title: Analysis of candidate genes and hypertension in African American adults.
abstract: OBJECTIVE
  We investigated the associations between hypertension status and the genotypes of four single nucleotide polymorphism (SNP) sites in four hypertension-related genes (Angiotensinogen [AGT], Angiotensin I Converting Enzyme [ACE], Angiotensinogen II receptor, subtype 1 [AGTR1], and Alpha 1-Antichymotrypsin [ACT or SERPINA3]), in an African American sample.
  
  
  METHODS
  DNA from 628 participants of the Carolina African American Twin Study of Aging project, a population-based study of African American adult twins, was genotyped using SNPs shown to be associated with hypertension in other studies.
  
  
  RESULTS
  The ACE SNP (ACE4 or A-240T) was associated with hypertension (P = .047 in a generalized estimating equations alternating logistics regression model that included age, body mass index, sex, and education. The analysis indicated a protective effect of the TT genotype (odds ratio [OR] 1.59, 95% confidence interval [CI] 1.03-2.48, P = .04) and of the AT genotype (OR 1.91, 95% CI 1.01-3.62, P = .047) compared with the AA genotype.
  
  
  CONCLUSIONS
  These results extend previous findings of associations of various polymorphisms of ACE to hypertension and support the association of hypertension to the A allele of ACE4. The potential for this polymorphism to alter expression by its position in the gene's promoter region suggests that future studies of altered ACE protein activity are warranted.
authors.affiliation: Department of Psychology and Neuroscience, Duke University, Box 90085, 9 Flowers Dr, Durham, NC 27708, USA. kwhit1@duke.edu
authors.forename: Keith E
authors.initials: KE
authors.lastname: Whitfield
authors.forename: Xiaopan
authors.initials: X
authors.lastname: Yao
authors.forename: K B
authors.initials: KB
authors.lastname: Boomer
authors.forename: George P
authors.initials: GP
authors.lastname: Vogler
authors.forename: Mark D
authors.initials: MD
authors.lastname: Hayward
authors.forename: David J
authors.initials: DJ
authors.lastname: Vandenbergh