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Find video protocols related to scientific articles indexed in Pubmed.
The correlation between reading and mathematics ability at age twelve has a substantial genetic component.
Nat Commun
PUBLISHED: 05-23-2014
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Dissecting how genetic and environmental influences impact on learning is helpful for maximizing numeracy and literacy. Here we show, using twin and genome-wide analysis, that there is a substantial genetic component to children's ability in reading and mathematics, and estimate that around one half of the observed correlation in these traits is due to shared genetic effects (so-called Generalist Genes). Thus, our results highlight the potential role of the learning environment in contributing to differences in a child's cognitive abilities at age twelve.
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Assessing multivariate gene-metabolome associations with rare variants using Bayesian reduced rank regression.
Bioinformatics
PUBLISHED: 03-24-2014
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A typical genome-wide association study searches for associations between single nucleotide polymorphisms (SNPs) and a univariate phenotype. However, there is a growing interest to investigate associations between genomics data and multivariate phenotypes, for example, in gene expression or metabolomics studies. A common approach is to perform a univariate test between each genotype-phenotype pair, and then to apply a stringent significance cutoff to account for the large number of tests performed. However, this approach has limited ability to uncover dependencies involving multiple variables. Another trend in the current genetics is the investigation of the impact of rare variants on the phenotype, where the standard methods often fail owing to lack of power when the minor allele is present in only a limited number of individuals.
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Chromosome X-wide association study identifies Loci for fasting insulin and height and evidence for incomplete dosage compensation.
PLoS Genet.
PUBLISHED: 02-01-2014
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The X chromosome (chrX) represents one potential source for the "missing heritability" for complex phenotypes, which thus far has remained underanalyzed in genome-wide association studies (GWAS). Here we demonstrate the benefits of including chrX in GWAS by assessing the contribution of 404,862 chrX SNPs to levels of twelve commonly studied cardiometabolic and anthropometric traits in 19,697 Finnish and Swedish individuals with replication data on 5,032 additional Finns. By using a linear mixed model, we estimate that on average 2.6% of the additive genetic variance in these twelve traits is attributable to chrX, this being in proportion to the number of SNPs in the chromosome. In a chrX-wide association analysis, we identify three novel loci: two for height (rs182838724 near FGF16/ATRX/MAGT1, joint P-value?=?2.71×10(-9), and rs1751138 near ITM2A, P-value?=?3.03×10(-10)) and one for fasting insulin (rs139163435 in Xq23, P-value?=?5.18×10(-9)). Further, we find that effect sizes for variants near ITM2A, a gene implicated in cartilage development, show evidence for a lack of dosage compensation. This observation is further supported by a sex-difference in ITM2A expression in whole blood (P-value?=?0.00251), and is also in agreement with a previous report showing ITM2A escapes from X chromosome inactivation (XCI) in the majority of women. Hence, our results show one of the first links between phenotypic variation in a population sample and an XCI-escaping locus and pinpoint ITM2A as a potential contributor to the sexual dimorphism in height. In conclusion, our study provides a clear motivation for including chrX in large-scale genetic studies of complex diseases and traits.
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An inherited duplication at the gene p21 Protein-Activated Kinase 7 (PAK7) is a risk factor for psychosis.
Hum. Mol. Genet.
PUBLISHED: 01-28-2014
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Identifying rare, highly penetrant risk mutations may be an important step in dissecting the molecular etiology of schizophrenia. We conducted a gene-based analysis of large (>100 kb), rare copy-number variants (CNVs) in the Wellcome Trust Case Control Consortium 2 (WTCCC2) schizophrenia sample of 1564 cases and 1748 controls all from Ireland, and further extended the analysis to include an additional 5196 UK controls. We found association with duplications at chr20p12.2 (P = 0.007) and evidence of replication in large independent European schizophrenia (P = 0.052) and UK bipolar disorder case-control cohorts (P = 0.047). A combined analysis of Irish/UK subjects including additional psychosis cases (schizophrenia and bipolar disorder) identified 22 carriers in 11 707 cases and 10 carriers in 21 204 controls [meta-analysis Cochran-Mantel-Haenszel P-value = 2 × 10(-4); odds ratio (OR) = 11.3, 95% CI = 3.7, ?]. Nineteen of the 22 cases and 8 of the 10 controls carried duplications starting at 9.68 Mb with similar breakpoints across samples. By haplotype analysis and sequencing, we identified a tandem ~149 kb duplication overlapping the gene p21 Protein-Activated Kinase 7 (PAK7, also called PAK5) which was in linkage disequilibrium with local haplotypes (P = 2.5 × 10(-21)), indicative of a single ancestral duplication event. We confirmed the breakpoints in 8/8 carriers tested and found co-segregation of the duplication with illness in two additional family members of one of the affected probands. We demonstrate that PAK7 is developmentally co-expressed with another known psychosis risk gene (DISC1) suggesting a potential molecular mechanism involving aberrant synapse development and plasticity.
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Genome-wide association analysis identifies 13 new risk loci for schizophrenia.
Stephan Ripke, Colm O'Dushlaine, Kimberly Chambert, Jennifer L Moran, Anna K Kähler, Susanne Akterin, Sarah E Bergen, Ann L Collins, James J Crowley, Menachem Fromer, Yunjung Kim, Sang Hong Lee, Patrik K E Magnusson, Nick Sanchez, Eli A Stahl, Stephanie Williams, Naomi R Wray, Kai Xia, Francesco Bettella, Anders D Borglum, Brendan K Bulik-Sullivan, Paul Cormican, Nick Craddock, Christiaan de Leeuw, Naser Durmishi, Michael Gill, Vera Golimbet, Marian L Hamshere, Peter Holmans, David M Hougaard, Kenneth S Kendler, Kuang Lin, Derek W Morris, Ole Mors, Preben B Mortensen, Benjamin M Neale, Francis A O'Neill, Michael J Owen, Milica Pejović Milovančević, Danielle Posthuma, John Powell, Alexander L Richards, Brien P Riley, Douglas Ruderfer, Dan Rujescu, Engilbert Sigurdsson, Teimuraz Silagadze, August B Smit, Hreinn Stefansson, Stacy Steinberg, Jaana Suvisaari, Sarah Tosato, Matthijs Verhage, James T Walters, , Douglas F Levinson, Pablo V Gejman, Claudine Laurent, Bryan J Mowry, Michael C O'Donovan, Ann E Pulver, Sibylle G Schwab, Dieter B Wildenauer, Frank Dudbridge, Jianxin Shi, Margot Albus, Madeline Alexander, Dominique Campion, David Cohen, Dimitris Dikeos, Jubao Duan, Peter Eichhammer, Stephanie Godard, Mark Hansen, F Bernard Lerer, Kung-Yee Liang, Wolfgang Maier, Jacques Mallet, Deborah A Nertney, Gerald Nestadt, Nadine Norton, George N Papadimitriou, Robert Ribble, Alan R Sanders, Jeremy M Silverman, Dermot Walsh, Nigel M Williams, Brandon Wormley, Maria J Arranz, Steven Bakker, Stephan Bender, Elvira Bramon, David Collier, Benedicto Crespo-Facorro, Jeremy Hall, Conrad Iyegbe, Assen Jablensky, René S Kahn, Luba Kalaydjieva, Stephen Lawrie, Cathryn M Lewis, Don H Linszen, Ignacio Mata, Andrew McIntosh, Robin M Murray, Roel A Ophoff, Jim van Os, Muriel Walshe, Matthias Weisbrod, Durk Wiersma, Peter Donnelly, Inês Barroso, Jenefer M Blackwell, Matthew A Brown, Juan P Casas, Aiden P Corvin, Panos Deloukas, Audrey Duncanson, Janusz Jankowski, Hugh S Markus, Christopher G Mathew, Colin N A Palmer, Robert Plomin, Anna Rautanen, Stephen J Sawcer, Richard C Trembath, Ananth C Viswanathan, Nicholas W Wood, Chris C A Spencer, Gavin Band, Celine Bellenguez, Colin Freeman, Garrett Hellenthal, Eleni Giannoulatou, Matti Pirinen, Richard D Pearson, Amy Strange, Zhan Su, Damjan Vukcevic, Cordelia Langford, Sarah E Hunt, Sarah Edkins, Rhian Gwilliam, Hannah Blackburn, Suzannah J Bumpstead, Serge Dronov, Matthew Gillman, Emma Gray, Naomi Hammond, Alagurevathi Jayakumar, Owen T McCann, Jennifer Liddle, Simon C Potter, Radhi Ravindrarajah, Michelle Ricketts, Avazeh Tashakkori-Ghanbaria, Matthew J Waller, Paul Weston, Sara Widaa, Pamela Whittaker, Mark I McCarthy, Kari Stefansson, Edward Scolnick, Shaun Purcell, Steven A McCarroll, Pamela Sklar, Christina M Hultman, Patrick F Sullivan.
Nat. Genet.
PUBLISHED: 08-01-2013
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Schizophrenia is an idiopathic mental disorder with a heritable component and a substantial public health impact. We conducted a multi-stage genome-wide association study (GWAS) for schizophrenia beginning with a Swedish national sample (5,001 cases and 6,243 controls) followed by meta-analysis with previous schizophrenia GWAS (8,832 cases and 12,067 controls) and finally by replication of SNPs in 168 genomic regions in independent samples (7,413 cases, 19,762 controls and 581 parent-offspring trios). We identified 22 loci associated at genome-wide significance; 13 of these are new, and 1 was previously implicated in bipolar disorder. Examination of candidate genes at these loci suggests the involvement of neuronal calcium signaling. We estimate that 8,300 independent, mostly common SNPs (95% credible interval of 6,300-10,200 SNPs) contribute to risk for schizophrenia and that these collectively account for at least 32% of the variance in liability. Common genetic variation has an important role in the etiology of schizophrenia, and larger studies will allow more detailed understanding of this disorder.
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Assessing association between protein truncating variants and quantitative traits.
Bioinformatics
PUBLISHED: 07-16-2013
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In sequencing studies of common diseases and quantitative traits, power to test rare and low frequency variants individually is weak. To improve power, a common approach is to combine statistical evidence from several genetic variants in a region. Major challenges are how to do the combining and which statistical framework to use. General approaches for testing association between rare variants and quantitative traits include aggregating genotypes and trait values, referred to as collapsing, or using a score-based variance component test. However, little attention has been paid to alternative models tailored for protein truncating variants. Recent studies have highlighted the important role that protein truncating variants, commonly referred to as loss of function variants, may have on disease susceptibility and quantitative levels of biomarkers. We propose a Bayesian modelling framework for the analysis of protein truncating variants and quantitative traits.
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Imputation-based meta-analysis of severe malaria in three African populations.
PLoS Genet.
PUBLISHED: 05-01-2013
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Combining data from genome-wide association studies (GWAS) conducted at different locations, using genotype imputation and fixed-effects meta-analysis, has been a powerful approach for dissecting complex disease genetics in populations of European ancestry. Here we investigate the feasibility of applying the same approach in Africa, where genetic diversity, both within and between populations, is far more extensive. We analyse genome-wide data from approximately 5,000 individuals with severe malaria and 7,000 population controls from three different locations in Africa. Our results show that the standard approach is well powered to detect known malaria susceptibility loci when sample sizes are large, and that modern methods for association analysis can control the potential confounding effects of population structure. We show that pattern of association around the haemoglobin S allele differs substantially across populations due to differences in haplotype structure. Motivated by these observations we consider new approaches to association analysis that might prove valuable for multicentre GWAS in Africa: we relax the assumptions of SNP-based fixed effect analysis; we apply Bayesian approaches to allow for heterogeneity in the effect of an allele on risk across studies; and we introduce a region-based test to allow for heterogeneity in the location of causal alleles.
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Analysis of immune-related loci identifies 48 new susceptibility variants for multiple sclerosis.
, Ashley H Beecham, Nikolaos A Patsopoulos, Dionysia K Xifara, Mary F Davis, Anu Kemppinen, Chris Cotsapas, Tejas S Shah, Chris Spencer, David Booth, An Goris, Annette Oturai, Janna Saarela, Bertrand Fontaine, Bernhard Hemmer, Claes Martin, Frauke Zipp, Sandra D'Alfonso, Filippo Martinelli-Boneschi, Bruce Taylor, Hanne F Harbo, Ingrid Kockum, Jan Hillert, Tomas Olsson, Maria Ban, Jorge R Oksenberg, Rogier Hintzen, Lisa F Barcellos, Cristina Agliardi, Lars Alfredsson, Mehdi Alizadeh, Carl Anderson, Robert Andrews, Helle Bach Søndergaard, Amie Baker, Gavin Band, Sergio E Baranzini, Nadia Barizzone, Jeffrey Barrett, Celine Bellenguez, Laura Bergamaschi, Luisa Bernardinelli, Achim Berthele, Viola Biberacher, Thomas M C Binder, Hannah Blackburn, Izaura L Bomfim, Paola Brambilla, Simon Broadley, Bruno Brochet, Lou Brundin, Dorothea Buck, Helmut Butzkueven, Stacy J Caillier, William Camu, Wassila Carpentier, Paola Cavalla, Elisabeth G Celius, Irène Coman, Giancarlo Comi, Lucia Corrado, Leentje Cosemans, Isabelle Cournu-Rebeix, Bruce A C Cree, Daniele Cusi, Vincent Damotte, Gilles Defer, Silvia R Delgado, Panos Deloukas, Alessia di Sapio, Alexander T Dilthey, Peter Donnelly, Bénédicte Dubois, Martin Duddy, Sarah Edkins, Irina Elovaara, Federica Esposito, Nikos Evangelou, Barnaby Fiddes, Judith Field, Andre Franke, Colin Freeman, Irene Y Frohlich, Daniela Galimberti, Christian Gieger, Pierre-Antoine Gourraud, Christiane Graetz, Andrew Graham, Verena Grummel, Clara Guaschino, Athena Hadjixenofontos, Hakon Hakonarson, Christopher Halfpenny, Gillian Hall, Per Hall, Anders Hamsten, James Harley, Timothy Harrower, Clive Hawkins, Garrett Hellenthal, Charles Hillier, Jeremy Hobart, Muni Hoshi, Sarah E Hunt, Maja Jagodic, Ilijas Jelcic, Angela Jochim, Brian Kendall, Allan Kermode, Trevor Kilpatrick, Keijo Koivisto, Ioanna Konidari, Thomas Korn, Helena Kronsbein, Cordelia Langford, Malin Larsson, Mark Lathrop, Christine Lebrun-Frenay, Jeannette Lechner-Scott, Michelle H Lee, Maurizio A Leone, Virpi Leppä, Giuseppe Liberatore, Benedicte A Lie, Christina M Lill, Magdalena Lindén, Jenny Link, Felix Luessi, Jan Lycke, Fabio Macciardi, Satu Mannisto, Clara P Manrique, Roland Martin, Vittorio Martinelli, Deborah Mason, Gordon Mazibrada, Cristin McCabe, Inger-Lise Mero, Julia Mescheriakova, Loukas Moutsianas, Kjell-Morten Myhr, Guy Nagels, Richard Nicholas, Petra Nilsson, Fredrik Piehl, Matti Pirinen, Siân E Price, Hong Quach, Mauri Reunanen, Wim Robberecht, Neil P Robertson, Mariaemma Rodegher, David Rog, Marco Salvetti, Nathalie C Schnetz-Boutaud, Finn Sellebjerg, Rebecca C Selter, Catherine Schaefer, Sandip Shaunak, Ling Shen, Simon Shields, Volker Siffrin, Mark Slee, Per Soelberg Sorensen, Melissa Sorosina, Mireia Sospedra, Anne Spurkland, Amy Strange, Emilie Sundqvist, Vincent Thijs, John Thorpe, Anna Ticca, Pentti Tienari, Cornelia van Duijn, Elizabeth M Visser, Steve Vucic, Helga Westerlind, James S Wiley, Alastair Wilkins, James F Wilson, Juliane Winkelmann, John Zajicek, Eva Zindler, Jonathan L Haines, Margaret A Pericak-Vance, Adrian J Ivinson, Graeme Stewart, David Hafler, Stephen L Hauser, Alastair Compston, Gil McVean, Philip De Jager, Stephen J Sawcer, Jacob L McCauley.
Nat. Genet.
PUBLISHED: 04-24-2013
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Using the ImmunoChip custom genotyping array, we analyzed 14,498 subjects with multiple sclerosis and 24,091 healthy controls for 161,311 autosomal variants and identified 135 potentially associated regions (P < 1.0 × 10(-4)). In a replication phase, we combined these data with previous genome-wide association study (GWAS) data from an independent 14,802 subjects with multiple sclerosis and 26,703 healthy controls. In these 80,094 individuals of European ancestry, we identified 48 new susceptibility variants (P < 5.0 × 10(-8)), 3 of which we found after conditioning on previously identified variants. Thus, there are now 110 established multiple sclerosis risk variants at 103 discrete loci outside of the major histocompatibility complex. With high-resolution Bayesian fine mapping, we identified five regions where one variant accounted for more than 50% of the posterior probability of association. This study enhances the catalog of multiple sclerosis risk variants and illustrates the value of fine mapping in the resolution of GWAS signals.
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A Genome-Wide Association Analysis of a Broad Psychosis Phenotype Identifies Three Loci for Further Investigation.
Biol. Psychiatry
PUBLISHED: 03-27-2013
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Genome-wide association studies (GWAS) have identified several loci associated with schizophrenia and/or bipolar disorder. We performed a GWAS of psychosis as a broad syndrome rather than within specific diagnostic categories.
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Transcriptome and genome sequencing uncovers functional variation in humans.
Nature
PUBLISHED: 02-07-2013
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Genome sequencing projects are discovering millions of genetic variants in humans, and interpretation of their functional effects is essential for understanding the genetic basis of variation in human traits. Here we report sequencing and deep analysis of messenger RNA and microRNA from lymphoblastoid cell lines of 462 individuals from the 1000 Genomes Project--the first uniformly processed high-throughput RNA-sequencing data from multiple human populations with high-quality genome sequences. We discover extremely widespread genetic variation affecting the regulation of most genes, with transcript structure and expression level variation being equally common but genetically largely independent. Our characterization of causal regulatory variation sheds light on the cellular mechanisms of regulatory and loss-of-function variation, and allows us to infer putative causal variants for dozens of disease-associated loci. Altogether, this study provides a deep understanding of the cellular mechanisms of transcriptome variation and of the landscape of functional variants in the human genome.
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Common variants in the HLA-DRB1-HLA-DQA1 HLA class II region are associated with susceptibility to visceral leishmaniasis.
Nat. Genet.
PUBLISHED: 01-06-2013
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To identify susceptibility loci for visceral leishmaniasis, we undertook genome-wide association studies in two populations: 989 cases and 1,089 controls from India and 357 cases in 308 Brazilian families (1,970 individuals). The HLA-DRB1-HLA-DQA1 locus was the only region to show strong evidence of association in both populations. Replication at this region was undertaken in a second Indian population comprising 941 cases and 990 controls, and combined analysis across the three cohorts for rs9271858 at this locus showed P(combined) = 2.76 × 10(-17) and odds ratio (OR) = 1.41, 95% confidence interval (CI) = 1.30-1.52. A conditional analysis provided evidence for multiple associations within the HLA-DRB1-HLA-DQA1 region, and a model in which risk differed between three groups of haplotypes better explained the signal and was significant in the Indian discovery and replication cohorts. In conclusion, the HLA-DRB1-HLA-DQA1 HLA class II region contributes to visceral leishmaniasis susceptibility in India and Brazil, suggesting shared genetic risk factors for visceral leishmaniasis that cross the epidemiological divides of geography and parasite species.
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Interaction between ERAP1 and HLA-B27 in ankylosing spondylitis implicates peptide handling in the mechanism for HLA-B27 in disease susceptibility.
David M Evans, Chris C A Spencer, Jennifer J Pointon, Zhan Su, David Harvey, Grazyna Kochan, Udo Oppermann, Udo Opperman, Alexander Dilthey, Matti Pirinen, Millicent A Stone, Louise Appleton, Loukas Moutsianas, Loukas Moutsianis, Stephen Leslie, Tom Wordsworth, Tony J Kenna, Tugce Karaderi, Gethin P Thomas, Michael M Ward, Michael H Weisman, Claire Farrar, Linda A Bradbury, Patrick Danoy, Robert D Inman, Walter Maksymowych, Dafna Gladman, Proton Rahman, , Ann Morgan, Helena Marzo-Ortega, Paul Bowness, Karl Gaffney, J S Hill Gaston, Malcolm Smith, Jacome Bruges-Armas, Ana-Rita Couto, Rosa Sorrentino, Fabiana Paladini, Manuel A Ferreira, Huji Xu, Yu Liu, Lei Jiang, Carlos López-Larrea, Roberto Díaz-Peña, Antonio López-Vázquez, Tetyana Zayats, Gavin Band, Celine Bellenguez, Hannah Blackburn, Jenefer M Blackwell, Elvira Bramon, Suzannah J Bumpstead, Juan P Casas, Aiden Corvin, Nicholas Craddock, Panos Deloukas, Serge Dronov, Audrey Duncanson, Sarah Edkins, Colin Freeman, Matthew Gillman, Emma Gray, Rhian Gwilliam, Naomi Hammond, Sarah E Hunt, Janusz Jankowski, Alagurevathi Jayakumar, Cordelia Langford, Jennifer Liddle, Hugh S Markus, Christopher G Mathew, Owen T McCann, Mark I McCarthy, Colin N A Palmer, Leena Peltonen, Robert Plomin, Simon C Potter, Anna Rautanen, Radhi Ravindrarajah, Michelle Ricketts, Nilesh Samani, Stephen J Sawcer, Amy Strange, Richard C Trembath, Ananth C Viswanathan, Matthew Waller, Paul Weston, Pamela Whittaker, Sara Widaa, Nicholas W Wood, Gilean McVean, John D Reveille, B Paul Wordsworth, Matthew A Brown, Peter Donnelly.
Nat. Genet.
PUBLISHED: 12-21-2011
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Ankylosing spondylitis is a common form of inflammatory arthritis predominantly affecting the spine and pelvis that occurs in approximately 5 out of 1,000 adults of European descent. Here we report the identification of three variants in the RUNX3, LTBR-TNFRSF1A and IL12B regions convincingly associated with ankylosing spondylitis (P < 5 × 10(-8) in the combined discovery and replication datasets) and a further four loci at PTGER4, TBKBP1, ANTXR2 and CARD9 that show strong association across all our datasets (P < 5 × 10(-6) overall, with support in each of the three datasets studied). We also show that polymorphisms of ERAP1, which encodes an endoplasmic reticulum aminopeptidase involved in peptide trimming before HLA class I presentation, only affect ankylosing spondylitis risk in HLA-B27-positive individuals. These findings provide strong evidence that HLA-B27 operates in ankylosing spondylitis through a mechanism involving aberrant processing of antigenic peptides.
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Estimating haplotype frequencies by combining data from large DNA pools with database information.
IEEE/ACM Trans Comput Biol Bioinform
PUBLISHED: 03-01-2011
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We assume that allele frequency data have been extracted from several large DNA pools, each containing genetic material of up to hundreds of sampled individuals. Our goal is to estimate the haplotype frequencies among the sampled individuals by combining the pooled allele frequency data with prior knowledge about the set of possible haplotypes. Such prior information can be obtained, for example, from a database such as HapMap. We present a Bayesian haplotyping method for pooled DNA based on a continuous approximation of the multinomial distribution. The proposed method is applicable when the sizes of the DNA pools and/or the number of considered loci exceed the limits of several earlier methods. In the example analyses, the proposed model clearly outperforms a deterministic greedy algorithm on real data from the HapMap database. With a small number of loci, the performance of the proposed method is similar to that of an EM-algorithm, which uses a multinormal approximation for the pooled allele frequencies, but which does not utilize prior information about the haplotypes. The method has been implemented using Matlab and the code is available upon request from the authors.
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Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.
, Stephen Sawcer, Garrett Hellenthal, Matti Pirinen, Chris C A Spencer, Nikolaos A Patsopoulos, Loukas Moutsianas, Alexander Dilthey, Zhan Su, Colin Freeman, Sarah E Hunt, Sarah Edkins, Emma Gray, David R Booth, Simon C Potter, An Goris, Gavin Band, Annette Bang Oturai, Amy Strange, Janna Saarela, Celine Bellenguez, Bertrand Fontaine, Matthew Gillman, Bernhard Hemmer, Rhian Gwilliam, Frauke Zipp, Alagurevathi Jayakumar, Roland Martin, Stephen Leslie, Stanley Hawkins, Eleni Giannoulatou, Sandra D'Alfonso, Hannah Blackburn, Filippo Martinelli Boneschi, Jennifer Liddle, Hanne F Harbo, Marc L Perez, Anne Spurkland, Matthew J Waller, Marcin P Mycko, Michelle Ricketts, Manuel Comabella, Naomi Hammond, Ingrid Kockum, Owen T McCann, Maria Ban, Pamela Whittaker, Anu Kemppinen, Paul Weston, Clive Hawkins, Sara Widaa, John Zajicek, Serge Dronov, Neil Robertson, Suzannah J Bumpstead, Lisa F Barcellos, Rathi Ravindrarajah, Roby Abraham, Lars Alfredsson, Kristin Ardlie, Cristin Aubin, Amie Baker, Katharine Baker, Sergio E Baranzini, Laura Bergamaschi, Roberto Bergamaschi, Allan Bernstein, Achim Berthele, Mike Boggild, Jonathan P Bradfield, David Brassat, Simon A Broadley, Dorothea Buck, Helmut Butzkueven, Ruggero Capra, William M Carroll, Paola Cavalla, Elisabeth G Celius, Sabine Cepok, Rosetta Chiavacci, Françoise Clerget-Darpoux, Katleen Clysters, Giancarlo Comi, Mark Cossburn, Isabelle Cournu-Rebeix, Mathew B Cox, Wendy Cozen, Bruce A C Cree, Anne H Cross, Daniele Cusi, Mark J Daly, Emma Davis, Paul I W de Bakker, Marc Debouverie, Marie Beatrice D'hooghe, Katherine Dixon, Rita Dobosi, Bénédicte Dubois, David Ellinghaus, Irina Elovaara, Federica Esposito, Claire Fontenille, Simon Foote, Andre Franke, Daniela Galimberti, Angelo Ghezzi, Joseph Glessner, Refujia Gomez, Olivier Gout, Colin Graham, Struan F A Grant, Franca Rosa Guerini, Hakon Hakonarson, Per Hall, Anders Hamsten, Hans-Peter Hartung, Rob N Heard, Simon Heath, Jeremy Hobart, Muna Hoshi, Carmen Infante-Duarte, Gillian Ingram, Wendy Ingram, Talat Islam, Maja Jagodic, Michael Kabesch, Allan G Kermode, Trevor J Kilpatrick, Cecilia Kim, Norman Klopp, Keijo Koivisto, Malin Larsson, Mark Lathrop, Jeannette S Lechner-Scott, Maurizio A Leone, Virpi Leppä, Ulrika Liljedahl, Izaura Lima Bomfim, Robin R Lincoln, Jenny Link, Jianjun Liu, Aslaug R Lorentzen, Sara Lupoli, Fabio Macciardi, Thomas Mack, Mark Marriott, Vittorio Martinelli, Deborah Mason, Jacob L McCauley, Frank Mentch, Inger-Lise Mero, Tania Mihalova, Xavier Montalban, John Mottershead, Kjell-Morten Myhr, Paola Naldi, William Ollier, Alison Page, Aarno Palotie, Jean Pelletier, Laura Piccio, Trevor Pickersgill, Fredrik Piehl, Susan Pobywajlo, Hong L Quach, Patricia P Ramsay, Mauri Reunanen, Richard Reynolds, John D Rioux, Mariaemma Rodegher, Sabine Roesner, Justin P Rubio, Ina-Maria Rückert, Marco Salvetti, Erika Salvi, Adam Santaniello, Catherine A Schaefer, Stefan Schreiber, Christian Schulze, Rodney J Scott, Finn Sellebjerg, Krzysztof W Selmaj, David Sexton, Ling Shen, Brigid Simms-Acuna, Sheila Skidmore, Patrick M A Sleiman, Cathrine Smestad, Per Soelberg Sørensen, Helle Bach Søndergaard, Jim Stankovich, Richard C Strange, Anna-Maija Sulonen, Emilie Sundqvist, Ann-Christine Syvänen, Francesca Taddeo, Bruce Taylor, Jenefer M Blackwell, Pentti Tienari, Elvira Bramon, Ayman Tourbah, Matthew A Brown, Ewa Tronczynska, Juan P Casas, Niall Tubridy, Aiden Corvin, Jane Vickery, Janusz Jankowski, Pablo Villoslada, Hugh S Markus, Kai Wang, Christopher G Mathew, James Wason, Colin N A Palmer, H-Erich Wichmann, Robert Plomin, Ernest Willoughby, Anna Rautanen, Juliane Winkelmann, Michael Wittig, Richard C Trembath, Jacqueline Yaouanq, Ananth C Viswanathan, Haitao Zhang, Nicholas W Wood, Rebecca Zuvich, Panos Deloukas, Cordelia Langford, Audrey Duncanson, Jorge R Oksenberg, Margaret A Pericak-Vance, Jonathan L Haines, Tomas Olsson, Jan Hillert, Adrian J Ivinson, Philip L De Jager, Leena Peltonen, Graeme J Stewart, David A Hafler, Stephen L Hauser, Gil McVean, Peter Donnelly, Alastair Compston.
Nature
PUBLISHED: 02-04-2011
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Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.
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Dissection of the genetics of Parkinsons disease identifies an additional association 5 of SNCA and multiple associated haplotypes at 17q21.
Hum. Mol. Genet.
PUBLISHED: 11-02-2010
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We performed a genome-wide association study (GWAS) in 1705 Parkinsons disease (PD) UK patients and 5175 UK controls, the largest sample size so far for a PD GWAS. Replication was attempted in an additional cohort of 1039 French PD cases and 1984 controls for the 27 regions showing the strongest evidence of association (P< 10(-4)). We replicated published associations in the 4q22/SNCA and 17q21/MAPT chromosome regions (P< 10(-10)) and found evidence for an additional independent association in 4q22/SNCA. A detailed analysis of the haplotype structure at 17q21 showed that there are three separate risk groups within this region. We found weak but consistent evidence of association for common variants located in three previously published associated regions (4p15/BST1, 4p16/GAK and 1q32/PARK16). We found no support for the previously reported SNP association in 12q12/LRRK2. We also found an association of the two SNPs in 4q22/SNCA with the age of onset of the disease.
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A genome-wide association study identifies new psoriasis susceptibility loci and an interaction between HLA-C and ERAP1.
Nat. Genet.
PUBLISHED: 03-30-2010
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To identify new susceptibility loci for psoriasis, we undertook a genome-wide association study of 594,224 SNPs in 2,622 individuals with psoriasis and 5,667 controls. We identified associations at eight previously unreported genomic loci. Seven loci harbored genes with recognized immune functions (IL28RA, REL, IFIH1, ERAP1, TRAF3IP2, NFKBIA and TYK2). These associations were replicated in 9,079 European samples (six loci with a combined P < 5 × 10?? and two loci with a combined P < 5 × 10??). We also report compelling evidence for an interaction between the HLA-C and ERAP1 loci (combined P = 6.95 × 10??). ERAP1 plays an important role in MHC class I peptide processing. ERAP1 variants only influenced psoriasis susceptibility in individuals carrying the HLA-C risk allele. Our findings implicate pathways that integrate epidermal barrier dysfunction with innate and adaptive immune dysregulation in psoriasis pathogenesis.
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Estimating population haplotype frequencies from pooled SNP data using incomplete database information.
Bioinformatics
PUBLISHED: 10-27-2009
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Information about haplotype structures gives a more detailed picture of genetic variation between individuals than single-locus analyses. Databases that contain the most frequent haplotypes of certain populations are developing rapidly (e.g. the HapMap database for single-nucleotide polymorphisms in humans). Utilization of such prior information about the prevailing haplotype structures makes it possible to estimate the haplotype frequencies also from large DNA pools. When genetic material from dozens of individuals is pooled together and analysed in a single genotyping, the overall number of genotypings and the costs of the genetic studies are reduced.
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Bayesian quantitative trait locus mapping based on reconstruction of recent genetic histories.
Genetics
PUBLISHED: 07-20-2009
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We assume that quantitative measurements on a considered trait and unphased genotype data at certain marker loci are available on a sample of individuals from a background population. Our goal is to map quantitative trait loci by using a Bayesian model that performs, and makes use of, probabilistic reconstructions of the recent unobserved genealogical history (a pedigree and a gene flow at the marker loci) of the sampled individuals. This work extends variance component-based linkage analysis to settings where the unobserved pedigrees are considered as latent variables. In addition to the measured trait values and unphased genotype data at the marker loci, the method requires as an input estimates of the population allele frequencies and of a marker map, as well as some parameters related to the population size and the mating behavior. Given such data, the posterior distribution of the trait parameters (the number, the locations, and the relative variance contributions of the trait loci) is studied by using the reversible-jump Markov chain Monte Carlo methodology. We also introduce two shortcuts related to the trait parameters that allow us to do analytic integration, instead of stochastic sampling, in some parts of the algorithm. The method is tested on two simulated data sets. Comparisons with traditional variance component linkage analysis and association analysis demonstrate the benefits of our approach in a gene mapping context.
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Bayesian refinement of association signals for 14 loci in 3 common diseases.
Nat. Genet.
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To further investigate susceptibility loci identified by genome-wide association studies, we genotyped 5,500 SNPs across 14 associated regions in 8,000 samples from a control group and 3 diseases: type 2 diabetes (T2D), coronary artery disease (CAD) and Graves disease. We defined, using Bayes theorem, credible sets of SNPs that were 95% likely, based on posterior probability, to contain the causal disease-associated SNPs. In 3 of the 14 regions, TCF7L2 (T2D), CTLA4 (Graves disease) and CDKN2A-CDKN2B (T2D), much of the posterior probability rested on a single SNP, and, in 4 other regions (CDKN2A-CDKN2B (CAD) and CDKAL1, FTO and HHEX (T2D)), the 95% sets were small, thereby excluding most SNPs as potentially causal. Very few SNPs in our credible sets had annotated functions, illustrating the limitations in understanding the mechanisms underlying susceptibility to common diseases. Our results also show the value of more detailed mapping to target sequences for functional studies.
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Common variants at the MHC locus and at chromosome 16q24.1 predispose to Barretts esophagus.
Zhan Su, Laura J Gay, Amy Strange, Claire Palles, Gavin Band, David C Whiteman, Francesco Lescai, Cordelia Langford, Manoj Nanji, Sarah Edkins, Anouk van der Winkel, David Levine, Peter Sasieni, Celine Bellenguez, Kimberley Howarth, Colin Freeman, Nigel Trudgill, Art T Tucker, Matti Pirinen, Maikel P Peppelenbosch, Luc J W van der Laan, Ernst J Kuipers, Joost P H Drenth, Wilbert H Peters, John V Reynolds, Dermot P Kelleher, Ross McManus, Heike Grabsch, Hans Prenen, Raf Bisschops, Kausila Krishnadath, Peter D Siersema, Jantine W P M van Baal, Mark Middleton, Russell Petty, Richard Gillies, Nicola Burch, Pradeep Bhandari, Stuart Paterson, Cathryn Edwards, Ian Penman, Kishor Vaidya, Yeng Ang, Iain Murray, Praful Patel, Weimin Ye, Paul Mullins, Anna H Wu, Nigel C Bird, Helen Dallal, Nicholas J Shaheen, Liam J Murray, Konrad Koss, Leslie Bernstein, Yvonne Romero, Laura J Hardie, Rui Zhang, Helen Winter, Douglas A Corley, Simon Panter, Harvey A Risch, Brian J Reid, Ian Sargeant, Marilie D Gammon, Howard Smart, Anjan Dhar, Hugh McMurtry, Haythem Ali, Geoffrey Liu, Alan G Casson, Wong-Ho Chow, Matt Rutter, Ashref Tawil, Danielle Morris, Chuka Nwokolo, Peter Isaacs, Colin Rodgers, Krish Ragunath, Chris MacDonald, Chris Haigh, David Monk, Gareth Davies, Saj Wajed, David Johnston, Michael Gibbons, Sue Cullen, Nicholas Church, Ruth Langley, Michael Griffin, Derek Alderson, Panos Deloukas, Sarah E Hunt, Emma Gray, Serge Dronov, Simon C Potter, Avazeh Tashakkori-Ghanbaria, Mark Anderson, Claire Brooks, Jenefer M Blackwell, Elvira Bramon, Matthew A Brown, Juan P Casas, Aiden Corvin, Audrey Duncanson, Hugh S Markus, Christopher G Mathew, Colin N A Palmer, Robert Plomin, Anna Rautanen, Stephen J Sawcer, Richard C Trembath, Ananth C Viswanathan, Nicholas Wood, Gosia Trynka, Cisca Wijmenga, Jean-Baptiste Cazier, Paul Atherfold, Anna M Nicholson, Nichola L Gellatly, Deborah Glancy, Sheldon C Cooper, David Cunningham, Tore Lind, Julie Hapeshi, David Ferry, Barrie Rathbone, Julia Brown, Sharon Love, Stephen Attwood, Stuart MacGregor, Peter Watson, Scott Sanders, Weronica Ek, Rebecca F Harrison, Paul Moayyedi, John de Caestecker, Hugh Barr, Elia Stupka, Thomas L Vaughan, Leena Peltonen, Chris C A Spencer, Ian Tomlinson, Peter Donnelly, Janusz A Z Jankowski, .
Nat. Genet.
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Barretts esophagus is an increasingly common disease that is strongly associated with reflux of stomach acid and usually a hiatus hernia, and it strongly predisposes to esophageal adenocarcinoma (EAC), a tumor with a very poor prognosis. We report the first genome-wide association study on Barretts esophagus, comprising 1,852 UK cases and 5,172 UK controls in the discovery stage and 5,986 cases and 12,825 controls in the replication stage. Variants at two loci were associated with disease risk: chromosome 6p21, rs9257809 (Pcombined=4.09×10(-9); odds ratio (OR)=1.21, 95% confidence interval (CI)=1.13-1.28), within the major histocompatibility complex locus, and chromosome 16q24, rs9936833 (Pcombined=2.74×10(-10); OR=1.14, 95% CI=1.10-1.19), for which the closest protein-coding gene is FOXF1, which is implicated in esophageal development and structure. We found evidence that many common variants of small effect contribute to genetic susceptibility to Barretts esophagus and that SNP alleles predisposing to obesity also increase risk for Barretts esophagus.
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Including known covariates can reduce power to detect genetic effects in case-control studies.
Nat. Genet.
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Genome-wide association studies (GWAS) search for associations between genetic variants and disease status, typically via logistic regression. Often there are covariates, such as sex or well-established major genetic factors, that are known to affect disease susceptibility and are independent of tested genotypes at the population level. We show theoretically and with data from recent GWAS on multiple sclerosis, psoriasis and ankylosing spondylitis that inclusion of known covariates can substantially reduce power for the identification of associated variants when the disease prevalence is lower than a few percent. Whether the inclusion of such covariates reduces or increases power to detect genetic effects depends on various factors, including the prevalence of the disease studied. When the disease is common (prevalence of >20%), the inclusion of covariates typically increases power, whereas, for rarer diseases, it can often decrease power to detect new genetic associations.
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Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke.
Nat. Genet.
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Genetic factors have been implicated in stroke risk, but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) for ischemic stroke and its subtypes in 3,548 affected individuals and 5,972 controls, all of European ancestry. Replication of potential signals was performed in 5,859 affected individuals and 6,281 controls. We replicated previous associations for cardioembolic stroke near PITX2 and ZFHX3 and for large vessel stroke at a 9p21 locus. We identified a new association for large vessel stroke within HDAC9 (encoding histone deacetylase 9) on chromosome 7p21.1 (including further replication in an additional 735 affected individuals and 28,583 controls) (rs11984041; combined P = 1.87 × 10(-11); odds ratio (OR) = 1.42, 95% confidence interval (CI) = 1.28-1.57). All four loci exhibited evidence for heterogeneity of effect across the stroke subtypes, with some and possibly all affecting risk for only one subtype. This suggests distinct genetic architectures for different stroke subtypes.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.