Browsing by Author "Sequeira, A.F."
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- 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.
- Functional impact of global rare copy number variation in autism spectrum disordersPublication . Pinto, D.; Pagnamenta, A.T.; Klei, L.; Anney, R.; Merico, D.; Regan, R.; Conroy, J.; Magalhaes, T.R.; Correia, C.; Abrahams, B.S.; Almeida, J.; Bacchelli, E.; Bader, G.D.; Bailey, A.J.; Baird, G.; Battaglia, A.; Berney, T.; Bolshakova, N.; Bölte, S.; Bolton, P.F.; Bourgeron, T.; Brennan, S.; Brian, J.; Bryson, S.E.; Carson, A.R.; Casallo, G.; Casey, J.; Chung, B.H.; Cochrane, L.; Corsello, C.; Crawford, E.L.; Crossett, A.; Cytrynbaum, C.; Dawson, G.; de Jonge, M.; Delorme, R.; Drmic, I.; Duketis, E.; Duque, F.; Estes, A.; Farrar, P.; Fernandez, B.A.; Folstein, S.E.; Fombonne, E.; Freitag, C.M.; Gilbert, J.; Gillberg, C.; Glessner, J.T.; Goldberg, J.; Green, A.; Green, J.; Guter, S.J.; Hakonarson, H.; Heron, E.A.; Hill, M.; Holt, R.; Howe, J.L.; Hughes, G.; Hus, V.; Igliozzi, R.; Kim, C.; Klauck, S.M.; Kolevzon, A.; Korvatska, O.; Kustanovich, V.; Lajonchere, C.M.; Lamb, J.A.; Laskawiec, M.; Leboyer, M.; Le Couteur, A.; Leventhal, B.L.; Lionel, A.C.; Liu, X.Q.; Lord, C.; Lotspeich, L.; Lund, S.C.; Maestrini, E.; Mahoney, W.; Mantoulan, C.; Marshall, C.R.; McConachie, H.; McDougle, C.J.; McGrath, J.; McMahon, W.M.; Merikangas, A.; Migita, O.; Minshew, N.J.; Mirza, G.K.; Munson, J.; Nelson, S.F.; Noakes, C.; Noor, A.; Nygren, G.; Oliveira, G.; Papanikolaou, K.; Parr, J.R.; Parrini, B.; Paton, T.; Pickles, A.; Pilorge, M.; Piven, J.; Ponting, C.P.; Posey, D.J.; Poustka, A.; Poustka, F.; Prasad, A.; Ragoussis, J.; Renshaw, K.; Rickaby, J.; Roberts, W.; Roeder, K.; Roge, B.; Rutter, M.L.; Bierut, L.J.; Rice, J.P.; Salt, J.; Sansom, K.; Sato, D.; Segurado, R.; Sequeira, A.F.; Senman, L.; Shah, N.; Sheffield, V.C.; Soorya, L.; Sousa, I.; Stein, O.; Sykes, N.; Stoppioni, V.; Strawbridge, C.; Tancredi, R.; Tansey, K.; Thiruvahindrapduram, B.; Thompson, A.P.; Thomson, S.; Tryfon, A.; Tsiantis, J.; Van Engeland, H.; Vincent, J.B.; Volkmar, F.; Wallace, S.; Wang, K.; Wang, Z.; Wassink, T.H.; Webber, C.; Weksberg, R.; Wing, K.; Wittemeyer, K.; Wood, S.; Wu, J.; Yaspan, B.L.; Zurawiecki, D.; Zwaigenbaum, L.; Buxbaum, J.D.; Cantor, R.M.; Cook, E.H.; Coon, H.; Cuccaro, M.L.; Devlin, B.; Ennis, S.; Gallagher, L.; Geschwind, D.H.; Gill, M.; Haines, J.L.; Hallmayer, J.; Miller, J.; Monaco, A.P.; Nurnberger Jr, J.I.; Paterson, A.D.; Pericak-Vance, M.A.; Schellenberg, G.D.; Szatmari, P.; Vicente, A.M.; Vieland, V.J.; Wijsman, E.M.; Scherer, S.W.; Sutcliffe, J.S.; Betancur, C.The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare (<1% frequency) copy number variation in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic copy number variants (CNVs) (1.19 fold, P = 0.012), especially so for loci previously implicated in either ASD and/or intellectual disability (1.69 fold, P = 3.4 x 10(-4)). Among the CNVs there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes such as SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene sets involved in cellular proliferation, projection and motility, and GTPase/Ras signalling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.
- Genetic and Functional Analyses of SHANK2 Mutations Suggest a Multiple Hit Model of Autism Spectrum DisordersPublication . Leblond, C.S.; Heinrich, J.; Delorme, R.; Proepper, C.; Betancur, C.; Huguet, G.; Konyukh, M.; Chaste, P.; Ey, E.; Rastam, M.; Anckarsäter, H.; Nygren, G.; Gillberg, I.C.; Melke, J.; Toro, R.; Regnault, B.; Fauchereau, F.; Mercati, O.; Lemière, N.; Skuse, D.; Poot, M.; Holt, R.; Monaco, A.P.; Järvelä, I.; Kantojärvi, K.; Vanhala, R.; Curran, S.; Collier, D.A.; Bolton, P.; Chiocchetti, A; Klauck, S.M.; Poustka, F.; Freitag, C.M.; Waltes, R.; Kopp, M.; Duketis, E.; Bacchelli, E.; Minopoli, F.; Ruta, L.; Battaglia, A.; Mazzone, L.; Maestrini, E.; Sequeira, A.F.; Oliveira, B.; Vicente, A.M.; Oliveira, G.; Pinto, D.; Scherer, S.W.; Zelenika, D.; Delepine, M.; Lathrop, M.; Bonneau, D.; Guinchat, V.; Devillard, F.; Assouline, B.; Mouren, M.C.; Leboyer, M.; Gillberg, C.; Boeckers, T.M.Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. While many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. Here, following the discovery of two de novo SHANK2 deletions by the Autism Genome Project, we identified a novel 421 kb de novo SHANK2 deletion in a patient with autism. We then sequenced SHANK2 in 455 patients with ASD and 431 controls and integrated these results with those reported by Berkel et al. 2010 (n = 396 patients and n = 659 controls). We observed a significant enrichment of variants affecting conserved amino acids in 29 of 851 (3.4%) patients and in 16 of 1,090 (1.5%) controls (P = 0.004, OR = 2.37, 95% CI = 1.23-4.70). In neuronal cell cultures, the variants identified in patients were associated with a reduced synaptic density at dendrites compared to the variants only detected in controls (P = 0.0013). Interestingly, the three patients with de novo SHANK2 deletions also carried inherited CNVs at 15q11-q13 previously associated with neuropsychiatric disorders. In two cases, the nicotinic receptor CHRNA7 was duplicated and in one case the synaptic translation repressor CYFIP1 was deleted. These results strengthen the role of synaptic gene dysfunction in ASD but also highlight the presence of putative modifier genes, which is in keeping with the "multiple hit model" for ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.
- Increased BDNF levels and NTRK2 gene association suggest a disruption of BDNF/TrkB signaling in autismPublication . Correia, C.T.; Coutinho, A.M.; Sequeira, A.F.; Sousa, I.G.; Lourenço Venda, L.; Almeida, J.P.; Abreu, R.L.; Lobo, C.; Miguel, T.S.; Conroy, J.; Cochrane, L.; Gallagher, L.; Gill, M.; Ennis, S.; Oliveira, G.G.; Vicente, A.M.The brain-derived neurotrophic factor (BDNF), a neurotrophin fundamental for brain development and function, has previously been implicated in autism. In this study, the levels of BDNF in platelet-rich plasma were compared between autistic and control children, and the role of two genetic factors that might regulate this neurotrophin and contribute to autism etiology, BDNF and NTRK2, was examined. We found that BDNF levels in autistic children (n = 146) were significantly higher (t = 6.82; P < 0.0001) than in control children (n = 50) and were positively correlated with platelet serotonin distribution (r = 0.22; P = 0.004). Heritability of BDNF was estimated at 30% and therefore candidate genes BDNF and NTRK2 were tested for association with BDNF level distribution in this sample, and with autism in 469 trio families. Genetic association analysis provided no evidence for BDNF or NTRK2 as major determinants of the abnormally increased BDNF levels in autistic children. A significant association with autism was uncovered for six single nucleotide polymorphisms (SNPs) [0.004 (Z((1df)) = 2.85) < P < 0.039 (Z((1df)) = 2.06)] and multiple haplotypes [5 × 10(-4) (χ((3df)) = 17.77) < P < 0.042 (χ((9df)) = 17.450)] in the NTRK2 gene. These results do not withstand correction for multiple comparisons, however, reflect a trend toward association that supports a role of NTRK2 as a susceptibility factor for the disorder. Genetic variation in the BDNF gene had no impact on autism risk. By substantiating the previously observed increase in BDNF levels in autistic children in a larger patient set, and suggesting a genetic association between NTRK2 and autism, this study integrates evidence from multiple levels supporting the hypothesis that alterations in BDNF/tyrosine kinase B (TrkB) signaling contribute to an increased vulnerability to autism.
- A novel approach of homozygous haplotype sharing identifies candidate genes in autism spectrum disorderPublication . Casey, J.P.; Magalhaes, T.; Conroy, J.M.; Regan, R.; Shah, N.; Anney, R.; Shields, D.C.; Abrahams, B.S.; Almeida, J.; Bacchelli, E.; Bailey, A.J.; Piven, J.; Posey, D.J.; Poustka, A.; Poustka, F.; Ragoussis, J.; Roge, B.; Rutter, M.L.; Sequeira, A.F.; Soorya, L.; Sousa, I.; Wittemeyer, K.; Sykes, N.; Stoppioni, V.; Tancredi, R.; Tauber, M.; Thompson, A.P.; Thomson, S.; Tsiantis, J.; Van Engeland, H.; Vincent, J.B.; Volkmar, F.; Yaspan, B.L.; Vorstman, J.A.; Wallace, S.; Wang, K.; Wassink, T.H.; White, K.; Wing, K.; Zwaigenbaum, L.; Betancur, C.; Buxbaum, J.D.; Cantor, R.M.; Cook, E.H.; Coon, H.; Cuccaro, M.L.; Geschwind, D.H.; Baird, G.; Haines, J.L.; Hallmayer, J.; Monaco, A.P.; Nurnberger, J.I. Jr; Pericak-Vance, M.A.; Schellenberg, G.D.; Scherer, S.W.; Sutcliffe, J.S.; Szatmari, P.; Vieland, V.J.; Battaglia, A.; Wijsman, E.M.; Green, A.; Gill, M.; Gallagher, L.; Vicente, A.M.; Ennis, S.; Berney, T.; Bolshakova, N.; Bolton, P.F.; Bourgeron, T.; Brennan, S.; Cali, P.; Correia, C.; Corsello, C.; Coutanche, M.; Dawson, G.; de Jonge, M.; Delorme, R.; Duketis, E.; Duque, F.; Estes, A.; Farrar, P.; Fernandez, B.A.; Folstein, S.E.; Foley, S.; Fombonne, E.; Freitag, C.M.; Gilbert, J.; Gillberg, C.; Glessner, J.T.; Green, J.; Guter, S.J.; Hakonarson, H.; Holt, R.; Hughes, G.; Hus, V.; Igliozzi, R.; Kim, C.; Klauck, S.M.; Kolevzon, A.; Lamb, J.A.; Leboyer, M.; Le Couteur, A.; Leventhal, B.L.; Lord, C.; Lund, S.C.; Maestrini, E.; Mantoulan, C.; Marshall, C.R.; McConachie, H.; McDougle, C.J.; McGrath, J.; McMahon, W.M.; Merikangas, A.; Miller, J.; Minopoli, F.; Mirza, G.K.; Munson, J.; Nelson, S.F.; Nygren, G.; Oliveira, G.; Pagnamenta, A.T.; Papanikolaou, K.; Parr, J.R.; Parrini, B.; Pickles, A.; Pinto, D.Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiology. It is primarily characterized by altered cognitive ability including impaired language and communication skills and fundamental deficits in social reciprocity. Despite some notable successes in neuropsychiatric genetics, overall, the high heritability of ASD (~90%) remains poorly explained by common genetic risk variants. However, recent studies suggest that rare genomic variation, in particular copy number variation, may account for a significant proportion of the genetic basis of ASD. We present a large scale analysis to identify candidate genes which may contain low-frequency recessive variation contributing to ASD while taking into account the potential contribution of population differences to the genetic heterogeneity of ASD. Our strategy, homozygous haplotype (HH) mapping, aims to detect homozygous segments of identical haplotype structure that are shared at a higher frequency amongst ASD patients compared to parental controls. The analysis was performed on 1,402 Autism Genome Project trios genotyped for 1 million single nucleotide polymorphisms (SNPs). We identified 25 known and 1,218 novel ASD candidate genes in the discovery analysis including CADM2, ABHD14A, CHRFAM7A, GRIK2, GRM3, EPHA3, FGF10, KCND2, PDZK1, IMMP2L and FOXP2. Furthermore, 10 of the previously reported ASD genes and 300 of the novel candidates identified in the discovery analysis were replicated in an independent sample of 1,182 trios. Our results demonstrate that regions of HH are significantly enriched for previously reported ASD candidate genes and the observed association is independent of gene size (odds ratio 2.10). Our findings highlight the applicability of HH mapping in complex disorders such as ASD and offer an alternative approach to the analysis of genome-wide association data.
- Pharmacogenetics of risperidone therapy in autism: association analysis of eight candidate genes with drug efficacy and adverse drug reactionsPublication . Correia, C.T.; Almeida, J.P.; Santos, P.E.; Sequeira, A.F.; Marques, C.E.; Miguel, T.S.; Abreu, R.L.; Oliveira, G.G.; Vicente, A.M.Little has been reported on the factors, genetic or other, that underlie the variability in individual response, particularly for autism. In this study we simultaneously explored the effects of multiple candidate genes on clinical improvement and occurrence of adverse drug reactions, in 45 autistic patients who received monotherapy with risperidone up to 1 year. Candidate genes involved in the pharmacokinetics (CYP2D6 and ABCB1) and pharmacodynamics (HTR2A, HTR2C, DRD2, DRD3, HTR6) of the drug, and the brain-derived neurotrophic factor (BDNF) gene, were analysed. Using the generalized estimating equation method these genes were tested for association with drug efficacy, assessed with the Autism Treatment Evaluation Checklist, and with safety and tolerability measures, such as prolactin levels, body mass index (BMI), waist circumference and neurological adverse effects, including extrapyramidal movements. Our results confirm that risperidone therapy was very effective in reducing some autism symptoms and caused few serious adverse effects. After adjusting for confounding factors, the HTR2A c.-1438G>A, DRD3 Ser9Gly, HTR2C c.995G>A and ABCB1 1236C>T polymorphisms were predictors for clinical improvement with risperidone therapy. The HTR2A c.-1438G>A, HTR2C c.68G>C (p.C33S), HTR6 c.7154-2542C>T and BDNF c.196G>A (p.V66M) polymorphisms influenced prolactin elevation. HTR2C c.68G>C and CYP2D6 polymorphisms were associated with risperidone-induced increase in BMI or waist circumference. We thus identified for the first time several genes implicated in risperidone efficacy and safety in autism patients. Although association results require replication, given the small sample size, the study makes a preliminary contribution to the personalized therapy of risperidone in autism.
- Recurrent duplications of the annexin A1 gene (ANXA1) in autism spectrum disordersPublication . Correia, C.T.; Conceição, I.C.; Oliveira, B.; Coelho, J.; Sousa, I.; Sequeira, A.F.; Almeida, J.; Café, C.; Duque, F; Mouga, S.; Roberts, W.; Gao, K.; Lowe, J.K.; Thiruvahindrapuram, B.; Walker, S.; Marshall, C.R.; Pinto, D.; Nurnberger, J.I.; Scherer, S.W.; Geschwind, D.H.; Oliveira, G.; Vicente, A.M.Validating the potential pathogenicity of copy number variants (CNVs) identified in genome-wide studies of autism spectrum disorders (ASD) requires detailed assessment of case/control frequencies, inheritance patterns, clinical correlations, and functional impact. Here, we characterize a small recurrent duplication in the annexin A1 (ANXA1) gene, identified by the Autism Genome Project (AGP) study.