title: Sequence variation of bradykinin receptors B1 and B2 and association with hypertension.
abstract: OBJECTIVE
  To identify variants in the complete genomic sequence of the two subtypes of bradykinin receptors: B1 (BDKRB1) and B2 (BDKRB2) and to examine the association of these variants with essential hypertension.
  
  
  METHODS
  A case-control design comparing hypertensive and normotensive individuals was used.
  
  
  METHODS
  A 64.4 kb genomic region containing the BDKRB1 and BDKRB2 genes was sequenced in 30 African-American individuals. A total of 282 single-nucleotide polymorphisms (SNPs) were identified. A total of 21 SNPs were genotyped in our complete cohorts of hypertensive and normotensive African-Americans (n = 218), American-Caucasians (n = 220) and Greek-Caucasians (n = 194). Pair-wise correlation coefficients were computed to assess linkage disequilibrium (LD) patterns among the SNPs. Chi-squared tests and logistic regression were used to assess association between the SNPs and hypertension status.
  
  
  RESULTS
  Pairwise LD demonstrated a general pattern of decline with increasing distance, which was consistent among the three groups with less LD in African-Americans. One SNP in the promoter region of BDKRB2 (rs1799722) was associated with hypertension (P = 0.044) in African-Americans. One SNP in BDKRB2 and three SNPs in BDKRB1 were associated with hypertension (P-values between 0.026 and 0.0004) in American-Caucasians. Haplotypes including those four SNPs and one SNP in B2, which results in an amino acid change, demonstrated a significant haplotype frequency difference between hypertensive and normotensive American-Caucasians (P = 0.025).
  
  
  CONCLUSIONS
  These results support the hypothesis that the African-American population is an older population compared with the other samples and the two bradykinin receptors may play a role in blood pressure regulation.
authors.affiliation: Hypertension Section, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts 02118, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Cui
authors.forename: Efthymia
authors.initials: E
authors.lastname: Melista
authors.forename: Irmarie
authors.initials: I
authors.lastname: Chazaro
authors.forename: Yuejian
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhou
authors.forename: Athanasios J
authors.initials: AJ
authors.lastname: Manolis
authors.forename: Clinton T
authors.initials: CT
authors.lastname: Baldwin
authors.forename: Anita L
authors.initials: AL
authors.lastname: Destefano
authors.forename: Haralambos
authors.initials: H
authors.lastname: Gavras
mesh_terms: D001741:Black or African American / Q000235:genetics*; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D006239:Haplotypes; D006801:Humans; D006973:Hypertension / Q000208:ethnology* / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D043783:Receptor, Bradykinin B1 / Q000235:genetics*; D043782:Receptor, Bradykinin B2 / Q000235:genetics*; D044465:White People / Q000235:genetics*
chemical_list: D043783:Receptor, Bradykinin B1; D043782:Receptor, Bradykinin B2