Abstract WP132: A Genome Wide Association Study in Patients with Symptomatic Intracranial Atherostenosis

Abstract

Introduction and objective: Intracranial atherosclerosis (ICAS) is a major cause of stroke worldwide, and its genetic background remains largely unexplored. The previous studies performed have been based on candidate-gene strategy. We aimed to perform a genome-wide association study (GWAs) to find genetic risk factors associated with symptomatic ICAS. Methods: We studied a cohort of 83 Caucasian patients with ischemic stroke attributed to symptomatic ICAS and 315 controls genotyped with Human Core Exome (Illumina). A score combining number and severity of intracranial stenoses was used to assess ICAS severity in each patient. Quality controls, 1000G imputation and association analysis were performed through PLINK, R, IMPUTE2 and SNPTEST software following previous recommendations. Sex, age, principal components and vascular risk factors were used as covariates. Results: Several loci with a genome wide significant association (P<1E-08) were found to be associated with ICAS severity score. The most robust association was found for locus in chromosome 18 (p=3.05E-14). Conclusion: This GWAS in symptomatic ICAS patients has revealed potential genes associated with ICAS presence and severity. These findings need to be replicated in other cohorts, ideally in patients from different ethnicities.