@article {6297, title = {Multilocus genetic risk score associates with ischemic stroke in case-control and prospective cohort studies.}, journal = {Stroke}, volume = {45}, year = {2014}, month = {2014 Feb}, pages = {394-402}, abstract = {

BACKGROUND AND PURPOSE: Genome-wide association studies have revealed multiple common variants associated with known risk factors for ischemic stroke (IS). However, their aggregate effect on risk is uncertain. We aimed to generate a multilocus genetic risk score (GRS) for IS based on genome-wide association studies data from clinical-based samples and to establish its external validity in prospective population-based cohorts.

METHODS: Three thousand five hundred forty-eight clinic-based IS cases and 6399 controls from the Wellcome Trust Case Control Consortium 2 were used for derivation of the GRS. Subjects from the METASTROKE consortium served as a replication sample. The validation sample consisted of 22 751 participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium. We selected variants that had reached genome-wide significance in previous association studies on established risk factors for IS.

RESULTS: A combined GRS for atrial fibrillation, coronary artery disease, hypertension, and systolic blood pressure significantly associated with IS both in the case-control samples and in the prospective population-based studies. Subjects in the top quintile of the combined GRS had >2-fold increased risk of IS compared with subjects in the lowest quintile. Addition of the combined GRS to a simple model based on sex significantly improved the prediction of IS in the combined clinic-based samples but not in the population-based studies, and there was no significant improvement in net reclassification.

CONCLUSIONS: A multilocus GRS based on common variants for established cardiovascular risk factors was significantly associated with IS both in clinic-based samples and in the general population. However, the improvement in clinical risk prediction was found to be small.

}, keywords = {Adult, Aged, Aged, 80 and over, Atrial Fibrillation, Blood Pressure, Brain Ischemia, Case-Control Studies, Cohort Studies, Coronary Artery Disease, Female, Genetic Predisposition to Disease, Genetic Variation, Genome-Wide Association Study, Humans, Hypertension, Male, Middle Aged, Multilocus Sequence Typing, Polymorphism, Single Nucleotide, Population, Prospective Studies, Reproducibility of Results, Risk Assessment, Risk Factors, Sex Factors, Stroke}, issn = {1524-4628}, doi = {10.1161/STROKEAHA.113.002938}, author = {Malik, Rainer and Bevan, Steve and Nalls, Michael A and Holliday, Elizabeth G and Devan, William J and Cheng, Yu-Ching and Ibrahim-Verbaas, Carla A and Verhaaren, Benjamin F J and Bis, Joshua C and Joon, Aron Y and de Stefano, Anita L and Fornage, Myriam and Psaty, Bruce M and Ikram, M Arfan and Launer, Lenore J and van Duijn, Cornelia M and Sharma, Pankaj and Mitchell, Braxton D and Rosand, Jonathan and Meschia, James F and Levi, Christopher and Rothwell, Peter M and Sudlow, Cathie and Markus, Hugh S and Seshadri, Sudha and Dichgans, Martin} } @article {6849, title = {Rare and Coding Region Genetic Variants Associated With Risk of Ischemic Stroke: The NHLBI Exome Sequence Project.}, journal = {JAMA Neurol}, volume = {72}, year = {2015}, month = {2015 Jul}, pages = {781-8}, abstract = {

IMPORTANCE: Stroke is the second leading cause of death and the third leading cause of years of life lost. Genetic factors contribute to stroke prevalence, and candidate gene and genome-wide association studies (GWAS) have identified variants associated with ischemic stroke risk. These variants often have small effects without obvious biological significance. Exome sequencing may discover predicted protein-altering variants with a potentially large effect on ischemic stroke risk.

OBJECTIVE: To investigate the contribution of rare and common genetic variants to ischemic stroke risk by targeting the protein-coding regions of the human genome.

DESIGN, SETTING, AND PARTICIPANTS: The National Heart, Lung, and Blood Institute (NHLBI) Exome Sequencing Project (ESP) analyzed approximately 6000 participants from numerous cohorts of European and African ancestry. For discovery, 365 cases of ischemic stroke (small-vessel and large-vessel subtypes) and 809 European ancestry controls were sequenced; for replication, 47 affected sibpairs concordant for stroke subtype and an African American case-control series were sequenced, with 1672 cases and 4509 European ancestry controls genotyped. The ESP{\textquoteright}s exome sequencing and genotyping started on January 1, 2010, and continued through June 30, 2012. Analyses were conducted on the full data set between July 12, 2012, and July 13, 2013.

MAIN OUTCOMES AND MEASURES: Discovery of new variants or genes contributing to ischemic stroke risk and subtype (primary analysis) and determination of support for protein-coding variants contributing to risk in previously published candidate genes (secondary analysis).

RESULTS: We identified 2 novel genes associated with an increased risk of ischemic stroke: a protein-coding variant in PDE4DIP (rs1778155; odds ratio, 2.15; P = 2.63 {\texttimes} 10(-8)) with an intracellular signal transduction mechanism and in ACOT4 (rs35724886; odds ratio, 2.04; P = 1.24 {\texttimes} 10(-7)) with a fatty acid metabolism; confirmation of PDE4DIP was observed in affected sibpair families with large-vessel stroke subtype and in African Americans. Replication of protein-coding variants in candidate genes was observed for 2 previously reported GWAS associations: ZFHX3 (cardioembolic stroke) and ABCA1 (large-vessel stroke).

CONCLUSIONS AND RELEVANCE: Exome sequencing discovered 2 novel genes and mechanisms, PDE4DIP and ACOT4, associated with increased risk for ischemic stroke. In addition, ZFHX3 and ABCA1 were discovered to have protein-coding variants associated with ischemic stroke. These results suggest that genetic variation in novel pathways contributes to ischemic stroke risk and serves as a target for prediction, prevention, and therapy.

}, keywords = {Aged, Brain Ischemia, Exome, Female, Genetic Predisposition to Disease, Genetic Variation, Genome-Wide Association Study, Humans, Male, Middle Aged, Muscle Proteins, National Heart, Lung, and Blood Institute (U.S.), Nuclear Proteins, Open Reading Frames, Palmitoyl-CoA Hydrolase, Stroke, United States}, issn = {2168-6157}, doi = {10.1001/jamaneurol.2015.0582}, author = {Auer, Paul L and Nalls, Mike and Meschia, James F and Worrall, Bradford B and Longstreth, W T and Seshadri, Sudha and Kooperberg, Charles and Burger, Kathleen M and Carlson, Christopher S and Carty, Cara L and Chen, Wei-Min and Cupples, L Adrienne and DeStefano, Anita L and Fornage, Myriam and Hardy, John and Hsu, Li and Jackson, Rebecca D and Jarvik, Gail P and Kim, Daniel S and Lakshminarayan, Kamakshi and Lange, Leslie A and Manichaikul, Ani and Quinlan, Aaron R and Singleton, Andrew B and Thornton, Timothy A and Nickerson, Deborah A and Peters, Ulrike and Rich, Stephen S} } @article {6991, title = {Genome-Wide Association Analysis of Young-Onset Stroke Identifies a Locus on Chromosome 10q25 Near HABP2.}, journal = {Stroke}, volume = {47}, year = {2016}, month = {2016 Feb}, pages = {307-16}, abstract = {

BACKGROUND AND PURPOSE: Although a genetic contribution to ischemic stroke is well recognized, only a handful of stroke loci have been identified by large-scale genetic association studies to date. Hypothesizing that genetic effects might be stronger for early- versus late-onset stroke, we conducted a 2-stage meta-analysis of genome-wide association studies, focusing on stroke cases with an age of onset <60 years.

METHODS: The discovery stage of our genome-wide association studies included 4505 cases and 21 968 controls of European, South-Asian, and African ancestry, drawn from 6 studies. In Stage 2, we selected the lead genetic variants at loci with association P<5{\texttimes}10(-6) and performed in silico association analyses in an independent sample of <=1003 cases and 7745 controls.

RESULTS: One stroke susceptibility locus at 10q25 reached genome-wide significance in the combined analysis of all samples from the discovery and follow-up stages (rs11196288; odds ratio =1.41; P=9.5{\texttimes}10(-9)). The associated locus is in an intergenic region between TCF7L2 and HABP2. In a further analysis in an independent sample, we found that 2 single nucleotide polymorphisms in high linkage disequilibrium with rs11196288 were significantly associated with total plasma factor VII-activating protease levels, a product of HABP2.

CONCLUSIONS: HABP2, which encodes an extracellular serine protease involved in coagulation, fibrinolysis, and inflammatory pathways, may be a genetic susceptibility locus for early-onset stroke.

}, keywords = {Adult, African Continental Ancestry Group, Age of Onset, Aged, Asian Continental Ancestry Group, Brain Ischemia, Chromosomes, Human, Pair 10, Computer Simulation, DNA, Intergenic, European Continental Ancestry Group, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Male, Middle Aged, Odds Ratio, Polymorphism, Single Nucleotide, Serine Endopeptidases, Stroke}, issn = {1524-4628}, doi = {10.1161/STROKEAHA.115.011328}, author = {Cheng, Yu-Ching and Stanne, Tara M and Giese, Anne-Katrin and Ho, Weang Kee and Traylor, Matthew and Amouyel, Philippe and Holliday, Elizabeth G and Malik, Rainer and Xu, Huichun and Kittner, Steven J and Cole, John W and O{\textquoteright}Connell, Jeffrey R and Danesh, John and Rasheed, Asif and Zhao, Wei and Engelter, Stefan and Grond-Ginsbach, Caspar and Kamatani, Yoichiro and Lathrop, Mark and Leys, Didier and Thijs, Vincent and Metso, Tiina M and Tatlisumak, Turgut and Pezzini, Alessandro and Parati, Eugenio A and Norrving, Bo and Bevan, Steve and Rothwell, Peter M and Sudlow, Cathie and Slowik, Agnieszka and Lindgren, Arne and Walters, Matthew R and Jannes, Jim and Shen, Jess and Crosslin, David and Doheny, Kimberly and Laurie, Cathy C and Kanse, Sandip M and Bis, Joshua C and Fornage, Myriam and Mosley, Thomas H and Hopewell, Jemma C and Strauch, Konstantin and M{\"u}ller-Nurasyid, Martina and Gieger, Christian and Waldenberger, Melanie and Peters, Annette and Meisinger, Christine and Ikram, M Arfan and Longstreth, W T and Meschia, James F and Seshadri, Sudha and Sharma, Pankaj and Worrall, Bradford and Jern, Christina and Levi, Christopher and Dichgans, Martin and Boncoraglio, Giorgio B and Markus, Hugh S and Debette, Stephanie and Rolfs, Arndt and Saleheen, Danish and Mitchell, Braxton D} }