@article {1248, title = {European ancestry as a risk factor for atrial fibrillation in African Americans.}, journal = {Circulation}, volume = {122}, year = {2010}, month = {2010 Nov 16}, pages = {2009-15}, abstract = {

BACKGROUND: Despite a higher burden of standard atrial fibrillation (AF) risk factors, African Americans have a lower risk of AF than whites. It is unknown whether the higher risk is due to genetic or environmental factors. Because African Americans have varying degrees of European ancestry, we sought to test the hypothesis that European ancestry is an independent risk factor for AF.

METHODS AND RESULTS: We studied whites (n=4543) and African Americans (n=822) in the Cardiovascular Health Study (CHS) and whites (n=10 902) and African Americans (n=3517) in the Atherosclerosis Risk in Communities (ARIC) Study (n=3517). Percent European ancestry in African Americans was estimated with 1747 ancestry informative markers from the Illumina custom ITMAT-Broad-CARe array. Among African Americans without baseline AF, 120 of 804 CHS participants and 181 of 3517 ARIC participants developed incident AF. A meta-analysis from the 2 studies revealed that every 10\% increase in European ancestry increased the risk of AF by 13\% (hazard ratio, 1.13; 95\% confidence interval, 1.03 to 1.23; P=0.007). After adjustment for potential confounders, European ancestry remained a predictor of incident AF in each cohort alone, with a combined estimated hazard ratio for each 10\% increase in European ancestry of 1.17 (95\% confidence interval, 1.07 to 1.29; P=0.001). A second analysis using 3192 ancestry informative markers from a genome-wide Affymetrix 6.0 array in ARIC African Americans yielded similar results.

CONCLUSIONS: European ancestry predicted risk of incident AF. Our study suggests that investigating genetic variants contributing to differential AF risk in individuals of African versus European ancestry will be informative.

}, keywords = {African Americans, Aged, Atrial Fibrillation, European Continental Ancestry Group, Female, Genome-Wide Association Study, Humans, Male, Middle Aged, Risk Factors}, issn = {1524-4539}, doi = {10.1161/CIRCULATIONAHA.110.958306}, author = {Marcus, Gregory M and Alonso, Alvaro and Peralta, Carmen A and Lettre, Guillaume and Vittinghoff, Eric and Lubitz, Steven A and Fox, Ervin R and Levitzky, Yamini S and Mehra, Reena and Kerr, Kathleen F and Deo, Rajat and Sotoodehnia, Nona and Akylbekova, Meggie and Ellinor, Patrick T and Paltoo, Dina N and Soliman, Elsayed Z and Benjamin, Emelia J and Heckbert, Susan R} } @article {1316, title = {Large-scale candidate gene analysis in whites and African Americans identifies IL6R polymorphism in relation to atrial fibrillation: the National Heart, Lung, and Blood Institute{\textquoteright}s Candidate Gene Association Resource (CARe) project.}, journal = {Circ Cardiovasc Genet}, volume = {4}, year = {2011}, month = {2011 Oct}, pages = {557-64}, abstract = {

BACKGROUND: The genetic background of atrial fibrillation (AF) in whites and African Americans is largely unknown. Genes in cardiovascular pathways have not been systematically investigated.

METHODS AND RESULTS: We examined a panel of approximately 50,000 common single-nucleotide polymorphisms (SNPs) in 2095 cardiovascular candidate genes and AF in 3 cohorts with participants of European (n=18,524; 2260 cases) or African American descent (n=3662; 263 cases) in the National Heart, Lung, and Blood Institute{\textquoteright}s Candidate Gene Association Resource. Results in whites were followed up in the German Competence Network for AF (n=906, 468 cases). The top result was assessed in relation to incident ischemic stroke in the Cohorts for Heart and Aging Research in Genomic Epidemiology Stroke Consortium (n=19,602 whites, 1544 incident strokes). SNP rs4845625 in the IL6R gene was associated with AF (relative risk [RR] C allele, 0.90; 95\% confidence interval [CI], 0.85-0.95; P=0.0005) in whites but did not reach statistical significance in African Americans (RR, 0.86; 95\% CI, 0.72-1.03; P=0.09). The results were comparable in the German AF Network replication, (RR, 0.71; 95\% CI, 0.57-0.89; P=0.003). No association between rs4845625 and stroke was observed in whites. The known chromosome 4 locus near PITX2 in whites also was associated with AF in African Americans (rs4611994; hazard ratio, 1.40; 95\% CI, 1.16-1.69; P=0.0005).

CONCLUSIONS: In a community-based cohort meta-analysis, we identified genetic association in IL6R with AF in whites. Additionally, we demonstrated that the chromosome 4 locus known from recent genome-wide association studies in whites is associated with AF in African Americans.

}, keywords = {African Americans, Aged, Alleles, Atrial Fibrillation, Chromosomes, Human, Pair 4, Cohort Studies, European Continental Ancestry Group, Female, Humans, Male, Middle Aged, National Heart, Lung, and Blood Institute (U.S.), Polymorphism, Single Nucleotide, Receptors, Interleukin-6, Risk Factors, Stroke, United States}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.110.959197}, author = {Schnabel, Renate B and Kerr, Kathleen F and Lubitz, Steven A and Alkylbekova, Ermeg L and Marcus, Gregory M and Sinner, Moritz F and Magnani, Jared W and Wolf, Philip A and Deo, Rajat and Lloyd-Jones, Donald M and Lunetta, Kathryn L and Mehra, Reena and Levy, Daniel and Fox, Ervin R and Arking, Dan E and Mosley, Thomas H and M{\"u}ller-Nurasyid, Martina and Young, Taylor R and Wichmann, H-Erich and Seshadri, Sudha and Farlow, Deborah N and Rotter, Jerome I and Soliman, Elsayed Z and Glazer, Nicole L and Wilson, James G and Breteler, Monique M B and Sotoodehnia, Nona and Newton-Cheh, Christopher and K{\"a}{\"a}b, Stefan and Ellinor, Patrick T and Alonso, Alvaro and Benjamin, Emelia J and Heckbert, Susan R} } @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} } @article {6084, title = {Novel loci associated with PR interval in a genome-wide association study of 10 African American cohorts.}, journal = {Circ Cardiovasc Genet}, volume = {5}, year = {2012}, month = {2012 Dec}, pages = {639-46}, abstract = {

BACKGROUND: The PR interval, as measured by the resting, standard 12-lead ECG, reflects the duration of atrial/atrioventricular nodal depolarization. Substantial evidence exists for a genetic contribution to PR, including genome-wide association studies that have identified common genetic variants at 9 loci influencing PR in populations of European and Asian descent. However, few studies have examined loci associated with PR in African Americans.

METHODS AND RESULTS: We present results from the largest genome-wide association study to date of PR in 13 415 adults of African descent from 10 cohorts. We tested for association between PR (ms) and ≈2.8 million genotyped and imputed single-nucleotide polymorphisms. Imputation was performed using HapMap 2 YRI and CEU panels. Study-specific results, adjusted for global ancestry and clinical correlates of PR, were meta-analyzed using the inverse variance method. Variation in genome-wide test statistic distributions was noted within studies (λ range: 0.9-1.1), although not after genomic control correction was applied to the overall meta-analysis (λ: 1.008). In addition to generalizing previously reported associations with MEIS1, SCN5A, ARHGAP24, CAV1, and TBX5 to African American populations at the genome-wide significance level (P<5.0 {\texttimes} 10(-8)), we also identified a novel locus: ITGA9, located in a region previously implicated in SCN5A expression. The 3p21 region harboring SCN5A also contained 2 additional independent secondary signals influencing PR (P<5.0 {\texttimes} 10(-8)).

CONCLUSIONS: This study demonstrates the ability to map novel loci in African Americans as well as the generalizability of loci associated with PR across populations of African, European, and Asian descent.

}, keywords = {Adult, African Americans, Cohort Studies, Electrocardiography, Female, Genetic Loci, Genome-Wide Association Study, Humans, Male, Meta-Analysis as Topic, Middle Aged, Polymorphism, Single Nucleotide}, issn = {1942-3268}, doi = {10.1161/CIRCGENETICS.112.963991}, author = {Butler, Anne M and Yin, Xiaoyan and Evans, Daniel S and Nalls, Michael A and Smith, Erin N and Tanaka, Toshiko and Li, Guo and Buxbaum, Sarah G and Whitsel, Eric A and Alonso, Alvaro and Arking, Dan E and Benjamin, Emelia J and Berenson, Gerald S and Bis, Josh C and Chen, Wei and Deo, Rajat and Ellinor, Patrick T and Heckbert, Susan R and Heiss, Gerardo and Hsueh, Wen-Chi and Keating, Brendan J and Kerr, Kathleen F and Li, Yun and Limacher, Marian C and Liu, Yongmei and Lubitz, Steven A and Marciante, Kristin D and Mehra, Reena and Meng, Yan A and Newman, Anne B and Newton-Cheh, Christopher and North, Kari E and Palmer, Cameron D and Psaty, Bruce M and Quibrera, P Miguel and Redline, Susan and Reiner, Alex P and Rotter, Jerome I and Schnabel, Renate B and Schork, Nicholas J and Singleton, Andrew B and Smith, J Gustav and Soliman, Elsayed Z and Srinivasan, Sathanur R and Zhang, Zhu-Ming and Zonderman, Alan B and Ferrucci, Luigi and Murray, Sarah S and Evans, Michele K and Sotoodehnia, Nona and Magnani, Jared W and Avery, Christy L} } @article {6570, title = {A common SCN5A variant is associated with PR interval and atrial fibrillation among African Americans.}, journal = {J Cardiovasc Electrophysiol}, volume = {25}, year = {2014}, month = {2014 Nov}, pages = {1150-7}, abstract = {

OBJECTIVE: We examined the association of rs7626962 (S1103Y) or rs7629265, a variant in high linkage disequilibrium with S1103Y (r(2) = 0.87 - 1), with sudden cardiac death (SCD) and atrial fibrillation (AF) among African Americans.

BACKGROUND: The SCN5A missense variant S1103Y has been associated with SCD among African Americans in small case-control studies, but larger population-based studies are needed to validate these findings. The association of this variant with AF has not been fully explored.

METHODS: Using genotyping data on over 7,000 African Americans from 5 cohorts (Atherosclerosis Risk in Communities [ARIC], Cleveland Family Study [CFS], Jackson Heart Study [JHS], Multi-Ethnic Study of Atherosclerosis [MESA], Cardiovascular Health Study [CHS]), we examined the association of rs7629265 with electrocardiographic PR, QRS, and QT intervals, and with incident AF and SCD. We examined association of S1103Y (rs7626962) with SCD using a population-based case-control study of SCD Cardiac Arrest Blood Study (CABS).

RESULTS: Meta-analyses across 5 cohorts demonstrated that rs7629265 was significantly associated with PR duration (β = -4.1 milliseconds; P = 2.2{\texttimes}10(-6) ), but not significantly associated with QRS or QT intervals. In meta-analyses of prospectively followed ARIC and CHS participants (n = 3,656), rs7629265 was associated with increased AF risk (n = 299 AF cases; HR = 1.74, P = 1.9 {\texttimes} 10(-4) ). By contrast, rs7629265 was not significantly associated with SCD risk in ARIC (n = 83 SCD cases; P = 0.30) or CHS (n = 54 SCD cases; P = 0.47). Similarly, S1103Y was not significantly associated with SCD risk in CABS (n = 225 SCD cases; P = 0.29).

CONCLUSION: The common SCN5A variant, rs7629265, is associated with increased AF risk and shorter PR interval among African Americans. In contrast to prior reports, we found no evidence of association of rs7629265 or rs7626962 (S1103Y) with SCD risk in the general population.

}, keywords = {Adult, African Americans, Aged, Aged, 80 and over, Atrial Fibrillation, Case-Control Studies, Cohort Studies, Death, Sudden, Cardiac, Female, Genetic Variation, Humans, Male, Middle Aged, NAV1.5 Voltage-Gated Sodium Channel, Prospective Studies, Risk Factors, Single-Blind Method}, issn = {1540-8167}, doi = {10.1111/jce.12483}, author = {Ilkhanoff, Leonard and Arking, Dan E and Lemaitre, Rozenn N and Alonso, Alvaro and Chen, Lin Y and Durda, Peter and Hesselson, Stephanie E and Kerr, Kathleen F and Magnani, Jared W and Marcus, Gregory M and Schnabel, Renate B and Smith, J Gustav and Soliman, Elsayed Z and Reiner, Alexander P and Sotoodehnia, Nona} }