Genetic overlap between diagnostic subtypes of ischemic stroke

Background and Purpose: Despite moderate heritability, the phenotypic heterogeneity of ischemic stroke has hampered gene discovery, motivating analyses of diagnostic subtypes with reduced sample sizes. We assessed evidence for a shared genetic basis among the 3 major subtypes: large artery atherosclerosis (LAA), cardioembolism, and small vessel disease (SVD), to inform potential cross-subtype analyses. Methods: Analyses used genome-wide summary data for 12 389 ischemic stroke cases (including 2167 LAA, 2405 cardioembolism, and 1854 SVD) and 62 004 controls from the Metastroke consortium. For 4561 cases and 7094 controls, individual-level genotype data were also available. Genetic correlations between subtypes were estimated using linear mixed models and polygenic profile scores. Meta-analysis of a combined LAA-SVD phenotype (4021 cases and 51 976 controls) was performed to identify shared risk alleles. Results: High genetic correlation was identified between LAA and SVD using linear mixed models (rg=0.96, SE=0.47, P=9×10-4) and profile scores (rg=0.72; 95% confid

Serum magnesium and calcium levels in relation to ischemic stroke : Mendelian randomization study

ObjectiveTo determine whether serum magnesium and calcium concentrations are causally associated with ischemic stroke or any of its subtypes using the mendelian randomization approach.MethodsAnalyses were conducted using summary statistics data for 13 single-nucleotide polymorphisms robustly associated with serum magnesium (n = 6) or serum calcium (n = 7) concentrations. The corresponding data for ischemic stroke were obtained from the MEGASTROKE consortium (34,217 cases and 404,630 noncases).ResultsIn standard mendelian randomization analysis, the odds ratios for each 0.1 mmol/L (about 1 SD) increase in genetically predicted serum magnesium concentrations were 0.78 (95% confidence interval [CI] 0.69-0.89; p = 1.3 7 10-4) for all ischemic stroke, 0.63 (95% CI 0.50-0.80; p = 1.6 7 10-4) for cardioembolic stroke, and 0.60 (95% CI 0.44-0.82; p = 0.001) for large artery stroke; there was no association with small vessel stroke (odds ratio 0.90, 95% CI 0.67-1.20; p = 0.46). Only the association with cardioembolic stroke was robust in sensitivity analyses. There was no association of genetically predicted serum calcium concentrations with all ischemic stroke (per 0.5 mg/dL [about 1 SD] increase in serum calcium: odds ratio 1.03, 95% CI 0.88-1.21) or with any subtype.ConclusionsThis study found that genetically higher serum magnesium concentrations are associated with a reduced risk of cardioembolic stroke but found no significant association of genetically higher serum calcium concentrations with any ischemic stroke subtype

COL4A2 is associated with lacunar ischemic stroke and deep ICH: meta-analyses among 21,500 cases and 40,600 controls

Collaborators (233): McArdle PF, Wong Q, Gwinn K, Achterberg S, Algra A, Amouyel P, Arnett DK, Arsava EM, Attia J, Ay H, Bartz TM, Battey T, Benavente OR, Bevan S, Biffi A, Bis JC, Blanton SH, P J, Boncoraglio GB, Brown RD Jr, Burgess AI, Carrera C, Chapman Smith SN, Chasman DI, Chauhan G, Wei-Min Chen F, Cheng YC, Cloonan LK, Cole JW, Cotlarciuc I, Cruchaga C, Cuadrado-Godia E, Dawson J, Debette S, Delavaran H, Dell CA, Doheny KF, Dong C, Duggan DJ, Engström G, Evans MK, Pallejà XE, Faul JD, Fornage M, Frossard PM, Furie K, Gamble DM, Gieger C, Giese AK, Giralt-Steinhauer E, González HM, Goris A, Gretarsdottir S, Grewal RP, Grittner U, Gustafsson S, Han B, Hankey GJ, Heitsch L, Higgins P, Hochberg MC, Holliday E, Hopewell JC, Horenstein RB, Howard G, Ikram MA, Ilinca A, Ingelsson E, Irvin MR, Jackson RD, Jern C, Johnson JA, Jood K, Kahn MS, Kaplan R, Kappelle LJ, Kardia SL, Keene KL, Kissela BM, Kleindorfer DO, Koblar S, Labovitz D, Launer LJ, Laurie CC, Laurie CA, Lee CH, Lee JM, Lemmens R, Levi C, Leys D, Longstreth WT Jr, Maguire J, Manichaikul A, McClure LA, McDonough CW, Meisinger C, Melander O, Meschia JF, Mola-Caminal M, Mosley TH, Müller-Nurasyid M, Nalls MA, O'Connell JR, Ois Á, Papanicolaou GJ, Peddareddygari LR, Pedersén A, Pera J, Peters A, Poole D, Psaty BM, Rabionet R, Raffeld MR, Rasheed A, Redfors P, Reiner AP, Rexrode K, Ribasés M, Rich SS, Robberecht W, Rodríguez-Campello A, Rolfs A, Roquer J, Rose LM, Rosenbaum D, Rost NS, Rothwell PM, Rundek T, Ryan KA, Sacco RL, Sale MM, Saleheen D, Salomaa V, Sánchez-Mora C, Schmidt CO, Schmidt H, Schmidt R, Schürks M, Scott R, Segal HC, Seiler S, Sharma P, Shuldiner AR, Silver B, Smith JA, Bsc CS, Sparks MJ, Stanne T, Stefansson K, Stine OC, Strauch K, Sturm J, Tajuddin SM, Talbert RL, Tatlisumak T, Thijs V, Thorleifsson G, Thorsteindottir U, Trompet S, Valant V, Waldenberger M, Walters M, Wang L, P J, Wang XQ, Wassertheil-Smoller S, Weir DR, Wiggins KL, Williams SR, Wloch-Kopec D, Woodfield R, Wu O, Xu H, Zonderman AB, de Bakker PIW, Kittner SJ, Bevan S, Hopewell JC, Holliday EG, Zhao W, Abrantes P, Amouyel P, Attia JR, Battey TW, Berger K, Boncoraglio GB, Chauhan G, Cheng YC, Chen WM, Clarke R, Cotlarciuc I, Debette S, Ferro JM, Gamble DM, Ilinca A, Kittner SJ, Lemmens R, Levi CR, Lichtner P, Liu J, Meschia JF, Oliveira SA, Pera J, Reiner AP, Rothwell PM, Sharma P, Tatlisumak T, Thijs V, Vicente AM, Saleheen D, Thorsteinsdottir U, DeStefano AL, Gretarsdottir S, Donnelly P, Barroso I, Blackwell JM, Bramon E, Brown MA, Casas JP, Corvin A, Deloukas P, Duncanson A, Jankowski J, Markus HS, Mathew CG, Palmer CN, Plomin R, Rautanen A, Sawcer SJ, Trembath RC, Viswanathan AC, Wood NW, Spencer CC.Vicente AM - Departamento de Promoção da Saúde e Prevenção de Doenças Não Transmissíveis.Objective: To determine whether common variants in familial cerebral small vessel disease (SVD) genes confer risk of sporadic cerebral SVD. Methods: We meta-analyzed genotype data from individuals of European ancestry to determine associations of common single nucleotide polymorphisms (SNPs) in 6 familial cerebral SVD genes (COL4A1, COL4A2, NOTCH3, HTRA1, TREX1, and CECR1) with intracerebral hemorrhage (ICH) (deep, lobar, all; 1,878 cases, 2,830 controls) and ischemic stroke (IS) (lacunar, cardioembolic, large vessel disease, all; 19,569 cases, 37,853 controls). We applied data quality filters and set statistical significance thresholds accounting for linkage disequilibrium and multiple testing. Results: A locus in COL4A2 was associated (significance threshold p < 3.5 × 10−4) with both lacunar IS (lead SNP rs9515201: odds ratio [OR] 1.17, 95% confidence interval [CI] 1.11–1.24, p = 6.62 × 10−8) and deep ICH (lead SNP rs4771674: OR 1.28, 95% CI 1.13–1.44, p = 5.76 × 10−5). A SNP in HTRA1 was associated (significance threshold p < 5.5 × 10−4) with lacunar IS (rs79043147: OR 1.23, 95% CI 1.10–1.37, p = 1.90 × 10−4) and less robustly with deep ICH. There was no clear evidence for association of common variants in either COL4A2 or HTRA1 with non-SVD strokes or in any of the other genes with any stroke phenotype. Conclusions: These results provide evidence of shared genetic determinants and suggest common pathophysiologic mechanisms of distinct ischemic and hemorrhagic cerebral SVD stroke phenotypes, offering new insights into the causal mechanisms of cerebral SVD.This work was funded in part by NIH grants U01 NS069208 and P30 DK072488 (SiGN). M.D. and R.M. were supported by grants from the Deutsche Forschungsgemeinschaft (CRC 1123 [B3] and Munich Cluster for Systems Neurology [SyNergy]), the German Federal Ministry of Education and Research (BMBF, e:Med programme e:AtheroSysMed), the FP7/2007–2103 European Union project CVgenes@target (grant agreement Health-F2-2013-601456), the European Union Horizon 2020 projects SVDs@target (grant agreement 66688) and CoSTREAM (grant agreement 667375), the Fondation Leducq (Transatlantic Network of Excellence on the Pathogenesis of Small Vessel Disease of the Brain), the Vascular Dementia Research Foundation, and the Jackstaedt Foundation. G.P. and M.C. were supported by the Canadian Stroke Network, Canadian Institutes of Health Research, and Heart & Stroke Foundation. N.S.R. acknowledges the National Institute of Neurologic Disorders and Stroke K23NS064052, R01NS086905, and R01NS082285.info:eu-repo/semantics/publishedVersio

Against digital ontology

The paper argues that digital ontology (the ultimate nature of reality is digital, and the universe is a computational system equivalent to a Turing Machine) should be carefully distinguished from informational ontology (the ultimate nature of reality is structural), in order to abandon the former and retain only the latter as a promising line of research. Digital vs. analogue is a Boolean dichotomy typical of our computational paradigm, but digital and analogue are only "modes of presentation" of Being (to paraphrase Kant), that is, ways in which reality is experienced or conceptualised by an epistemic agent at a given level of abstraction. A preferable alternative is provided by an informational approach to structural realism, according to which knowledge of the world is knowledge of its structures. The most reasonable ontological commitment turns out to be in favour of an interpretation of reality as the totality of structures dynamically interacting with each other. The paper is the first part (the pars destruens) of a two-part piece of research. The pars construens, entitled "A Defence of Informational Structural Realism", is developed in a separate article, also published in this journal

Genome-wide association meta-analysis of functional outcome after ischemic stroke

Altres ajuts: The Stroke Genetics Network (SiGN) study was funded by a cooperative agreement grant from the US National Institute of Neurological Disorders and Stroke (NINDS), NIH (U01 NS069208 and R01 NS100178). SAHLSIS was supported by the Swedish Heart and Lung Foundation (HLF-20160316), the Swedish Research Council (K2014-64X-14605-12-5), the Swedish Stroke Association, the Swedish state (under the "Avtal om Läkarutbildning och Medicinsk Forskning, ALF") (ALFGBG-720081). Australian Stroke Genetics Collaboration study was supported by the National Health and Medical Research Council, Australia. Stroke Pharmacogenomics and Genetics group was supported by Invictus plus network, Generation project, and Miguel Servet programme from Instituto de Salud Carlos III, GODs project and Epigenesis project from Marató de TV3 Foundation and Agaur from Generalitat de Catalunya Government. Arne Lindgren was supported by the Swedish Heart and Lung Foundation, Region Skåne, Skåne University Hospital, the Freemasons Lodge of Instruction EOS in Lund, Lund University, the Foundation of Färs & Frosta-one of Spar-banken Skåne's ownership Foundations, and the Swedish Stroke Association. Martin Söderholm was supported by grants from the Swedish Stroke Association, the Foundation of Färs & Frosta-one of Sparbanken Skåne's ownership Foundations, and the Swedish government (under the "Avtal om Läkarutbildning och Medicinsk Forskning, ALF"). Annie Pedersen was supported by grants from the Swedish government (under the "Avtal om Läkarutbildning och Medi-cinsk Forskning, ALF") and the Gothenburg Foundation for Neurological Research. Natalia Rost was in part supported by NIH-NINDS (R01NS086905 and R01NS082285). Daniel Strbian was supported by the Finnish Subsidiary Governmental Fund (VTR). The authors thank NINDS for funding the genotyping of patients included in the SiGN study (U01 NS069208 and R01 NS100178) and Sólveig Grétarsdóttir for genotyping a subsample of the SAHLSIS cohort.ObjectiveTo discover common genetic variants associated with poststroke outcomes using a genome-wide association (GWA) study.MethodsThe study comprised 6,165 patients with ischemic stroke from 12 studies in Europe, the United States, and Australia included in the GISCOME (Genetics of Ischaemic Stroke Functional Outcome) network. The primary outcome was modified Rankin Scale score after 60 to 190 days, evaluated as 2 dichotomous variables (0-2 vs 3-6 and 0-1 vs 2-6) and subsequently as an ordinal variable. GWA analyses were performed in each study independently and results were meta-analyzed. Analyses were adjusted for age, sex, stroke severity (baseline NIH Stroke Scale score), and ancestry. The significance level was p < 5 × 10.ResultsWe identified one genetic variant associated with functional outcome with genome-wide significance (modified Rankin Scale scores 0-2 vs 3-6, p = 5.3 × 10). This intronic variant (rs1842681) in the LOC105372028 gene is a previously reported trans-Expression quantitative trait locus for PPP1R21, which encodes a regulatory subunit of protein phosphatase 1. This ubiquitous phosphatase is implicated in brain functions such as brain plasticity. Several variants detected in this study demonstrated suggestive association with outcome (p < 10), some of which are within or near genes with experimental evidence of influence on ischemic stroke volume and/or brain recovery (e.g., NTN4, TEK, and PTCH1).ConclusionsIn this large GWA study on functional outcome after ischemic stroke, we report one significant variant and several variants with suggestive association to outcome 3 months after stroke onset with plausible mechanistic links to poststroke recovery. Future replication studies and exploration of potential functional mechanisms for identified genetic variants are warranted

Genetic variants in CETP increase risk of intracerebral hemorrhage

OBJECTIVE: In observational epidemiologic studies, higher plasma high-density lipoprotein cholesterol (HDL-C) has been associated with increased risk of intracerebral hemorrhage (ICH). DNA sequence variants that decrease cholesteryl ester transfer protein (CETP) gene activity increase plasma HDL-C; as such, medicines that inhibit CETP and raise HDL-C are in clinical development. Here, we test the hypothesis that CETP DNA sequence variants associated with higher HDL-C also increase risk for ICH. METHODS: We performed 2 candidate-gene analyses of CETP. First, we tested individual CETP variants in a discovery cohort of 1,149 ICH cases and 1,238 controls from 3 studies, followed by replication in 1,625 cases and 1,845 controls from 5 studies. Second, we constructed a genetic risk score comprised of 7 independent variants at the CETP locus and tested this score for association with HDL-C as well as ICH risk. RESULTS: Twelve variants within CETP demonstrated nominal association with ICH, with the strongest association at the rs173539 locus (odds ratio [OR] = 1.25, standard error [SE] = 0.06, p = 6.0 x 10-4 ) with no heterogeneity across studies (I2 = 0%). This association was replicated in patients of European ancestry (p = 0.03). A genetic score of CETP variants found to increase HDL-C by approximately 2.85mg/dl in the Global Lipids Genetics Consortium was strongly associated with ICH risk (OR = 1.86, SE = 0.13, p = 1.39 x 10-6 ). INTERPRETATION: Genetic variants in CETP associated with increased HDL-C raise the risk of ICH. Given ongoing therapeutic development in CETP inhibition and other HDL-raising strategies, further exploration of potential adverse cerebrovascular outcomes may be warranted. Ann Neurol 2016;80:730-740