title: Susceptible and protective eNOS haplotypes in hypertensive black and white subjects.
abstract: Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene have been inconsistently associated with hypertension. This inconsistency may derive from population stratification secondary to ethnic diversity, and consideration limited to only one rather than combinations of polymorphisms. We studied three genetic variations in the eNOS gene: a single nucleotide polymorphism in the promoter region (T-786C), in exon 7 (Glu298Asp), and a variable number of tandem repeats in intron 4 (b/a) of the eNOS gene in hypertensives (112 whites and 91 blacks) and normotensives (113 whites and 87 blacks). In addition, we also examined the association of eNOS gene haplotypes with hypertension in white and black subjects. No differences were observed in the frequencies of genotypes and alleles of the three polymorphisms when white hypertensives and white normotensives were compared, or when black hypertensives and black normotensives were compared (all P>0.05). Conversely, the haplotypes "T Asp b" and "C Glu b" were more common among white (16 and 24%, respectively) and black (17 and 16%, respectively) normotensives than in white (7 and 8%, respectively) and black (4 and 6%, respectively) hypertensives, respectively (all P<0.0039). In addition, the haplotype "C Asp b" was more commonly found in white hypertensives than in white normotensives (P=0.0007). These results suggest a contribution of eNOS haplotypes to the development of hypertension that is obscured when specific eNOS genotypes alone are considered. In addition, our results suggest two eNOS haplotypes associated with a protective effect against hypertension in both ethnic groups, and one eNOS haplotype conferring susceptibility to hypertension in white subjects.
authors.affiliation: Department of Pharmacology, Faculty of Medicine of Ribeirao Preto, University of Sao Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirao Preto, SP, Brazil.
authors.forename: Valeria Cristina
authors.initials: VC
authors.lastname: Sandrim
authors.forename: Eduardo Barbosa
authors.initials: EB
authors.lastname: Coelho
authors.forename: Fernando
authors.initials: F
authors.lastname: Nobre
authors.forename: Gustavo Marin
authors.initials: GM
authors.lastname: Arado
authors.forename: Vera Lucia
authors.initials: VL
authors.lastname: Lanchote
authors.forename: Jose Eduardo
authors.initials: JE
authors.lastname: Tanus-Santos
mesh_terms: D000328:Adult; D044383:Black People / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D006973:Hypertension / Q000201:enzymology* / Q000235:genetics* / Q000517:prevention & control; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D018598:Minisatellite Repeats; D052250:Nitric Oxide Synthase Type III / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D044465:White People / Q000235:genetics*
chemical_list: D007527:Isoenzymes; D052250:Nitric Oxide Synthase Type III