Percorrer por autor "Nunes, Ana"
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- Evidence for an association of prenatal exposure to particulate matter with clinical severity of Autism Spectrum DisorderPublication . Santos, João Xavier; Sampaio, Pedro; Rasga, Célia; Martiniano, Hugo; Faria, Clarissa; Café, Cátia; Oliveira, Alexandra; Duque, Frederico; Oliveira, Guiomar; Sousa, Lisete; Nunes, Ana; Moura Vicente, AstridEarly-life exposure to air pollutants, including ozone (O3), particulate matter (PM2.5 or PM10, depending on diameter of particles), nitrogen dioxide (NO2) and sulfur dioxide (SO2) has been suggested to contribute to the etiology of Autism Spectrum Disorder (ASD). In this study, we used air quality monitoring data to examine whether mothers of children with ASD were exposed to high levels of air pollutants during critical periods of pregnancy, and if higher exposure levels may lead to a higher clinical severity in their offspring. We used public data from the Portuguese Environment Agency to estimate exposure to these pollutants during the first, second and third trimesters of pregnancy, full pregnancy and first year of life of the child, for 217 subjects with ASD born between 2003 and 2016. These subjects were stratified in two subgroups according to clinical severity, as defined by the Autism Diagnostic Observational Schedule (ADOS). For all time periods, the average levels of PM2.5, PM10 and NO2 to which the subjects were exposed were within the admissible levels defined by the European Union. However, a fraction of these subjects showed exposure to levels of PM2.5 and PM10 above the admissible threshold. A higher clinical severity was associated with higher exposure to PM2.5 (p = 0.001), NO2 (p = 0.011) and PM10 (p = 0.041) during the first trimester of pregnancy, when compared with milder clinical severity. After logistic regression, associations with higher clinical severity were identified for PM2.5 exposure during the first trimester (p = 0.002; OR = 1.14, 95%CI: 1.05–1.23) and full pregnancy (p = 0.04; OR = 1.07, 95%CI: 1.00–1.15) and for PM10 (p = 0.02; OR = 1.07, 95%CI: 1.01–1.14) exposure during the third trimester. Exposure to PM is known to elicit neuropathological mechanisms associated with ASD, including neuroinflammation, mitochondrial disruptions, oxidative stress and epigenetic changes. These results offer new insights on the impact of earlylife exposure to PM in ASD clinical severity.
- Gene-environment interactions in Autism Spectrum Disorder (ASD)Publication . Xavier Santos, João; Rasga, Célia; Marques, Ana Rita; Asif, Muhammad; Café, Cátia; Nunes, Ana; Oliveira, Guiomar; Moura-Vicente, AstridAutism Spectrum Disorder – Background: Phenotypically heterogeneous neurodevelopmental disorder, with a global prevalence rate of 1% , characterized by deficits in social communication and interaction and stereotyped and repetitive behaviours. - Genetic factors, namely rare copy number variants (CNVs), are responsible for a considerable fraction of ASD cases . - The recent heritability estimates of approximately 50% suggest a role of nongenetic factors in ASD etiology. - Pre-, peri- and post-natal exposure to toxic environmental factors has been implicated in the development of the disorder[5][6] . - ASD is most probably explained by a polygenic and multifactorial mechanism that involves genetic, environmental and epigenetic interactions. Objectives: 1. To identify specific exposure patterns to environmental toxicants, potentially involved in ASD etiology, in a dataset of Portuguese children diagnosed with the disorder, aged 7-9 years old; 2. To identify variants of ASD-candidate genes interacting with environmental factors 3. To build a global mathematical model that integrates genetic and environmental biomarkers with clinical data for risk assessment in ASD.
- Gene-environment interactions in Autism Spectrum Disorders (ASD)Publication . Xavier Santos, João; Rasga, Célia; Parisi, Andrea; Nunes, Ana; Vicente, A.M.Objectives: 1. To identify specific exposure patterns to environmental toxicants, potentially involved in ASD etiology, in a dataset of Portuguese children diagnosed with ASD aged 7-9 years; 2. To identify genetic variants interacting with environmental and epigenetic factors; 3. To build a global model that integrates genetic, environmental and epigenetic factors for risk assessment in ASD.
- Gene-environment interactions in Autism Spectrum Disorders (ASD)Publication . Santos, João Xavier; Parisi, Andrea; Rasga, Célia; Nunes, Ana; Vicente, A.M.Spectrum Disorder (ASD), is a heterogeneous neurodevelopmental disorder with na estimated global prevalence rate of 17:10000, and a male to female ratio of 4:1. Patients with ASD presente language and communication difficulties and stereotyped behaviours. Comorbidity with other disorders, such as Intelectual Disability, Fragile-X syndrome (FXS) epilepsy and tuberous sclerosis frequently occurs. ASD presents amultifactorial etiopathology, and genetic factos alone are not suficiente to explain how the syndrome arises, with recente studies establishing ASD heritability at approximately 50%. Pre-, peri- and post-natal exposure to toxic environmental factos has been implicated in the development of ASD. Involvement of epigenetic regulatory mechanisms has been suggested, supported by the occurrence of autistic symptoms in patients with disorders aris ing from epigenetic mutations, such as FXS. A polygenic and epistatic model is a strong hypothesis to explain ASD. The main goal of this project is to identify specific exposure patterns to environmental toxicants in children diagnosed with ASD and integrate the results with genetic and epigenetic data.
- Prevalence of Autism Spectrum Disorder in the Centro region of Portugal: a population based study of school age children within the ASDEU projectPublication . Rasga, Célia; Santos, João Xavier; Café, Cátia; Oliveira, Alexandra; Duque, Frederico; Posada, Manuel; Nunes, Ana; Oliveira, Guiomar; Vicente, Astrid MouraIntroduction: Accurate prevalence estimates for Autism Spectrum Disorder (ASD) are fundamental to adequately program medical and educational resources for children. However, estimates vary globally and across Europe, and it is therefore wise to conduct epidemiological studies in defined geo-cultural contexts. Methods: We used a population screening approach to estimate the prevalence of ASD in the Centro region of Portugal, using a harmonized protocol as part of the Autism Spectrum Disorders in the European Union (ASDEU) project. Results: The overall prevalence was estimated at 0.5% (95% CI 0.3-0.7), higher in schools with Autism Units (3.3%, 95%CI 2.7-3.9) than in regular schools (0.3%, 95% CI 0.1-0.5) or schools with Multiple Disability Units (0.3%, 95% CI 0.04-0.6). Discussion: The results indicate that the diagnosis of ASD is followed by the most effective educational policies in Centro Region. The variability in prevalence estimates across the different regions from the ASDEU project, and globally, is discussed.
- Prevalência da perturbação do espectro do autismo na região Centro de Portugal: um estudo no âmbito do projeto ASDEUPublication . Rasga, Célia; Santos, João Xavier; Café, Cátia; Oliveira, Alexandra; Duque, Frederico; Nunes, Ana; Oliveira, Guiomar; Vicente, Astrid MouraA prevalência da perturbação do espectro do autismo (PEA) em crianças foi estimada na região Centro de Portugal, no âmbito do projeto Autism Spectrum Disorders in the European Union (ASDEU). A metodologia de estudo baseou-se no rastreio de crianças entre os 7 e 9 anos matriculadas, no ano letivo de 2016/2017, em escolas primárias desta região. O rastreio incluiu todas as escolas com unidades de apoio especializado para crianças com problemas de neurodesenvolvimento e cerca de 10% das escolas regulares, selecionadas aleatoriamente. A sinalização das crianças foi feita pelos professores com recurso a um questionário estruturado, previamente validado, após consentimento parental. O diagnóstico foi feito através de avaliação clínica e funcional direta por equipa clínica especializada. Foram rastreadas 13 690 crianças de 173 escolas. A prevalência estimada para a PEA na região Centro foi de 0,5% (IC95% 0,3-0,7). Nas escolas com unidades de apoio especializado para autismo, observou-se uma prevalência substancialmente mais elevada de 3,3% (IC95% 2,7-3,9), indicando que a maioria das crianças está a receber o apoio educativo mais indicado. A prevalência de PEA na região Centro foi comparável a outros países envolvidos no projeto ASDEU, tendo-se, no entanto, observado assimetrias regionais na Europa.
- Prevalência da perturbação do espectro do autismo na região Centro de Portugal: Um estudo no âmbito do projeto ASDEUPublication . Rasga, Célia; Santos, João; Café, Cátia; Oliveira, Alexandra; Duque, Frederico; Nunes, Ana; Oliveira, Guiomar; Vicente, AstridA prevalência da perturbação do espectro do autismo (PEA) em crianças foi estimada na região Centro de Portugal, no âmbito do projeto Autism Spectrum Disorders in the European Union (ASDEU). A metodologia de estudo baseou-se no rastreio de crianças entre os 7 e 9 anos matricula- das, no ano letivo de 2016/2017, em escolas primárias desta região. O rastreio incluiu todas as escolas com unidades de apoio especializado para crianças com problemas de neurodesenvolvimento e cerca de 10% das escolas regulares, selecionadas aleatoriamente. A sinalização das crianças foi feita pelos professores com recurso a um questionário estruturado, previamente validado, após consentimento parental. O diagnóstico foi feito através de avaliação clínica e funcional direta por equipa clínica especializada. Foram rastreadas 13 690 crianças de 173 escolas. A prevalência estimada para a PEA na região Centro foi de 0,5% (IC95% 0,3-0,7). Nas escolas com unidades de apoio especializado para autismo, observou-se uma prevalência substancialmente mais elevada de 3,3% (IC95% 2,7-3,9), indicando que a maioria das crianças está a receber o apoio educativo mais indicado. A prevalência de PEA na região Centro foi comparável a outros países envolvidos no projeto ASDEU, tendo-se, no entanto, observado assimetrias regionais na Europa.
- A Role for Gene-Environment Interactions in Autism Spectrum Disorder Is Supported by Variants in Genes Regulating the Effects of Exposure to XenobioticsPublication . Santos, João Xavier; Rasga, Célia; Marques, Ana Rita; Martiniano, Hugo; Asif, Muhammad; Vilela, Joana; Oliveira, Guiomar; Sousa, Lisete; Nunes, Ana; Vicente, Astrid M.Heritability estimates support the contribution of genetics and the environment to the etiology of Autism Spectrum Disorder (ASD), but a role for gene-environment interactions is insufficiently explored. Genes involved in detoxification pathways and physiological permeability barriers (e.g., blood-brain barrier, placenta and respiratory airways), which regulate the effects of exposure to xenobiotics during early stages of neurodevelopment when the immature brain is extremely vulnerable, may be particularly relevant in this context. Our objective was to identify genes involved in the regulation of xenobiotic detoxification or the function of physiological barriers (the XenoReg genes) presenting predicted damaging variants in subjects with ASD, and to understand their interaction patterns with ubiquitous xenobiotics previously implicated in this disorder. We defined a panel of 519 XenoReg genes through literature review and database queries. Large ASD datasets were inspected for in silico predicted damaging Single Nucleotide Variants (SNVs) (N = 2,674 subjects) or Copy Number Variants (CNVs) (N = 3,570 subjects) in XenoReg genes. We queried the Comparative Toxicogenomics Database (CTD) to identify interaction pairs between XenoReg genes and xenobiotics. The interrogation of ASD datasets for variants in the XenoReg gene panel identified 77 genes with high evidence for a role in ASD, according to pre-specified prioritization criteria. These include 47 genes encoding detoxification enzymes and 30 genes encoding proteins involved in physiological barrier function, among which 15 are previous reported candidates for ASD. The CTD query revealed 397 gene-environment interaction pairs between these XenoReg genes and 80% (48/60) of the analyzed xenobiotics. The top interacting genes and xenobiotics were, respectively, CYP1A2, ABCB1, ABCG2, GSTM1, and CYP2D6 and benzo-(a)-pyrene, valproic acid, bisphenol A, particulate matter, methylmercury, and perfluorinated compounds. Individuals carrying predicted damaging variants in high evidence XenoReg genes are likely to have less efficient detoxification systems or impaired physiological barriers. They can therefore be particularly susceptible to early life exposure to ubiquitous xenobiotics, which elicit neuropathological mechanisms in the immature brain, such as epigenetic changes, oxidative stress, neuroinflammation, hypoxic damage, and endocrine disruption. As exposure to environmental factors may be mitigated for individuals with risk variants, this work provides new perspectives to personalized prevention and health management policies for ASD.