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Variants in CXADR and F2RL1 are associated with blood pressure and obesity in African-Americans in regions identified through admixture mapping

aDepartment of Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, Cleveland, Ohio bDepartment of Genetics, Stanford University School of Medicine, Stanford, California cDepartment of Preventive Medicine and Epidemiology, Loyola University of Chicago Stritch School of Medicine, Maywood, Illinois dDivision of Epidemiology, Human Genetics and Environmental Sciences, The University of Texas Health Science Center at Houston School of Public Health, Houston, Texas eDivision of Biostatistics, Washington University in St Louis School of Medicine, St Louis, Missouri fDepartment of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland gDivision of Cardiology, Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi iDepartment of Epidemiology and Biostatistics, Institute for Human Genetics, University of California, San Francisco, California, USA.
Journal of Hypertension (Impact Factor: 4.22). 08/2012; 30(10):1970-1976. DOI: 10.1097/HJH.0b013e3283578c80
Source: PubMed

ABSTRACT OBJECTIVE:: Genetic variants in 296 genes in regions identified through admixture mapping of hypertension, BMI, and lipids were assessed for association with hypertension, blood pressure (BP), BMI, and high-density lipoprotein cholesterol (HDL-C). METHODS:: This study identified coding SNPs identified from HapMap2 data that were located in genes on chromosomes 5, 6, 8, and 21, wherein ancestry association evidence for hypertension, BMI, or HDL-C was identified in previous admixture mapping studies. Genotyping was performed in 1733 unrelated African-Americans from the National Heart, Lung and Blood Institute's Family Blood Pressure Project, and gene-based association analyses were conducted for hypertension, SBP, DBP, BMI, and HDL-C. A gene score based on the number of minor alleles of each SNP in a gene was created and used for gene-based regression analyses, adjusting for age, age, sex, local marker ancestry, and BMI, as applicable. An individual's African ancestry estimated from 2507 ancestry-informative markers was also adjusted for to eliminate any confounding due to population stratification. RESULTS:: CXADR (rs437470) on chromosome 21 was associated with SBP and DBP with or without adjusting for local ancestry (P < 0.0006). F2RL1 (rs631465) on chromosome 5 was associated with BMI (P = 0.0005). Local ancestry in these regions was associated with the respective traits as well. CONCLUSION:: This study suggests that CXADR and F2RL1 likely play important roles in BP and obesity variation, respectively; and these findings are consistent with those of other studies, so replication and functional analyses are necessary.

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Priya B Shetty