Genetic variations of beta 2-adrenergic receptor gene are associated with essential hypertension in Xinjiang Kazakans

Objective The aims of the present study were to investigate the associations of 46 A>G, 79 C>G, 491 C>T and 659 C>G genetic variants of the human beta 2-adrenergic receptor (β2-AR), ADRB2, gene with essential hypertension (EH) in Xinjiang Kazakans population.Methods A gender-matched case-control (271 hypertensive cases and 267 normotensive controls) study was used to investigate the associations of the four variations in the coding region of ADRB2 with EH. The genotypes of the variants were identified by the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) methods. Results 46 A>G, 79 C>G and 659 C>G polymorphisms were common in the Kazakan population, but 491 C>T was a mutation (frequency of T allele was only 0.003) and only found in EH group. The frequency distributions of genotypes and alleles for 659 OG between the EH and control groups was significantly different (P<0.05), while those for 46 A>G and 79 C>G polymorphisms were not statistically different. Logistic regression analysis suggested that the G allele of 659 C>G polymorphism was a risk factor for hypertension (minor allele vs common homo; odds ratio, 13.240,95% CI, 4.052-43.274; P<0.05). Covariance analysis showed that systolic and diastolic blood pressure levels in GG+CG group of 659 OG were significantly higher than those in the CC group, but no significant difference of blood pressure were found between common homo and minor allele for 46 A>G and 79C>G polymorphisms. Haplotype analysis showed that two hyplotypes, H1: 46A-79C-491C-523C(48%)and H5:46A-79C-491C-659G, were associated with EH.Conclusion ADRB2 genetic variants may play independent roles in the molecular genetic mechanism of EH in Xinjiang Kazakans population.