ADRB2 polymorphisms and asthma susceptibility: transmission disequilibrium test and meta-analysis

Abstract

Background: The beta(2)-adrenergic receptor (ADRB2) is the most common adrenergic receptor in the lung, and associations between ADRB2 polymorphisms and intermediate phenotypes of asthma have been reported. Four missense polymorphisms (Arg16Gly, Gln27Glu, Val34Met, and Thr164Ile) and one polymorphism in the 5' leader cistron of the ADRB2 messenger RNA has been identified. In vitro studies have shown that these missense polymorphisms can affect ADRB2 function.

Methods: To examine possible associations of ADRB2 polymorphisms with asthma susceptibility, we performed transmission disequilibrium tests (TDT) of 137 Japanese families identified through children with atopic asthma.

Results: We did not find associations between any alleles of the ADRB2 polymorphisms and asthma by TDT (p > 0.1). We also performed a meta-analysis of data from all available studies. The random-effects model showed no significant odds ratio for the Arg16Gln (odds ratio = 1.05, p = 0.53) or Gln27Glu (odds ratio = 1.12, p = 0.22) polymorphism.

Conclusion: Our data indicate that ADRB2 does not contribute substantially to susceptibility to asthma, but it is possible that these polymorphisms influence disease activity and drug responses in individuals with asthma.