@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 {6634, title = {Evaluation of the metabochip genotyping array in African Americans and implications for fine mapping of GWAS-identified loci: the PAGE study.}, journal = {PLoS One}, volume = {7}, year = {2012}, month = {2012}, pages = {e35651}, abstract = {

The Metabochip is a custom genotyping array designed for replication and fine mapping of metabolic, cardiovascular, and anthropometric trait loci and includes low frequency variation content identified from the 1000 Genomes Project. It has 196,725 SNPs concentrated in 257 genomic regions. We evaluated the Metabochip in 5,863 African Americans; 89\% of all SNPs passed rigorous quality control with a call rate of 99.9\%. Two examples illustrate the value of fine mapping with the Metabochip in African-ancestry populations. At CELSR2/PSRC1/SORT1, we found the strongest associated SNP for LDL-C to be rs12740374 (p = 3.5 {\texttimes} 10(-11)), a SNP indistinguishable from multiple SNPs in European ancestry samples due to high correlation. Its distinct signal supports functional studies elsewhere suggesting a causal role in LDL-C. At CETP we found rs17231520, with risk allele frequency 0.07 in African Americans, to be associated with HDL-C (p = 7.2 {\texttimes} 10(-36)). This variant is very rare in Europeans and not tagged in common GWAS arrays, but was identified as associated with HDL-C in African Americans in a single-gene study. Our results, one narrowing the risk interval and the other revealing an associated variant not found in Europeans, demonstrate the advantages of high-density genotyping of common and rare variation for fine mapping of trait loci in African American samples.

}, keywords = {African Americans, Cardiovascular Diseases, Cholesterol Ester Transfer Proteins, Cholesterol, HDL, Cholesterol, LDL, Chromosomes, Human, Cohort Studies, Gene Frequency, Genome-Wide Association Study, Genotype, Humans, Metabolic Diseases, Polymorphism, Single Nucleotide, Quantitative Trait Loci}, issn = {1932-6203}, doi = {10.1371/journal.pone.0035651}, author = {Buyske, Steven and Wu, Ying and Carty, Cara L and Cheng, Iona and Assimes, Themistocles L and Dumitrescu, Logan and Hindorff, Lucia A and Mitchell, Sabrina and Ambite, Jose Luis and Boerwinkle, Eric and B{\r u}zkov{\'a}, Petra and Carlson, Chris S and Cochran, Barbara and Duggan, David and Eaton, Charles B and Fesinmeyer, Megan D and Franceschini, Nora and Haessler, Jeffrey and Jenny, Nancy and Kang, Hyun Min and Kooperberg, Charles and Lin, Yi and Le Marchand, Lo{\"\i}c and Matise, Tara C and Robinson, Jennifer G and Rodriguez, Carlos and Schumacher, Fredrick R and Voight, Benjamin F and Young, Alicia and Manolio, Teri A and Mohlke, Karen L and Haiman, Christopher A and Peters, Ulrike and Crawford, Dana C 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} }