Frequency of single nucleotide platelet receptor gene polymorphism (P2Y12-i744T>C) in coronary artery disease patients among Tamilian population

Several factors contribute to the development of coronary artery disease (CAD). Adenosine diphosphate (ADP) activated P2Y12 receptor also plays a key role in platelet activation and aggregation. It has been found that common variation in the P2Y12 gene was associated with increased platelet aggregation resulting in adverse cardiovascular outcomes. Thus, polymorphisms in the ADP receptor P2Y12 may contribute to the development of CAD. This study aims to determine the frequency distribution of platelet receptor polymorphism P2Y12 (i744T>C) in Tamilian population and to predict its possible role in CAD. Three hundred seventy-one subjects were recruited comprising of 221 healthy volunteers and 150 patients with CAD belonging to either sex, aged 18-60 years of Tamilian origin. Genomic DNA was extracted using phenol-chloroform method. Genotyping was done by PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism). The C allele frequency of P2Y12 polymorphism in controls and cases was 8.4% and 17.7%, respectively. The TT, TC, and CC genotype frequencies in controls and cases were 83.7%, 15.8%, 0.5% and 66.7%, 31.3%, 2%, respectively. The genotype frequencies were in Hardy-Weinberg equilibrium. There was a significant association (p < 0.05) between the mutant genotypes of P2Y12 (i744T>C) polymorphism  and risk of CAD. The odds ratio was found to be 2.6. The variant allele frequency of P2Y12-i744T>C was significantly different from other populations. There was a significant association between the mutant genotypes of P2Y12 (i744T>C) polymorphism  and risk of developing CAD. Thus, the present study will emphasize on the relevance of pharmacogenetic testing of P2Y12 (i744T>C)  receptor gene polymorphism in CAD patients.

Gly460Trp polymorphism of the ADD1 gene and essential hypertension in an Indian population: A meta-analysis on hypertension risk

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.

Association of aldosterone synthase (CYP11B2 C-344T) gene polymorphism & susceptibility to essential hypertension in a south Indian Tamil population

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.