Association of b 2 -Adrenergic Receptor Polymorphisms with Asthma in a North Indian Population Niti Birbian • Jagtar Singh • Surinder Kumar Jindal • Neha Singla Received: 26 March 2012 / Accepted: 23 June 2012 / Published online: 21 July 2012 Ó Springer Science+Business Media, LLC 2012 Abstract Background b 2 -Adrenergic receptor (b 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 b 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 b 2 AR-16 and b 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 b 2 AR-16 and b 2 AR-27 polymorphisms were genotyped by PCR– RFLP. Results Statistical analysis for the b 2 AR-16 polymor- phism revealed that the mutant Gly16 allele was signifi- cantly 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. How- ever, the b 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 b 2 AR-16 polymorphism confers a decreased risk toward asthma while the b 2 AR-27 poly- morphism is not associated with asthma in the studied North Indian population. Keywords Asthma Á b 2 -Adrenergic receptor (b 2 AR) Á b 2 AR-16 and b 2 AR-27 gene polymorphisms Á North Indian population Á PCR–RFLP Introduction Over the last decade, the prevalence of atopic diseases such as asthma, dermatitis, and allergic rhinitis has been on the rise globally, and understanding the mechanisms of onset and severity of allergy has offered a great challenge to researchers and scientists worldwide due to the complex interplay of genetic and environmental factors [1]. According to the second National Family Health Survey (NFHS 2), conducted in 1998–1999, asthma is the most common disease in India compared to tuberculosis, dia- betes, malaria, and thyroid. A large number of case–control studies have been con- ducted in the recent past worldwide to investigate the role of the various cytokine gene polymorphisms associated with asthma. The results have been found to vary pro- foundly, with differences in the asthmatic populations studied across the world revealing that they are not simi- larly significant, but leading to a definite conclusion that asthma is a complex polygenic disease that certainly does not follow a classic Mendelian pattern of inheritance [2]. As a result, it makes it all the more crucial to identify the genetic makeup associated with the complexity of asthma. N. Birbian Á J. Singh (&) Á N. Singla Department of Biotechnology, Panjab University, Chandigarh, India e-mail: jagtar72@gmail.com N. Birbian e-mail: nitibirbian@yahoo.com N. Singla e-mail: taurusneha@gmail.com S. K. Jindal Department of Pulmonary Medicine, PGIMER, Chandigarh, India e-mail: skjindal@indiachest.org 123 Lung (2012) 190:497–504 DOI 10.1007/s00408-012-9407-7