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


CONCLUSIONS
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.
Department of Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
Priya B
PB
Shetty
Hua
H
Tang
Bamidele O
BO
Tayo
Alanna C
AC
Morrison
Craig L
CL
Hanis
Dabeeru C
DC
Rao
Jeffery H
JH
Young
Ervin R
ER
Fox
Eric
E
Boerwinkle
Richard S
RS
Cooper
Neil J
NJ
Risch
Xiaofeng
X
Zhu
D001741:Black or African American / Q000235:genetics*; D001794:Blood Pressure / Q000235:genetics*; D002891:Chromosomes, Human, Pair 21; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000208:ethnology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D018179:Receptors, Thrombin / Q000235:genetics*
C568771:CLMP protein, human; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D018179:Receptors, Thrombin; C105295:protease-activated receptor 3