Recently, two common sequence variants on 9p21, tagged by rs10757278-G and rs10811661-T, were reported to be associated with coronary artery disease (CAD) and type 2 diabetes (T2D), respectively. We proceeded to further investigate the contributions of these variants to arterial diseases and T2D. Here we report that rs10757278-G is associated with, in addition to CAD, abdominal aortic aneurysm (AAA; odds ratio (OR) = 1.31, P = 1.2 x 10(-12)) and intracranial aneurysm (OR = 1.29, P = 2.5 x 10(-6)), but not with T2D. This variant is the first to be described that affects the risk of AAA and intracranial aneurysm in many populations. The association of rs10811661-T to T2D replicates in our samples, but the variant does not associate with any of the five arterial diseases examined. These findings extend our insight into the role of the sequence variant tagged by rs10757278-G and show that it is not confined to atherosclerotic diseases.

Saccular intracranial aneurysms (IAs) are balloon-like dilations of the intracranial arterial wall; their hemorrhage commonly results in severe neurologic impairment and death. We report a second genome-wide association study with discovery and replication cohorts from Europe and Japan comprising 5,891 cases and 14,181 controls with ∼832,000 genotyped and imputed SNPs across discovery cohorts. We identified three new loci showing strong evidence for association with IA in the combined data set, including intervals near RBBP8 on 18q11.2 (OR=1.22, P=1.1×10-12), STARD13/KL on 13q13.1 (OR=1.20, P=2.5×10-9) and a gene-rich region on 10q24.32 (OR=1.29, P=1.2×10-9). We also confirmed prior associations near SOX17 (8q11.23-q12.1; OR=1.28, P=1.3×10-12) and CDKN2A/B (9p21.3; OR=1.31, P=1.5×10-22). It is noteworthy that several putative risk genes play a role in cell-cycle progression, potentially affecting proliferation and senescence of progenitor cell populations that are responsible for vascular formation and repair.

Stroke is the world’s third leading cause of death. One cause of stroke, intracranial aneurysm, affects ~2% of the population and accounts for 500,000 hemorrhagic strokes annually in midlife (median age 50), most often resulting in death or severe neurological impairment1. The pathogenesis of intracranial aneurysm is unknown, and because catastrophic hemorrhage is commonly the first sign of disease, early identification is essential. We carried out a multistage genome-wide association study (GWAS) of Finnish, Dutch and Japanese cohorts including over 2,100 intracranial aneurysm cases and 8,000 controls. Genome-wide genotyping of the European cohorts and replication studies in the Japanese cohort identified common SNPs on chromosomes 2q, 8q and 9p that show significant association with intracranial aneurysm with odds ratios 1.24-1.36. The loci on 2q and 8q are new, whereas the 9p locus was previously found to be associated with arterial diseases, including intracranial aneurysm2-5. Associated SNPs on 8q likely act via SOX17, which is required for formation and maintenance of endothelial cells6-8, suggesting a role in development and repair of the vasculature; CDKN2A at 9p may have a similar role9. These findings have implications for the pathophysiology, diagnosis and therapy of intracranial aneurysm.

Rupture of an intracranial aneurysm leads to subarachnoid hemorrhage, a severe type of stroke. To discover new risk loci and the genetic architecture of intracranial aneurysms, we performed a cross-ethnic, genome-wide association study in 10,754 cases and 306,882 controls of European and East Asian ancestry. We discovered 17 risk loci, 11 of which are new. We reveal a polygenic architecture and explain over half of the disease heritability. We show a high genetic correlation between ruptured and unruptured intracranial aneurysms. We also find a suggestive role for endothelial cells using gene mapping and heritability enrichment. Drug target enrichment shows pleiotropy between intracranial aneurysms and anti-epileptic and sex hormone drugs,

We performed a genome-wide association study on 1,292 individuals with abdominal aortic aneurysms (AAAs) and 30,503 controls from Iceland and The Netherlands, with a follow-up of top markers in up to 3,267 individuals with AAAs and 7,451 controls. The A allele of rs7025486 on 9q33 was found to associate with AAA, with an odds ratio (OR) of 1.21 and P = 4.6 × 10−10. In tests for association with other vascular diseases, we found that rs7025486[A] is associated with early onset myocardial infarction (OR = 1.18, P = 3.1 × 10−5), peripheral arterial disease (OR = 1.14, P = 3.9 × 10−5) and pulmonary embolism (OR = 1.20, P = 0.00030), but not with intracranial aneurysm or ischemic stroke. No association was observed between rs7025486[A] and common risk factors for arterial and venous diseases—that is, smoking, lipid levels, obesity, type 2 diabetes and hypertension. Rs7025486 is located within DAB2IP, which encodes an inhibitor of cell growth and survival.

MethodsWe conducted a systematic review and meta-analysis of studies reporting circulating IL-6 in AAA, and new investigations of the association between a common non-synonymous functional variant (Asp358Ala) in the IL-6R gene (IL6R) and AAA, followed the analysis of the variant both in vitro and in vivo.Inflammation may play a role in the development of abdominal aortic aneurysms (AAA). Interleukin-6 (IL-6) signalling through its receptor (IL-6R) is one pathway that could be exploited pharmacologically. We investigated this using a Mendelian randomization approach.ResultsUp to October 2011, we identified seven studies (869 cases, 851 controls). Meta-analysis demonstrated that AAA cases had higher levels of IL-6 than controls [standardized mean difference (SMD) = 0.46 SD, 95% CI = 0.25–0.66, I2 = 70%, P = 1.1 × 10–5 random effects]. Meta-analysis of five studies (4524 cases/15 710 controls) demonstrated that rs7529229 (which tags the non-synonymous variant Asp358Ala, rs2228145) was associated with a lower risk of AAA, per Ala358 allele odds ratio 0.84, 95% CI: 0.80–0.89, I2 = 0%, P = 2.7 × 10–11). In vitro analyses in lymphoblastoid cell lines demonstrated a reduction in the expression of downstream targets (STAT3, MYC and ICAM1) in response to IL-6 stimulation in Ala358 carriers.ConclusionsA Mendelian randomization approach provides robust evidence that signalling via the IL-6R is likely to be a causal pathway in AAA. Drugs that inhibit IL-6R may play a role in AAA management.

Background The genetic basis of lacunar stroke is poorly understood, with a single locus on 16q24 identified to date. We sought to identify novel associations and provide mechanistic insights into the disease. MethodsWe did a pooled analysis of data from newly recruited patients with an MRI-confirmed diagnosis of lacunar stroke and existing genome-wide association studies (GWAS). Patients were recruited from hospitals in the UK as part of the UK DNA Lacunar Stroke studies 1 and 2 and from collaborators within the International Stroke Genetics Consortium. Cases and controls were stratified by ancestry and two meta-analyses were done: a European ancestry analysis, and a transethnic analysis that included all ancestry groups. We also did a multi-trait analysis of GWAS, in a joint analysis with a study of cerebral white matter hyperintensities (an aetiologically related radiological trait), to find additional genetic associations. We did a transcriptome-wide association study (TWAS) to detect genes for which expression is associated with lacunar stroke; identified significantly enriched pathways using multi-marker analysis of genomic annotation; and evaluated cardiovascular risk factors causally associated with the disease using mendelian randomisation.Findings Our meta-analysis comprised studies from Europe, the USA, and Australia, including 7338 cases and 254 798 con trols, of which 2987 cases (matched with 29 540 controls) were confirmed using MRI. Five loci (ICA1L-WDR12-CARF-NBEAL1, ULK4, SPI1-SLC39A13-PSMC3-RAPSN, ZCCHC14, ZBTB14-EPB41L3) were found to be associa ted with lacunar stroke in the European or transethnic meta-analyses. A further seven loci (SLC25A44-PMF1-BGLAP,

LPA sequence variants were associated with atherosclerotic burden, but not with primarily thrombotic phenotypes.