Browsing by Author "Brito, Filomena"
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- A 1.77 Mb deletion in 3p26.3 encompassing CNTN6 and CNTN4 genes: case reportPublication . Brito, Filomena; Marques, Bárbara; Pedro, Sónia; Serafim, Silvia; Gonçalves, Rui; Freixo, João; Correia, HildebertoChromosome microarray analysis is a powerful diagnostic tool and is being used as a first-line approach to detect chromosome imbalances associated with intellectual disability, dysmorphic features and congenital abnormalities. This test enables the identification of new copy number variants (CNVs) and their association with new microdeletion/microduplication syndromes in patients previously without diagnosis. We report the case of a 7 year-old female with moderate intellectual disability, severe speech delay and auto and hetero aggressivity with a previous 45,XX,der(13;14)mat karyotype performed at a younger age. Affymetrix CytoScan 750K chromosome microarray analysis was performed detecting a 1.77 Mb deletion at 3p26.3, encompassing 2 OMIM genes, CNTN6 and CNTN4. These genes play an important role in the formation, maintenance, and plasticity of functional neuronal networks. Deletions or mutations in CNTN4 gene have been implicated in intellectual disability and learning disabilities. Disruptions or deletions in the CNTN6 gene have been associated with development delay and other neurodevelopmental disorders. The haploinsufficiency of these genes has been suggested to participate to the typical clinical features of 3p deletion syndrome. Nevertheless inheritance from a healthy parent has been reported, suggesting incomplete penetrance and variable phenotype for this CNV. We compare our patient with other similar reported cases, adding additional value to the phenotype-genotype correlation of deletions in this region.
- 6q terminal deletion: a new contribution to genotype-phenotype correlationPublication . Simão, Laurentino; Marques, Bárbara; Sónia, Pedro; Antunes, Diana; Brito, Filomena; Silva, Neuza; Nunes, Luis; Correia, HildebertoDeletion of chromosome 6q is a relatively rare clinical entity associated to a considerable variability of the phenotypic spectrum. Mental retardation, facial dimorphisms, seizures, and brain abnormalities are typical features of this syndrome but until recently genotype-phenotype correlations have been scarce. We report a 15-year-old boy with slight developmental delay, intellectual disability, hypotonia, bilateral eye cataracts, mycrocephaly, agenesis of the corpus callosum, ventriculomegaly, paroxysmal attacks, kyphoscoliosis and trigonocephaly. Cytogenetic analysis revealed a de novo karyotype 46,XY,del(6)(q25.3). Microarrays genomic analysis with Cytoscan 750K allowed the refinement of the breakpoint region to 6q26q27, spanning approximately 7.76 Mb. The variation of the features attributed to 6q deletion syndrome is due primarily to differences in size and location of the segmental aneuploidy. Several studies suggest that deletions of 6q25 region can cause more severe anomalies that those including 6q26-27. Absence of IUGR, ear anomalies, ear loss, cleft palate, cardiac defects and genital hypoplasia in our patient are compatible with studies that generally correlate those features with deletions of 6q25 region. In addition, our patient presents retinal abnormalities, which has been associated to 6q26-q27 deletion. Some new candidate genes, localized at 6qter, have recently been described as being associated with some clinical features; an example is the candidate gene DLL1 and holoprosencephaly. Analysis of the breakpoints in most cases revealed a potential common breakpoint region at 8.0-9.0Mb from the chromosome 6q terminus where a fragile site exists (FRA6E). This suggests the breakage at the FRA6E may be the mechanism behind chromosome 6q subtelomeric deletions in some of the cases.Once the genotype-phenotype correlations have been scarce until now, with this study we aim to contribute to a better knowledge of the genotype-phenotype correlation of 6q terminal deletion and help to identify critical regions for several clinical features and developmental relevant genes.
- 9q34.3 microdeletion by MLPA in a fetus with cardiac defectsPublication . Marques, Bárbara; Ferreira, Cristina; Brito, Filomena; Alves, Cristina; Carvalho, Lucilia; Furtado, José; Ventura, Catarina; Silva, Marisa; Simão, Laurentino; Correia, Joaquim; Correia, Hildeberto
- Análise cromossómica: Abordagem teórico-práticaPublication . Brito, Filomena
- Anomalias cromossómicas - Síndromes e Estratégias de DiagnósticoPublication . Brito, Filomena; Correia, Hildeberto
- Anomalias Cromossómicas: Síndromes e Estratégias de DiagnósticoPublication . Brito, Filomena; Marques, Bárbara; Correia, Hildeberto
- Anomalias cromossómicas: síndromes e estratégias de diagnósticoPublication . Correia, Hildeberto; Brito, Filomena; Serafim, SilviaObjetivo: Divulgar a atividade da Unidade de Citogenética (UCI) do Departamento de Genética Humana do Instituto Nacional de Saúde Dr. Ricardo Jorge (INSA): 1. Anomalias Cromossómicas e metodologias laboratoriais; 2. Síndromes/indicações clínicas e estratégias de diagnóstico; 3. Teste genético de array; 4. Apresentação de casos clínicos.
- CitogenéticaPublication . Brito, Filomena
- A Citogenética /Citogenética Molecular no diagnóstico de doenças Genéticas de base cromossómicaPublication . Brito, Filomena; Correia, HildebertoObjetivo: Dar conhecimento dos testes de genética efetuados na Unidade de Citogenética (UCI) para identificação de alterações num cromossoma ou gene, permitindo a prevenção e diagnóstico de doenças genéticas
- A Citogenética/Citogenética Molecular no Diagnóstico de Doenças Genéticas de Base Cromossómica e Doenças Hematológicas MalignasPublication . Correia, Hildeberto; Brito, Filomena; Geraldes, Maria do CéuSobre a Citogenética/Citogenética Molecular no Diagnóstico de Doenças Genéticas de Base Cromossómica e Doenças Hematológicas Malignas.
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