Method of detecting and predicting bronchodilatory response to beta agonist

Provided is a method of detecting single nucleotide polymorphism (SNP) in beta2AR gene associated with pharmacogenetic response in a human subject suffering from asthma, wherein said method is carried out on a blood sample of a subject who has been identified and categorized as a phenotypically good responder or poor responder to a pharmaco-logically active dose of a fast acting beta2 agonist, said method comprising the steps of: (a) isolating genomic DNA from the blood sample of the subject suffering from asthma; (b) amplifying the genomic DNA obtained in step (a) using specified PCR primers (c) sequencing the amplified PCR product obtained in step (b) and identifying the SNP of the sequenced PCR product to detect the specific beta2AR genotypes; (d) screening for polymorphism at position 46 to detect the specific SNP in beta2AR gene using specified snapshot primers, until the penultimate position of the SNP identified in step (c), and; (e) validating the subject for presence of SNP at nucleotide position 46 in beta2AR gene using specified allele specific oligonucleotides. Further provided are corresponding pharmaco-genetic marker polynucleotides comprising at least 20 base pairs encompassing the A/G polymorphism at position 46.