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Consistent but indirect evidence has implicated genetic factors in smoking behavior1,2. We report meta-analyses of several smoking phenotypes within cohorts of the Tobacco and Genetics Consortium (n = 74,053). We also partnered with the European Network of Genetic and Genomic Epidemiology (ENGAGE) and Oxford-GlaxoSmithKline (Ox-GSK) consortia to follow up the 15 most significant regions (n > 140,000). We identified three loci associated with number of cigarettes smoked per day. The strongest association was a synonymous 15q25 SNP in the nicotinic receptor gene CHRNA3 (rs1051730[A], β = 1.03, standard error (s.e.) = 0.053, P = 2.8 × 10−73). Two 10q25 SNPs (rs1329650[G], β = 0.367, s.e. = 0.059, P = 5.7 × 10−10; and rs1028936[A], β = 0.446, s.e. = 0.074, P = 1.3 × 10−9) and one 9q13 SNP in EGLN2 (rs3733829[G], β = 0.333, s.e. = 0.058, P = 1.0 × 10−8) also exceeded genome-wide significance for cigarettes per day. For smoking initiation, eight SNPs exceeded genome-wide significance, with the strongest association at a nonsynonymous SNP in BDNF on chromosome 11 (rs6265[C], odds ratio (OR) = 1.06, 95% confidence interval (Cl) 1.04–1.08, P = 1.8 × 10−8). One SNP located near DBH on chromosome 9 (rs3025343[G], OR = 1.12, 95% Cl 1.08–1.18, P = 3.6 × 10−8) was significantly associated with smoking cessation.
Previous genome-wide association studies (GWAS) for smoking behavior (Supplementary Table 1) have identified a chromosome-15 nicotinic acetylcholine receptor gene cluster as being associated with smoking quantity3. The Tobacco and Genetics (TAG) Consortium conducted GWAS meta-analyses across 16 studies originally designed to evaluate other phenotypes (for example, cardiovascular disease and type 2 diabetes). We examined four carefully harmonized smoking phenotypes (see Online Methods)—smoking initiation (ever versus never been a regular smoker), age of smoking initiation, smoking quantity (number of cigarettes smoked per day, CPD) and smoking cessation (former versus current smokers)—among people of European ancestry (Table 1). Smoking cessation contrasted former versus current smokers, where current smokers reported at interview that they presently smoked and former smokers had quit smoking at least 1 year before interview. Smokers who had quit smoking for less than 1 year at interview were excluded from the analysis to minimize misclassification, as relapse after initial smoking cessation occurs in 70% to 80% of former smokers within the first year4.
The 16 TAG studies performed their own genotyping, quality control and imputation (see Supplementary Tables 2 and 3 and Online Methods). Studies ranged in size from n = 585 to n = 22,037 and were genotyped on six different platforms. Genotype imputation5 resulted in a common set of ~2.5 million SNPs (Supplementary Table 3). Imputed allele dosages for each SNP (that is, the number of copies of the minor allele) were tested for association with each smoking phenotype, using an additive model.
We performed a fixed-effect meta-analysis for each smoking phenotype by computing pooled inverse variance–weighted β coefficients, s.e. values and z-scores for each SNP6. Fixed-effects analyses are regarded as the most efficient method for discovery in the GWAS setting7,8. Heterogeneity across studies was investigated using the I2 statistic9. Random-effects analyses are presented in Supplementary Table 4. We used a significance threshold of P < 5 × 10−8 (refs. 10,11).
In the initial TAG meta-analysis, only one locus contained SNPs that exceeded genome-wide significance for one of the four phenotypes (Fig. 1 and Supplementary Table 4). A total of 130 SNPs in the 15q25.1 nicotinic receptor gene cluster were significantly associated with CPD (n = 38,181, minimum P = 4.2 × 10−35 at rs12914385 in CHRNA3). One SNP approached significance for smoking cessation (n = 41,278, minimum P = 5.5 × 10−8 for rs7872903, located ~17 kb 5′ of DBH on chromosome 9). No SNPs were significantly associated with ever versus never regular smokers (n = 74,035, minimum P = 2.2 × 10−7 at rs16941640 in CDC27) or age of smoking initiation (n = 24,114, minimum P = 1.6 × 10−6 at rs2806464, located 3′ of DISC1) in the initial TAG meta-analysis.
To follow up associations identified in the TAG Consortium analyses, we partnered with the ENGAGE and Oxford-GlaxoSmithKline (Ox-GSK) consortia and conducted a reciprocal exchange of summary results for the 15 most significant genetic regions for three smoking phenotypes12,13. Our regions were defined by clusters of P values < 10−4 (that is, where the correlations (r2) were >0.5 and/or the SNPs were located <50 kb apart; Supplementary Table 5). Sample sizes across the three consortia were n = 143,023 for smoking initiation, n = 73,853 for CPD and n = 64,924 for smoking cessation (data on age of smoking initiation were not available in ENGAGE or Ox-GSK).
Results of the most significant SNPs for each smoking phenotype across the three consortia are summarized in Table 2. We identified three loci associated with CPD. The synonymous SNP rs1051730 in CHRNA3 showed the strongest association: each copy of the A allele corresponded to an increase in smoking quantity of 1 CPD (β = 1.03, s.e. = 0.056, P = 2.8 × 10−73, I2 = 0.66; Fig. 2) and accounted for 0.5% of the variance in CPD. The SNP rs16969968[G], which has been proposed as a causal variant in this region14, was the second most significant SNP associated with CPD (P = 5.57 × 10−72; Supplementary Fig. 1). In tests of association for SNPs within the 15q25.1 region conditional on rs1051730, we observed residual associations, with the most significant signals at rs684513[G] (P = 6.3 × 10−9), in CHRNA5, and rs9788682[G] (P = 1.06 × 10−8) and rs7163730[G] (P = 1.22 × 10−8), in LOC123688 (Supplementary Fig. 2 and Supplementary Table 6). Our results suggest that several markers within this region may influence CPD independently. Fine mapping and the use of the 1000 Genomes Project data should help refine these signals. We investigated whether the 15q25.1 region was associated with smoking initiation and smoking cessation as well, but no SNP in that region exceeded genome-wide significance (smoking initiation minimum P = 0.98; smoking cessation minimum P = 1.75 × 10−5).
In addition, markers within regions on chromosomes 10q23 and 19q13 were significantly associated with CPD. The SNPs rs1329650[G] (β = 0.367, s.e. = 0.059, P = 5.7 × 10−10; Fig. 2) and rs1028936[A] (β = 0.446, s.e. = 0.074, P = 1.3 × 10−9; Supplementary Fig. 1) are located in a noncoding RNA (LOC100188947), where each additional copy of a risk allele corresponded to an increase in smoking quantity of ~0.5 CPD. Linkage disequilibrium (LD) between these SNPs is moderate (r 2 = 0.46), suggesting that they may represent one signal. To our knowledge, this region has not been previously investigated in relation to smoking behavior or other addiction phenotypes.
The third locus identified for CPD lies in the first intron of EGLN2 on chromosome 19q13, 40 kb from the 3′ end of CYP2A6. One SNP, rs3733829, exceeded genome-wide significance, and each copy of the G allele corresponded to an increase in smoking quantity of <0.5 CPD (β = 0.333, s.e. = 0.058, P = 1.0 × 10−8; Fig. 2). CYP2A6 is an established candidate gene for smoking, as it encodes for an enzyme involved in the metabolic inactivation of nicotine to cotinine15. Many allelic variants of CYP2A6 result in slower metabolism of nicotine16 and are associated with lower prevalence of smoking and lower amounts of cigarette use16,17. We interpret this finding with caution, as only one SNP upstream of CYP2A6 was observed and the strength of its association was moderate. However, the 19q13 region merits continued investigation given its biological plausibility as involved in nicotine metabolism and because several markers within this region were identified in the ENGAGE Consortium12. The SNP identified in our study (rs3733829) lies directly between, and shows moderate LD with, the two most significant markers identified in ENGAGE.
Eight SNPs around BDNF exceeded genome-wide significance for smoking initiation analyses across the three consortia (Fig. 3). The minimum P value was at the missense variant rs6265 (P = 1.8 × 10−8) located in the first exon of BDNF on chromosome 11. Each copy of rs6265[C] conferred a 6% increase in the relative risk of regular smoking (OR = 1.06, 95% c.i. 1.04–1.08); rs6265 accounted for 0.03% of the variance. BDNF belongs to a family of neurotrophins that regulate synaptic plasticity and survival of cholinergic and dopaminergic neurons18. The eight SNPs overlap an antisense transcript (BDNFos). BDNF is expressed at high levels in the prefrontal cortex and hippocampus, which are brain regions implicated in the cognitive-enhancing effects of nicotine19. Although the molecular mechanisms underlying this association have yet to be elucidated, it is plausible that genetic variation at BDNF could alter the rewarding effects of nicotine through modulation of dopamine reward circuits and could contribute to the salience of nicotine’s effects by altering formation of drug-related memories that promote continued use after initial exposure. The SNP rs6265 has been found to be associated with substance-related disorders, eating disorders and schizophrenia20. Most recently, it was identified in a GWAS for body mass index21; the allele associated with a greater body mass index was the same allele associated with regular smoking in our study.
For smoking cessation, one SNP, located 23 kb 5′ of DBH on chromosome 9, achieved genome-wide significance: rs3025343[G] was associated with former smoking status (OR = 1.12, 95% c.i. 1.08–1.18, P = 3.6 × 10−8; Fig. 3) and accounted for 0.19% of the variance in smoking cessation. Because DBH catalyzes conversion of dopamine to norepinephrine, there has been interest in DBH as a candidate gene for various psychiatric phenotypes, including smoking behavior22. Although the SNP identified in this study does not cause amino acid residue changes in DBH, gene expression may be modified either directly or through other variant(s) in strong LD. This view is supported by evidence that a genetic variant (C1021T or rs1611115), located upstream of the DBH translational start site, accounts for 51% of the variation in plasma-DBH activity in European-Americans22. Alternatively, the SNP identified in our study or a variant in LD may influence expression of other genes nearby (ADAMTSL2, FAM163B or SARDH), which would introduce new pathways to our current understanding of addiction biology.
To our knowledge, the sample sizes for the TAG Consortium alone and combined with the ENGAGE and Ox-GSK consortia are among the largest genetic meta-analyses yet conducted23. Notably, most of the loci identified in this study reside in or near known candidate genes involved in the neurobiology of smoking, which differs from the results of previous GWAS, in which variants identified have generally not been in regions previously suspected. The lack of findings for smoking initiation and cessation is noteworthy in light of considerable genetic epidemiological data suggesting a role for genetic factors in different aspects of smoking behavior (for example, heritability estimates are often >0.50)1, and we note that the loci identified do not of themselves account for more than small fractions of the phenotypic heritability. Additional smoking behavior loci may be identified with improved genomic coverage and analysis of gene-gene and gene-environment interaction, copy number variation or epigenetic effects. We acknowledge that imprecision in phenotypic assessment and differences across studies could have added noise sufficient to blur all but the most prominent genetic signals. Smoking behavior obtained by questionnaires may be subject to phenotypic misclassification. Recent work24 has shown that genetic variation at 15q25.1 influences cotinine (the main and long-lived metabolite of nicotine) measurements more strongly than it influences CPD values obtained by means of a questionnaire. Future smoking GWAS that use biomarkers or longitudinal assessments that refine phenotypic assessments by incorporating time to quitting or relapsing to smoking may be required. In addition, inclusion of multiple ethnic groups will enhance the investigation of the genetics of smoking.
Notably, the five significant loci identified in these meta-analyses were each associated with only one specific smoking phenotype. Our findings suggests that separate genetic loci contribute modestly to phenotypic variability in each aspect of smoking behavior, which, in turn, may have implications for the way in which smoking cessation therapies and tobacco control efforts are designed and targeted.
Methods and any associated references are available in the online version of the paper at http://www.nature.com/naturegenetics/.
This work was funded by the University of North Carolina Lineberger Comprehensive Cancer Center University Cancer Research Fund Award and by US National Cancer Institute K07 CA118412 to H.F. Statistical analyses were carried out on the Genetic Cluster Computer (see URLs), which is supported by the Netherlands Scientific Organization (NWO 480-05-003). Acknowledgments for studies included in TAG are listed in the Supplementary Note.
Helena Furberg1,2, YunJung Kim1, Jennifer Dackor1, Eric Boerwinkle3, Nora Franceschini4, Diego Ardissino5, Luisa Bernardinelli6,7, Pier M Mannucci8, Francesco Mauri9, Piera A Merlini9, Devin Absher10, Themistocles L Assimes11, Stephen P Fortmann12, Carlos Iribarren13, Joshua W Knowles11, Thomas Quertermous11, Luigi Ferrucci14, Toshiko Tanaka15, Joshua C Bis16,17, Curt D Furberg18, Talin Haritunians19, Barbara McKnight16,20, Bruce M Psaty16,17,21,22, Kent D Taylor19, Evan L Thacker16,23, Peter Almgren24, Leif Groop24, Claes Ladenvall24, Michael Boehnke25, Anne U Jackson25, Karen L Mohlke1,2, Heather M Stringham25, Jaakko Tuomilehto26–28, Emelia J Benjamin29,30, Shih-Jen Hwang31, Daniel Levy32, Sarah Rosner Preis31, Ramachandran S Vasan29,32, Jubao Duan33, Pablo V Gejman33, Douglas F Levinson34, Alan R Sanders33, Jianxin Shi35, Esther H Lips36, James D McKay36, Antonio Agudo37, Luigi Barzan38, Vladimir Bencko39, Simone Benhamou40,41, Xavier Castellsagué37, Cristina Canova42, David I Conway43, Eleonora Fabianova44, Lenka Foretova45, Vladimir Janout46, Claire M Healy47, Ivana Holcátová39, Kristina Kjaerheim48, Pagona Lagiou49, Jolanta Lissowska50, Ray Lowry51, Tatiana V Macfarlane52, Dana Mates53, Lorenzo Richiardi54, Peter Rudnai55, Neonilia Szeszenia-Dabrowska56, David Zaridze57, Ariana Znaor58, Mark Lathrop59,60, Paul Brennan36, Stefania Bandinelli61, Timothy M Frayling62, Jack M Guralnik63, Yuri Milaneschi64, John R B Perry62, David Altshuler65–70, Roberto Elosua71, Sek Kathiresan65,68,72, Gavin Lucas71, Olle Melander73, Christopher J O’Donnell74, Veikko Salomaa75, Stephen M Schwartz16, Benjamin F Voight76, Brenda W Penninx77,78, Johannes H Smit77,78, Nicole Vogelzangs77,78, Dorret I Boomsma79, Eco J C de Geus79, Jacqueline M Vink79, Gonneke Willemsen79, Stephen J Chanock80, Fangyi Gu81, Susan E Hankinson82, David J Hunter81, Albert Hofman83, Henning Tiemeier83,84, Andre G Uitterlinden83,85, Cornelia M van Duijn83,86, Stefan Walter83,87, Daniel I Chasman88, Brendan M Everett88,89, Guillaume Paré88, Paul M Ridker88,89, Ming D Li90, Hermine H Maes91,92, Janet Audrain-McGovern93, Danielle Posthuma94,95, Laura M Thornton96, Caryn Lerman93,97, Jaakko Kaprio26,75,98, Jed E Rose99, John P A Ioannidis100–102, Peter Kraft81, Dan-Yu Lin103 & Patrick F Sullivan1,2
1Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, USA. 2University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA. 3Human Genetics Center and Institute for Molecular Medicine, University of Texas Health Science Center, Houston, Texas, USA. 4Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA. 5Division of Cardiology, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy. 6Statistical Laboratory, Centre for Mathematical Sciences, University of Cambridge, Cambridge, UK. 7Department of Applied Health Sciences, University of Pavia, Pavia, Italy. 8Department of Internal Medicine and Medical Specialties, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico, Ospedale Maggiore, Mangiagalli e Regina Elena, University of Milan, Milan, Italy. 9Department of Cardiology, Azienda Ospedaliera Niguarda Ca’ Granda, Milan, Italy. 10HudsonAlpha Institute for Biotechnology, Huntsville, Alabama, USA. 11Cardiovascular Medicine, Stanford University, Stanford, California, USA. 12Stanford Prevention Research Center, Stanford University, Stanford, California, USA. 13Kaiser Permanente Northern California Division of Research, Oakland, California, USA. 14National Institute on Aging, Baltimore, Maryland, USA. 15Medstart Research Institute, National Institute on Aging, Baltimore, Maryland, USA. 16Cardiovascular Health Research Unit, University of Washington, Seattle, Washington, USA. 17Department of Medicine, University of Washington, Seattle, Washington, USA. 18Division of Public Health Sciences, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA. 19Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA. 20Department of Biostatistics, University of Washington, Seattle, Washington, USA. 21Department of Epidemiology and Health Services, University of Washington, Seattle, Washington, USA. 22Group Health Research Institute, Seattle, Washington, USA. 23Department of Epidemiology, University of Washington, Seattle, Washington, USA. 24Department of Clinical Sciences, Diabetes and Endocrinology Unit, Lund University, Malmö, Sweden. 25Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA. 26Hjelt Institute, Department of Public Health, University of Helsinki, Helsinki, Finland. 27Diabetes Prevention Unit, National Institute for Health and Welfare, Helsinki, Finland. 28Finland South Ostrobothnia Central Hospital, Seinäjoki, Finland. 29Boston University School of Medicine, Boston, Massachusetts, USA. 30Boston University School of Public Health, Boston, Massachusetts, USA. 31Center for Population Studies, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA. 32Department of Medicine, Sections of Preventive Medicine and Cardiology, Boston University School of Medicine, Boston, Massachusetts, USA. 33Center for Psychiatric Genetics, NorthShore University HealthSystem Research Institute, Evanston, Illinois, USA. 34Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, California, USA. 35Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA. 36International Agency for Research on Cancer (IARC), Lyon, France. 37Institut Català d’Oncologia, Barcelona, Spain. 38General Hospital, Pordenone, Italy. 39Institute of Hygiene and Epidemiology, First Faculty of Medicine, Charles University, Prague, Czech Republic. 40Institut National de la santé et de la Recherche Medicalé (INSERM) U794, Paris, France. 41Institut Gustave Roussy, Villejuif, France. 42Department of Environmental Medicine and Public Health, University of Padua, Padua, Italy. 43University of Glasgow Medical Faculty Dental School, Glasgow, UK. 44Specialized Institute of Hygiene and Epidemiology, Banska Bystrica, Slovakia. 45Department of Cancer Epidemiology and Genetics, Masaryk Memorial Cancer Institute, Brno, Czech Republic. 46Palacky University, Olomouc, Czech Republic. 47Trinity College School of Dental Science, Dublin, Ireland. 48Cancer Registry of Norway, Oslo, Norway. 49University of Athens School of Medicine, Athens, Greece. 50Department of Cancer Epidemiology and Prevention, Maria Sklodowska-Curie Cancer Center and Institute of Oncology, Warsaw, Poland. 51University of Newcastle Dental School, Newcastle, UK. 52University of Aberdeen School of Medicine, Aberdeen, UK. 53Institute of Public Health, Bucharest, Romania. 54Center for Experimental Research and Medical Studies, University of Turin, Turin, Italy. 55National Institute of Environmental Health, Budapest, Hungary. 56Department of Epidemiology, Institute of Occupational Medicine, Lodz, Poland. 57Institute of Carcinogenesis, Cancer Research Centre, Moscow, Russia. 58Croatian National Cancer Registry, Zagreb, Croatia. 59Centre National de Genotypage, Institut Genomique, Comissariat à l’énergie Atomique, Evry, France. 60Fondation Jean Dausset-Centre d‘Étude du Polymorphisme Humain (CEPH), Paris, France. 61Geriatric Unit, Azienda Sanitaria di Firenze, Florence, Italy. 62Genetics of Complex Traits, Peninsula Medical School, The University of Exeter, Exeter, UK. 63Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, Maryland, USA. 64Tuscany Health Regional Agency, Florence, Italy. 65Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. 66Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, USA. 67Diabetes Unit, Massachusetts General Hospital, Boston, Massachusetts, USA. 68Center for Human Genetics Research, Massachusetts General Hospital, Boston, Massachusetts, USA. 69Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA. 70Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA. 71Cardiovascular Epidemiology and Genetics, Institut Municipal d’Investigacio Medica, Barcelona, Spain. 72Harvard Medical School, Boston, Massachusetts, USA. 73Department of Clinical Sciences, Hypertension and Cardiovascular Diseases, University Hospital Malmö, Lund University, Malmö, Sweden. 74National Heart, Lung, and Blood Institute’s Framingham Heart Study, Framingham, Massachusetts, USA. 75National Institute for Health and Welfare (THL), Helsinki, Finland. 76Program in Medical and Population Genetics, Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA. 77EMGO Institute, Vrije Universiteit (VU) Medical Center, Amsterdam, The Netherlands. 78Department of Psychiatry, VU University Medical Center, Amsterdam, The Netherlands. 79Biological Psychology, VU University Amsterdam, Amsterdam, The Netherlands. 80Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA. 81Program in Molecular and Genetic Epidemiology, Department of Epidemiology, Harvard University, Boston, Massachusetts, USA. 82Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA. 83Department of Epidemiology, Erasmus Medical Center, Member of the Netherlands Consortium on Healthy Aging, Rotterdam, The Netherlands. 84Department of Child and Adolescent Psychiatry, Erasmus Medical Center, Rotterdam, The Netherlands. 85Department of Internal Medicine, Erasmus Medical Center, Rotterdam, The Netherlands. 86Centre for Medical Systems Biology, Erasmus Medical Center, Rotterdam, The Netherlands. 87Department of Public Health, Erasmus Medical Center, Rotterdam, The Netherlands. 88Division of Preventive Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA. 89Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA. 90Department of Psychiatry and Neurobehavioural Sciences, University of Virginia, Charlottesville, Virginia, USA. 91Virginia Institute for Psychiatric and Behavioral Genetics, Virginia Commonwealth University, Richmond, Virginia, USA. 92Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, USA. 93Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA. 94Department of Functional Genomics, VU Amsterdam, Amsterdam, The Netherlands. 95Department of Medical Genomics, VU University Medical Center Amsterdam, Amsterdam, The Netherlands. 96Department of Psychiatry, University of North Carolina, Chapel Hill, North Carolina, USA. 97Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania, USA. 98Institute for Molecular Medicine, University of Helsinki, Helsinki, Finland. 99Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina, USA. 100Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece. 101Tufts Clinical and Translational Science Institute, Tufts University School of Medicine, Boston, Massachusetts, USA. 102Center for Genetic Epidemiology and Modeling, Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts, USA. 103Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina, USA. Correspondence should be addressed to H.F. (ude.cnu.dem@grebruf_aneleh) or P.F.S. (ude.cnu.dem@villusfp).
Note: Supplementary information is available on the Nature Genetics website.
AUTHOR CONTRIBUTIONSTAG: study conception, design, management: H.F., P.F.S., Y.K., J. Dackor; TAG Statistical Working Group: D.-Y.L., P.K., J.P.A.I., D.P., H.F., Y.K., J. Dackor, S.P.F., N.F., E.H.L., J.D.M., J.M.V., D.I.B., D.L., B.M.E., E.L.T., B. McKnight, P.F.S., D. Absher; TAG Phenotype Working Group: C. Lerman, J.K., H.H.M., L.M.T., J.A.-M., E.H.L., J.E.R., M.D.L., J.M.V., H.F., Y.K., J. Dackor, S.P.F., P.F.S., E.L.T.; data analysis: Y.K., D.M.A., F.G., E.H.L., J.D.M., J.M.V., A.U.J., L. Bernardinelli, S.R.P., S.-J.H., B.M.E., C. Ladenvall, J.R.B.P., T.T., E.L.T., J.C.B., G.L., S.W.; TAG Manuscript Writing Group: H.F., Y.K., J. Dackor, P.F.S., C. Lerman, M.D.L., J.K., J.A.-M., P.K. All authors reviewed and approved the final version of the manuscript. The corresponding authors had access to the full data set of summary results contributed by each study.
ARIC: study conception, design, management: E.B.; phenotype collection, data management: N.F.; sample processing and genotyping: N.F.; data analysis: Y.K., N.F.
Atherosclerosis Thrombosis and Vascular Biology Italian Study Group: study conception, design, management: L. Bernardinelli, P.M.M., P.A.M., D. Ardissino; phenotype collection, data management: F.M., L. Bernandinelli; data analysis: L. Bernandinelli.
ADVANCE: study conception, design, management: S.P.F., D. Absher, T.Q., C.I., T.L.A., J.W.K.; phenotype collection, data management: S.P.F., T.Q., C.I., T.L.A., J.W.K.; sample processing and genotyping: D. Absher, T.Q.; data analysis: S.P.F., D. Absher, T.L.A., J.W.K.
Baltimore Longitudinal Study of Aging: study conception, design, management: L. Ferrucci; phenotype collection, data management: L. Ferrucci; data analysis: T.T.
CHS: study conception, design, management: B.M.P., J.C.B., C.D.F.; phenotype collection, data management: B.M.P.; sample processing and genotyping: T.H., K.D.T.; data analysis: B.M.P., E.L.T., J.C.B., B. McKnight.
DGI: study conception, design, management: L.G.; phenotype collection, data management: P.A.; data analysis: P.A., C. Ladenvall.
FUSION: study conception, design, management: K.L.M., M.B.; phenotype collection, data management: H.M.S., J.T.; data analysis: H.M.S., A.U.J.
Framingham Heart Study: study conception, design, management: R.S.V., E.J.B., D.L.; phenotype collection, data management: S.R.P., R.S.V., S.-J.H., E.J.B., D.L.; data analysis: S.R.P., S.-J.H.
GAIN: study conception, design, management: D.F.L., P.V.G.; phenotype collection, data management: A.R.S., D.F.L., J. Duan, J.S., P.V.G.; sample processing and genotyping: J. Duan, P.V.G.; data analysis: A.R.S., D.F.L., J. Duan, J.S., P.V.G. IARC/ARCAGE/Central European GWAS: phenotype collection, data management: D.Z., N.S.-D., J.L., P.R., E.F., D.M., V.B., L. Foretova, V.J., S. Benhamou, P.L., I.H., L.R., K.K., A.A., X.C., T.V.M., L. Barzan, C.C., R.L., D.I. Conway, A.Z., C.M.H., P.B.; sample processing and genotyping: J.D.M., M.L., P.B.; data analysis: E.H.L., J.D.M.
InCHIANTI: study conception, design, management: T.M.F., J.M.G., S. Bandinelli; phenotype collection, data management: Y.M.; data analysis: J.R.B.P.
MIGEN: study conception, design, management: R.E., V.S., O.M., C.J.O., D. Altshuler; phenotype collection, data management: G.L., S.M.S., R.E., V.S., B.F.V., O.M., S.K., C.J.O.; sample processing and genotyping: S.K., D. Altshuler; data analysis: G.L., B.F.V., D. Altshuler
NESDA: study conception, design, management: B.W.P., J.H.S.; phenotype collection, data management: B.W.P., J.H.S., N.V.; sample processing and genotyping: B.W.P., J.H.S.; data analysis: N.V.
NTR: study conception, design, management: D.I.B., G.W., E.J.C.d.G.; phenotype collection, data management: D.I.B., G.W., E.J.C.d.G., J.M.V.; sample processing and genotyping: D.I.B., G.W., E.J.C.d.G.; data analysis: J.M.V.
NHS: phenotype collection, data management: S.E.H., D.J.H., P.K., F.G.; sample processing and genotyping: S.J.C., S.E.H., D.J.H., P.K.; data analysis: S.J.C., F.G., P.K.
Rotterdam: study conception, design, management: A.H.; phenotype collection, data management: H.T., A.G.U.; sample processing and genotyping: H.T., A.G.U.; data analysis: H.T., A.G.U., S.W., C.M.v.D.
WGHS: study conception, design, management: B.M.E., G.P., D.I. Chasman, P.M.R.; phenotype collection, data management: B.M.E., G.P., D.I. Chasman, P.M.R.; sample processing and genotyping: G.P., D.I. Chasman; data analysis: B.M.E., G.P., D.I. Chasman.
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The authors declare no competing financial interests.
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