Estudo do cariotipo constitucional e dos tecidos envolvidos na lesão de crianças portadoras de defeito do tubo neural (DTN) por meio de analise citogenetica convencional e FISH
Danielle Ribeiro Lucon
DISSERTAÇÃO
Português
(Broch.)
T/UNICAMP L964e
Campins, SP : [s.n.], 2004.
157p. : il.
Orientador: Denise Pontes Cavalcanti
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
Resumo: A associação entre anomalias cromossômicas, especialmente de aneuploidias e defeito do tubo neural (DTN) é bem conhecida, principalmente se o DTN é associado com outra malformação. Recentemente, estudos em modelos animais, utilizando a técnica de hibridização in situ com fluorescência...
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Resumo: A associação entre anomalias cromossômicas, especialmente de aneuploidias e defeito do tubo neural (DTN) é bem conhecida, principalmente se o DTN é associado com outra malformação. Recentemente, estudos em modelos animais, utilizando a técnica de hibridização in situ com fluorescência (FISH), identificaram aneuploidias em tecido nervoso. Com o objetivo de verificar a freqüência e a possível ocorrência de anormalidade cromossômica restrita ao tecido cérebro-vascular (CV) em fetos e recém-nascidos com DTN, foram utilizadas técnicas de citogenética convencional em linfócitos e tecido CV, e análise desse por FISH-Multiprobe. A análise pelo FISH foi realizada em 10 recém-nascidos normais a fim de estabelecer o intervalo de confiança (IC) dos sinais diplóides. Foram avaliados 41 casos de DTN, que foram divididos em 3 grupos, de acordo com a amostra coletada e estudo citogenético: 1) grupo com cariótipo de linfócitos e de tecido CV, 13 casos; 2) grupo com cariótipo de tecido cérebro-vascular, 5 casos; e 3) grupo de pacientes com cariótipo de linfócitos, 23 casos. No grupo 1, três pacientes apresentaram cariótipo anormal restrito ao tecido CV: mos 92,XXYY/46,XY, mos 92,XXXX/46,XX, monossomia do cromossomo 6 em mosaico, representando dois casos de espinha bífida e um caso de anencefalia, respectivamente. A freqüência de anomalias cromossômicas nesse estudo foi de 6%. Foi possível observar uma maior porcentagem de aneuploidias restritas ao tecido CV. A porcentagem de aneuploidias encontradas neste tecido foi de 15% quando estudados por citogenética convencional e de 25% quando analisados por FISH. No grupo 2, todos os casos apresentaram cariótipo normal. No grupo 3, dois casos de anencefalia apresentaram cariótipo anormal: chi 47,XY,+21/46,XX e mos 92,XXYY/46,XY e dois casos apresentaram heteromorfismos 46,XY,inv(9qh) (espinha bífida) e 46,XX,21ps+ (encefalocele). Concluindo, há uma maior porcentagem de alteração cromossômica restrita ao tecido cérebro-vascular. Essa porcentagem foi semelhante à porcentagem encontrada em tecidos nervosos de roedores. Estes resultados sugerem que anomalias numéricas podem ser muito comuns em tecidos envolvidos no defeito do tubo neural. Entretanto, estes resultados sugerem que estudos futuros com tecido neural em humanos sejam fundamentais para esclarecer a relação entre anomalia cromossômica e tecido nervoso
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Abstract: The association between chromosomal abnormalities, specially aneuploidies and neural tube defects (NTDs) is well known, principally when NTD is not the only malformation present. Recently, research in animal models, using fluorescence in situ hybridization (FISH) identified aneuploidy in...
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Abstract: The association between chromosomal abnormalities, specially aneuploidies and neural tube defects (NTDs) is well known, principally when NTD is not the only malformation present. Recently, research in animal models, using fluorescence in situ hybridization (FISH) identified aneuploidy in neural tissues. The aims of this work were to identify the frequency of chromosomal abnormalities in NTDs fetuses and newborns and the possible association of them restricted to cérebro-vascular (CV) tissue. For the detection of aneuploidy conventional cytogenetic studies on lymphocytes and CV tissue and interphase FISH of CV tissue utilizing alfa-centromeric probes of 18 chromosomes
(FISH-Multiprobe/Cytocell) were performed. In order to establish the confidence interval of the diploid signals the interphase FISH analysis was performed in 10 control individuals, showing mean near to 100%. Forty one NTDs cases were evaluated and separated into three groups, according to the collected samples and their analysis. Group 1: karyotype from lymphocytes and CV tissue and FISH analysis from both, 13 cases. Group 2: karyotype from CV tissue, 5 cases. Group 3: karyotype from lymphocytes, 23 cases. In group 1, 4 (31,0%) presented abnormal karyotypes restricted to CV tissue: mos 92,XXYY/46,XY, mos92,XXXX/46,XY on spina bifida and monossomy of the chromosome 6 in mosaic on anencephaly. The frequency of chromosomic anomalies in that study was of 6%. A larger percentage of restricted aneuploidies on CV tissue was observed. The aneuploidies percentage found in this tissue was of 15% when studied by conventional cytogenetics and of 25% when analyzed by FISH. In group 2, all samples presented normal karyotypes. In group 3, two cases of anencephaly presented abnormal karyotype: chi47,XY,+21/46,XX and mos92,XXYY/46,XY and two cases presented heteromorphisms 46,XY,inv9(qh) (spina bifida ) and 46,XX,21ps+ (encephalocele). There is a greater proportion of aneuploidy restricted to CV tissue. The percentage observed in that tissue was 25%, similar to neural tissues of rodents in experimental studies (33%). These results suggest that numeric anomalies can be very common in tissue involved with NTD. However, these results suggest that further studies with neural tissue in humans are fundamental to explain the relationship between chromosomic anomaly and nervous tissue Ver menos
(FISH-Multiprobe/Cytocell) were performed. In order to establish the confidence interval of the diploid signals the interphase FISH analysis was performed in 10 control individuals, showing mean near to 100%. Forty one NTDs cases were evaluated and separated into three groups, according to the collected samples and their analysis. Group 1: karyotype from lymphocytes and CV tissue and FISH analysis from both, 13 cases. Group 2: karyotype from CV tissue, 5 cases. Group 3: karyotype from lymphocytes, 23 cases. In group 1, 4 (31,0%) presented abnormal karyotypes restricted to CV tissue: mos 92,XXYY/46,XY, mos92,XXXX/46,XY on spina bifida and monossomy of the chromosome 6 in mosaic on anencephaly. The frequency of chromosomic anomalies in that study was of 6%. A larger percentage of restricted aneuploidies on CV tissue was observed. The aneuploidies percentage found in this tissue was of 15% when studied by conventional cytogenetics and of 25% when analyzed by FISH. In group 2, all samples presented normal karyotypes. In group 3, two cases of anencephaly presented abnormal karyotype: chi47,XY,+21/46,XX and mos92,XXYY/46,XY and two cases presented heteromorphisms 46,XY,inv9(qh) (spina bifida ) and 46,XX,21ps+ (encephalocele). There is a greater proportion of aneuploidy restricted to CV tissue. The percentage observed in that tissue was 25%, similar to neural tissues of rodents in experimental studies (33%). These results suggest that numeric anomalies can be very common in tissue involved with NTD. However, these results suggest that further studies with neural tissue in humans are fundamental to explain the relationship between chromosomic anomaly and nervous tissue Ver menos
Estudo do cariotipo constitucional e dos tecidos envolvidos na lesão de crianças portadoras de defeito do tubo neural (DTN) por meio de analise citogenetica convencional e FISH
Danielle Ribeiro Lucon
Estudo do cariotipo constitucional e dos tecidos envolvidos na lesão de crianças portadoras de defeito do tubo neural (DTN) por meio de analise citogenetica convencional e FISH
Danielle Ribeiro Lucon
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