Variant Rs556621 on Chromosome 6p21.1 and the Risk of Ischemic Stroke in Chinese Populations: A Meta-Analysis

There are inconsistencies in the published findings on the association of variant rs556621 in an intergenic region on Chromosome 6p21.1 with the risk of developing ischemic stroke (IS) and a major IS subtype (large artery atherosclerosis, LAA) in Chinese populations. We conducted a meta-analysis to evaluate the association of variant rs556621 with IS/LAA risk using ten studies involving 3644 IS cases and 3692 controls (including seven studies involving 2268 LAA cases and 2268 controls) from China. The AA genotype increased IS risk (AA versus CC: odds ratio [OR] 1.19, 95% confidence interval [CI] 1.03-1.36, P = 0.015; AA versus CA + CC: OR 1.23, 95% CI 1.09-1.39, P = 0.001). Subgroup analysis also suggested that rs556621 contributed to the risk of IS both in Chinese Han and the miscellaneous group. However, these results were stable in Chinese Han but not in the miscellaneous group. When restricting our analysis to the LAA subtype, similar results were obtained. This meta-analysis is the first meta-analysis on the correlation between rs556621 and the susceptibility of IS/LAA and demonstrates that rs556621 is associated with IS/LAA risk in Chinese populations. Further meta-analysis warrants larger well-designed investigations to assess these effects.