Background: β(2)-Adrenergic receptor (β(2)AR), a G-protein coupled receptor, is present on the bronchial smooth muscle cells and results in bronchodilation upon activation. The genetic factors determining β(2)AR expression and function may not only alter the response of an individual to the therapy but also may serve as predictive markers for response to the agonists used in the therapy. The present study aimed at evaluating the role of β(2)AR-16 and β(2)AR-27 gene polymorphisms in asthma.
Methods: A case-control study was performed with a total of 824 adult subjects, including 410 asthmatics and 414 healthy controls from regions of North India. The β(2)AR-16 and β(2)AR-27 polymorphisms were genotyped by PCR-RFLP.
Results: Statistical analysis for the β(2)AR-16 polymorphism revealed that the mutant Gly16 allele was significantly associated with asthma, with OR = 0.80, 95 % CI = 0.65-0.99, and P = 0.032. The Gly16/Gly16 mutant genotype also confers decreased risk toward asthma, with OR = 0.65, 95 % CI = 0.41-1.02, and P = 0.049. However, the β(2)AR-27 polymorphism was not associated with asthma as it did not reach statistical significance, with OR = 0.86, 95 % CI = 0.69-1.07, and P = 0.163.
Conclusion: The β(2)AR-16 polymorphism confers a decreased risk toward asthma while the β(2)AR-27 polymorphism is not associated with asthma in the studied North Indian population.