@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 {6861, title = {White Matter Lesion Progression: Genome-Wide Search for Genetic Influences.}, journal = {Stroke}, volume = {46}, year = {2015}, month = {2015 Nov}, pages = {3048-57}, abstract = {

BACKGROUND AND PURPOSE: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants associated with WML progression in elderly participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium.

METHODS: Heritability of WML progression was calculated in the Framingham Heart Study. The genome-wide association study included 7773 elderly participants from 10 cohorts. To assess the relative contribution of genetic factors to progression of WML, we compared in 7 cohorts risk models including demographics, vascular risk factors plus single-nucleotide polymorphisms that have been shown to be associated cross-sectionally with WML in the current and previous association studies.

RESULTS: A total of 1085 subjects showed WML progression. The heritability estimate for WML progression was low at 6.5\%, and no single-nucleotide polymorphisms achieved genome-wide significance (P<5{\texttimes}10(-8)). Four loci were suggestive (P<1{\texttimes}10(-5)) of an association with WML progression: 10q24.32 (rs10883817, P=1.46{\texttimes}10(-6)); 12q13.13 (rs4761974, P=8.71{\texttimes}10(-7)); 20p12.1 (rs6135309, P=3.69{\texttimes}10(-6)); and 4p15.31 (rs7664442, P=2.26{\texttimes}10(-6)). Variants that have been previously related to WML explained only 0.8\% to 11.7\% more of the variance in WML progression than age, vascular risk factors, and baseline WML burden.

CONCLUSIONS: Common genetic factors contribute little to the progression of age-related WML in middle-aged and older adults. Future research on determinants of WML progression should focus more on environmental, lifestyle, or host-related biological factors.

}, keywords = {Adult, Aged, Cohort Studies, Disease Progression, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Leukoencephalopathies, Male, Middle Aged, Prospective Studies, White Matter}, issn = {1524-4628}, doi = {10.1161/STROKEAHA.115.009252}, author = {Hofer, Edith and Cavalieri, Margherita and Bis, Joshua C and DeCarli, Charles and Fornage, Myriam and Sigurdsson, Sigurdur and Srikanth, Velandai and Trompet, Stella and Verhaaren, Benjamin F J and Wolf, Christiane and Yang, Qiong and Adams, Hieab H H and Amouyel, Philippe and Beiser, Alexa and Buckley, Brendan M and Callisaya, Michele and Chauhan, Ganesh and de Craen, Anton J M and Dufouil, Carole and van Duijn, Cornelia M and Ford, Ian and Freudenberger, Paul and Gottesman, Rebecca F and Gudnason, Vilmundur and Heiss, Gerardo and Hofman, Albert and Lumley, Thomas and Martinez, Oliver and Mazoyer, Bernard and Moran, Chris and Niessen, Wiro J and Phan, Thanh and Psaty, Bruce M and Satizabal, Claudia L and Sattar, Naveed and Schilling, Sabrina and Shibata, Dean K and Slagboom, P Eline and Smith, Albert and Stott, David J and Taylor, Kent D and Thomson, Russell and T{\"o}glhofer, Anna M and Tzourio, Christophe and van Buchem, Mark and Wang, Jing and Westendorp, Rudi G J and Windham, B Gwen and Vernooij, Meike W and Zijdenbos, Alex and Beare, Richard and Debette, Stephanie and Ikram, M Arfan and Jukema, J Wouter and Launer, Lenore J and Longstreth, W T and Mosley, Thomas H and Seshadri, Sudha and Schmidt, Helena and Schmidt, Reinhold} }