Browsing by Author "Almeida, J."
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- Association of the alpha4 integrin subunit gene (ITGA4) with autismPublication . Correia, C.; Coutinho, A.M.; Almeida, J.; Lontro, R.; Lobo, C.; Miguel, T.S.; Martins, M.; Gallagher, L.; Conroy, J.; Gill, M.; Oliveira, G.; Vicente, A.M.In the present work, we provide further evidence for the involvement of the integrin alpha-4 precursor gene (ITGA4) in the etiology of autism, by replicating previous findings of a genetic association with autism in various independent populations. The ITGA4 gene maps to the autism linkage region on 2q31-33 and is therefore a plausible positional candidate. We tested eight single nucleotide polymorphisms (SNPs) in the ITGA4 gene region for association with autism in a sample of 164 nuclear families. Evidence for association was found for the rs155100 marker (P = 0.019) and for a number of specific marker haplotypes containing this SNP (0.00053 < P < 0.022). alpha4 integrins are known to play a key role in neuroinflammatory processes, which are hypothesized to contribute to autism. In this study, an association was found between the ITGA4 rs1449263 marker and levels of a serum autoantibody directed to brain tissue, which was previously shown to be significantly more frequent in autistic patients than in age-matched controls in our population. This result suggests that the ITGA4 gene could be involved in a neuroimmune process thought to occur in autistic patients and, together with previous findings, offers a new perspective on the role of integrins in the etiology of autism to which little attention has been paid so far.
- Brief report: High frequency of biochemical markers for mitochondrial dysfunction in autism: no association with the mitochondrial aspartate/glutamate carrier SLC25A12 genePublication . Correia, C.; Coutinho, A.M.; Diogo, L.; Grazina, M.; Marques, C.; Miguel, T.; Ataíde, A.; Almeida, J.; Borges, L.; Oliveira, C.; Oliveira, G.; Vicente, A.M.In the present study we confirm the previously reported high frequency of biochemical markers of mitochondrial dysfunction, namely hyperlactacidemia and increased lactate/pyruvate ratio, in a significant fraction of 210 autistic patients. We further examine the involvement of the mitochondrial aspartate/glutamate carrier gene (SLC25A12) in mitochondrial dysfunction associated with autism. We found no evidence of association of the SLC25A12 gene with lactate and lactate/pyruvate distributions or with autism in 241 nuclear families with one affected individual. We conclude that while mitochondrial dysfunction may be one of the most common medical conditions associated with autism, variation at the SLC25A12 gene does not explain the high frequency of mitochondrial dysfunction markers and is not associated with autism in this sample of autistic patients.
- Convergence of genes and cellular pathways dysregulated in autism spectrum disordersPublication . Pinto, D.; Delaby, E.; Merico, D.; Barbosa, M.; Merikangas, A.; Klei, L; Thiruvahindrapuram, B.; Xu, X.; Ziman, R.; Wang, Z.; Vorstman, J.A.; Thompson, A.; Regan, R.; Pilorge, M.; Pellecchia, G.; Pagnamenta, A.T.; Oliveira, B.; Marshall, C.R.; Magalhães, T.R.; Lowe, J.K.; Howe, J.L.; Griswold, A.J.; Gilbert, J.; Duketis, E.; Dombroski, B.A.; De Jonge, M.V.; Cuccaro, M.; Crawford, E.L.; Correia, C.T.; Conroy, J.; Conceição, I.C; Chiocchetti, A.G.; Casey, J.P.; Cai, G.; Cabrol, C.; Bolshakova, N.; Bacchelli, E.; Anney, R.; Gallinger, S.; Cotterchio, M.; Casey, G.; Zwaigenbaum, L.; Wittemeyer, K.; Wing, K.; Wallace, S.; van Engeland, H.; Tryfon, A.; Thomson, S.; Soorya, L.; Rogé, B.; Roberts, W.; Poustka, F.; Mouga, S.; Minshew, N.; McInnes, L.A.; McGrew, S.G.; Lord, C.; Leboyer, M.; Le Couteur, A.S.; Kolevzon, A.; Jiménez González, P.; Jacob, S.; Holt, R.; Guter, S.; Green, J.; Green, A.; Gillberg, C.; Fernandez, B.A.; Duque, F.; Delorme, R.; Dawson, G.; Chaste, P.; Café, C.; Brennan, S.; Bourgeron, T.; Bolton, P.F.; Bölte, S.; Bernier, R.; Baird, G.; Bailey, A.J.; Anagnostou, E.; Almeida, J.; Wijsman, E.M.; Vieland, V.J.; Vicente, A.M.; Schellenberg, G.D.; Pericak-Vance, M.; Paterson, A.D.; Parr, J.R.; Oliveira, G.; Nurnberger, J.I.; Monaco, A.P.; Maestrini, E.; Klauck, S.M.; Hakonarson, H.; Haines, J.L.; Geschwind, D.H.; Freitag, C.M.; Folstein, S.E.; Ennis, S.; Coon, H.; Battaglia, A.; Szatmari, P.; Sutcliffe, J.S.; Hallmayer, J.; Gill, M.; Cook, E.H.; Buxbaum, J.D.; Devlin, B.; Gallagher, L.; Betancur, C.Rare copy-number variation (CNV) is an important source of risk for autism spectrum disorders (ASDs). We analyzed 2,446 ASD-affected families and confirmed an excess of genic deletions and duplications in affected versus control groups (1.41-fold, p = 1.0 × 10(-5)) and an increase in affected subjects carrying exonic pathogenic CNVs overlapping known loci associated with dominant or X-linked ASD and intellectual disability (odds ratio = 12.62, p = 2.7 × 10(-15), ∼3% of ASD subjects). Pathogenic CNVs, often showing variable expressivity, included rare de novo and inherited events at 36 loci, implicating ASD-associated genes (CHD2, HDAC4, and GDI1) previously linked to other neurodevelopmental disorders, as well as other genes such as SETD5, MIR137, and HDAC9. Consistent with hypothesized gender-specific modulators, females with ASD were more likely to have highly penetrant CNVs (p = 0.017) and were also overrepresented among subjects with fragile X syndrome protein targets (p = 0.02). Genes affected by de novo CNVs and/or loss-of-function single-nucleotide variants converged on networks related to neuronal signaling and development, synapse function, and chromatin regulation.
- Copy number variants involving components of the glutamatergic synaptic pathway in ASD patientsPublication . Oliveira, B.A.; Conceição, I.C.; Correia, C.A.; Café, C.; Almeida, J.; Mouga, S.; Duque, F.; Oliveira, G.; Vicente, A.M.Copy Number Variants (CNVs) play an important role in susceptibility to Autism Spectrum Disorders (ASD), in particular when deleting or duplicating genes involved in synaptic structure and function such as glutamatergic synapse genes. Identifying CNVs of etiologic relevance for ASD that include glutamatergic genes may contribute to the understanding of glutamate-related pathogenic mechanisms in this disorder.
- Definition of a putative pathological region in PARK2 associated with autism spectrum disorder through in silico analysis of its functional structurePublication . Conceição, I.C.; Rama, M.M.; Oliveira, B.; Café, C.; Almeida, J.; Mouga, S.; Duque, F.; Oliveira, G.; Vicente, A.M.Objective: The PARK2 gene encodes Parkin, a component of a multiprotein E3 ubiquitin ligase complex that targets substrate proteins for proteasomal degradation. PARK2 mutations are frequently associated with Parkinson’s disease, but structural alterations have also been described in patients with neurodevelopmental disorders (NDD), suggesting a pathological effect ubiquitous to neurodevelopmental and neurodegenerative brain processes. The present study aimed to define the critical regions for NDD within PARK2. Materials and methods: To clarify PARK2 involvement in NDDs, we examined the frequency and location of copy number variants (CNVs) identified in patients from our sample and reported in the literature and relevant databases, and compared with control populations. Results: Overall, the frequency of PARK2 CNVs was higher in controls than in NDD cases. However, closer inspection of the CNV location in PARK2 showed that the frequency of CNVs targeting the Parkin C-terminal, corresponding to the ring-between-ring (RBR) domain responsible for Parkin activity, is significantly higher in NDD cases than in controls. In contrast, CNVs targeting the N-terminal of Parkin, including domains that regulate ubiquitination activity, are very common both in cases and in controls. Conclusion: Although PARK2 may be a pathological factor for NDDs, likely not all variants are pathogenic, and a conclusive assessment of PARK2 variant pathogenicity requires an accurate analysis of their location within the coding region and encoded functional domains.
- Differential diagnosis of Autism Spectrum Disorder (ASD) by CNV detection – can early diagnosis be improved?Publication . Kwiatkowska, K.; Conceição, I.C.; Rodrigues, A.C.; Picanço, I.; Marques, I.; Melo, J.; Ferreira, S.; Café, C.; Almeida, J.; Mouga, S.; Oliveira, G.; Vicente, A.M.Autism Spectum Disorder (ASD) is an impairment in neurodevelopment that can be recognized in the first years of life. Symptoms are diverse and vary in severity, determining prognosis and influencing the integration in the community. ASD is characterized by difficulties in interpersonal interaction, verbal and nonverbal communication, and by uncommon interests, inappropriate and uncontrolled behaviors, and repetitive activities. Specific and early diagnosis allows early and effective intervention that improves learning, communication and social skills of autistic children.
- Dysfunction of the Heteromeric KV7.3/KV7.5 Potassium Channel is Associated with Autism Spectrum DisordersPublication . Gilling, M.; Rasmussen, H.B.; Calloe, K.; Sequeira, A.F.; Barreto, M.; Oliveira, G.; Almeida, J.; Lauritsen, M.B.; Ullmann, R.; Boonen, S.E.; Brondum-Nielsen, K.; Kalscheuer, V.M.; Tümer, Z.; Vicente, A.M.; Schmitt, N.; Tommerup, N.Heterozygous mutations in the KCNQ3 gene on chromosome 8q24 encoding the voltage-gated potassium channel KV7.3 subunit have previously been associated with rolandic epilepsy and idiopathic generalized epilepsy (IGE) including benign neonatal convulsions. We identified a de novo t(3;8) (q21;q24) translocation truncating KCNQ3 in a boy with childhood autism. In addition, we identified a c.1720C > T [p.P574S] nucleotide change in three unrelated individuals with childhood autism and no history of convulsions. This nucleotide change was previously reported in patients with rolandic epilepsy or IGE and has now been annotated as a very rare SNP (rs74582884) in dbSNP. The p.P574S KV7.3 variant significantly reduced potassium current amplitude in Xenopus laevis oocytes when co-expressed with KV7.5 but not with KV7.2 or KV7.4. The nucleotide change did not affect trafficking of heteromeric mutant KV7.3/2, KV7.3/4, or KV7.3/5 channels in HEK 293 cells or primary rat hippocampal neurons. Our results suggest that dysfunction of the heteromeric KV7.3/5 channel is implicated in the pathogenesis of some forms of autism spectrum disorders, epilepsy, and possibly other psychiatric disorders and therefore, KCNQ3 and KCNQ5 are suggested as candidate genes for these disorders.
- Expression Profile of Circulating miRNAs in Autism Spectrum DisordersPublication . Rodrigues, A.C.; Conceição, I.C.; Kwiatkowska, K.; Picanço, I.; Café, C.; Almeida, J.; Mouga, S.; Enguita, F.J.; Oliveira, G.; Vicente, A.M.Autism Spectrum Disorder (ASD) is a common disorder with an heterogeneous clinical presentation and unclear etiology. Rare, highly penetrant, variants explain approximately 20% of ASD genetic liability, while common genetic factors of low effect, which combine in affected individuals to reach a pathological threshold, have not yet been identified. Epigenetic factors may additionally modulate the effect of genetic variants. ASD overlaps with other Neurodevelopmental Disorders (NDD), both in clinical aspects and in causative genetic variants, frequently rendering specific diagnosis difficult1,5. Here we hypothesize that, while genetic variants overlap in a large extent between NDDs, epigenetic factors may regulate the expression, activity or function of genetic factors, leading to the characteristic phenotypic presentation that differentiates ASD from other NDDs. To test this hypothesis, we addressed the role of epigenetic factors in ASD, focusing on microRNAs (miRNAs). These small noncoding RNA molecules negatively regulate gene expression, influencing many biological processes and, because they are released from pathological tissues to plasma in disease situations, may constitute useful biomarkers. We thus profiled miRNAs in plasma from ASD patients and patients with other NDDs.
- Expression Profile of Circulating miRNAs in Autism Spectrum Disorders Population samplePublication . Conceição, I.C.; Rodrigues, A.C.; Kwiatkowska, K.; Picanço, I.; Café, C.; Almeida, J.; Mouga, S.; Enguita, F.J.; Oliveira, G.; Vicente, A.M.Autism Spectrum Disorder (ASD) is a common complex disorder, highly heterogeneous and with unclear etiology. While many different rare variants are known to be etiological factors for ASD, they don’t completely explain the genetic variance in this disorder, and common genetic variants could not, thus far, be identified. The possible contribution of epigenetic factors, such as deregulated miRNAs expression, should be addressed. miRNAs are small noncoding RNA molecules that negatively regulate gene expression via degradation or translational repression of their target messenger RNAs. miRNAs play critical roles in several biological processes, and are associated with human pathology. Recent studies have suggested that miRNAs in plasma and serum might be derived from circulating blood cells under healthy conditions, but might be released from pathological tissues during illness. The strong correlation between circulating and tissue miRNAs indicates that circulating miRNAs might be biomarkers for diseases, including central nervous system disorders. We are currently assessing miRNA profiles in plasma from ASD patients and patients with other neurodevelopmental disabilities (eg. psychomotor developmental delay, intellectual disability, etc).
- Farming a wild seaweed and changes to its composition, bioactivity, and bioaccessibility: The Saccorhiza polyschides case studyPublication . Cardoso, C.; Almeida, J.; Coelho, I.; Delgado, I.; Gomes, R.; Quintã, R.; Bandarra, N.M.; Afonso, C.The nutritional value, elemental and fatty acid composition as well as key biological activities were determined in a large brown seaweed species (Saccorhiza polyschides, abundant in European shores), taking into account the effects of wild vs farmed and land-based vs open sea Integrated Multi-Trophic Aquaculture (IMTA) system dichotomies. The results showed that S. polyschides has significant amounts of relevant nutrients, some biological activity (anti-inflammatory), high contents of the essential elements Se (1.07–1.79 mg/kg dw) and I (367–522 mg/kg dw), and a high bioaccessibility of I. However, As levels should be monitored, given their high bioaccessibility (∼60–70% range), and I levels may translate into excessive I intake if too much seaweed is consumed (if daily consumption of dried S. polyschides exceeds 3 g dw). Regarding the wild-farmed dichotomy, wild S. polyschides had a moderately higher nutritional value, including a better ω3/ω6 ratio, but a lower Se content than farmed S. polyschides, 0.80 ± 0.01 vs 0.58–0.69 and 1.07 ± 0.05 vs 1.16–1.79 mg/kg dw, respectively. Furthermore, bioaccessibility of elements was not much affected by cultivation. Concerning land-based vs open sea IMTA, in comparison to S. polyschides in earthen ponds, lower Hg and Pb contamination, but higher Cd levels were determined in the seaweed cultivated in open sea. S. polyschides farming per se did not have a large deleterious impact on the characteristics of this edible seaweed and may ensure the production of large amounts of algal biomass for feed, food, and nutraceutical applications.