@article {1347, title = {Association of genetic variants and incident coronary heart disease in multiethnic cohorts: the PAGE study.}, journal = {Circ Cardiovasc Genet}, volume = {4}, year = {2011}, month = {2011 Dec}, pages = {661-72}, abstract = {

BACKGROUND: Genome-wide association studies identified several single nucleotide polymorphisms (SNP) associated with prevalent coronary heart disease (CHD), but less is known of associations with incident CHD. The association of 13 published CHD SNPs was examined in 5 ancestry groups of 4 large US prospective cohorts.

METHODS AND RESULTS: The analyses included incident coronary events over an average 9.1 to 15.7 follow-up person-years in up to 26 617 white individuals (6626 events), 8018 black individuals (914 events), 1903 Hispanic individuals (113 events), 3669 American Indian individuals (595 events), and 885 Asian/Pacific Islander individuals (66 events). We used Cox proportional hazards models (with additive mode of inheritance) adjusted for age, sex, and ancestry (as needed). Nine loci were statistically associated with incident CHD events in white participants: 9p21 (rs10757278; P=4.7 {\texttimes} 10(-41)), 16q23.1 (rs2549513; P=0.0004), 6p24.1 (rs499818; P=0.0002), 2q36.3 (rs2943634; P=6.7 {\texttimes} 10(-6)), MTHFD1L (rs6922269, P=5.1 {\texttimes} 10(-10)), APOE (rs429358; P=2.7{\texttimes}10(-18)), ZNF627 (rs4804611; P=5.0 {\texttimes} 10(-8)), CXCL12 (rs501120; P=1.4 {\texttimes} 10(-6)) and LPL (rs268; P=2.7 {\texttimes} 10(-17)). The 9p21 region showed significant between-study heterogeneity, with larger effects in individuals age 55 years or younger and in women. Inclusion of coronary revascularization procedures among the incident CHD events introduced heterogeneity. The SNPs were not associated with CHD in black participants, and associations varied in other US minorities.

CONCLUSIONS: Prospective analyses of white participants replicated several reported cross-sectional CHD-SNP associations.

}, keywords = {Aged, Aged, 80 and over, Continental Population Groups, Coronary Disease, Female, Genome-Wide Association Study, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide, Prospective Studies}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.111.960096}, author = {Franceschini, Nora and Carty, Cara and B{\r u}zkov{\'a}, Petra and Reiner, Alex P and Garrett, Tiana and Lin, Yi and V{\"o}ckler, Jens-S and Hindorff, Lucia A and Cole, Shelley A and Boerwinkle, Eric and Lin, Dan-Yu and Bookman, Ebony and Best, Lyle G and Bella, Jonathan N and Eaton, Charles and Greenland, Philip and Jenny, Nancy and North, Kari E and Taverna, Darin and Young, Alicia M and Deelman, Ewa and Kooperberg, Charles and Psaty, Bruce and Heiss, Gerardo} } @article {6083, title = {Fine-mapping and initial characterization of QT interval loci in African Americans.}, journal = {PLoS Genet}, volume = {8}, year = {2012}, month = {2012}, pages = {e1002870}, abstract = {

The QT interval (QT) is heritable and its prolongation is a risk factor for ventricular tachyarrhythmias and sudden death. Most genetic studies of QT have examined European ancestral populations; however, the increased genetic diversity in African Americans provides opportunities to narrow association signals and identify population-specific variants. We therefore evaluated 6,670 SNPs spanning eleven previously identified QT loci in 8,644 African American participants from two Population Architecture using Genomics and Epidemiology (PAGE) studies: the Atherosclerosis Risk in Communities study and Women{\textquoteright}s Health Initiative Clinical Trial. Of the fifteen known independent QT variants at the eleven previously identified loci, six were significantly associated with QT in African American populations (P<=1.20{\texttimes}10(-4)): ATP1B1, PLN1, KCNQ1, NDRG4, and two NOS1AP independent signals. We also identified three population-specific signals significantly associated with QT in African Americans (P<=1.37{\texttimes}10(-5)): one at NOS1AP and two at ATP1B1. Linkage disequilibrium (LD) patterns in African Americans assisted in narrowing the region likely to contain the functional variants for several loci. For example, African American LD patterns showed that 0 SNPs were in LD with NOS1AP signal rs12143842, compared with European LD patterns that indicated 87 SNPs, which spanned 114.2 Kb, were in LD with rs12143842. Finally, bioinformatic-based characterization of the nine African American signals pointed to functional candidates located exclusively within non-coding regions, including predicted binding sites for transcription factors such as TBX5, which has been implicated in cardiac structure and conductance. In this detailed evaluation of QT loci, we identified several African Americans SNPs that better define the association with QT and successfully narrowed intervals surrounding established loci. These results demonstrate that the same loci influence variation in QT across multiple populations, that novel signals exist in African Americans, and that the SNPs identified as strong candidates for functional evaluation implicate gene regulatory dysfunction in QT prolongation.

}, keywords = {African Americans, Aged, Computational Biology, Electrocardiography, European Continental Ancestry Group, Female, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Linkage Disequilibrium, Male, Metagenomics, Middle Aged, Polymorphism, Single Nucleotide, Quantitative Trait Loci, Quantitative Trait, Heritable, Risk Factors, Tachycardia, United States}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1002870}, author = {Avery, Christy L and Sethupathy, Praveen and Buyske, Steven and He, Qianchuan and Lin, Dan-Yu and Arking, Dan E and Carty, Cara L and Duggan, David and Fesinmeyer, Megan D and Hindorff, Lucia A and Jeff, Janina M and Klein, Liviu and Patton, Kristen K and Peters, Ulrike and Shohet, Ralph V and Sotoodehnia, Nona and Young, Alicia M and Kooperberg, Charles and Haiman, Christopher A and Mohlke, Karen L and Whitsel, Eric A and North, Kari E} } @article {6629, title = {Trans-ethnic fine-mapping of lipid loci identifies population-specific signals and allelic heterogeneity that increases the trait variance explained.}, journal = {PLoS Genet}, volume = {9}, year = {2013}, month = {2013 Mar}, pages = {e1003379}, abstract = {

Genome-wide association studies (GWAS) have identified ~100 loci associated with blood lipid levels, but much of the trait heritability remains unexplained, and at most loci the identities of the trait-influencing variants remain unknown. We conducted a trans-ethnic fine-mapping study at 18, 22, and 18 GWAS loci on the Metabochip for their association with triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), respectively, in individuals of African American (n = 6,832), East Asian (n = 9,449), and European (n = 10,829) ancestry. We aimed to identify the variants with strongest association at each locus, identify additional and population-specific signals, refine association signals, and assess the relative significance of previously described functional variants. Among the 58 loci, 33 exhibited evidence of association at P<1 {\texttimes} 10(-4) in at least one ancestry group. Sequential conditional analyses revealed that ten, nine, and four loci in African Americans, Europeans, and East Asians, respectively, exhibited two or more signals. At these loci, accounting for all signals led to a 1.3- to 1.8-fold increase in the explained phenotypic variance compared to the strongest signals. Distinct signals across ancestry groups were identified at PCSK9 and APOA5. Trans-ethnic analyses narrowed the signals to smaller sets of variants at GCKR, PPP1R3B, ABO, LCAT, and ABCA1. Of 27 variants reported previously to have functional effects, 74\% exhibited the strongest association at the respective signal. In conclusion, trans-ethnic high-density genotyping and analysis confirm the presence of allelic heterogeneity, allow the identification of population-specific variants, and limit the number of candidate SNPs for functional studies.

}, keywords = {African Americans, Apolipoproteins A, Cholesterol, HDL, Cholesterol, LDL, European Continental Ancestry Group, Genome-Wide Association Study, Humans, Lipoproteins, HDL, Lipoproteins, LDL, Proprotein Convertases, Serine Endopeptidases, Triglycerides}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1003379}, author = {Wu, Ying and Waite, Lindsay L and Jackson, Anne U and Sheu, Wayne H-H and Buyske, Steven and Absher, Devin and Arnett, Donna K and Boerwinkle, Eric and Bonnycastle, Lori L and Carty, Cara L and Cheng, Iona and Cochran, Barbara and Croteau-Chonka, Damien C and Dumitrescu, Logan and Eaton, Charles B and Franceschini, Nora and Guo, Xiuqing and Henderson, Brian E and Hindorff, Lucia A and Kim, Eric and Kinnunen, Leena and Komulainen, Pirjo and Lee, Wen-Jane and Le Marchand, Lo{\"\i}c and Lin, Yi and Lindstr{\"o}m, Jaana and Lingaas-Holmen, Oddgeir and Mitchell, Sabrina L and Narisu, Narisu and Robinson, Jennifer G and Schumacher, Fred and Stan{\v c}{\'a}kov{\'a}, Alena and Sundvall, Jouko and Sung, Yun-Ju and Swift, Amy J and Wang, Wen-Chang and Wilkens, Lynne and Wilsgaard, Tom and Young, Alicia M and Adair, Linda S and Ballantyne, Christie M and B{\r u}zkov{\'a}, Petra and Chakravarti, Aravinda and Collins, Francis S and Duggan, David and Feranil, Alan B and Ho, Low-Tone and Hung, Yi-Jen and Hunt, Steven C and Hveem, Kristian and Juang, Jyh-Ming J and Kes{\"a}niemi, Antero Y and Kuusisto, Johanna and Laakso, Markku and Lakka, Timo A and Lee, I-Te and Leppert, Mark F and Matise, Tara C and Moilanen, Leena and Nj{\o}lstad, Inger and Peters, Ulrike and Quertermous, Thomas and Rauramaa, Rainer and Rotter, Jerome I and Saramies, Jouko and Tuomilehto, Jaakko and Uusitupa, Matti and Wang, Tzung-Dau and Boehnke, Michael and Haiman, Christopher A and Chen, Yii-der I and Kooperberg, Charles and Assimes, Themistocles L and Crawford, Dana C and Hsiung, Chao A and North, Kari E and Mohlke, Karen L} } @article {6598, title = {Evidence of heterogeneity by race/ethnicity in genetic determinants of QT interval.}, journal = {Epidemiology}, volume = {25}, year = {2014}, month = {2014 Nov}, pages = {790-8}, abstract = {

BACKGROUND: QT interval (QT) prolongation is an established risk factor for ventricular tachyarrhythmia and sudden cardiac death. Previous genome-wide association studies in populations of the European descent have identified multiple genetic loci that influence QT, but few have examined these loci in ethnically diverse populations.

METHODS: Here, we examine the direction, magnitude, and precision of effect sizes for 21 previously reported SNPs from 12 QT loci, in populations of European (n = 16,398), African (n = 5,437), American Indian (n = 5,032), Hispanic (n = 1,143), and Asian (n = 932) descent as part of the Population Architecture using Genomics and Epidemiology (PAGE) study. Estimates obtained from linear regression models stratified by race/ethnicity were combined using inverse-variance weighted meta-analysis. Heterogeneity was evaluated using Cochran{\textquoteright}s Q test.

RESULTS: Of 21 SNPs, 7 showed consistent direction of effect across all 5 populations, and an additional 9 had estimated effects that were consistent across 4 populations. Despite consistent direction of effect, 9 of 16 SNPs had evidence (P < 0.05) of heterogeneity by race/ethnicity. For these 9 SNPs, linkage disequilibrium plots often indicated substantial variation in linkage disequilibrium patterns among the various racial/ethnic groups, as well as possible allelic heterogeneity.

CONCLUSIONS: These results emphasize the importance of analyzing racial/ethnic groups separately in genetic studies. Furthermore, they underscore the possible utility of trans-ethnic studies to pinpoint underlying casual variants influencing heritable traits such as QT.

}, keywords = {Aged, Continental Population Groups, Electrocardiography, Female, Genetic Predisposition to Disease, Haplotypes, Humans, Long QT Syndrome, Male, Middle Aged, Phenotype, Polymorphism, Single Nucleotide, Quantitative Trait Loci, Quantitative Trait, Heritable, Risk Factors}, issn = {1531-5487}, doi = {10.1097/EDE.0000000000000168}, author = {Seyerle, Amanda A and Young, Alicia M and Jeff, Janina M and Melton, Phillip E and Jorgensen, Neal W and Lin, Yi and Carty, Cara L and Deelman, Ewa and Heckbert, Susan R and Hindorff, Lucia A and Jackson, Rebecca D and Martin, Lisa W and Okin, Peter M and Perez, Marco V and Psaty, Bruce M and Soliman, Elsayed Z and Whitsel, Eric A and North, Kari E and Laston, Sandra and Kooperberg, Charles and Avery, Christy L} }