@article {5863, title = {Genetic risk factors for ischaemic stroke and its subtypes (the METASTROKE collaboration): a meta-analysis of genome-wide association studies.}, journal = {Lancet Neurol}, volume = {11}, year = {2012}, month = {2012 Nov}, pages = {951-62}, abstract = {

BACKGROUND: Various genome-wide association studies (GWAS) have been done in ischaemic stroke, identifying a few loci associated with the disease, but sample sizes have been 3500 cases or less. We established the METASTROKE collaboration with the aim of validating associations from previous GWAS and identifying novel genetic associations through meta-analysis of GWAS datasets for ischaemic stroke and its subtypes.

METHODS: We meta-analysed data from 15 ischaemic stroke cohorts with a total of 12 389 individuals with ischaemic stroke and 62 004 controls, all of European ancestry. For the associations reaching genome-wide significance in METASTROKE, we did a further analysis, conditioning on the lead single nucleotide polymorphism in every associated region. Replication of novel suggestive signals was done in 13 347 cases and 29 083 controls.

FINDINGS: We verified previous associations for cardioembolic stroke near PITX2 (p=2{\textperiodcentered}8{\texttimes}10(-16)) and ZFHX3 (p=2{\textperiodcentered}28{\texttimes}10(-8)), and for large-vessel stroke at a 9p21 locus (p=3{\textperiodcentered}32{\texttimes}10(-5)) and HDAC9 (p=2{\textperiodcentered}03{\texttimes}10(-12)). Additionally, we verified that all associations were subtype specific. Conditional analysis in the three regions for which the associations reached genome-wide significance (PITX2, ZFHX3, and HDAC9) indicated that all the signal in each region could be attributed to one risk haplotype. We also identified 12 potentially novel loci at p<5{\texttimes}10(-6). However, we were unable to replicate any of these novel associations in the replication cohort.

INTERPRETATION: Our results show that, although genetic variants can be detected in patients with ischaemic stroke when compared with controls, all associations we were able to confirm are specific to a stroke subtype. This finding has two implications. First, to maximise success of genetic studies in ischaemic stroke, detailed stroke subtyping is required. Second, different genetic pathophysiological mechanisms seem to be associated with different stroke subtypes.

FUNDING: Wellcome Trust, UK Medical Research Council (MRC), Australian National and Medical Health Research Council, National Institutes of Health (NIH) including National Heart, Lung and Blood Institute (NHLBI), the National Institute on Aging (NIA), the National Human Genome Research Institute (NHGRI), and the National Institute of Neurological Disorders and Stroke (NINDS).

}, keywords = {Brain Ischemia, Databases, Genetic, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Risk Factors, Stroke}, issn = {1474-4465}, doi = {10.1016/S1474-4422(12)70234-X}, author = {Traylor, Matthew and Farrall, Martin and Holliday, Elizabeth G and Sudlow, Cathie and Hopewell, Jemma C and Cheng, Yu-Ching and Fornage, Myriam and Ikram, M Arfan and Malik, Rainer and Bevan, Steve and Thorsteinsdottir, Unnur and Nalls, Mike A and Longstreth, Wt and Wiggins, Kerri L and Yadav, Sunaina and Parati, Eugenio A and DeStefano, Anita L and Worrall, Bradford B and Kittner, Steven J and Khan, Muhammad Saleem and Reiner, Alex P and Helgadottir, Anna and Achterberg, Sefanja and Fernandez-Cadenas, Israel and Abboud, Sherine and Schmidt, Reinhold and Walters, Matthew and Chen, Wei-Min and Ringelstein, E Bernd and O{\textquoteright}Donnell, Martin and Ho, Weang Kee and Pera, Joanna and Lemmens, Robin and Norrving, Bo and Higgins, Peter and Benn, Marianne and Sale, Michele and Kuhlenb{\"a}umer, Gregor and Doney, Alexander S F and Vicente, Astrid M and Delavaran, Hossein and Algra, Ale and Davies, Gail and Oliveira, Sofia A and Palmer, Colin N A and Deary, Ian and Schmidt, Helena and Pandolfo, Massimo and Montaner, Joan and Carty, Cara and de Bakker, Paul I W and Kostulas, Konstantinos and Ferro, Jose M and van Zuydam, Natalie R and Valdimarsson, Einar and Nordestgaard, B{\o}rge G and Lindgren, Arne and Thijs, Vincent and Slowik, Agnieszka and Saleheen, Danish and Par{\'e}, Guillaume and Berger, Klaus and Thorleifsson, Gudmar and Hofman, Albert and Mosley, Thomas H and Mitchell, Braxton D and Furie, Karen and Clarke, Robert and Levi, Christopher and Seshadri, Sudha and Gschwendtner, Andreas and Boncoraglio, Giorgio B and Sharma, Pankaj and Bis, Joshua C and Gretarsdottir, Solveig and Psaty, Bruce M and Rothwell, Peter M and Rosand, Jonathan and Meschia, James F and Stefansson, Kari and Dichgans, Martin and Markus, Hugh S} } @article {6108, title = {Ischemic stroke is associated with the ABO locus: the EuroCLOT study.}, journal = {Ann Neurol}, volume = {73}, year = {2013}, month = {2013 Jan}, pages = {16-31}, abstract = {

OBJECTIVE: End-stage coagulation and the structure/function of fibrin are implicated in the pathogenesis of ischemic stroke. We explored whether genetic variants associated with end-stage coagulation in healthy volunteers account for the genetic predisposition to ischemic stroke and examined their influence on stroke subtype.

METHODS: Common genetic variants identified through genome-wide association studies of coagulation factors and fibrin structure/function in healthy twins (n = 2,100, Stage 1) were examined in ischemic stroke (n = 4,200 cases) using 2 independent samples of European ancestry (Stage 2). A third clinical collection having stroke subtyping (total 8,900 cases, 55,000 controls) was used for replication (Stage 3).

RESULTS: Stage 1 identified 524 single nucleotide polymorphisms (SNPs) from 23 linkage disequilibrium blocks having significant association (p < 5 {\texttimes} 10(-8)) with 1 or more coagulation/fibrin phenotypes. The most striking associations included SNP rs5985 with factor XIII activity (p = 2.6 {\texttimes} 10(-186)), rs10665 with FVII (p = 2.4 {\texttimes} 10(-47)), and rs505922 in the ABO gene with both von Willebrand factor (p = 4.7 {\texttimes} 10(-57)) and factor VIII (p = 1.2 {\texttimes} 10(-36)). In Stage 2, the 23 independent SNPs were examined in stroke cases/noncases using MOnica Risk, Genetics, Archiving and Monograph (MORGAM) and Wellcome Trust Case Control Consortium 2 collections. SNP rs505922 was nominally associated with ischemic stroke (odds ratio = 0.94, 95\% confidence interval = 0.88-0.99, p = 0.023). Independent replication in Meta-Stroke confirmed the rs505922 association with stroke, beta (standard error, SE) = 0.066 (0.02), p = 0.001, a finding specific to large-vessel and cardioembolic stroke (p = 0.001 and p = < 0.001, respectively) but not seen with small-vessel stroke (p = 0.811).

INTERPRETATION: ABO gene variants are associated with large-vessel and cardioembolic stroke but not small-vessel disease. This work sheds light on the different pathogenic mechanisms underpinning stroke subtype.

}, keywords = {ABO Blood-Group System, Adolescent, Adult, Aged, Aged, 80 and over, Blood Coagulation, Brain Ischemia, Cohort Studies, Europe, Female, Genetic Loci, Genetic Predisposition to Disease, Genetic Variation, Genome-Wide Association Study, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Stroke, Young Adult}, issn = {1531-8249}, doi = {10.1002/ana.23838}, author = {Williams, Frances M K and Carter, Angela M and Hysi, Pirro G and Surdulescu, Gabriela and Hodgkiss, Dylan and Soranzo, Nicole and Traylor, Matthew and Bevan, Steve and Dichgans, Martin and Rothwell, Peter M W and Sudlow, Cathie and Farrall, Martin and Silander, Kaisa and Kaunisto, Mari and Wagner, Peter and Saarela, Olli and Kuulasmaa, Kari and Virtamo, Jarmo and Salomaa, Veikko and Amouyel, Philippe and Arveiler, Dominique and Ferrieres, Jean and Wiklund, Per-Gunnar and Ikram, M Arfan and Hofman, Albert and Boncoraglio, Giorgio B and Parati, Eugenio A and Helgadottir, Anna and Gretarsdottir, Solveig and Thorsteinsdottir, Unnur and Thorleifsson, Gudmar and Stefansson, Kari and Seshadri, Sudha and DeStefano, Anita and Gschwendtner, Andreas and Psaty, Bruce and Longstreth, Will and Mitchell, Braxton D and Cheng, Yu-Ching and Clarke, Robert and Ferrario, Marco and Bis, Joshua C and Levi, Christopher and Attia, John and Holliday, Elizabeth G and Scott, Rodney J and Fornage, Myriam and Sharma, Pankaj and Furie, Karen L and Rosand, Jonathan and Nalls, Mike and Meschia, James and Mosely, Thomas H and Evans, Alun and Palotie, Aarno and Markus, Hugh S and Grant, Peter J and Spector, Tim D} }