β2-adrenergic receptor polymorphisms and response to salbutamol among Indian asthmatics∗

Introduction: The β2-adrenergic receptor (β2AR or ADRβ2) is the target for β2-agonist drugs used for bronchodilation in asthma and other respiratory diseases. The aim of this study was to identify common single nucleotide polymorphisms (SNPs) and haplotypes in asthmatics and healthy individuals from an Indian population, and determine the influence of β2AR SNPs in responsiveness to β2-agonist therapy in asthma patients. Methods: Ten variable SNP sites within a span of 2.193 kb were identified in the β2AR gene by sequencing and genotyping 374 bronchial asthma patients and healthy individuals from an Indian population. Spirometry tests were performed on 80 unrelated patients before and after administration of 200 μg of salbutamol. A postbronchodilator forced expiratory volume in one second (FEV1) change of ≥ 15.3% was considered a good response, and a change of < 15.3% was defined as a poor response, to salbutamol. Results: The pattern of linkage disequilibrium between the ten SNPs showed a single, linked S...