Runs of homozygosity (ROHs) are recognised signature of recessive inheritance. Contributions of ROHs to the genetic architecture of coronary artery disease and regulation of gene expression in cells relevant to atherosclerosis are not known. Our combined analysis of 24,320 individuals from 11 populations of white European ethnicity showed an association between coronary artery disease and both the count and the size of ROHs. Individuals with coronary artery disease had approximately 0.63 (95% CI: 0.4-0.8) excess of ROHs when compared to coronary artery disease-free controls (P=1.49x10-9 ). The average total length of ROHs was approximately 1046.92 (95% CI: 634.4-1459.5) kb greater in individuals with coronary artery disease than controls (P=6.61x10-7 ). None of the identified individual ROHs was associated with coronary artery disease after correction for multiple testing. However, in aggregate burden analysis, ROHs favouring increased risk of coronary artery disease were much more common than those showing the opposite direction of association with coronary artery disease (P=2.69x10-33). Individual ROHs showed significant associations with monocyte and macrophage expression of genes in their close proximity – subjects with several individual ROHs showed significant differences in the expression of 44 mRNAs in monocytes and 17 mRNAs in macrophages when compared to subjects without those ROHs. This study provides evidence for an excess of homozygosity in coronary artery disease in outbred populations and suggest the potential biological relevance of ROHs in cells of importance to the pathogenesis of atherosclerosis. ; This study was supported by the Alumni Association of University of Leicester PhD studentship and International Mentoring Travel Award by American Heart Association to PC. MT is supported by the British Heart Foundation. NJS holds a personal chair supported by the British Heart Foundation and is a UK NIHR senior investigator. CPN is funded by the British Heart Foundation. The Cardiogenics project was supported by the European Union 6th Framework Program (LSHM-CT-2006-037593). The UKBS collection of Common Controls has been funded by the Wellcome Trust grant 084183/Z/07/Z and by NIHR programme grant to NHSBT (RP-PG-0310-1002). The collection was established as part of the WTCCC.
Supplementary information accompanies this paper at http://www.nature.com/srep ; In recent years, genome-wide association studies have identified 58 independent risk loci for coronary artery disease (CAD) on the autosome. However, due to the sex-specific data structure of the X chromosome, it has been excluded from most of these analyses. While females have 2 copies of chromosome X, males have only one. Also, one of the female X chromosomes may be inactivated. Therefore, special test statistics and quality control procedures are required. Thus, little is known about the role of X-chromosomal variants in CAD. To fill this gap, we conducted a comprehensive X-chromosome-wide meta-analysis including more than 43,000 CAD cases and 58,000 controls from 35 international study cohorts. For quality control, sex-specific filters were used to adequately take the special structure of X-chromosomal data into account. For single study analyses, several logistic regression models were calculated allowing for inactivation of one female X-chromosome, adjusting for sex and investigating interactions between sex and genetic variants. Then, meta-analyses including all 35 studies were conducted using random effects models. None of the investigated models revealed genome-wide significant associations for any variant. Although we analyzed the largest-to-date sample, currently available methods were not able to detect any associations of X-chromosomal variants with CAD. ; This work was supported by the German Federal Ministry of Education and Research (BMBF) within the framework of the e:Med research and funding concept (grant 01ZX1313A-2014). The ADVANCE study was supported by a grant from the Reynold's Foundation and NHLBI grant HL087647. Sample collection in the Cardiogenics Consortium (http://www.cardiogenics.eu/web/) was funded by the 6th Framework Program of the European Union (LSHM-CT-2006-037593). We thank all the participants and clinicians involved in the recruitment process at Cambridge and Leicester (UK), Luebeck and Regensburg (Germany), and Paris (France). CATHGEN was supported by NIH grants HL095987 and HL101621. The Cleveland Clinic Gene Bank study was funded by P01HL076491 (to S.L.H). EGCUT was supported by Estonian Research Council grant no. IUT20-60 and Research Roadmap grant no. 3.2.0304.11-0312 and by University Tartu grant no. ARENG SP1GV. The FGENTCARD-Functional Genomic diagnostic tools for coronary artery disease project was funded by an EU FP6 award. We thank the patients for agreeing to participate in the study. We thank Sonia Youhanna, Nour Moukalled and Bariaa Khalil for their help with subject recruitment and data collection. The work of FINCAVAS was supported by the Competitive Research Funding of the Tampere University Hospital (Grant 9M048 and 9N035), the Finnish Cultural Foundation, the Finnish Foundation for Cardiovascular Research, the Emil Aaltonen Foundation, Finland, and the Tampere Tuberculosis Foundation. The authors thank the staff of the Department of Clinical Physiology for collecting the exercise test data. The GerMIFS studies were supported by grants from the German Federal Ministry of Education and Research (BMBF) within the framework of NGFN and NGFN-plus (Atherogenomics) and e:Med research and funding concept (e:AtheroSysMed, grant 01ZX1313A-2014), the Fondation Leducq (CADgenomics: Understanding CAD Genes, 12CVD02), and the European Union Sixth Framework Programme FP6 (under grant agreement FP6-LIFESCIHEALTH (Cardiogenics)) and the Seventh Framework Programme FP7/2007-2013 under grant agreement n° HEALTH-F2-2013-601456 (CVgenes-at-target). The Heart Protection Study (HPS) (ISRCTN48489393) was supported by the UK Medical Research Council (MRC), British Heart Foundation, Merck and Co (manufacturers of simvastatin), and Roche Vitamins Ltd (manufacturers of vitamins). Genotyping was supported by a grant to Oxford University and CNG from Merck and Co. Jemma C. Hopewell acknowledges support from the British Heart Foundation (FS/14/55/30806). HPS acknowledges the National Blood Service (NBS) donors and UK Twin study for using as population controls. A full list of the investigators who contributed to the generation of the NBS data is available from www.wtccc.org.uk. Funding for the project was provided by the Wellcome Trust under award 07611. The UK Twin study was funded by the Wellcome Trust; European Community"s Seventh Framework Programme (FP7/2007–2013). The Helsinki Sudden Death Study (HSDS) was financially supported by EU's 7th Framework Programme (grant no. 201668 for AtheroRemo), the Tampere University Foundation, the Tampere University Hospital Medical Funds (grants X51001, 9M048 and 9N035 for Terho Lehtimäki, the Emil Aaltonen Foundation (Terho Lehtimäki, the Finnish Foundation of Cardiovascular Research (Terho Lehtimäki, Pekka J. Karhunen), the Pirkanmaa Regional Fund of the Finnish Cultural Foundation, the Yrjö Jahnsson Foundation, and the Tampere Tuberculosis Foundation (Terho Lehtimäki). LIFE-Heart is a part of the LIFE – Leipzig Research Center for Civilization Diseases, Universität Leipzig. LIFE is funded by means of the European Union, by the European Regional Development Fund (ERDF) and by means of the Free State of Saxony within the framework of the excellence initiative. The LOLIPOP study is supported by the National Institute for Health Research (NIHR) Comprehensive Biomedical Research Centre Imperial College Healthcare NHS Trust, the British Heart Foundation (SP/04/002), the Medical Research Council (G0601966, G0700931), the Wellcome Trust (084723/Z/08/Z), the NIHR (RP-PG-0407-10371), European Union FP7 (EpiMigrant, 279143) and Action on Hearing (G51). We thank the participants and research staff who made the study possible. LURIC was supported by the 7th Framework Program (integrated project AtheroRemo, grant agreement number 201668 and RiskyCAD, grant agreement number 305739) of the European Union and by the INTERREG IV Oberrhein Program (Project A28, Genetic mechanisms of cardiovascular diseases) with support from the European Regional Development Fund (ERDF) and the Wissenschaftsoffensive TMO. We extend our appreciation to the participants of the LURIC study and thank the LURIC study team who were either temporarily or permanently involved in patient recruitment as well as sample and data handling, in addition to the laboratory staff at the Ludwigshafen General Hospital and the Universities of Freiburg and Ulm, Germany. The MIGen study was funded by R01HL087676 from the US National Heart, Lung, and Blood Institute. The Mount Sinai IPM Biobank Program is supported by The Andrea and Charles Bronfman Philanthropies. It was in part supported by NHGRI U01HG007417. OHGS_A2, OHGS_B2, and OHGS_C2 were funded by Canadian Institutes of Health Research (# MOP-2380941 to R.M.), (#MOP82810, MOP77682 to R.R., A.F.S. & R.M.); Canada Foundation for Innovation (#11966 to R.R., R.M. & A.F.S.; Heart & Stroke Foundation of Canada (#NA6001, #NA6650 to R.M). PIVUS was supported by Knut and Alice Wallenberg Foundation (Wallenberg Academy Fellow), European Research Council (ERC Starting Grant), Swedish Diabetes Foundation (grant no. 2013-024), Swedish Research Council (grant no. 2012-1397), and Swedish Heart-Lung Foundation (20120197). We thank the SNP&SEQ Technology Platform in Uppsala (www.genotyping.se) for excellent genotyping. The computations were performed on resources provided by SNIC through Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) under Project b2011036. PROCARDIS was supported by the European Community Sixth Framework Program (LSHM-CT- 2007-037273), AstraZeneca, the British Heart Foundation, the Swedish Research Council, the Knut and Alice Wallenberg Foundation, the Swedish Heart-Lung Foundation, the Torsten and Ragnar Söderberg Foundation, the Strategic Cardiovascular Program of Karolinska Institutet and Stockholm County Council, the Foundation for Strategic Research and the Stockholm County Council (560283). Research in SDS was partly supported by NIH grants -R01DK082766 funded by the National Institute of Diabetes and Digestive and Kidney Diseases and NOT-HG-11-009 funded by National Genome Research Institute, and VPR Bridge grant from University of Oklahoma Health Sciences Center, Oklahoma City, USA. Recruitment for THISEAS was partially funded by a research grant (PENED 2003) from the Greek General Secretary of Research and Technology; we thank all the dieticians and clinicians for their contribution to the project. TwinGene was supported by grants from the Ministry for Higher Education, the Swedish Research Council (M-2005-1112 and 2009-2298), GenomEUtwin (EU/QLRT-2001-01254; QLG2-CT-2002-01254), NIH grant DK U01-066134, Knut and Alice Wallenberg Foundation (Wallenberg Academy Fellow), European Research Council (ERC Starting Grant), Swedish Diabetes Foundation (grant no. 2013-024), Swedish Research Council (grant no. 2012-1397), and Swedish Heart-Lung Foundation (20120197). We thank the SNP&SEQ Technology Platform in Uppsala (www.genotyping.se) for excellent genotyping. The computations were performed on resources provided by SNIC through Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) under Project b2011036. ULSAM was supported by Knut and Alice Wallenberg Foundation (Wallenberg Academy Fellow), European Research Council (ERC Starting Grant), Swedish Diabetes Foundation (grant no. 2013-024), Swedish Research Council (grant no. 2012-1397), and Swedish Heart-Lung Foundation (20120197). We thank the SNP&SEQ Technology Platform in Uppsala (www.genotyping.se) for excellent genotyping. The computations were performed on resources provided by SNIC through Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) under Project b2011036. Recruitment for the WTCCC study was funded by the British Heart Foundation and genotyping by the Wellcome Trust. Themistocles L. Assimes was supported by an NIDDK career development award DK088942. Panos Deloukas's work forms part of the research themes contributing to the translational research portfolio of Barts Cardiovascular Biomedical Research Unit which is supported and funded by the National Institute for Health Research. Analysis was partly supported by BHF grant (to Panos Deloukas) RG/14/5/30893. Martin Farrall and Hugh Watkins acknowledge the support of the Wellcome Trust core award (090532/Z/09/Z) and Martin Farrall, Hugh Watkins and Theodosios Kyriakou, the BHF Centre of Research Excellence. Anuj Goel, Hugh Watkins and Theodosios Kyriakou acknowledge European Union Seventh Framework Programme FP7/2007-2013 under grant agreement no. HEALTH-F2-2013-601456 (CVGenes@Target) & and Anuj Goel, the Wellcome Trust Institutional strategic support fund. The UK Twin study was funded by the Wellcome Trust; European Community's Seventh Framework Programme (FP7/2007-2013). PoBI samples from the Wellcome Trust funded People of the British Isles project. Sekar Kathiresan is supported by the Donovan Family Foundation, Fondation Leducq, MGH Research Scholar Award, and R01 HL107816. Andrew P. Morris is a Wellcome Trust Senior Fellow in Basic Biomedical Science, funded under grant WT098017. Christopher P. Nelson and Nilesh J. Samani are funded by the British Heart Foundation and Nilesh J. Samani is a UK NIUHR Senior Investigator. Christopher P. Nelson and Nilesh J. Samani are funded by the British Heart Foundation and Nilesh J. Samani is a UK NIUHR Senior Investigator. Samuli Ripatti was supported by the Academy of Finland Center of Excellence in Complex Disease Genetics (Grant No. 213506 and 129680), Academy of Finland (Grant No. 251217 and 285380), the Finnish foundation for Cardiovascular Research, the Sigrid Juselius Foundation and the European Community's Seventh Framework Programme (FP7/2007-2013) through the BioSHaRE-EU (Biobank Standardisation and Harmonisation for Research Excellence in the European Union) project, grant agreement 261433. Alexandre F. R. Stewart is supported by operating grants from the Canadian Institute of Health Research and Natural Sciences and Engineering Research Council of Canada. Hong-Hee Won is supported by a postdoctoral award from the American Heart Association (15POST23280019). ; Peer-reviewed ; Publisher Version
