@article {1562, title = {Association of genomic loci from a cardiovascular gene SNP array with fibrinogen levels in European Americans and African-Americans from six cohort studies: the Candidate Gene Association Resource (CARe).}, journal = {Blood}, volume = {117}, year = {2011}, month = {2011 Jan 06}, pages = {268-75}, abstract = {

Several common genomic loci, involving various immunity- and metabolism-related genes, have been associated with plasma fibrinogen in European Americans (EAs). The genetic determinants of fibrinogen in African Americans (AAs) are poorly characterized. Using a vascular gene-centric array in 23,634 EA and 6657 AA participants from 6 studies comprising the Candidate Gene Association Resource project, we examined the association of 47,539 common and lower frequency variants with fibrinogen concentration. We identified a rare Pro265Leu variant in FGB (rs6054) associated with lower fibrinogen. Common fibrinogen gene single nucleotide polymorphisms (FGB rs1800787 and FGG rs2066861) significantly associated with fibrinogen in EAs were prevalent in AAs and showed consistent associations. Several fibrinogen locus single nucleotide polymorphism associated with lower fibrinogen were exclusive to AAs; these include a newly reported association with FGA rs10050257. For IL6R, IL1RN, and NLRP3 inflammatory gene loci, associations with fibrinogen were concordant between EAs and AAs, but not at other loci (CPS1, PCCB, and SCL22A5-IRF1). The association of FGG rs2066861 with fibrinogen differed according to assay type used to measure fibrinogen. Further characterization of common and lower-frequency genetic variants that contribute to interpopulation differences in fibrinogen phenotype may help refine our understanding of the contribution of hemostasis and inflammation to atherothrombotic risk.

}, keywords = {Adult, African Americans, Aged, Cardiovascular Diseases, Cohort Studies, European Continental Ancestry Group, Female, Fibrinogen, Genetic Predisposition to Disease, Haplotypes, Humans, Male, Middle Aged, Phenotype, Polymorphism, Single Nucleotide, Risk Factors}, issn = {1528-0020}, doi = {10.1182/blood-2010-06-289546}, author = {Wassel, Christina L and Lange, Leslie A and Keating, Brendan J and Taylor, Kira C and Johnson, Andrew D and Palmer, Cameron and Ho, Lindsey A and Smith, Nicholas L and Lange, Ethan M and Li, Yun and Yang, Qiong and Delaney, Joseph A and Tang, Weihong and Tofler, Geoffrey and Redline, Susan and Taylor, Herman A and Wilson, James G and Tracy, Russell P and Jacobs, David R and Folsom, Aaron R and Green, David and O{\textquoteright}Donnell, Christopher J and Reiner, Alexander P} } @article {1305, title = {Genome-wide association study for serum urate concentrations and gout among African Americans identifies genomic risk loci and a novel URAT1 loss-of-function allele.}, journal = {Hum Mol Genet}, volume = {20}, year = {2011}, month = {2011 Oct 15}, pages = {4056-68}, abstract = {

Serum urate concentrations are highly heritable and elevated serum urate is a key risk factor for gout. Genome-wide association studies (GWAS) of serum urate in African American (AA) populations are lacking. We conducted a meta-analysis of GWAS of serum urate levels and gout among 5820 AA and a large candidate gene study among 6890 AA and 21 708 participants of European ancestry (EA) within the Candidate Gene Association Resource Consortium. Findings were tested for replication among 1996 independent AA individuals, and evaluated for their association among 28 283 EA participants of the CHARGE Consortium. Functional studies were conducted using (14)C-urate transport assays in mammalian Chinese hamster ovary cells. In the discovery GWAS of serum urate, three loci achieved genome-wide significance (P< 5.0 {\texttimes} 10(-8)): a novel locus near SGK1/SLC2A12 on chromosome 6 (rs9321453, P= 1.0 {\texttimes} 10(-9)), and two loci previously identified in EA participants, SLC2A9 (P= 3.8 {\texttimes} 10(-32)) and SLC22A12 (P= 2.1 {\texttimes} 10(-10)). A novel rare non-synonymous variant of large effect size in SLC22A12, rs12800450 (minor allele frequency 0.01, G65W), was identified and replicated (beta -1.19 mg/dl, P= 2.7 {\texttimes} 10(-16)). (14)C-urate transport assays showed reduced urate transport for the G65W URAT1 mutant. Finally, in analyses of 11 loci previously associated with serum urate in EA individuals, 10 of 11 lead single-nucleotide polymorphisms showed direction-consistent association with urate among AA. In summary, we identified and replicated one novel locus in association with serum urate levels and experimentally characterize the novel G65W variant in URAT1 as a functional allele. Our data support the importance of multi-ethnic GWAS in the identification of novel risk loci as well as functional variants.

}, keywords = {Adult, African Americans, Aged, Animals, CHO Cells, Cricetinae, European Continental Ancestry Group, Female, Genetic Loci, Genetic Predisposition to Disease, Genome-Wide Association Study, Genotype, Gout, Humans, Loss of Heterozygosity, Male, Middle Aged, Organic Anion Transporters, Organic Cation Transport Proteins, Polymorphism, Single Nucleotide, Uric Acid, Young Adult}, issn = {1460-2083}, doi = {10.1093/hmg/ddr307}, author = {Tin, Adrienne and Woodward, Owen M and Kao, Wen Hong Linda and Liu, Ching-Ti and Lu, Xiaoning and Nalls, Michael A and Shriner, Daniel and Semmo, Mariam and Akylbekova, Ermeg L and Wyatt, Sharon B and Hwang, Shih-Jen and Yang, Qiong and Zonderman, Alan B and Adeyemo, Adebowale A and Palmer, Cameron and Meng, Yan and Reilly, Muredach and Shlipak, Michael G and Siscovick, David and Evans, Michele K and Rotimi, Charles N and Flessner, Michael F and K{\"o}ttgen, Michael and Cupples, L Adrienne and Fox, Caroline S and K{\"o}ttgen, Anna} } @article {6179, title = {Impact of ancestry and common genetic variants on QT interval in African Americans.}, journal = {Circ Cardiovasc Genet}, volume = {5}, year = {2012}, month = {2012 Dec}, pages = {647-55}, abstract = {

BACKGROUND: Ethnic differences in cardiac arrhythmia incidence have been reported, with a particularly high incidence of sudden cardiac death and low incidence of atrial fibrillation in individuals of African ancestry. We tested the hypotheses that African ancestry and common genetic variants are associated with prolonged duration of cardiac repolarization, a central pathophysiological determinant of arrhythmia, as measured by the electrocardiographic QT interval.

METHODS AND RESULTS: First, individual estimates of African and European ancestry were inferred from genome-wide single-nucleotide polymorphism (SNP) data in 7 population-based cohorts of African Americans (n=12,097) and regressed on measured QT interval from ECGs. Second, imputation was performed for 2.8 million SNPs, and a genome-wide association study of QT interval was performed in 10 cohorts (n=13,105). There was no evidence of association between genetic ancestry and QT interval (P=0.94). Genome-wide significant associations (P<2.5 {\texttimes} 10(-8)) were identified with SNPs at 2 loci, upstream of the genes NOS1AP (rs12143842, P=2 {\texttimes} 10(-15)) and ATP1B1 (rs1320976, P=2 {\texttimes} 10(-10)). The most significant SNP in NOS1AP was the same as the strongest SNP previously associated with QT interval in individuals of European ancestry. Low probability values (P<10(-5)) were observed for SNPs at several other loci previously identified in genome-wide association studies in individuals of European ancestry, including KCNQ1, KCNH2, LITAF, and PLN.

CONCLUSIONS: We observed no difference in duration of cardiac repolarization with global genetic indices of African American ancestry. In addition, our genome-wide association study extends the association of polymorphisms at several loci associated with repolarization in individuals of European ancestry to include individuals of African ancestry.

}, keywords = {Adult, African Americans, Aged, Electrocardiography, European Continental Ancestry Group, Female, Genealogy and Heraldry, Genetic Variation, Genome, Human, Genome-Wide Association Study, Humans, Male, Middle Aged, Polymorphism, Single Nucleotide}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.112.962787}, author = {Smith, J Gustav and Avery, Christy L and Evans, Daniel S and Nalls, Michael A and Meng, Yan A and Smith, Erin N and Palmer, Cameron and Tanaka, Toshiko and Mehra, Reena and Butler, Anne M and Young, Taylor and Buxbaum, Sarah G and Kerr, Kathleen F and Berenson, Gerald S and Schnabel, Renate B and Li, Guo and Ellinor, Patrick T and Magnani, Jared W and Chen, Wei and Bis, Joshua C and Curb, J David and Hsueh, Wen-Chi and Rotter, Jerome I and Liu, Yongmei and Newman, Anne B and Limacher, Marian C and North, Kari E and Reiner, Alexander P and Quibrera, P Miguel and Schork, Nicholas J and Singleton, Andrew B and Psaty, Bruce M and Soliman, Elsayed Z and Solomon, Allen J and Srinivasan, Sathanur R and Alonso, Alvaro and Wallace, Robert and Redline, Susan and Zhang, Zhu-Ming and Post, Wendy S and Zonderman, Alan B and Taylor, Herman A and Murray, Sarah S and Ferrucci, Luigi and Arking, Dan E and Evans, Michele K and Fox, Ervin R and Sotoodehnia, Nona and Heckbert, Susan R and Whitsel, Eric A and Newton-Cheh, Christopher} }