scholarly journals Genome-Wide Association Study Meta-Analysis of Stroke in 22 000 Individuals of African Descent Identifies Novel Associations With Stroke

Stroke ◽  
2020 ◽  
Vol 51 (8) ◽  
pp. 2454-2463
Author(s):  
Keith L. Keene ◽  
Hyacinth I. Hyacinth ◽  
Joshua C. Bis ◽  
Steven J. Kittner ◽  
Braxton D. Mitchell ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Meta Analysis ◽  
African Descent ◽  
Genome Wide Association ◽  
Minority Population ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Genome Wide ◽  
A Genome

Background and Purpose: Stroke is a complex disease with multiple genetic and environmental risk factors. Blacks endure a nearly 2-fold greater risk of stroke and are 2× to 3× more likely to die from stroke than European Americans. Methods: The COMPASS (Consortium of Minority Population Genome-Wide Association Studies of Stroke) has conducted a genome-wide association meta-analysis of stroke in >22 000 individuals of African ancestry (3734 cases, 18 317 controls) from 13 cohorts. Results: In meta-analyses, we identified one single nucleotide polymorphism (rs55931441) near the HNF1A gene that reached genome-wide significance ( P =4.62×10 −8 ) and an additional 29 variants with suggestive evidence of association ( P <1×10 −6 ), representing 24 unique loci. For validation, a look-up analysis for a 100 kb region flanking the COMPASS single nucleotide polymorphism was performed in SiGN (Stroke Genetics Network) Europeans, SiGN Hispanics, and METASTROKE (Europeans). Using a stringent Bonferroni correction P value of 2.08×10 −3 (0.05/24 unique loci), we were able to validate associations at the HNF1A locus in both SiGN ( P =8.18×10 −4 ) and METASTROKE ( P =1.72×10 −3 ) European populations. Overall, 16 of 24 loci showed evidence for validation across multiple populations. Previous studies have reported associations between variants in the HNF1A gene and lipids, C-reactive protein, and risk of coronary artery disease and stroke. Suggestive associations with variants in the SFXN4 and TMEM108 genes represent potential novel ischemic stroke loci. Conclusions: These findings represent the most thorough investigation of genetic determinants of stroke in individuals of African descent, to date.

scholarly journals Replication of Top Loci From COL4A1/2 Associated With White Matter Hyperintensity Burden in Patients With Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (12) ◽  
pp. 3751-3755
Author(s):  
Jiang Li ◽  
Vida Abedi ◽  
Ramin Zand ◽  
Christoph J. Griessenauer ◽  
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Ischemic Stroke ◽  
Odds Ratio ◽  
Association Studies ◽  
Genome Wide Association ◽  
White Matter Hyperintensity ◽  
Genome Wide Association Studies ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Genome Wide

Background and Purpose: The purpose of this study was to replicate the top loci associated with white matter hyperintensity (WMH) phenotypes identified by large genome-wide association studies and the loci identified from the previous candidate gene studies. Methods: A total of 946 Geisinger MyCode patients with acute ischemic stroke with validated European ancestry and magnetic resonance imaging data were included in this study. Log-transformed WMH volume, as a quantitative trait, was calculated by a fully automated quantification process. The genome-wide association studies was carried out by a linear mixed regression model (GEMMA). A candidate-single nucleotide polymorphism analysis by including known single nucleotide polymorphisms, reported from a meta-analysis and several large GWAS for WMH, was conducted in all cases and binary converted extreme cases. Results: No genome-wide significantly associated variants were identified. In a candidate-single nucleotide polymorphism study, rs9515201 ( COL4A2 ) and rs3744028 ( TRIM65 ), 2 known genetic loci, showed nominal or trend of association with the WMH volume (β=0.13 and P =0.001 for rs9515201; β=0.094 and P =0.094 for rs3744028), and replicated in a subset of extreme cases versus controls (odds ratio=1.78, P =7.74×10 − 4 for rs9515201; odds ratio=1.53, P =0.047 for rs3744028, respectively). MTHFR677 cytosine/thymine (rs1801133) also showed an association with the binary WMH with odds ratio=1.47 for T allele ( P =0.019). Conclusions: Replication of COL4A1/2 associated with WMH reassures that the genetic risk factors for monogenic and polygenic ischemic stroke are shared at gene level.

scholarly journals An Analysis Pipeline for Genome-wide Association Studies

2008 ◽  
Vol 6 ◽  
pp. CIN.S966 ◽  
Author(s):  
Stefan Stefanov ◽  
James Lautenberger ◽  
Bert Gold
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Missing Values ◽  
Association Studies ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Population Difference ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Genome Wide ◽  
And Control

We developed an efficient pipeline to analyze genome-wide association study single nucleotide polymorphism scan results. Perl scripts were used to convert genotypes called using the BRLMM algorithm into a modified PB format. We computed summary statistics characteristic of our case and control populations including allele counts, missing values, heterozygosity, measures of compliance with Hardy-Weinberg equilibrium, and several population difference statistics. In addition, we computed association tests, including exact tests of association for genotypes, alleles, the Cochran-Armitage linear trend test, and dominant, recessive, and overdominant models at every single nucleotide polymorphism (SNP). In addition, pairwise linkage disequilbrium statistics were elaborated, using the command line version of HaploView, which was possible by writing a reformatting script. Additional Perl scripts permit loading the results into a MySQL database conjoined with a Generic Genome Browser (gbrowse) for comprehensive visualization. This browser incorporates a download feature that provides actual case and control genotypes to users in associated genomic regions. Thus, re-analysis “on the fly” is possible for casual browser users from anywhere on the Internet.

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