ABSTRACT
BACKGROUND: The role of beta2-agonist is still important to control bronchoconstriction in asthma. Polymorphisms at aminoacid positions 16 and 27 of the beta2-adrenoceptor gene are associated with asthma phenotype. Glu 27 allele is associated with negatively with bronchial hyperresponsiveness(BHR) in asthmatic subjects and Gln 27 allele is associated positively with IgE levels, and Gly16 Gln27 haplotype is suggested to be positively associated with BHR in a population study. And Gly16 Gln27 haplotypes are positively associated with nocturnal cough in atopic subjects. To evaluate the association between beta2-adrenoceptor polymorphisms as asthmatic phenotypes, the frequency of beta2-adrenoceptor polymorphsisms at 2 sites(Arg16->Gly 16 and Gln 27 -> Glu 27) were examined in asthmatic and normal children. METHODS: Ninty nine asthmatic children and seventy three normal children were enrolled. Asthma phenotypes were determined by physician and bronchial responsiveness and genotypes of beta2-adrenoceptor polymorphisms were determined with PCR based methods. RESULTS: The polymorphisms at aminoacid 16 and 27 of beta2-adrenoceptor gene was not different between asthmatic and normal children. The haplotype frequency of aminoacid 16 and 27 polymorphisms of beta2-adrenoceptor gene was not different between asthmatic and normal children. Haplotypes of aminoacid 16 and 27 was not associated with total eosinophil count, eosinophil %, and total IgE in asthmatic children. Haplotypes of aminoacid 16 and 27 was not associated with PC20, and response of FEV1 after beta2-agonist in asthmatic children. CONCLUSION: beta2-adrenoceptor polymorphisms is not associated with the expression of asthma, atopy, bronchial hyperresponsiveness, and response to beta2-agonist in Korean children.