Abstract
To characterise type 2 diabetes (T2D) associated variation across the allele frequency spectrum, we conducted a meta-analysis of genome-wide association data from 26,676 T2D cases and 132,532 controls of European ancestry after imputation using the 1000 Genomes multi-ethnic reference panel. Promising association signals were followed-up in additional data sets (of 14,545 or 7,397 T2D cases and 38,994 or 71,604 controls). We identified 13 novel T2D-associated loci (p<5×10-8), including variants near the GLP2R, GIP, and HLA-DQA1 genes. Our analysis brought the total number of independent T2D associations to 128 distinct signals at 113 loci. Despite substantially increased sample size and more complete coverage of low-frequency variation, all novel associations were driven by common SNVs. Credible sets of potentially causal variants were generally larger than those based on imputation with earlier reference panels, consistent with resolution of causal signals to common risk haplotypes. Stratification of T2D-associated loci based on T2D-related quantitative trait associations revealed tissue-specific enrichment of regulatory annotations in pancreatic islet enhancers for loci influencing insulin secretion, and in adipocytes, monocytes and hepatocytes for insulin action-associated loci. These findings highlight the predominant role played by common variants of modest effect and the diversity of biological mechanisms influencing T2D pathophysiology.
Type 2 diabetes (T2D) has rapidly increased in prevalence in recent years and represents a major component of the global disease burden (1). Previous efforts to use genome-wide association studies (GWAS) to characterise the genetic component of T2D risk have largely focused on common variants (minor allele frequency [MAF]>5%). These studies have identified close to 100 loci, almost all of them currently defined by common alleles associated with modest (typically 5-20%) increases in T2D risk (2–6). Direct sequencing of whole genomes or exomes offers the most comprehensive approach for extending discovery efforts to the detection of low-frequency (0.5%<MAF<5%) and rare (MAF<0.5%) risk and protective alleles, some of which might have greater impact on individual predisposition. However, extensive sequencing has, thus far, been limited to relatively small sample sizes (at most, a few thousand cases), restricting power to detect rarer risk alleles, even if they are of large effect (7–9). Whilst evidence of rare variant associations has been detected in some candidate gene studies (10,11), the largest study to date, involving exome sequencing in ~13,000 subjects, found little trace of rare variant association effects (9).
Here, we implement a complementary strategy that makes use of imputation into existing GWAS samples from the DIAbetes Genetics Replication And Meta-analysis (DIAGRAM) Consortium with sequence-based reference panels (12). This strategy allows the detection of common and low-frequency (but not rare) variant associations in extremely large samples (13), and facilitates the fine-mapping of causal variants. We performed a European ancestry meta-analysis of GWAS with 26,676 T2D cases and 132,532 controls, and followed up our findings in additional independent European ancestry studies of 14,545 T2D cases and 38,994 controls genotyped using the Metabochip (4). All contributing studies were imputed against the March 2012 multi-ethnic 1000 Genomes Project (1000G) reference panel of 1,092 whole-genome sequenced individuals (12). Our study provides near-complete evaluation of common variants with much improved coverage of low-frequency variants, and the combined sample size considerably exceeds that of the largest previous T2D GWAS meta-analyses in individuals of European ancestry (4). In addition to genetic discovery, we fine-map novel and established T2D-associated loci to identify regulatory motifs and cell types enriched for potential causal variants, and pathways through which T2D-associated loci increase disease susceptibility.
Research Design and Methods
Research participants
The DIAGRAM stage 1 meta-analyses is comprised of 26,676 T2D cases and 132,532 controls (effective sample size, Neff=72,143 individuals, defined as 4/[(1/Ncases)+(1/Ncontrols)]) from 18 studies genotyped using commercial genome-wide single-nucleotide variant (SNV) arrays (Supplementary Table 1). The Metabochip stage 2 follow up is comprised of 14,545 T2D cases and 38,994 controls (Neff=38,645) from 16 non-overlapping stage 1 studies (4,14). We performed additional follow-up in 2,796 T2D cases and 4,601 controls from the EPIC-InterAct (15) and 9,747 T2D cases and 61,857 controls from the GERA study (16) (Supplementary Material).
Statistical analyses
We imputed autosomal and X chromosome SNVs using the all ancestries 1000G reference panel (1,092 individuals from Africa, Asia, Europe, and the Americas [March, 2012 release]) using miniMAC (17) or IMPUTE2 (18). After imputation, from each study we removed monomorphic variants or those with imputation quality r2-hat<0.3 (miniMAC) or proper-info<0.4 (IMPUTE2, SNPTEST). Each study performed T2D association analysis using logistic regression, adjusting for age, sex, and principal components for ancestry, under an additive genetic model. We performed inverse-variance weighted fixed-effect meta-analyses of the 18 stage 1 GWAS (Supplementary Table 1). Fifteen of the 18 studies repeated analyses also adjusting for body mass index (BMI). SNVs reaching suggestive significance p<10-5 in the stage 1 meta-analysis were followed-up. Novel loci were selected using the threshold for genome-wide significance (p<5×10-8) in the combined stage 1 and stage 2 meta-analysis. For the 23 variants with no proxy (r2≥0.6) available in Metabochip with 1000G imputation in the fine-mapping regions, the stage 1 result was followed-up in EPIC-InterAct and GERA (Neff=40,637), both imputed to 1000G variant density (Supplementary Material).
Approximate conditional analysis with GCTA
We performed approximate conditional analysis in the stage 1 sample using GCTA v1.24 (19,20). We analysed SNVs in the 1Mb-window around each lead variant, conditioning on the lead SNV at each locus (Supplementary Material) (21). We considered loci to contain multiple distinct signals if multiple SNVs reached locus-wide significance (p<10-5), accounting for the approximate number of variants in each 1Mb window (14).
Fine-mapping analyses using credible set mapping
To identify 99% credible sets of causal variants for each distinct association signal, we performed fine-mapping for loci at which the lead independent SNV reached p<5×10-4 in the stage 1 meta-analysis. We performed credible set mapping using the T2D stage 1 meta-analysis results to obtain the minimal set of SNVs with cumulative posterior probability>0.99 (Supplementary Material).
Type 1 diabetes (T1D)/T2D discrimination analysis
Given the overlap between loci previously associated with T1D and the associated T2D loci, we used an inverse variance weighted Mendelian randomisation approach (22) to test whether this was likely to reflect misclassification of T1D cases as individuals with T2D in the current study (Supplementary Material).
Expression quantitative trait locus (eQTL) analysis
To look for potential biological overlap of T2D lead variants and eQTL variants, we extracted the lead (most significantly associated) eQTL for each tested gene from existing datasets for a range of tissues (Supplementary Material). We concluded that a lead T2D SNV showed evidence of association with gene expression if it was in high LD (r2>0.8) with the lead eQTL SNV (p<5×10-6).
Hierarchical clustering of T2D-related metabolic phenotypes
Starting with the T2D associated SNVs, we obtained T2D-related quantitative trait Z-scores from published HapMap-based GWAS meta-analysis for: fasting glucose, fasting insulin adjusted for BMI, homeostasis model assessment for beta-cell function (HOMA-B), homeostasis model assessment for insulin resistance (HOMA-IR) (23); 2-hour glucose adjusted for BMI (24); proinsulin (25); corrected insulin response (CIR) (26); BMI (27); high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total cholesterol, and triglycerides (28). When an association result for a SNV was not available, we used the results for the variant in highest LD and only for variants with r2>0.6. We performed clustering of phenotypic effects using Z-scores for association with T2D risk alleles and standard methods (Supplementary Material) (29).
Functional annotation and enrichment analysis
We tested for enrichment of genomic and epigenomic annotations using chromatin states for 93 cell types (after excluding cancer cell lines) from the NIH Epigenome Roadmap project, and binding sites for 165 transcription factors (TF) from ENCODE (30) and Pasquali et al. (31). Using fractional logistic regression, we then tested for the effect of variants with each cell type and TF annotation on the variant posterior probabilities (πc) using all variants within 1Mb of the lead SNV for each distinct association signal from the fine-mapping analyses (Supplementary Material). In each analysis, we considered an annotation significant if it reached a Bonferroni-corrected p<1.9×10-4 (i.e. 0.05/258 annotations).
Pathway analyses with DEPICT
We used the Data-driven Expression Prioritized Integration for Complex Traits (DEPICT) tool (32) to (i) prioritize genes that may represent promising candidates for T2D pathophysiology, and (ii) identify reconstituted gene sets that are enriched in genes from associated regions and might be related to T2D biological pathways. As input, we used independent SNVs from the stage 1 meta-analysis SNVs with p<10-5 and lead variants at established loci (Supplementary Material). For the calculation of empirical enrichment p values, we used 200 sets of SNVs randomly drawn from entire genome within regions matching by gene density; we performed 20 replications for false discovery rate (FDR) estimation.
Results
Novel loci detected in T2D GWAS and Metabochip-based follow-up
The stage 1 GWAS meta-analysis included 26,676 T2D cases and 132,532 controls and evaluated 12.1M SNVs, of which 11.8M were autosomal and 260k mapped to the X chromosome. Of these, 3.9M variants had MAF between 0.5% and 5%, a near fifteen-fold increase in the number of low-frequency variants tested for association compared to previous array-based T2D GWAS meta-analyses (2,4) (Supplementary Table 2). Of the 52 signals showing promising evidence of association (p<10-5) in stage 1, 29 could be followed up in the stage 2 Metabochip data. In combined stage 1 and stage 2 data, 13 novel loci were detected at genome-wide significance (Table 1, Figure 1, Supplementary Figure 1A-D, Supplementary Table 3).
Table 1. Novel loci associated with T2D from the combination of 1000G-imputed GWAS meta-analysis (stage 1) and Metabochip follow-up (stage 2).
Locus name* | Stage 1 | Stage 2 | Stage1+Stage2 | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chr:Position | SNV† | EA/NEA | EAF | OR (CI 95%) | P-value | Chr:Position | SNV‡ | r2 with lead SNV | EA/NEA | EAF | OR (95% CI) | P-value | OR (95% CI) ¢ | P-value | |
ACSL1 | 4:185708807 | rs60780116 | T/C | 0.84 | 1.09 (1.06-1.13) | 7.38x10-8 | 4:185714289 | rs1996546 | 0.62 | G/T | 0.86 | 1.08 (1.03-1.13) | 5.60x10-4 | 1.09 (1.06-1.12) | 1.98x10-10 |
HLA-DQA1 | 6:32594309 | rs9271774 | C/A | 0.74 | 1.10 (1.06-1.14) | 3.30x10-7 | 6:32594328 | rs9271775 | 0.91 | T/C | 0.80 | 1.08 (1.03-1.13) | 7.59x10-4 | 1.09 (1.06-1.12) | 1.11x10-9 |
SLC35D3 | 6:137287702 | rs6918311 | A/G | 0.53 | 1.07 (1.04-1.10) | 6.67x10-7 | 6:137299152 | rs4407733 | 0.92 | A/G | 0.52 | 1.05 (1.02-1.08) | 1.63x10-3 | 1.06 (1.04-1.08) | 6.78x10-9 |
MNX1 | 7:157027753 | rs1182436 | C/T | 0.80 | 1.08 (1.05-1.12) | 8.30x10-7 | 7:157031407 | rs1182397 | 0.92 | G/T | 0.85 | 1.06 (1.02-1.11) | 4.38x10-3 | 1.08 (1.05-1.10) | 1.71x10-8 |
ABO | 9:136155000 | rs635634 | T/C | 0.18 | 1.08 (1.05-1.12) | 3.59x10-7 | 9:136154867 | rs495828 | 0.83 | T/G | 0.20 | 1.06 (1.01-1.10) | 1.23x10-2 | 1.08 (1.05-1.10) | 2.30x10-8 |
PLEKHA1 | 10:124186714 | rs2292626 | C/T | 0.50 | 1.09 (1.06-1.11) | 1.75x10-12 | 10:124167512 | rs2421016 | 0.99 | C/T | 0.50 | 1.05 (1.02-1.08) | 2.30x10-3 | 1.07 (1.05-1.09) | 1.51x10-13 |
HSD17B12 | 11:43877934 | rs1061810 | A/C | 0.28 | 1.08 (1.05-1.11) | 5.29x10-9 | 11:43876435 | rs3736505 | 0.92 | G/A | 0.30 | 1.05 (1.01-1.08) | 4.82x10-3 | 1.07 (1.05-1.09) | 3.95x10-10 |
MAP3K11 | 11:65364385 | rs111669836 | A/T | 0.25 | 1.07 (1.04-1.10) | 7.43x10-7 | 11:65365171 | rs11227234 | 1.00 | T/G | 0.24 | 1.05 (1.01-1.08) | 8.77x10-3 | 1.06 (1.04-1.09) | 4.12x10-8 |
NRXN3 | 14:79945162 | rs10146997 | G/A | 0.21 | 1.07 (1.04-1.10) | 4.59x10-6 | 14:79939993 | rs17109256 | 0.98 | A/G | 0.21 | 1.07 (1.03-1.11) | 1.27x10-4 | 1.07 (1.05-1.09) | 2.27x10-9 |
CMIP | 16:81534790 | rs2925979 | T/C | 0.30 | 1.08 (1.05-1.10) | 2.72x10-8 | 16:81534790 | rs2925979 | 1.00 | T/C | 0.31 | 1.05 (1.02-1.08) | 3.06x10-3 | 1.07 (1.04-1.09) | 2.27x10-9 |
ZZEF1 | 17:4014384 | rs7224685 | T/G | 0.30 | 1.07 (1.04-1.10) | 2.00x10-7 | 17:3985864 | rs8068804 | 0.95 | A/G | 0.31 | 1.07 (1.03-1.11) | 4.11x10-4 | 1.07 (1.05-1.09) | 3.23x10-10 |
GLP2R | 17:9780387 | rs78761021 | G/A | 0.34 | 1.07 (1.05-1.10) | 5.49x10-8 | 17:9791375 | rs17676067 | 0.87 | C/T | 0.31 | 1.03 (1.00-1.07) | 3.54x10-2 | 1.06 (1.04-1.08) | 3.04x10-8 |
GIP | 17:46967038 | rs79349575 | A/T | 0.51 | 1.07 (1.04-1.09) | 2.61x10-7 | 17:47005193 | rs15563 | 0.78 | G/A | 0.54 | 1.04 (1.01-1.07) | 2.09x10-2 | 1.06 (1.03-1.08) | 4.43x10-8 |
The nearest gene is listed; this does not imply this is the biologically relevant gene;
Lead SNV types: all map outside transcripts except rs429358 (missense variant) and rs1061810 (3’UTR);
Stage 2: proxy SNV (r2>0.6 with stage 1 lead SNV) was used when no stage 1 SNV was available.
The meta-analysis OR is aligned to the Stage 1 SNV risk allele. Abbreviations: Chr – chromosome, CI – confidence interval, EA - effect allele, EAF – effect allele frequency, OR – odds ratio, NEA – non-effect allele.
Lead SNVs at all 13 novel loci were common. Although detected here using 1000G imputed data, all 13 were well captured by variants in the HapMap CEU reference panel (2 directly, 10 via proxies with r2>0.8, and one via proxy with r2=0.62) (Supplementary Materials). At all 13, lead variants defined through 1000G and those seen when the SNP density was restricted to HapMap content, had broadly similar evidence of association and were of similar frequency (Supplementary Figure 2; Supplementary Table 3). Throughout this manuscript, loci are named for the gene nearest to the lead SNV, unless otherwise specified (Table 1, Supplementary Materials: Biology box).
Adjustment for BMI revealed no additional genome-wide significant associations for T2D and, at most known and novel loci, there were only minimal differences in statistical significance and estimated T2D effect size between BMI-adjusted and unadjusted models. The four signals at which we observed a significant effect of BMI adjustment (pheterogeneity<4.4×10-4; based on 0.05/113 variants currently or previously reported to be associated with T2D at genome-wide significance) were FTO and MC4R (at which the T2D association is known to reflect a primary effect on BMI), and TCF7L2 and SLC30A8 (at which T2D associations were strengthened after BMI-adjustment) (Supplementary Figure 3; Supplementary Table 4).
Insights into genetic architecture of T2D
In this meta-analysis, we tested 3.9M low-frequency variants (r2≥0.3 or proper-info≥0.4; minor allele present in ≥3 studies) for T2D association, constituting 96.7% of the low-frequency variants ascertained by the 1000G European Panel (March 2012) (Supplementary Table 2). For variants with risk-allele frequencies (RAF) of 0.5%, 1%, or 5%, we had 80% power to detect association (p<5×10-8) for allelic ORs of 1.80, 1.48, and 1.16, respectively, after accounting for imputation quality (Figure 1, Supplementary Table 5). Despite the increased coverage and sample size, we identified no novel low-frequency variants at genome-wide significance (Figure 1).
Since we had only been able to test 29 of the 52 promising stage 1 signals on the Metabochip, we investigated whether this failure to detect low-frequency variant associations with T2D could be a consequence of selective variant inclusion on the Metabochip. Amongst the remaining 23 variants, none reached genome-wide significance after aggregating with GWAS data available from EPIC-InterAct. Six of these 23 SNVs had MAF<5%, and for these we performed additional follow-up in the GERA study. However, none reached genome-wide significance in a combined analysis of stage 1, EPIC-InterAct and GERA (a total of 39,219 cases and 198,990 controls) (Supplementary Table 6). Therefore, despite substantially enlarged sample sizes that would have allowed us to detect low-frequency risk alleles with modest effect sizes, the overwhelming majority of variants for which T2D-association can be detected with these sample sizes are themselves common.
To identify loci containing multiple distinct signals, we performed approximate conditional analysis within the established and novel GWAS loci and detected two such novel common variant signals (Supplementary Table 7) (19,20). At the ANKRD55 locus, we identified a previously-unreported distinct (pconditional<10-5) association signal led by rs173964 (pconditional=3.54×10-7, MAF=26%) (Supplementary Table 7, Supplementary Figure 4). We also observed multiple signals of association at loci with previous reports of such signals (4,14), including CDKN2A/B (3 signals in total), DGKB, KCNQ1 (6 signals), HNF4A, and CCND2 (3 signals) (Supplementary Table 7, Supplementary Figure 4). At CCND2, in addition to the main signal with lead SNV rs4238013, we detected: (i) a novel distinct signal led by a common variant, rs11063018 (pconditional=2.70×10-7, MAF=19%); and (ii) a third distinct signal led by a low-frequency protective allele (rs188827514, MAF=0.6%; ORconditional=0.60, pconditional=1.24×10-6) (Supplementary Figure 5A, Supplementary Table 7), which represents the same distinct signal as that at rs76895963 (pconditional=1.0) reported in the Icelandic population (Supplementary Figure 5B) (7). At HNF4A, we confirm recent analyses (obtained in partially-overlapping data) (14) that a low-frequency missense variant (rs1800961, p.Thr139Ile, MAF=3.7%) is associated with T2D, and is distinct from the known common variant GWAS signal (which we map here to rs12625671).
We evaluated the trans-ethnic heterogeneity of allelic effects (i.e. discordance in the direction and/or magnitude of estimated odds ratios) at novel loci on the basis of Cochran’s Q statistics from the largest T2D trans-ancestry GWAS meta-analysis to date (2). Using reported summary statistics from that study, we observed no significant evidence of heterogeneity of effect size (Bonferroni correction pCochran’s Q<0.05/13=0.0038) between major ancestral groups at any of the 13 loci (Supplementary Table 8). These results are consistent with these loci being driven by common causal variants that are widely distributed across populations.
1000G variant density for identification of potentially causal genetic variants
We used credible set fine-mapping (33) to investigate whether 1000G imputation allowed us to better resolve the specific variants driving 95 distinct T2D association signals at 82 loci (Supplementary Material). 99% credible sets included between 1 and 7,636 SNVs; 25 included fewer than 20 SNVs, 16 fewer than 10 (Supplementary Tables 9 and 10). We compared 1000G-based credible sets with those constructed from HapMap SNVs alone (Figure 2B, Supplementary Table 9). At all but three of the association signals (two at KCNQ1 and rs1800961 at HNF4A), 1000G imputation resulted in larger credible sets (median increase of 34 variants) spanning wider genomic intervals (median interval size increase of 5kb) (Figure 2B, Supplementary Table 9). The 1000G-defined credible sets included >85% of the SNVs in the corresponding HapMap sets (Supplementary Table 9). Despite the overall larger credible sets, we asked whether 1000G imputation enabled an increase in the posterior probability afforded to the lead SNVs, but found no evidence to this effect (Figure 2C).
Within the 50 loci previously associated with T2D in Europeans (4) which had at least modest evidence of association in the current analyses (p<5x10-4), we asked whether the lead SNV in 1000G-imputed analysis was of similar frequency to that observed in HapMap analyses. Only at TP53INP1, was the most strongly associated 1000G-imputed SNV (rs11786613, OR=1.21, p=1.6x10-6, MAF=3.2%) of substantially lower frequency than the lead HapMap-imputed SNV (3) (rs7845219, MAF=47.7%, Figure 2A). rs11786613 was neither present in HapMap, nor on the Metabochip (Supplementary Figure 6). Reciprocal conditioning of this low-frequency SNV and the previously identified common lead SNV (rs7845219: OR=1.05, p=5.0x10-5, MAF=47.5%) indicated that the two signals were likely to be distinct but the signal at rs11786613 did not meet our threshold (pconditional<10-5) for locus-wide significance (Supplementary Figure 4).
Pathophysiological insights from novel T2D associations
Among the 13 novel T2D-associated loci, many (such as those near HLA-DQA1, NRXN3, GIP, ABO and CMIP) included variants previously implicated in predisposition to other diseases and traits (r2>0.6 with the lead SNV) (Supplementary Table 3, Supplementary Materials: Biology box). For example, the novel association at SNV rs1182436 lies ~120Kb upstream of MNX1, a gene implicated in pancreatic hypoplasia and neonatal diabetes (34–36).
The lead SNV rs78761021 at the GLP2R locus, encoding the receptor for glucagon-like peptide 2, is in strong LD (r2=0.87) with a common missense variant in GLP2R (rs17681684, D470N, p=3×10-7). These signals were strongly dependent and mutually extinguished in reciprocal conditional analyses, consistent with the coding variant being causal and implicating GLP2R as the putative causal gene (Supplementary Figure 7). While previously suggested to regulate energy balance and glucose tolerance (37), GLP2R has primarily been implicated in gastrointestinal function (38,39). In contrast, GLP1R, encoding the GLP-1 receptor (the target for a major class of T2D therapies (40)) is more directly implicated in pancreatic islet function and variation at this gene has been associated with glucose levels and T2D risk (41).
We also observed associations with T2D centred on rs9271774 near HLA-DQA1 (Table 1), a region showing a particularly strong association with T1D (42). There is considerable heterogeneity within, and overlap between, the clinical presentations of T1D and T2D, but these can be partially resolved through measurement of islet cell autoantibodies (43). Such measures were not uniformly available across studies contributing to our meta-analysis (Supplementary Table 1). We therefore considered whether the adjacency between T1D- and T2D-risk loci was likely to reflect misclassification of individuals with autoimmune diabetes as cases in the present study.
Three lines of evidence make this unlikely. First, the lead T1D-associated SNV in the HLA region (rs6916742) was only weakly associated with T2D in the present study (p=0.01), and conditioning on this variant had only modest impact on the T2D-association signal at rs9271774 (punconditional=3.3x10-7; pconditional=9.1x10-6). Second, of 52 published genome-wide significant T1D-association GWAS signals, 50 were included in the current analysis: only six of these reached even nominal association with T2D (p<0.05; Supplementary Figure 8), and at one of these six (BCAR1), the T1D risk-allele was protective for T2D. Third, in genetic risk score (GRS) analyses, the combined effect of these 50 T1D signals on T2D risk was of only nominal significance (OR =1.02[1.00, 1.03], p=0.026), and significance was eliminated when the 6 overlapping loci were excluded (OR =1.00[0.98, 1.02], p=0.73). In combination, these findings argue against substantial misclassification and indicate that the signal at HLA-DQA1 is likely to be a genuine T2D signal.
Potential genes and pathways underlying the T2D loci: eQTL and pathway analysis
Cis-eQTLs analyses highlighted four genes as possible effector transcripts: ABO (pancreatic islets), PLEKHA1 (whole blood), HSD17B12 (adipose, liver, muscle, whole blood) at the respective loci, and HLA-DRB5 expression (adipose, pancreatic islets, whole blood) at the HLA-DQA1 locus (Supplementary Table 11).
We next asked whether large-scale gene expression data, mouse phenotypes, and protein-protein interaction (PPI) networks could implicate specific gene candidates and gene sets in the aetiology of T2D. Using DEPICT (32), 29 genes were prioritised as driving observed associations (FDR<0.05), including ACSL1 and CMIP among the genes mapping to the novel loci (Supplementary Table 12). These analyses also identified 20 enriched reconstituted gene sets (FDR<5%) falling into 4 groups (Supplementary Figure 9; complete results, including gene prioritisation, can be downloaded from https://onedrive.live.com/redir?resid=7848F2AF5103AA1B!1505&authkey=!AIC31supgUwjZVU&ithint=file%2cxlsx). These included pathways related to mammalian target of rapamycin (mTOR), based on co-regulation of the IDE, TLE1, SPRY2, CMIP, and MTMR3 genes (44).
Overlap of associated variants with regulatory annotations
We observed significant enrichment for T2D-associated credible set variants in pancreatic islet active enhancers and/or promoters (log odds [β]=0.74, p=4.2x10-8) and FOXA2 binding sites (β=1.40, p=4.1×10-7), as previously reported (Supplementary Table 13) (14). We also observed enrichment for T2D-associated variants in coding exons (β=1.56, p=7.9x10-5), in EZH2-binding sites across many tissues (β=1.35, p=5.3x10-6), and in binding sites for NKX2.2 (β=1.73, p=4.1x10-8) and PDX1 (β=1.46, p=7.4x10-6) in pancreatic islets (Supplementary Figure 10).
Even though credible sets were generally larger, analyses performed on the 1000G imputed results produced stronger evidence of enrichment than equivalent analyses restricted to SNVs present in HapMap. This was most notably the case for variants within coding exons (β=1.56, p=7.9x10-5 in 1000G compared to β=0.68, p=0.62 in HapMap), and likely reflects more complete capture of the true causal variants in the more densely imputed credible sets. Single lead SNVs overlapping an enriched annotation accounted for the majority of the total posterior probability (πc>0.5) at seven loci. For example, the lead SNV (rs8056814) at BCAR1 (πc=0.57) overlaps an islet enhancer (Supplementary Figure 11A), while the newly-identified low-frequency signal at TP53INP1 overlaps an islet promoter element (rs117866713; πc=0.53) (Figure 2D) (31).
We applied hierarchical clustering to the results of diabetes-related quantitative trait associations for the set of T2D-associated loci from the present study, identifying three main clusters of association signals with differing impact on quantitative traits (Supplementary Table 9). The first, including GIPR, C2CDC4A, CDKAL1, GCK, TCF7L2, GLIS3, THADA, IGF2BP2, and DGKB involved loci with a primary impact on insulin secretion and processing (26,29). The second cluster captured loci (including PPARG, KLF14, and IRS1) disrupting insulin action. The third cluster, showing marked associations with BMI and lipid levels, included NRXN3, CMIP, APOE, and MC4R, but not FTO, which clustered alone.
In regulatory enhancement analyses, we observed strong tissue-specific enrichment patterns broadly consistent with the phenotypic characteristics of the physiologically-stratified locus subsets. The cluster of loci disrupting insulin secretion showed the most marked enrichment for pancreatic islet regulatory elements (β=0.91, p=9.5×10-5). In contrast, the cluster of loci implicated in insulin action was enriched for annotations from adipocytes (β=1.3, p=2.7×10-11) and monocytes (β=1.4, p=1.4×10-12), and that characterised by associations with BMI and lipids showed preferential enrichment for hepatic annotations (β=1.15, p=5.8×10-4) (Figure 3A-C). For example, at the novel T2D-associated CMIP locus, previously associated with adiposity and lipid levels (28,45), the lead SNV (rs2925979, πc=0.91) overlaps an active enhancer element in both liver and adipose tissue, among others (Supplementary Figure 11B).
Discussion
In this large-scale study of T2D genetics, in which individual variants were assayed in up to 238,209 subjects, we identify 13 novel T2D-associated loci at genome-wide significance and refine causal variant location for the 13 novel and 69 established T2D loci. We also provide evidence for enrichment in regulatory elements at associated loci in tissues relevant for T2D, and demonstrate tissue-specific enrichment in regulatory annotations when T2D loci were stratified according to inferred physiological mechanism.
Together with loci reported in other recent publications (9), we calculate that the present analysis brings the total number of independent T2D associations to 128 distinct signals at 113 loci (Supplementary Table 3). Lead SNVs at all 13 novel loci were common (MAF > 0.15) and of comparable effect size (1.07≤OR≤1.10) to previously-identified common variant associations (2,4). Associations at the novel loci showed homogeneous effects across diverse ethnicities, supporting the evidence for coincident common risk alleles across ancestry groups (2). Moreover, we conclude that misclassification of diabetes subtype is not a major concern for these analyses and that the HLA-DQA1 signal represents genuine association with T2D, independent of nearby signals that influence T1D.
We observed a general increase in the size of credible sets with 1000G imputation compared to HapMap imputation. This is likely due to improved enumeration of potential causal common variants on known risk haplotypes, rather than resolution towards low-frequency variants of larger effect driving common variant associations. These findings are consistent with the inference (arising also from the other analyses reported here) that the T2D-risk signals identified by GWAS are overwhelmingly driven by common causal variants. In such a setting, imputation with denser reference panels, at least in ethnically restricted samples, provides more complete elaboration of the allelic content of common risk haplotypes. Finer resolution of those haplotypes that would provide greater confidence in the location of causal variants will likely require further expansion of trans-ethnic fine-mapping efforts (2). The distinct signals at the established CCND2 and TP53INP1 loci point to contributions of low-frequency variant associations of modest effect, but indicate that even larger samples will be required to robustly detect association signals at low frequency. Such new large datasets might be used to expand the follow-up of suggestive signals from our analysis.
The discovery of novel genome-wide significant association signals in the current analysis is attributable primarily to increased sample size, rather than improved genomic coverage. Although we queried a large proportion of the low-frequency variants present in the 1000G European reference haplotypes, and had >80% power to detect genome-wide significant associations with OR>1.8 for the tested low-frequency risk variants, we found no such low-frequency variant associations in either established or novel loci. Whilst low-frequency variant coverage in the present study was not complete, this observation adds to the growing evidence (2,4,9,46) that few low-frequency T2D-risk variants with moderate to strong effect sizes exist in European ancestry samples, and is consistent with a primary role for common variants of modest effect in T2D risk. The present study reinforces the conclusions from a recent study which imputed from whole-genome sequencing data - from 2,657 European T2D cases and controls, rather than 1000G - into a set of GWAS studies partially overlapping with the present meta-analysis. We demonstrated that the failure to detect low frequency associations in that study is not overcome by a substantial increase in sample size (9). It is worth emphasising that we did not, in this study, have sufficient imputation quality to test for T2D associations with rare variants and we cannot evaluate the collective contribution of variants with MAF<0.5% to T2D risk.
The development of T2D involves dysfunction of multiple mechanisms across several distinct tissues (9,29,31,47,48). When coupled with functional data, we saw larger effect estimates for enrichment of coding variants than observed with HapMap SNVs alone, consistent with more complete recovery of the causal variants through imputation using a denser reference panel. The functional annotation analyses also demonstrated that the stratification of T2D-risk loci according to primary physiological mechanism resulted in evidence for consistent and appropriate tissue-specific effects on transcriptional regulation. These analyses exemplify the use of a combination of human physiology and genomic annotation to position T2D GWAS loci with respect to the cardinal mechanistic components of T2D development. Extension of this approach is likely to provide a valuable in silico strategy to aid prioritisation of tissues for mechanistic characterisation of genetic associations. Using the hypothesis-free pathway analysis of T2D associations with DEPICT (32), we highlighted a causal role of mTOR signalling pathway in the aetiology of T2D not observed from individual loci associations. The mTOR pathway has previously been implicated in the link between obesity, insulin resistance, and T2D from cell and animal models (44,49).
The current results emphasize that progressively larger sample sizes, coupled with higher density sequence-based imputation (13), will continue to represent a powerful strategy for genetic discovery in T2D, and in complex diseases and traits more generally. At known T2D-associated loci, identification of the most plausible T2D causal variants will likely require large-scale multi-ethnic analyses, where more diverse haplotypes, reflecting different patterns of LD, in combination with functional (31,50,51) data allow refinement of association signals to smaller numbers of variants (2).
Supplementary Material
Acknowledgements
ARIC: The Atherosclerosis Risk in Communities Study is carried out as a collaborative study supported by National Heart, Lung, and Blood Institute contracts (HHSN268201100005C, HHSN268201100006C, HHSN268201100007C, HHSN268201100008C, HHSN268201100009C, HHSN268201100010C, HHSN268201100011C, and HHSN268201100012C), R01HL087641, R01HL59367 and R01HL086694; National Human Genome Research Institute contract U01HG004402; and National Institutes of Health contract HHSN268200625226C. Infrastructure was partly supported by Grant Number UL1RR025005, a component of the National Institutes of Health and NIH Roadmap for Medical Research. We wish to acknowledge the many contributions of Dr. Linda Kao, who helped direct the diabetes genetics working group in the ARIC Study until her passing in 2014. We thank the staff and participants of the ARIC study for their important contributions.
BioMe: This work is funded by The Mount Sinai IPM Biobank Program is supported by The Andrea and Charles Bronfman Philanthropies.
D2D2007: The FIN-D2D study has been financially supported by the hospital districts of Pirkanmaa, South Ostrobothnia, and Central Finland, the Finnish National Public Health Institute (National Institute for Health and Welfare), the Finnish Diabetes Association, the Ministry of Social Affairs and Health in Finland, the Academy of Finland (grant number 129293), the European Commission (Directorate C-Public Health grant agreement number 2004310), and Finland’s Slottery Machine Association.
DANISH: The study was funded by the Lundbeck Foundation and produced by the Lundbeck Foundation Centre for Applied Medical Genomics in Personalised Disease Prediction, Prevention and Care (LuCamp, www.lucamp.org), and Danish Council for Independent Research. The Novo Nordisk Foundation Center for Basic Metabolic Research is an independent Research Center at the University of Copenhagen, partially funded by an unrestricted donation from the Novo Nordisk Foundation (www.metabol.ku.dk).
DGI: This work was supported by a grant from Novartis. The Botnia study was supported by grants from the Signe and Ane Gyllenberg Foundation, Swedish Cultural Foundation in Finland, Finnish Diabetes Research Society, the Sigrid Juselius Foundation, Folkhälsan Research Foundation, Foundation for Life and Health in Finland, Jakobstad Hospital, Medical Society of Finland, Närpes Research Foundation and the Vasa and Närpes Health centers, the European Community's Seventh Framework Programme (FP7/2007-2013), the European Network for Genetic and Genomic Epidemiology (ENGAGE), the Collarative European Effort to Develop Diabetes Diagnostics (CEED/2008-2012), and the Swedish Research Council, including a Linné grant (No.31475113580).
DGDG: This work was funded by Genome Canada, Génome Quebec, and the Canada Foundation for Innovation. Cohort recruitment was supported by the Association Française des Diabetiques, INSERM, CNAMTS, Centre Hospitalier Universitaire Poitiers, La Fondation de France and the Endocrinology-Diabetology Department of the Corbeil-Essonnes Hospital. C. Petit, J-P. Riveline and S. Franc were instrumental in recruitment and S. Brunet, F. Bacot, R. Frechette, V. Catudal, M. Deweirder, F. Allegaert, P. Laflamme, P. Lepage, W. Astle, M. Leboeuf and S. Leroux provided technical assistance. K. Shazand and N. Foisset provided organizational guidance. We thank all individuals who participated as cases or controls in this study.
deCODE: The study was funded by deCODE Genetics/Amgen inc. and partly supported by ENGAGE HEALTH-F4-2007-201413. We thank the Icelandic study participants and the staff of deCODE Genetics core facilities and recruitment center for their contributions to this work.
DILGOM: The DILGOM study was supported by the Academy of Finland (grant number 118065). V.Salomaa was supported by the Academy of Finland (grant number 139635) and the Finnish Foundation for Cardiovascular Research. S.Mannisto was supported by the Academy of Finland (grant numbers 136895 and 263836). S.R. was supported by the Academy of Finland Center of Excellence in Complex Disease Genetics (grant numbers 213506 and 129680), the Academy of Finland (grant number 251217), the Finnish Foundation for Cardiovascular Research, and the Sigrid Juselius Foundation.
DRsEXTRA: The DR's EXTRA Study was supported by the Ministry of Education and Culture of Finland (627;2004-2011), the Academy of Finland (grant numbers 102318 and 123885), Kuopio University Hospital, the Finnish Diabetes Association, the Finnish Heart Association, the Päivikki and Sakari Sohlberg Foundation, and by grants from European Commission FP6 Integrated Project (EXGENESIS, LSHM-CT-2004-005272), the City of Kuopio, and the Social Insurance Institution of Finland (4/26/2010).
EGCUT: EU grant through the European Regional Development Fund (Project No. 2014-2020.4.01.15-0012), PerMedI (TerVE EstRC), EU H2020 grants 692145, 676550, 654248, and Estonian Research Council, Grant IUT20-60.
EMIL-Ulm: The EMIL Study received support by the State of Baden-Württemberg, Germany, the City of Leutkirch, Germany, and the German Research Council to B.O.B. (GRK 1041). The Ulm Diabetes Study Group received support by the German Research Foundation (DFG-GRK 1041) and the State of Baden-Wuerttemberg Centre of Excellence Metabolic Disorders to B.O.B.
EPIC-InterAct : This work was funded by the EU FP6 programme (grant number LSHM_CT_2006_037197). We thank all EPIC participants and staff for their contribution to the EPIC-InterAct study. We thank the lab team at the MRC Epidemiology Unit for sample management. I.B. was supported by grant WT098051.
FHS: This research was conducted in part using data and resources from the Framingham Heart Study of the National Heart Lung and Blood Institute of the National Institutes of Health and Boston University School of Medicine. The analyses reflect intellectual input and resource development from the Framingham Heart Study investigators participating in the SNP Health Association Resource (SHARe) project. This work was partially supported by the National Heart, Lung and Blood Institute's Framingham Heart Study (contract number N01-HC-25195) and its contract with Affymetrix, Inc for genotyping services (contract number N02-HL-6-4278). A portion of this research utilized the Linux Cluster for Genetic Analysis (LinGA-II) funded by the Robert Dawson Evans Endowment of the Department of Medicine at Boston University School of Medicine and Boston Medical Center. The work is also supported by National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK) R01 DK078616 to J.B.M., J.D. and J.C.F., NIDDK K24 DK080140 to J.B.M., NIDDK U01 DK085526 to H.C., J.D. and J.B.M., and a Massachusetts General Hospital Research Scholars Award to J.C.F..
FUSION: This work was funded by NIH grants U01 DK062370, R01-HG000376, R01-DK072193, and NIH intramural project number ZIA HG000024. Genome-wide genotyping was conducted by the Johns Hopkins University Genetic Resources Core. Facility SNP Center at the Center for Inherited Disease Research (CIDR), with support from CIDR NIH contract number N01-HG-65403.
GERA: Data came from a grant, the Resource for Genetic Epidemiology Research in Adult Health and Aging (RC2 AG033067; Schaefer and Risch, PIs) awarded to the Kaiser Permanente Research Program on Genes, Environment, and Health (RPGEH) and the UCSF Institute for Human Genetics. The RPGEH was supported by grants from the Robert Wood Johnson Foundation, the Wayne and Gladys Valley Foundation, the Ellison Medical Foundation, Kaiser Permanente Northern California, and the Kaiser Permanente National and Northern California Community Benefit Programs.
GoDARTS: This study was funded by the Wellcome Trust (084727/Z/08/Z, 085475/Z/08/Z, 085475/B/08/Z) and as part of the EU IMI-SUMMIT program. We acknowledge the support of the Health Informatics Centre, University of Dundee for managing and supplying the anonymised data and NHS Tayside, the original data owner. We are grateful to all the participants who took part in the Go-DARTS study, to the general practitioners, to the Scottish School of Primary Care for their help in recruiting the participants, and to the whole team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists, and nurses.
HEINZ NIXDORF RECALL (HNR): We thank the Heinz Nixdorf Foundation [Chairman: M. Nixdorf; Past Chairman: G. Schmidt (deceased)], the German Ministry of Education and Science (BMBF) for the generous support of this study. An additional research grant was received from Imatron Inc., South San Francisco, CA, which produced the EBCT scanners, and GE-Imatron, South San Francisco, CA, after the acquisition of Imatron Inc. We acknowledge the support of the Sarstedt AG & Co. (Nümbrecht, Germany) concerning laboratory equipment. We received support of the Ministry of Innovation, Science and Research, Nordrhine Westfalia for the genotyping of the Heinz Nixdorf Recall study participants. Technical support for the imputation of the Heinz Nixdorf Recall Study data on the Supercomputer Cray XT6m was provided by the Center for Information and Media Services, University of Duisburg-Essen. We are indebted to all the study participants and to the dedicated personnel of both the study center of the Heinz Nixdorf Recall study and the EBT-scanner facilities D. Grönemeyer, Bochum, and R. Seibel, Mülheim, as well as to the investigative group, in particular to U. Roggenbuck, U. Slomiany, E. M. Beck, A. Öffner, S. Münkel, M. Bauer, S. Schrader, R. Peter, and H. Hirche.
HPFS: This work was funded by the NIH grants P30 DK46200, DK58845, U01HG004399, and UM1CA167552.
IMPROVE and SCARFSHEEP: The IMPROVE study was supported by the European Commission (LSHM-CT-2007-037273), the Swedish Heart-Lung Foundation, the Swedish Research Council (8691), the Knut and Alice Wallenberg Foundation, the Foundation for Strategic Research, the Torsten and Ragnar Söderberg Foundation, the Strategic Cardiovascular Programme of Karolinska Institutet, and the Stockholm County Council (560183). The SCARFSHEEP study was supported by the Swedish Heart-Lung Foundation, the Swedish Research Council, the Strategic Cardiovascular Programme of Karolinska Institutet, the Strategic Support for Epidemiological Research at Karolinska Institutet, and the Stockholm County Council. B.S. acknowledges funding from the Magnus Bergvall Foundation and the Foundation for Old Servants. M.F. acknowledges funding from the Swedish e-science Research Center (SeRC). R.J.S. is supported by the Swedish Heart-Lung Foundation, the Tore Nilsson Foundation, the Thuring Foundation, and the Foundation for Old Servants. S.E.H. is funded by the British Heart Foundation (PG08/008).
KORAgen: The KORA research platform (KORA, Cooperative Research in the Region of Augsburg) was initiated and financed by the Helmholtz Zentrum München - German Research Center for Environmental Health, which is funded by the German Federal Ministry of Education and Research (BMBF) and by the State of Bavaria. The KORA research was supported within the Munich Center of Health Sciences (MC Health), Ludwig-Maximilians-Universität, as part of LMUinnovativ. Part of this project was supported by the German Center for Diabetes Research (DZD).
METSIM: The METSIM study was funded by the Academy of Finland (grant numbers 77299 and 124243).
NHS: This work was funded by the NIH grants P30 DK46200, DK58845, U01HG004399, and UM1CA186107.
PPP-MALMO-BOTNIA (PMB): The PPP-Botnia study has been financially supported by grants from the Sigrid Juselius Foundation, the Folkhälsan Research Foundation, the Ministry of Education in Finland, the Nordic Center of Excellence in Disease Genetics, the European Commission (EXGENESIS), the Signe and Ane Gyllenberg Foundation, the Swedish Cultural Foundation in Finland, the Finnish Diabetes Research Foundation, the Foundation for Life and Health in Finland, the Finnish Medical Society, the Paavo Nurmi Foundation, the Helsinki University Central Hospital Research Foundation, the Perklén Foundation, the Ollqvist Foundation, and the Närpes Health Care Foundation. The study has also been supported by the Municipal Heath Care Center and Hospital in Jakobstad and Health Care Centers in Vasa, Närpes and Korsholm. Studies from Malmö were supported by grants from the Swedish Research Council (SFO EXODIAB 2009-1039, LUDC 349-2008-6589, 521-2010-3490, 521-2010-3490, 521-2010-3490, 521-2007-4037, 521-2008-2974, ANDIS 825-2010-5983), the Knut and Alice Wallenberg Foundation (KAW 2009.0243), the Torsten and Ragnar Söderbergs Stiftelser (MT33/09), the IngaBritt and Arne Lundberg’s Research Foundation (grant number 359), and the Heart-Lung Foundation.
PIVUS and ULSAM: This work was funded by the Swedish Research Council, Swedish Heart-Lung Foundation, Knut och Alice Wallenberg Foundation, and Swedish Diabetes Foundation. Genome-wide genotyping was funded by the Wellcome Trust and performed by the SNP&SEQ Technology Platform in Uppsala (www.genotyping.se). We thank Tomas Axelsson, Ann-Christine Wiman, and Caisa Pöntinen for their assistance with genotyping. The SNP Technology Platform is supported by Uppsala University, Uppsala University Hospital, and the Swedish Research Council for Infrastructures.
Rotterdam Study: This work is funded by Erasmus Medical Center and Erasmus University, Rotterdam, Netherlands Organization for the Health Research and Development (ZonMw), the Research Institute for Diseases in the Elderly (RIDE), the Ministry of Education, Culture and Science, the Ministry for Health, Welfare and Sports, the European Commission (DG XII), and the Municipality of Rotterdam. This study is funded by the Research Institute for Diseases in the Elderly (014-93-015; RIDE2), the Netherlands Genomics Initiative (NGI)/Netherlands Organisation for Scientific Research (NWO) project nr. 050-060-810. The generation and management of GWAS genotype data for the Rotterdam Study is supported by the Netherlands Organisation of Scientific Research NWO Investments (nr. 175.010.2005.011, 911-03-012). We thank Pascal Arp, Mila Jhamai, Marijn Verkerk, Lizbeth Herrera and Marjolein Peters for their help in creating the GWAS database. The authors thank the study participants, the staff from the Rotterdam Study and the participating general practitioners and pharmacists.
SWEDISH TWIN REGISTRY (STR): This work was supported by grants from the US National Institutes of Health (AG028555, AG08724, AG04563, AG10175, AG08861), the Swedish Research Council, the Swedish Heart-Lung Foundation, the Swedish Foundation for Strategic Research, the Royal Swedish Academy of Science, and ENGAGE (within the European Union FP7 HEALTH-F4-2007-201413). Genotyping was performed by the SNP&SEQ Technology Platform in Uppsala (www.genotyping.se). We thank Tomas Axelsson, Ann-Christine Wiman, and Caisa Pöntinen for their excellent assistance with genotyping. The SNP Technology Platform is supported by Uppsala University, Uppsala University Hospital, and the Swedish Research Council for Infrastructures.
WARREN 2/58BC and WELLCOME TRUST CASE CONTROL CONSORTIUM (WTCCC): Collection of the UK type 2 diabetes cases was supported by Diabetes UK, BDA Research, and the UK Medical Research Council (Biomedical Collections Strategic Grant G0000649). The UK Type 2 Diabetes Genetics Consortium collection was supported by the Wellcome Trust (Biomedical Collections Grant GR072960). Metabochip genotyping was supported by the Wellcome Trust (Strategic Awards 076113, 083948, and 090367, and core support for the Wellcome Trust Centre for Human Genetics 090532), and analysis by the European Commission (ENGAGE HEALTH-F4-2007-201413), MRC (Project Grant G0601261), NIDDK (DK073490, DK085545 and DK098032), and Wellcome Trust (083270 and 098381). WTCCC is funded by Wellcome 076113 and 085475.
Institutional support for study design and analysis: This work was funded by MRC (G0601261), NIDDK (RC2-DK088389, U01-DK105535, U01-DK085545, U01-DK105535), FP7 (ENGAGE HEALTH-F4-2007-201413) and the Wellcome Trust (090532, 098381, 106130, and 090367)
Individual funding for study design and analysis: J.T.-F. is a Marie-Curie Fellow (PIEF-GA-2012-329156). M.K. is supported by the European Commission under the Marie Curie Intra-European Fellowship (project MARVEL, PIEF-GA-2013-626461). C.Langenberg, R.A.S. and N.J.W. are funded by the Medical Research Council (MC_UU_12015/1). L.M. is partially supported by 2010-2011 PRIN funds of the University of Ferrara – Holder: Prof. Guido Barbujani – and in part sponsored by the European Foundation for the Study of Diabetes (EFSD) Albert Renold Travel Fellowships for Young Scientists, and by the fund promoting internationalisation efforts of the University of Ferrara – Holder: Prof. Chiara Scapoli. A.P.M. is a Wellcome Trust Senior Fellow in Basic Biomedical Science (grant number WT098017). M.I.M. is a Wellcome Trust Senior Investigator. J.R.B.P is supported by the Wellcome Trust (WT092447MA). T.H.P. is supported by The Danish Council for Independent Research Medical Sciences (FSS) The Lundbeck Foundation and The Alfred Benzon Foundation. I.P. was in part funded by the Elsie Widdowson Fellowship, the Wellcome Trust Seed Award in Science (205915/Z/17/Z) and the European Union’s Horizon 2020 research and innovation programme (DYNAhealth, project number 633595). B.F.V. is supported by the NIH/NIDDK (R01DK101478) and the American Heart Association (13SDG14330006). E. Z. is supported by the Wellcome Trust (098051). S.E.H. is funded by British Heart Foundation PG08/008 and UCL BRC. V.Salomaa was supported by the Academy of Finland (grant # 139635) and by the Finnish Foundation for Cardiovascular Research.
Footnotes
AUTHOR CONTRIBUTIONS:
Writing and co-ordination group: R.A.S., L.J.S., R.M., L.M., K.J.G., M.K., J.D., A.P.M., M.B., M.I.M., I.P.
Central analysis group: R.A.S., L.J.S., R.M., L.M., C.M., A.P.M., M.B., M.I.M., I.P.
Additional lead analysts: L.M., K.J.G., M.K., N.P., T.H.P., A.D.J., J.D.E., T.F., Y.Lee, J.R.B.P., L.J., A.U.J.
GWAS cohort-level primary analysts: R.A.S., L.J.S., R.M., K.J.G., V.S., G.T., L.Q., N.R.V., A.Mahajan, H.Chen, P.A., B.F.V., H.G., M.M., J.S.R., N.W.R., N.R., L.C.K., E.M.L., S.M.W., C.Fuchsberger, P.K., C.M., P.C., M.L., Y.L., C.D., D.T., L.Y., C.Langenberg, A.P.M., I.P.
Metabochip cohort-level primary analysts: T.S., H.K., H.C., L.E., S.G., T.M.T, M.F., R.J.S.
Cohort sample collection, phenotyping, genotyping or additional analysis: R.A.S., H.G., R.B., A.B.H., A.K., G.S., N.D.K., J.L., L.L., T.M., M.R., B.T., T.E., E.M., C.F., C.L., D.Rybin, B.I., V.L., T.T., D.J.C., J.S.P., N.G., C.T.H., M.E.J., T.J., A.L., M.C.C., R.M.D., D.J.H., P.Kraft, Q.S., S.E., K.R.O., J.R.B.P., A.R.W., E.Z., J.T.-F., G.R.A., L.L.B., P.S.C., H.M.S., H.A.K., L.K., B.S., T.W.M., M.M.N., S.P., D.B., K.G., S.E.H., E.Tremoli, N.K., J.M., G.Steinbach, R.W., J.G.E., S.M., L.P., E.T., G.C., E.E., S.L., B.G., K.L., O.M., E.P.B., O.G., D.R., M.Blüher, P.Kovacs, A.T., N.M.M., C.S., T.M.F., A.T.H., I.B., B.B., H.B., P.W.F., A.B.G., D.P., Y.T.v.d.S., C.Langenberg, N.J.W., K.Strauch, M.B., M.I.M.
Metabochip cohort principal investigators: R.E., K.J., S.Moebus, U.d.F., A.H., M.S., P.D., P.J.D., T.M.F., A.T.H., S.R., V.Salomaa, N.L.P., B.O.B., R.N.B., F.S.C., K.L.M., J.T., T.H., O.B.P., I.B., C.Langenberg, N.J.W.
GWAS cohort principal investigators: L.Lannfelt, E.I., L.Lind, C.M.L., S.C., P.F., R.J.F.L., B.B., H.B., P.W.F., A.B.G., D.P., Y.T.v.d.S., D.A., L.C.G., C.Langenberg, N.J.W., E.S., C.Duijn van, J.C.F., J.B.M., E.B., C.G., K.Strauch, A.M., A.D.M., C.N.A.P., F.B.H., U.T., K.S., J.D., M.B., M.I.M.
GUARANTOR’S STATEMENT
Dr. Inga Prokopenko is the guarantor of this work and, as such, had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
COMPETING FINANCIAL INTERESTS STATEMENT
Inês Barroso and spouse own stock in GlaxoSmithKline and Incyte.
Jose C Florez has received consulting honoraria from Pfizer and PanGenX.
Valgerdur Steinthorsdottir, Gudmar Thorleifsson, Augustine Kong, Unnur Thorsteinsdottir, and Kari Stefansson are employed by deCODE 4 Genetics/Amgen inc.
Erik Ingelsson is a scientific advisor for Precision Wellness, Cellink and Olink Proteomics for work unrelated to the present project.
Mark I McCarthy sits on Advisory Panels for Pfizer and NovoNordisk, has received honoraria from Pfizer NovoNordisk and EliLilly, and is also a recipient of research funding from Pfizer, NovoNordisk, EliLilly, Takeda, Sanofi-Aventis, Merck, Boehringer-Ingelheim, Astra Zeneca, Janssen, Roche, Servier and Abbvie.
Robert A Scott, Laura J Scott, Reedik Mägi, Letizia Marullo, Kyle J Gaulton, Marika Kaakinen, Natalia Pervjakova, Tune H Pers, Andrew D Johnson, John D Eicher, Anne U Jackson, Teresa Ferreira, Yeji Lee, Clement Ma, Lu Qi, Natalie R Van Zuydam, Anubha Mahajan, Han Chen, Peter Almgren, Ben F Voight, Harald Grallert, Martina Müller-Nurasyid, Janina S Ried, N William Rayner, Neil Robertson, Lennart C Karssen, Elisabeth M van Leeuwen, Sara M Willems, Christian Fuchsberger, Phoenix Kwan, Tanya M Teslovich, Pritam Chanda, Man Li, Yingchang Lu, Christian Dina, Dorothee Thuillier, Loic Yengo, Longda Jiang, Thomas Sparso, Hans A Kestler, Himanshu Chheda, Lewin Eisele, Stefan Gustafsson, Mattias Frånberg, Rona J Strawbridge, Rafn Benediktsson, Astradur B Hreidarsson, Gunnar Sigurðsson, Nicola D Kerrison, Jian'an Luan, Liming Liang, Thomas Meitinger, Michael Roden, Barbara Thorand, Tõnu Esko, Evelin Mihailov, Caroline Fox, Ching-Ti Liu, Denis Rybin, Bo Isomaa, Valeriya Lyssenko, Tiinamaija Tuomi, David J Couper, James S Pankow, Niels Grarup, Christian T Have, Marit E Jørgensen, Torben Jørgensen, Allan Linneberg, Marilyn C Cornelis, Rob M van Dam, David J Hunter, Peter Kraft, Qi Sun, Sarah Edkins, Katharine R Owen, John RB Perry, Andrew R Wood, Eleftheria Zeggini, Juan Tajes-Fernandes, Goncalo R Abecasis, Lori L Bonnycastle, Peter S Chines, Heather M Stringham, Heikki A Koistinen, Leena Kinnunen, Bengt Sennblad, Thomas W Mühleisen, Markus M Nöthen, Sonali Pechlivanis, Damiano Baldassarre, Karl Gertow, Steve E Humphries, Elena Tremoli, Norman Klopp, Julia Meyer, Gerald Steinbach, Roman Wennauer, Johan G Eriksson, Satu Männistö, Leena Peltonen, Emmi Tikkanen, Guillaume Charpentier, Elodie Eury, Stéphane Lobbens, Bruna Gigante, Karin Leander, Olga McLeod, Erwin P Bottinger, Omri Gottesman, Douglas Ruderfer, Matthias Blüher, Peter Kovacs, Anke Tonjes, Nisa M Maruthur, Chiara Scapoli, Raimund Erbel, Karl-Heinz Jöckel, Susanne Moebus, Ulf de Faire, Anders Hamsten, Michael Stumvoll, Panagiotis Deloukas, Peter J Donnelly, Timothy M Frayling, Andrew T Hattersley, Samuli Ripatti, Veikko Salomaa, Nancy L Pedersen, Bernhard O Boehm, Richard N Bergman, Francis S Collins, Karen L Mohlke, Jaakko Tuomilehto, Torben Hansen, Oluf Pedersen, Lars Lannfelt, Lars Lind, Cecilia M Lindgren, Stephane Cauchi, Philippe Froguel, Ruth JF Loos, Beverley Balkau, Heiner Boeing, Paul W Franks, Aurelio Barricarte Gurrea, Domenico Palli, Yvonne T van der Schouw, David Altshuler, Leif C Groop, Claudia Langenberg, Nicholas J Wareham, Eric Sijbrands, Cornelia M van Duijn, James B Meigs, Eric Boerwinkle, Christian Gieger, Konstantin Strauch, Andres Metspalu, Andrew D Morris, Colin NA Palmer, Frank B Hu, Josée Dupuis, Andrew P Morris, Michael Boehnke, and Inga Prokopenko declare to have no competing financial interest.
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