About 80% of stroke is ischaemic, whereas 20% is due to primary haemorrhage.6 Ischaemic stroke itself includes several subtypes with differing pathophysiological mechanisms, the most common of which are large-vessel disease stroke, small-vessel disease stroke, and cardioembolic stroke.7 Various genetic variants that predispose to risk factors for stroke have also been shown in GWAS to predispose to ischaemic stroke.8, 9, 10 Two loci associated with atrial fibrillation (PITX2 and ZFHX3) were associated with cardioembolic stroke, whereas a locus on chromosome 9p21 originally associated with coronary artery disease was shown to be a risk factor for large-vessel stroke.8, 9, 10 The few novel stroke-associated loci reported to date have been mainly associated with stroke subtypes, rather than with the phenotype of ischaemic stroke. In Japanese populations, a variant in the protein kinase C family (PRKCH) was associated with small-vessel stroke.11 A meta-analysis of prospective population-based cohort studies reported an association with the 12p13 region, thought to be with the NINJ2 gene, although this result was not replicated in a larger case-control sample.12, 13 Recently, the Wellcome Trust Case Control Consortium 2
