ABSTRACT
Background & objective: Renin-angiotensin aldosterone system (RAAS) plays an important role in the regulation of blood pressure. Aldosterone, synthesized by aldosterone synthase in the adrenal cortex is encoded by the CYP11B2 gene. In this case-control study we examined the association between CYP11B2 C-344T polymorphism and essential hypertension in south Indian Tamil population. Methods: The study was conducted in 406 hypertensive cases and 424 healthy controls from Tamil population. Genotyping was performed by PCR-restriction fragment length polymorphism method. Statistical analysis was performed by logistic regression analysis. Results: The 344TT homozygous variant genotype (OR-1.8; 95% CI: 1.1-2.8; P=0.02) and T allele (P=0.007) were found to be significantly associated with hypertension. In gender based analysis, the risk was significantly higher in male hypertensives (OR-1.8; 95% CI: 1.0-3.6, P=0.05) but not in female subjects. Interpretation & conclusion: A significant association between CYP11B2 gene polymorphism and essential hypertension was observed and the risk was confined to male subjects in south Indian Tamil population.
Subject(s)
Adult , Cytochrome P-450 CYP11B2/genetics , DNA Primers/genetics , Electrophoresis, Polyacrylamide Gel , Ethnicity/genetics , Female , Genetic Predisposition to Disease/genetics , Genotype , Humans , Hypertension/genetics , India , Logistic Models , Male , Middle Aged , Odds Ratio , Polymorphism, Single Nucleotide/genetics , Renin-Angiotensin System/genetics , Renin-Angiotensin System/physiologyABSTRACT
Background & objectives: Several studies reported the polymorphisms of β1-adrenergic receptor gene in healthy volunteers and its influence on cardiovascular disorders. We investigated the genotype and allele frequencies of Ser49Gly and Arg389Gly polymorphism in healthy volunteers of South Indian Tamilian population vis-à-vis other major ethnic groups. Methods: The genetic variants were determined by using Taqman 5’ nuclease assay- real time PCR analysis in 533 normal healthy volunteers (18-60 yr; M=290; F=243). The allelic discrimination analysis was done by 7700 SDS software. Results: The estimated genotype and allele frequencies of Ser49Gly and Arg389Gly polymorphism were compared with other major populations. The frequencies of the variant alleles Gly49 and Gly389 were 15.1 and 25.8 per cent respectively. Interpretation & conclusions: Our study shows that interethnic variation exists in the polymorphisms of β1-adrenergic receptor gene and the results generated in this study might serve as a genetic marker for further studies in Tamilian (South India) population.
Subject(s)
Adult , Amino Acid Substitution/genetics , Ethnicity/genetics , Female , Gene Frequency , Genotype , Humans , India , Male , Middle Aged , Polymerase Chain Reaction/methods , Polymorphism, Genetic , Receptors, Adrenergic, beta-1/genetics , Young AdultABSTRACT
BACKGROUND: Essential hypertension is a complex genetic trait. Genetic variant of alpha adducin (ADD1) gene have been implicated as a risk factor for hypertension. Given its clinical significance, we investigated the association between ADD1 Gly460Trp gene polymorphism and essential hypertension in an Indian population. Further, a meta-analysis was carried out to estimate the risk of hypertension. METHODS: In the current study, 432 hypertensive cases and 461 healthy controls were genotyped for the Gly460Trp ADD1 gene polymorphism. Genotyping was determined by real time PCR using Taqman assay. Multiple logistic regression analysis was used to detect the association between Gly460Trp polymorphism and hypertension. RESULTS: No significant association was found in the genotype and allele distribution of Gly460Trp polymorphism with hypertension in our study. A total of 15 case-control studies were included in the meta-analysis. There was no evidence of the association of Gly460Trp polymorphism with hypertension in general or in any of the sub group. CONCLUSIONS: We found that the Gly460Trp polymorphism is not a risk factor for essential hypertension in a south Indian Tamilian population. However, the role of ADD1 polymorphism may not be excluded by a negative association study. Further, large and rigorous case-control studies that investigate gene–gene–environment interactions may generate more conclusive claims about the molecular genetics of hypertension.