GWAS in ischaemic stroke to date have used small discovery populations, with the largest including 3548 individuals.14 In other complex diseases, many additional associations have been detected as the discovery sample size has increased.15, 16, 17 This increase has usually been achieved by meta-analysis of independent datasets. Therefore, we established the METASTROKE collaboration to combine the available GWAS datasets of ischaemic stroke. Here, we describe the first paper from METASTROKE with a description of the constituent cohorts. Using this dataset, we attempted both to replicate previous GWAS associations with ischaemic stroke and to identify novel associations. Additionally, we determined whether stroke loci were specific to individual stroke subtypes.
