Browsing by Author "Ventura, C."
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- Anemia de Fanconi – Estudo retrospetivo num período 34 anosPublication . Ambrósio, A.P.; Silva, N.; Viegas, M.; Silva, M-C.; Ventura, C.; Correia, H.Introdução: A Anemia de Fanconi (AF) é uma doença rara, com uma frequência estimada de 1 a 5 per 1.000.000 de nascimentos, podendo este valor aumentar se for considerado um grupo étnico com consanguinidade. É uma doença autossómica recessiva, que poderá ter uma transmissão ligada ao cromossoma X. Doentes com AF podem apresentar malformações congénitas, falência da medula óssea (que se carateriza por pancitopénia), hipersensibilidade a agentes clastogénicos, fragilidade cromossómica e uma maior suscetibilidade para doenças oncológicas. Devido à grande complexidade desta patologia a primeira abordagem de diagnóstico, consiste na deteção de aberrações cromossómicas (quebras, rearranjos estruturais, radiais, anéis) em células de sangue periférico em cultura com um agente clastogénico como o diepoxibutano (DEB) ou mitomicina C (MMC). Objetivo: Neste trabalho pretende-se apresentar os resultados dos estudos de instabilidade cromossómica induzida por DEB e MMC efetuados na nossa instituição. Métodos: Foi realizada a análise de uma série retrospetiva de 34 anos (1980-2014) de 243 amostras enviadas ao laboratório citogenética com suspeita de AF e de 28 amostras de familiares de doentes com AF. No total, foram analisadas 260 amostras de sangue periférico, 6 de biópsia de pele, 3 de líquido amniótico, 1 de sangue do cordão e 1 de sangue medular. As amostras foram processadas segundo o protocolo estabelecido para a análise cromossómica de doenças associadas a fraturas, incluindo cultura celular com estimulação por MMC e/ou DED, para cada produto biológico, seguida de análise microscópica com determinação da instabilidade cromossómica induzida pelo DEB, de acordo com o protocolo estabelecido pelo International Fanconi Anemia Registry (IFAR). Resultados: Nas 243 amostras analisadas, foram identificados 37 casos com AF. Nos estudos citogenéticos dos familiares com AF foram identificados mais 2 casos positivos para AF. Foram ainda observados, em 4 amostras de suspeita de AF, cariotipos anormais. Conclusão: Neste trabalho foram identificados 39 novos casos com AF, oriundos maioritariamente da região de Lisboa e Vale do Tejo e alguns casos pontuais da região autónoma dos Açores, região centro e dos países africanos de língua oficial portuguesa (PALOP). Este estudo evidência que a maioria dos casos apresentados se encontra subdiagnosticado. Estes resultados não permitem estimar uma frequência de doentes com AF em Portugal, uma vez que não engloba indivíduos de todas as regiões portuguesas, por outro lado estão incluídos dois indivíduos de origem PALOP. É necessário estabelecer um registo nacional de doentes com AF, para se poder calcular a frequência desta patologia no nosso país.
- Bioethics and Genetic TestingPublication . Ventura, C.
- Contribution to macrophage activation to the genotoxic effect of nanofibers in lung epitheliumPublication . Ventura, C.; Uva, A.S.; Silva, M.J.Nanofibers are nano-objects with two similar dimensions in the nanoscale (size range from approximately 1nm to 100nm) and the third dimension significantly larger. The most widespread group of nanofibers is carbon nanotubes (CNTs) that consist of graphite sheets with a cylindrical arrangement of various lengths, and diameter at the nanoscale. CNTs may have a single, double or multiple walls arranged in concentric layers, and embedded metals. In recent years, several studies performed in rodents exposed to liquid suspensions of CNTs by intratracheal instillation or pharyngeal aspiration showed the development of acute or persistent pulmonary inflammation and persistent interstitial fibrosis with granuloma formation, and bronchiolar or bronchioloalveolar hyperplasia. High thin and crystalline CNTs may also have a carcinogenic effect similar to asbestos. Macrophages play a key role in the response to poorly soluble nanomaterials as nanofibers. Activated macrophages degrade SWCNTs via NADPH oxidase pathway facilitating lung clearance, and if oxidative species formation is exaggerated, injury to the neighbour cells can occur. After macrophage activation, nanofibers phagocytosis also leads to the release of cytokines (TNF-α, IL-6, etc.) and transcription factors associated to inflammation (NF-κB and AP-1). In addition, when nanofiber length exceeds the pleural macrophages length, it triggers an inflammatory response in the pleural cavity due to "frustrated phagocytosis", which in turn stimulates a cytokine proinflammatory response by adjacent mesothelial cells. Thin and highly crystalline CNTs may also have a piercing effect in the mesothelial cell membrane causing in vitro cytotoxicity, and in vivo inflammatory and carcinogenic effects. The aim of this work is to elucidate the role of macrophage activation in the genotoxic effects of a thick and high aspect ratio multiwalled CNT in human lung epithelium.
- Derivative chromosome 7 in a newborn with hypotelorism, cleft palate, agenesis of corpus callosum and semilobar holoprosencephalyPublication . Simão, L.; Serafim, S.; Brito, F.; Ventura, C.; Scortenschi, E.; Santos, V.; Correia, H.Cytogenetically visible unbalanced chromosome rearrangements involving the euchromatic regions most often result in severe phenotypic features. Often, it is not possible at microscopic level to distinguish if a chromosomal anomaly involves one or more than one chromosome. In these cases, the parents study is fundamental and is usually the first line of study. We report a female newborn with multiple anomalies. Ultrasonography at 32+6 weeks of gestation revealed moderate ventricular dilatation, microcephaly and intrauterine growth restriction (IUGR). Delivery was at 35 weeks and microcephaly, hypotelorism, complete medium cleft palate with nasal depression, agenesis of the corpus callosum, thalamic fusion and fusion of the lateral ventricles in the frontal region suggestive of semilobar holoprosencephaly (HPE) was observed. Seizures and nistagmus were described since the eighth day. Hypotonia was present. In addition, diabetes insipidus was diagnosed. Sepsis was developed at day 14 followed by death at day 18 in consequence of seizures and respiratory insuficiency. Cytogenetic analysis revealed an abnormal chromosome 7qter as a result of an unbalanced segregation of a maternal reciprocal translocation t(7;19), with breakpoints at 7q36.1 and 19q13.42. The newborn karyotype is 46,XX,der(7)t(7;19)(q36.1;q13.42)mat. The patient presented a partial trisomy of the region 19q13.42→qter and a partial monosomy of the region 7q36.1→7qter. Partial monosomy of chromosome 7qter has been characterized by a wide phenotypic manifestations, but HPE, microcephaly, midface hypoplasia, maxillary anomalies and sacral agenesis are frequently described. However, is not often reported in newborns. Partial trisomy 19q is a rare and severe condition, and has been described associated with low birth weight, growth retardation, microcephaly, seizures, dysmorphic facial features, short neck, clynodactyly, heart malformations, anomalies of the genitor-urinary and gastrointestinal tract. To our knowledge, there is only one previous case of der(7)t(7q;19q)(q36.1;q13.43) described, in a fetus who presented severe sacral agenesis and IUGR. The case herein reported presents some of the most common features of 7q36 partial monosomy and 19q terminal trisomy, although some of them are present in both conditions. The presence of those two imbalances may complicate the final phenotype but the important matter will be the counseling of the couple and to prevent future imbalances in their offspring.
- Interstitial deletion on chromosome 14q in prenatal diagnosisPublication . Simão, L.; Alves, C.; Marques, B.; Pedro, S.; Ferreira, C.; Viegas, M.; Ventura, C.; Furtado, J.; Cruz, J.; Martins, A.; Cohen, A.; Fernandes, R.; Freixo, J.; Correia, J.; Correia, H.A limited number of prenatal diagnosis (PND) cases have reported interstitial deletions of the long arm of chromosome 14 involving the 14q31-32 region. Those cases presented cardiac anomalies, urogenital anomalies, congenital diaphragmatic hernia, and mild pyelectasis. We report the PND of a 33-year-old pregnant woman, who underwent chorionic villus sampling at 12 weeks of gestation after a positive combined 1st trimester screen. The karyotype revealed a 14q interstitial deletion. Amniocentesis was performed at 18 weeks of gestation to confirm the deletion and to exclude a confined placental mosaicism and a microarray analysis was performed in order to accurately define the deletion breakpoints. Cytogenetics analysis revealed a karyotype 46,XY,del(14)(q31q32.2)dn. Microarray analysis allowed to redefined the breakpoints accurate localization and the identification of a ~21Mb deletion (arr[hg19] 14q31.1q32.31(79917376_101568230)x1). At 18 weeks of gestation the fetus presented abnormal fetal biometric parameters (occipitofrontal diameter, cephalic perimeter and abdominal circumference) on ultrasound. After counseling the couple opted for pregnancy termination. The postmorten analysis presented decreased biometry, low weight and low fetal size, facial dysmorphism, clinodactyly, club foot, overlapping fingers and short penis. In internal habitus he presented thymus hypoplasia, bladder hypoplasia, and horseshoe kidneys. The genotype-phenotype correlation in PND pure del(14q) cases is not well established. Furthermore, to our knowledge, del(14q) had not been reported so early in the gestation yet. In this case the positive 1st trimester screen was related to the inverted ductus venosus and low PAPP-A value. The urogenital anomalies (as horseshoe kidneys) and biometry anomalies are described in the literature. However, to our knowledge, some features of the present case were not seen in other reported cases, for instance clinodactyly, club foot, overlapping fingers, thymus hypoplasia and bladder hypoplasia. Other reports described cardiac and cerebral anomalies, diaphragmatic hernia, and also UPD(14)like phenotypes, which are possibly liked to the 14q32 imprinted region. The establishment of a phenotype-genotype correlation is difficult given the size of the deletion, which includes a large number of genes in distinct regions. Nevertheless, this work contributes to a better identification of additional features associated to del(14q) that can be present in PND.
- Mudanças no diagnóstico pré-natal cromossómico: indicações clínicas, amostras biológicas, metodologias e cromossomopatiasPublication . Simão, L.; Silva, M.; Alves, C.; Brito, F.; Serafim, S.; Ambrósio, P.; Geraldes, M.C.; Marques, B.; Ferreira, C.; Pedro, S.; Furtado, J.; Ventura, C.; Tristão, J.; Ferreira, A.; Correia, J.; Correia, H.Introdução: As mudanças no diagnóstico pré-natal de anomalias cromossómicas (DPN) nos últimos 10-15 anos foram contínuas e significativas. Objetivos: Propômo-nos analisar essa evolução: mudanças nas indicações clínicas; introdução das biópsias de vilosidades coriónicas (BVC); utilização do diagnóstico rápido de aneuploidias (DRA); estudos por microarray; alterações cromossómicas encontradas. Metodologia: Fez-se a avaliação retrospetiva nas gestações com amostras estudadas nos triénios 2004-2006 e 2014-2016. Analisaram-se os parâmetros indicação clínica, tipo de amostra, metodologias utilizadas e resultados. Resultados: Identificaram-se 68 fetos com cariotipo anormal em 2210 cariotipos (3,1%) em 2004-2006 e 208 fetos com cariotipo anormal em 2315 cariotipos (9,0%) em 2014-2016. A maior frequência de anomalias encontrou-se nos casos de rastreios ecográficos e combinados indicativos de risco acrescido de anomalia numérica e de progenitores portadores de alterações cromossómicas. As BVC permitiram respostas precoces nas gestações com anomalias numéricas e, adicionalmente, um aumento desses cariotipos (7.5% das amostras). O DRA permitiu ter uma resposta rápida nas anomalias numéricas mais frequentes (2 dias). As anomalias estruturais foram menos preponderantes nos cariotipos anormais (32,4% em 2004-2006 e 14.4% em 2014-2016). Discussão e conclusões: O DRA reduziu o tempo de resposta e das decisões sobre o futuro das gestações. O microarray permitiu identificar alterações sindromáticas em situações não resolúveis por outras metodologias. A utilização de BVC permite estabelecer uma melhor correlação fenotipo-genotipo em menores idades gestacionais. No entanto, as gestações com anomalias numéricas têm algum risco de perda fetal no primeiro e início do segundo trimestres. Assim, algumas BVC com cariotipos anormais resultariam em perdas espontâneas, o que poderia disponibilizar outros casos para DPN. Por outro lado, o menor número de anomalias estruturais equilibradas encontrado pode reduzir o conhecimento da variação genética nas famílias e na população. Um novo paradigma resulta da implementação dos testes não invasivos no DPN, para os quais ainda não conhecemos todas as limitações e repercussões.
- Prenatal diagnosis of idic(9)Publication . Simão, L.; Marques, B.; Cravo, J.; Ventura, C.; Correia, H.; Silva, M.; Mourinha, V.; Furtado, J.; Páramos, A.I.Tetrasomy of the short arm of chromosome 9 is a rare chromosome imbalance that may result from a supernumerary isochromosome 9 with the most recurrent breakpoints being 9p10, 9q12 and 9q13. On ultrasound, it usually presents with intrauterine growth restriction (IUGR), abnormal facial profile and ventriculomegaly. However, few reports establish a correlation between fetal features and the size of isochromosome or the presence of isodicentric 9. We report the clinical case of a 32-year-old pregnant woman, G2P1, underwent amniocentesis at 13 weeks of gestation with fetal increased nuchal translucency (7mm). The fetus also presented IUGR, cystic higroma, generalized subcutaneous edema, cardiac malformations, facial anomalies and fetal death. The karyotype was performed by standard in situ methods. Fluorescence in situ hybridization (FISH) was performed using centromeric probe CEP9. Conventional cytogenetic and FISH analyses revealed a supernumerary chromosome idic(9)(q12) in all cells examined. After counseling the couple opted for termination of pregnancy. The post-mortem analysis revealed a single umbilical arteria, IUGR, cystic higroma, facial dysmorphism with cleft lip and palate, hypertelorism and low set ears. These findings are in accordance with other reports. Nevertheless, the hypertelorism is not commonly described and such an early detection of a cardiac anomaly is uncommon. Additionaly the fetal death occurred early than in the most cases described in literature. Although breakpoint position effect on the severity on the phenotype is not consensual it has proposed that cases presenting with breakpoints on p10, on q12 or on q13 show a similar phenotype. However, cardiac defects seem more frequent on cases in which the abnormality includes 9q material. This work aims to contribute to a better karyotype-phenotype correlation in cases with tetrasomy 9p and isodicentric chromosomes idic(9).
- Rickettsia slovaca infection in humans, PortugalPublication . Sousa, R.; Pereira, B. I.; Nazareth, C.; Cabral, S.; Ventura, C.; Crespo, P.; Marques, N.; Cunha, S.Fifteen years after the initial detection of Rickettsia slovaca in ticks in Portugal, 3 autochthonous cases of R. slovaca infection were diagnosed in humans. All patients had an eschar on the scalp and lymphadenopathy; 2 patients had facial edema. R. slovaca infection was confirmed by serologic testing, culture, and PCR.