômica em arrays (array Genomic Hybridization- aGH). Para o Grupo I, o tamanho da deleção 22q11.2 proximal variou de 1,8 Mb a 3,3 Mb em 28 casos, sendo que um apresentou a deleção entre as LCRs (Low Copy Repeats) A-B e os demais 27 entre as LCRs A-D (região tipicamente deletada). Dois casos apresentaram deleções atípicas em 22q11.2: 3,6 Mb entre as LCRs B-F, elvolvendo as regiões 22q11.2 proximal e distal; e 1,5 Mb entre as LCRs D-E, envolvendo a região 22q11.2 distal. Além disso, foram observadas dez CNVs ? 300 kb relevantes fora da região 22q11.2, incluindo uma deleção em 11q14.3 e duplicações em 2q24.1-q24.2, 3p22.1, 5p15.2, 5q11.1, 6p21.2, 7p11.2, 15q13.3, 16q23.3 e Xp21.1. Para o Grupo II, foi observado um total de 25 CNVs ? 300 Kb relevantes. Destas, nove CNVs já foram descritas na literatura, incluindo deleções em 4q35.1-q35.2, 5p15.1-p15.33, 8p23.1, 10q22.3-q23.2, 16p11.2, 17q12 e 22q13.33; e duplicações em 3p26.3 e 3q26.2. As variações gênicas dentro dos pontos de quebra da região deletada 22q11.2, bem como as CNVs observadas em outras regiões cromossômicas contribuem para a variabilidade fenotípica observada nesta síndrome e confirmam a sobreposição desta com diferentes condições clínicas / Abstract: The Velocardiofacial Syndrome (VCFS) has a prevalence of ~1:4.000 births and shows variable phenotypic spectrum, including congenital heart defects (CHD). Microdeletions of ~3 Mb in 22q11.2 represent the main cause, however atypical deletions in this region have been reported, as well as similar phenotypes associated with changes in the number of DNA copies (Copy number variations, CNVs) in other chromosomal regions. This work aims to map the breakpoints of the 22q11.2 region and investigate CNVs in other regions of the genome in patients with the 22q11.2 deletion previously confirmed (Group I) and investigate CNVs on the genome of patients without the 22q11.2 deletion (Group II). We investigated 108 patients (30 from Group I and 78 from Group II) with clinical suspicion of VCFS and CHD for array Genomic Hybridization (aGH). For Group I, the size of proximal 22q11.2 deletion ranged from 1.8 Mb to 3.3 Mb in 28 cases, of these, one case had the deletion between LCRs (Low Copy Repeats) A-B and the other 27 between LCRs A-D (typically deleted region). Two cases had atypical deletions at 22q11.2: 3.6 Mb between LCRs B-F, involving proximal and distal 22q11.2 regions; and 1.5 Mb between LCRs D-E, involving distal 22q11.2 region. Additionally, we observed ten relevant CNVs ? 300 kb outside of 22q11.2 region, including a deletion in 11q14.3 and duplications in 2q24.1-q24.2, 3p22.1, 5p15.2, 5q11.1, 6p21.2, 7p11.2, 15q13.3, 16q23.3 and Xp21.1. For Group II, a total of 25 relevant CNVs ? 300 Kb was observed. Of these, nine CNVs have been described in the literature, including deletions in 4q35.1-q35.2, 5p15.1-p15.33, 8p23.1, 10q22.3-q23.2, 16p11.2, 17q12 and 22q13.33; and duplications in 3p26.3 and 3q26.2. Gene variations within the break points of the 22q11.2 deleted region and CNVs observed in other chromosomal regions contribute to phenotypic variability observed in this syndrome and confirm the overlapp with different clinical conditions / Doutorado / Ciencias Biomedicas / Doutora em Ciências Médicas

Orientador: Lucilene Arilho Ribeiro Bicudo / Resumo: A Síndrome de Microdeleção 22q11 (SD22q11), causada por uma deleção de aproximadamente 3Mb na região 22q11, apresenta uma frequencia média de 1 em 4000 a 9800 nascidos vivos sendo considera a síndrome de microdeleção mais frequente e a segunda causa mais comum de atraso no desenvolvimento e de doença congênita grave, após a síndrome de Down. De acordo com o tamanho e a localização da deleção, diferentes genes podem ser afetados e o principal gene considerado como responsável pelos sinais clássicos da síndrome é o TBX1. A SD22q11 caracteriza-se por um espectro fenotípico bastante amplo, com efeitos pleiotrópicos que resultam no acometimento de praticamente todos os órgãos e/ou sistemas, altamente variáveis com mais de 180 sinais clínicos já descritos, tanto físicos como comportamentais. Nesse trabalho aplicamos ferramentas de bioinformática com o intuito de descobrir padrões clínicos e sistêmicos da deleção 22q11, classificando casos sindrômicos em típicos e atípicos e estudando o impacto da deleção em redes de interação proteína-proteína (PPI). Para avaliação dos sinais clínicos que pudessem diferenciar pacientes sindrômicos foi aplicado uma metodologia baseada em aprendizado de máquina para classificar os casos em típico e atípico de acordo com os sinais clínicos através do algoritmo J48 (um algoritmo de árvore de decisão). As árvores de decisão selecionadas foram altamente precisas. Sinais clínicos como fissura oral, insuficiência velofaríngea, atraso no desenvolvimento de ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The 22q11 Microdeletion Syndrome (22q11DS), caused by a deletion of approximately 3Mb in the 22q11 region, has an average frequency of 1 in 4000 to 9800 live births and is considered the most frequent microdeletion syndrome and the second most common cause of developmental delay and severe congenital disease after Down syndrome. According to the size and location of the deletion, different genes may be affected and the main gene considered to be responsible for the classic signs of the syndrome is TBX1. 22q11DS is characterized by a very broad phenotypic spectrum with pleiotropic effects that result in the involvement of variable organs and/or systems with more than 180 clinical signs already described, both physical and behavioral. In this work, we applied bioinformatics tools to detect clinical and systemic patterns of 22q11 deletion, classifying typical and atypical syndromic cases, and studying the impact of deletion on protein-protein interaction (PPI) networks. To evaluate clinical signs that could differentiate syndromic patients, a machine-learning based methodology was used to classify the cases into typical and atypical according to the clinical signs through the algorithm J48 (a decision tree algorithm). The selected decision trees were highly accurate. Clinical signs such as oral fissure, velopharyngeal insufficiency, speech and language development delay, specific learning disability, behavioral abnormality and growth delay were indicative for case classification... (Complete abstract click electronic access below) / Mestre

Entre as síndromes de deleção do cromossomo 22q.11, a Síndrome de DiGeorge foi descrita em 1967 como uma imunodeficiência primária caracterizada por: malformações cardíacas, hipoparatireoidismo e ausência de timo. A incidência estimada é de 1: 3000 nascidos vivos e apesar disto seu reconhecimento ainda apresenta dificuldades devido à grande variabilidade fenotípica e diferentes nomenclaturas. Para o diagnóstico é necessário a presença do número de células T circulantes diminuído ou normal, número de células B circulantes normais e níveis séricos de imunoglobulinas diminuídos ou normais associado com os seguintes achados: hipoparatireoidismo, malformações cardíacas conotruncais, dismorfismo facial e detecção da deleção do cromossomo 22q.11. Os pacientes com Síndrome de DiGeorge apresentam graus variados de comprometimento tímico e há a necessidade de avaliação da função tímica objetiva e eficaz para este grupo de pacientes. Recentemente, a mensuração do TREC tem sido considerada adequada para avaliar a função tímica. O objetivo deste estudo foi avaliar a função tímica em pacientes com esta síndrome através de dados clínicos e laboratoriais associados à mensuração do TREC em células mononucleares periféricas. Os objetivos secundários foram descrever as características fenotípicas, as alterações imunológicas incluindo a quantificação de subpopulações de linfócitos T e sua ativação. A quantificação do TREC foi feita através de PCR quantitativo em tempo real e as subpopulações de linfócitos T e dos marcadores de ativação CD28+ e HLA-DR+, através de citometria de fluxo. Nesta casuística foram incluídos 14 pacientes, oito masculinos, com idade entre 8m a 18a11m. Todos os pacientes preencheram os critérios diagnósticos e em dois não foi detectada a deleção do 22q11.2. O achado mais freqüente foi o acometimento cardíaco em 12 pacientes, prevalecendo a tetralogia de Fallot. O dismorfismo facial foi observado em 11 pacientes, sendo as alterações orofaciais as mais comuns. Hipocalcemia esteve presente em cinco pacientes e em um deles havia associação com hipotireoidismo neonatal. Depressão foi observada em dois pacientes e atualmente nenhum paciente apresenta quadro de infecção de repetição. À avaliação da imunidade humoral, detectou-se cinco pacientes com concentrações séricas de IgM abaixo dos valores normais para a idade e na avaliação da anticorpogênese somente três pacientes responderam com títulos protetores para a o esquema vacinal completo para hepatite B e quatro para sarampo. A quantificação do número de TREC realizada em 12 pacientes mostrou-se reduzida em relação aos controles com uma significância estatística (p = 0,002). O número de linfócitos totais estava dentro dos valores normais, mas, os valores de CD3+ estavam diminuídos em nove, CD4+ em um e CD8+ em cinco pacientes. Observou-se maior expressão de marcadores de ativação linfocitária no grupo de pacientes que nos controles (p = 0, 002). Conclusão: Este estudo revelou que os pacientes avaliados apresentaram alteração tanto da imunidade celular como humoral em especial em relação à anticorpogênese pós vacinal e redução da subpopulação de linfócitos T. A reduzida quantidade de TREC em relação aos controles pode indicar uma disfunção tímica embora tenha sido observado normalidade linfocitária nestes pacientes / Among the syndromes of 22q.11 deletion, the DiGeorge Syndrome was first described in 1967 as a primary immunodeficiency characterized by: heart defects, hypoparathyroidism and absence of thymus. The estimated incidence is 1: 3000 live births and despite this, its recognition still presents difficulties due to large variability and different nomenclatures. For the diagnosis it is necessary the presence of the decreased or normal number of circulating T cells, normal number of circulating B cells and decreased or normal levels serum of immunoglobulins associated with the following findings: hypoparathyroidism, conotruncal heart defects, facial dimorphism and detection of 22q.11 deletion. Patients with DiGeorge syndrome have varying degrees of thymic commitment and there is a necessity for an objectively and effectively evaluation of thymic function to this group of patients. Recently, the measurement of TREC has been considered adequate to evaluate the thymic function. The aim of this study was to evaluate the thymic function in patients with this syndrome through clinical and laboratory data associated with the measurement of TREC in peripheral blood mononuclear cells. The secondary objectives were to describe the phenotypic characteristics, immune disorders including quantification of subpopulations of T lymphocytes and their activation. Quantification of TREC was performed by quantitative PCR in real time and the subpopulations of T lymphocytes and activation markers CD28+ and HLA-DR+, by flow cytometry. In this case series included 14 patients, eight male, aged 8m to 18y11m. All patients met the diagnostic criteria and two did not detect the 22q11.2 deletion. The most common finding was cardiac involvement in 12 patients, with prevalence of tetralogy of Fallot. The facial dimorphism was observed in 11 patients with orofacial changes being the most common. Hypocalcaemia was present in five patients and one of them was associated with neonatal hypothyroidism. Depression was observed in two patients and now, no patient presents recurrent infections. In the humoral immunity, we have found five patients with serum IgM below normal for age and only three patients responded with protective levels of antibodies to the complete vaccine schedule for hepatitis B and four for measles. The measurement of the number of TREC was performed in 12 patients and it was reduced compared to controls with a statistical significance (p = 0, 002). The total number of lymphocytes were within the normal range, but the values of CD3+ were decreased in nine, CD4+ in one and CD8+ in five patients. It was found a higher expression of markers of lymphocyte activation in the group of patients than in controls (p = 0, 002). Conclusion: This study revealed that in the patients studied both humoral and cellular immunity was compromised, in particular in relation to vaccinal response and reduction the subpopulation of T lymphocytes. The reduced amount of TREC when compared to controls may indicate a thymic dysfunction despite the normal lymphocytes in these patients

Entre as síndromes de deleção do cromossomo 22q.11, a Síndrome de DiGeorge foi descrita em 1967 como uma imunodeficiência primária caracterizada por: malformações cardíacas, hipoparatireoidismo e ausência de timo. A incidência estimada é de 1: 3000 nascidos vivos e apesar disto seu reconhecimento ainda apresenta dificuldades devido à grande variabilidade fenotípica e diferentes nomenclaturas. Para o diagnóstico é necessário a presença do número de células T circulantes diminuído ou normal, número de células B circulantes normais e níveis séricos de imunoglobulinas diminuídos ou normais associado com os seguintes achados: hipoparatireoidismo, malformações cardíacas conotruncais, dismorfismo facial e detecção da deleção do cromossomo 22q.11. Os pacientes com Síndrome de DiGeorge apresentam graus variados de comprometimento tímico e há a necessidade de avaliação da função tímica objetiva e eficaz para este grupo de pacientes. Recentemente, a mensuração do TREC tem sido considerada adequada para avaliar a função tímica. O objetivo deste estudo foi avaliar a função tímica em pacientes com esta síndrome através de dados clínicos e laboratoriais associados à mensuração do TREC em células mononucleares periféricas. Os objetivos secundários foram descrever as características fenotípicas, as alterações imunológicas incluindo a quantificação de subpopulações de linfócitos T e sua ativação. A quantificação do TREC foi feita através de PCR quantitativo em tempo real e as subpopulações de linfócitos T e dos marcadores de ativação CD28+ e HLA-DR+, através de citometria de fluxo. Nesta casuística foram incluídos 14 pacientes, oito masculinos, com idade entre 8m a 18a11m. Todos os pacientes preencheram os critérios diagnósticos e em dois não foi detectada a deleção do 22q11.2. O achado mais freqüente foi o acometimento cardíaco em 12 pacientes, prevalecendo a tetralogia de Fallot. O dismorfismo facial foi observado em 11 pacientes, sendo as alterações orofaciais as mais comuns. Hipocalcemia esteve presente em cinco pacientes e em um deles havia associação com hipotireoidismo neonatal. Depressão foi observada em dois pacientes e atualmente nenhum paciente apresenta quadro de infecção de repetição. À avaliação da imunidade humoral, detectou-se cinco pacientes com concentrações séricas de IgM abaixo dos valores normais para a idade e na avaliação da anticorpogênese somente três pacientes responderam com títulos protetores para a o esquema vacinal completo para hepatite B e quatro para sarampo. A quantificação do número de TREC realizada em 12 pacientes mostrou-se reduzida em relação aos controles com uma significância estatística (p = 0,002). O número de linfócitos totais estava dentro dos valores normais, mas, os valores de CD3+ estavam diminuídos em nove, CD4+ em um e CD8+ em cinco pacientes. Observou-se maior expressão de marcadores de ativação linfocitária no grupo de pacientes que nos controles (p = 0, 002). Conclusão: Este estudo revelou que os pacientes avaliados apresentaram alteração tanto da imunidade celular como humoral em especial em relação à anticorpogênese pós vacinal e redução da subpopulação de linfócitos T. A reduzida quantidade de TREC em relação aos controles pode indicar uma disfunção tímica embora tenha sido observado normalidade linfocitária nestes pacientes / Among the syndromes of 22q.11 deletion, the DiGeorge Syndrome was first described in 1967 as a primary immunodeficiency characterized by: heart defects, hypoparathyroidism and absence of thymus. The estimated incidence is 1: 3000 live births and despite this, its recognition still presents difficulties due to large variability and different nomenclatures. For the diagnosis it is necessary the presence of the decreased or normal number of circulating T cells, normal number of circulating B cells and decreased or normal levels serum of immunoglobulins associated with the following findings: hypoparathyroidism, conotruncal heart defects, facial dimorphism and detection of 22q.11 deletion. Patients with DiGeorge syndrome have varying degrees of thymic commitment and there is a necessity for an objectively and effectively evaluation of thymic function to this group of patients. Recently, the measurement of TREC has been considered adequate to evaluate the thymic function. The aim of this study was to evaluate the thymic function in patients with this syndrome through clinical and laboratory data associated with the measurement of TREC in peripheral blood mononuclear cells. The secondary objectives were to describe the phenotypic characteristics, immune disorders including quantification of subpopulations of T lymphocytes and their activation. Quantification of TREC was performed by quantitative PCR in real time and the subpopulations of T lymphocytes and activation markers CD28+ and HLA-DR+, by flow cytometry. In this case series included 14 patients, eight male, aged 8m to 18y11m. All patients met the diagnostic criteria and two did not detect the 22q11.2 deletion. The most common finding was cardiac involvement in 12 patients, with prevalence of tetralogy of Fallot. The facial dimorphism was observed in 11 patients with orofacial changes being the most common. Hypocalcaemia was present in five patients and one of them was associated with neonatal hypothyroidism. Depression was observed in two patients and now, no patient presents recurrent infections. In the humoral immunity, we have found five patients with serum IgM below normal for age and only three patients responded with protective levels of antibodies to the complete vaccine schedule for hepatitis B and four for measles. The measurement of the number of TREC was performed in 12 patients and it was reduced compared to controls with a statistical significance (p = 0, 002). The total number of lymphocytes were within the normal range, but the values of CD3+ were decreased in nine, CD4+ in one and CD8+ in five patients. It was found a higher expression of markers of lymphocyte activation in the group of patients than in controls (p = 0, 002). Conclusion: This study revealed that in the patients studied both humoral and cellular immunity was compromised, in particular in relation to vaccinal response and reduction the subpopulation of T lymphocytes. The reduced amount of TREC when compared to controls may indicate a thymic dysfunction despite the normal lymphocytes in these patients

Orientador: Vera Lucia Gil da Silva Lopes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-20T04:54:42Z (GMT). No. of bitstreams: 1 Vieira_TarsisAntonioPaiva_D.pdf: 3309313 bytes, checksum: 6d4805118bd5c929446b40064e1263b2 (MD5) Previous issue date: 2012 / Resumo: A aplicação de modernos conhecimentos sobre causa, efeito e métodos diagnósticos de doenças genéticas para cuidados de saúde é bastante complexa, especialmente no Brasil onde o sistema de saúde é predominantemente público. A síndrome de deleção 22q11.2 (S. Del 22q11.2) é a condição geneticamente determinada mais comum em indivíduos com anomalias palatais, com prevalência de 1/4.000 nascimentos. Considerando esta prevalência, as características do sistema de saúde e da atenção em genética no Brasil, o principal objetivo deste estudo foi realizar estudo multicêntrico para diagnóstico da S. Del 22q11.2 como modelo para otimização de estratégias diagnósticas em genética médica. Para isso, verificou-se a disponibilidade do diagnóstico laboratorial da S. Del 22q11.2 em 11 serviços de genética de diferentes regiões do país, e este foi centralizado nos Laboratórios de Citogenética Humana e Genética Molecular da FCM/UNICAMP por 30 meses. Foram estudados 100 pacientes (48M:52F) e as técnicas utilizadas foram FISH (Fluorescence in situ Hibridization) e MLPA (Multiplex Ligation-dependent Probe Amplification). Disponibilidade anterior e temporária do diagnóstico laboratorial de deleção em 22q11, vinculada a projetos de pesquisa, foi informada por sete instituições, sendo detectada desigualdade regional. Microdeleção em 22q11 foi identificada em 35% dos pacientes e aberrações cromossômicas não envolvendo a região 22q11 foram detectadas em três casos, obtendo-se conclusão diagnóstica em 38% dos casos. Encontrou-se diferença estatisticamente significativa para alguns sinais clínicos apresentados entre os pacientes com e sem deleção. As técnicas de FISH e MLPA mostraram 100% de sensibilidade e especificidade. Considerando a infraestrutura necessária e a adaptação da técnica de FISH, que permitiu reduzir a quantidade de sonda utilizada, esta foi eficaz, mais econômica e mais rápida em comparação a MLPA. A investigação centralizada mostrou-se vantajosa. Aponta-se o modelo estabelecido como uma estratégia importante e factível para o Brasil. Os resultados deste estudo propiciaram reflexões que culminaram em sugestões para o incremento desta abordagem para esta e outras condições geneticamente determinadas em nosso país / Abstract: The introduction of new technologies of molecular diagnosis for health care has been a challenge in the last years, especially in Brazil, where the majority of the population is served by the public health system. The 22q11.1 deletion syndrome is the most common syndrome that has palatal anomalies as a major feature, with a prevalence of 1/4000 births. Considering this prevalence, the Brazilian health system characteristics and the current situation of medical and clinical genetic services in the country, the main aim of this study was to conduct a multicenter study for 22q11.2 deletion diagnosis as a model for the optimization of diagnostic strategies in medical genetics. We investigated the access to laboratorial diagnosis of 22q11.2 deletion at 11 genetic services and centralized this diagnosis for 100 patients with palatal abnormalities and suspicion of 22q11.2 deletion syndrome, referred from these centers during 30 months, at the Cytogenetics and Molecular biology laboratories of the FCM/UNICAMP. To detect 22q11 deletions FISH (Fluorescence in situ Hibridization) and MLPA (Multiplex Ligation-dependent Probe Amplification) techniques were used. Previous and temporary availability for the diagnosis of 22q11 deletion, associated with research projects, was informed by seven centers, with remarkable geographic disparities. We detected 22q11 deletion in 35% of the patients, and chromosome abnormalities not related to 22q11 region in three patients; thus we reached diagnostic conclusion in 38% of the cases. There was significant difference between some clinical signs found in patients with or without 22q11 deletion. There was 100% of sensibility and specificity for both MLPA and FISH techniques. Considering the required infrastructure and the modifications in the FISH (allowing to reduce probe quantity), this technique was efficient, more economical and faster than MLPA. Centralizing the laboratorial diagnosis was considered advantageous, pointing to this model as an important and feasible strategy for genetic diagnosis in Brazil. These results allowed to suggestions for the improvement of laboratorial diagnosis of this and other genetic conditions in our country / Doutorado / Ciencias Biomedicas / Doutor em Ciências Médicas

<p>Microarray-based comparative genomic hybridization (array-CGH) has emerged as a versatile platform with a wide range of applications in molecular genetics. This thesis focuses on the development of array-CGH with a specific aim to approach disease-related questions through improved strategies in array construction and enhanced resolution of analysis. In <b>paper I</b>, we applied an array covering 11 Mb of 22q, encompassing the <i>NF2</i> locus, for deletion detection in sporadic schwannoma. Hemizygous deletions and tumor heterogeneity were identified. Array-CGH was established as a reliable platform for detection of DNA dosage alterations. <b>Paper II</b> described the construction of the<i> NF2</i> gene-specific microarray for high-resolution scanning of deletions in the <i>NF2</i> locus. We report a novel PCR-based non-redundant strategy for microarray fabrication, which considerably improved the sensitivity and reliability of deletion detection. <b>Paper III</b> reported the first tiling-path array comprehensively covering a human chromosome. The usefulness of the 22q-array was demonstrated by applying it to detect DNA dosage-alterations in 22q-associated disorders. In <b>paper IV</b>, we optimized array-CGH protocols for deletion detection in 22q11 deletion-syndrome. We showed that genomic and cDNA clones are not optimal for analysis of 22q11 locus and that PCR-based non-redundant strategy is reliable for deletion detection in such regions. In <b>paper V</b>, we utilized the 22q-array for understanding the genetic basis of schwannomatosis. Two commonly deleted regions were identified within the <i>IGL</i> and the <i>GSTT1/CABIN1</i> loci. Further investigations using high-resolution arrays, bioinformatic analysis and mutational screening were performed. Missense mutations, specific to the schwannomatosis- and NF2 samples, were identified in the <i>CABIN1 </i>gene. <b>Paper VI</b> described the first array-CGH study for comprehensive and high-resolution profiling of deletions spanning the 17q11 locus. Both typical and atypical deletions were identified in NF1 samples. Bioinformatic analysis revealed novel segmental duplications, which can potentially mediate 17q11 deletions.</p>

Microarray-based comparative genomic hybridization (array-CGH) has emerged as a versatile platform with a wide range of applications in molecular genetics. This thesis focuses on the development of array-CGH with a specific aim to approach disease-related questions through improved strategies in array construction and enhanced resolution of analysis. In <b>paper I</b>, we applied an array covering 11 Mb of 22q, encompassing the NF2 locus, for deletion detection in sporadic schwannoma. Hemizygous deletions and tumor heterogeneity were identified. Array-CGH was established as a reliable platform for detection of DNA dosage alterations. <b>Paper II</b> described the construction of the NF2 gene-specific microarray for high-resolution scanning of deletions in the NF2 locus. We report a novel PCR-based non-redundant strategy for microarray fabrication, which considerably improved the sensitivity and reliability of deletion detection. <b>Paper III</b> reported the first tiling-path array comprehensively covering a human chromosome. The usefulness of the 22q-array was demonstrated by applying it to detect DNA dosage-alterations in 22q-associated disorders. In <b>paper IV</b>, we optimized array-CGH protocols for deletion detection in 22q11 deletion-syndrome. We showed that genomic and cDNA clones are not optimal for analysis of 22q11 locus and that PCR-based non-redundant strategy is reliable for deletion detection in such regions. In <b>paper V</b>, we utilized the 22q-array for understanding the genetic basis of schwannomatosis. Two commonly deleted regions were identified within the IGL and the GSTT1/CABIN1 loci. Further investigations using high-resolution arrays, bioinformatic analysis and mutational screening were performed. Missense mutations, specific to the schwannomatosis- and NF2 samples, were identified in the CABIN1 gene. <b>Paper VI</b> described the first array-CGH study for comprehensive and high-resolution profiling of deletions spanning the 17q11 locus. Both typical and atypical deletions were identified in NF1 samples. Bioinformatic analysis revealed novel segmental duplications, which can potentially mediate 17q11 deletions.

L’acide rétinoïque (AR), dérivé actif de la vitamine A, agit comme un morphogène dans de nombreux processus de développement. Des études antérieures chez l’embryon de poulet (Hochgreb et al., 2003) ont montré que l’ AR est impliqué dans la régionalisation antéro-postérieure du tube cardiaque. Au cours de ma thèse, j’ai cherché à définir le rôle de l’AR dans le développement du coeur et plus particulièrement dans la régionalisation antéropostérieuredu territoire cardiaque. Pour cela, j’ai utilisé les mutants souris déficients pourl’enzyme RALDH2 permettant la synthèse d’AR. L’utilisation de marqueurs spécifiques des progéniteurs cardiaques nous a permis de montrer que l’AR est requis pour établir la bordure postérieure du second champ cardiaque (mésoderme splanchnique).Dans le but de mieux comprendre comment la voie de l’AR agit sur la spécification cardiaque, nous avons voulu identifier ses cibles dans le mésoderme splanchnique. Pour la première fois, nous montrons l’implication des gènes Hox dans la cardiogenèse précoce.L’analyse du lignage des cellules exprimant Hoxa1, Hoxa3 et Hoxb1 nous a permis demontrer que les pôles artériels et veineux ont la même origine au niveau du territoire cardiaque.Nous avons aussi étudié le rôle de l’AR dans la morphogenèse des arcs aortiques et de sesdérivés, en particulier son influence sur le développement de la quatrième artère des arcspharyngés. Cette étude a mis en évidence l’interaction génétique de Raldh2 et du facteur àboîte T, Tbx1, lors de la morphogenèse du quatrième arc aortique. En effet, la diminution de l’AR accélère la récupération des défauts de la quatrième artère des arcs pharyngés chez le modèle murin pour le syndrome de Di George (Tbx1+/-). Nos résultats suggèrent que l’AR estun modificateur de la micro-délétion 22q11 (syndrome de DiGeorge) chez l’homme, ceci pouvant expliquer en partie la grande variabilité des malformations cardiaques des patients DiGeorge.J’ai aussi participé à l’étude du rôle de l’AR dans la différenciation des progéniteurs du myocarde ventriculaire. Ces résultats montrent que l’AR est nécessaire à la différenciation de la population de cellules progénitrices du myocarde. La portée de ces résultats est importante et pourra conduire à plus long terme à la thérapie et la réparation du muscle cardiaque. Enfin,la dernière partie de l’étude se concentre sur le rôle de l’AR dans le développement de la vasculature coronaire. Ce morphogène semble influencer le positionnement des ostia coronaires à l’aorte. / Retinoic acid (RA), the active derivative of vitamin A (retinol), acts as a morphogen inseveral developmental processes. Previous studies in the chick embryo (Hochgreb et al.,2003) have indicated that RA signaling is required to antero-posterior patterning of the cardiac tube. The aim of my thesis was to define the role of RA signaling in heart development and in particular in the establishment of antero-posterior identity of the cardiac field. Thus, we used Raldh2 (Retinaldehyde dehydrogenase 2) mutants that are deficient for RA synthesis. To understand the role of RA, we examined the contribution of the second heart field to pharyngeal mesoderm, atria and outflow tract in Raldh2-/- embryos. Our findingsshown that embryo lacking RA synthesis enzyme RALDH2 have expansion of the secondheart field (splanchnic mesoderm).To better understand the mechanism by which RA signaling regulates the cardiac progenitors,we have identified its targets in the splanchnic mesoderm. We have shown for the first timethat Hox genes contribute to cardiogenesis. Moreover, genetically labeled cells analysis reveals a common origin of the arterial and venous poles in the cardiac field.Then, we have analyzed the role of RA in aortic arch remodeling, in particular its influence onfourth aortic arch arteries. This work demonstrates a genetic interaction between Raldh2 and the T-box factor, Tbx1, during fourth aortic arch formation. Our results shows that decreasedon RA level accelerates recovery of fourth aortic arch artery defects seen in Tbx1-/-, which is amodel of DiGeorge syndrome. Moreover, this study suggests that RA is a modifier of 22q11microdeletion (DiGeorge syndrome) in patient.In a collaborative work, we have analyzed the role of RA in differentiation of ventricular myocardium progenitors. Our results showed that the differentiation of the myocardial progenitor cells required RA. The impact of these results is crucial and would lead to therapyand cardiac muscle repair.The last part of my thesis focuses on the role of RA on coronary vascular development. This morphogen seems to influence the position of coronary ostia to the aorta.

Background: The 22q11 deletion syndrome (22q11DS), also known as DiGeorge Syndrome, affects ~1/5000 live born children. Congenital heart defects (typically outflow tract and interrupted aortic arch) are present in 75% of individuals with 22q11DS and are the major cause of mortality. Other defects are cleft palate, thymus hypoplasia, inner ear defects and neuropsychiatric abnormalities. Df(16)1 mice carry a ~1 Mb hemizygous deletion on mouse chromosome 16 in a region syntenic with 22q11 and phenocopies 22q11DS. TBX1 is a DNA-binding transcription factor located in this interval and is required for neural crest cell proliferation and migration and for cardiac development. TBX1 point mutations have been identified in patients with DiGeorge syndrome. Thus TBX1 is thought to be a major gene responsible for the cardiac phenotype in 22q11DS. A key unresolved issue is the mechanism of reduced penetrance of cardiac malformations. One possibility is environmental variation during cardiogenesis. A second possibility is that variation in the TBX1 protein interaction network results in variable penetrance of the phenotype. Mutations in TBX1 or interacting partners could affect the structure of this protein interaction network. Aim: The aim of this thesis is to characterize the molecular mechanism of TBX1 function using biochemical and genetic approaches and to define the role of environmental variation on the DiGeorge phenotype. Results First part. Interaction of Df(16)1 with high-fat maternal diet. To determine if a maternal high-fat diet affects the penetrance of cardiac and thymus malformations in the Df1 deletion mouse model, wild-type and Df1 heterozygous embryos from control and high-fat diet groups were analyzed. No significant difference in the penetrance or the severity of cardiac malformations between these groups was found. These results do not support the idea that change in the fat content of maternal diet affects phenotype in this model. Thus, it is possible that high-fat diet interacts specifically with left-right patterning rather than with the genetic control of pharyngeal arch development and neural crest cell migration and survival. Second part. George, a novel ENU induced mutation in Tbx1. The George mutation, identified and mapped to Chr16 between rs4161352 and D16Mit112, results in fully penetrant cleft palate, cardiac malformations (VSD, IAA, CAT), absent cochlea and abnormal semicircular canals, and absent thymus resembling the human DiGeorge phenotype. Tbx1 lies in this interval and sequencing identified a G > A point mutation in exon 3 which is predicted to cause a Arginine to Glutamine change at amino acid position 160. George fails to genetically complement a Tbx1 null allele, confirming that it is causative and that George is functionally a null allele. RT-PCR showed that the George mutation affects splicing, resulting in a transcript lacking exon 3. This causes the loss of 34 amino acids within the TBX1 T-box domain, thus predicting that it affects DNA binding. Transactivation assays show that while the R160Q amino acid substitution significantly reduces the transactivation capacity of TBX1, surprisingly the loss of exon 3 does not affect this function. Analysis of endogenous TBX1 in developing embryos by Western blot showed that the protein expression is absent or significantly reduced. This finding suggests that the observed George phenotype is caused primarily by a loss of TBX1 protein expression. Third part. Investigation of the protein interaction network surrounding TBX1. In order to get a better insight into the protein network surrounding TBX1, a TBX1 split renilla-luciferase protein complementation assay was set up which allowed to test the physical interaction between TBX1 and several putative interactors. It was found that GATA4, SMARCAD1, RBBP5 and PTDSR interact with wild-type TBX1 in HEK293T cells. The R160Q point mutation and the loss of exon 3 affect some of these interactions supporting the idea that variation in the protein interaction network may, at least in part, be responsible for the DGS phenotype.