β2-adrenoceptor gene polymorphisms

beta(2)-Adrenoceptors (AR) play an important role in regulation of vascular and bronchial smooth muscle tone; functional beta(2)-AR, however, also exist in human heart where they can mediate positive inotropic and chronotropic effects. Recent studies have discovered that beta(2)-AR are polymorphic. The most common single nucleotide polymorphisms (SNPs) are: Arg16Gly, Gln27Glu, Thr164IIe in the coding region, and Arg-16Gly in the 5 ' upstream peptide. These SNPs affect receptor function in vitro; however, conflicting data exist on their functional relevance in vivo. This might be due to the fact that the four SNPs in the 5 ' upstream peptide and in the coding region, respectively, are linked and form certain haplotypes. This review gives an overview on the contribution Of beta(2)-AR polymorphisms to cardiovascular diseases or altered drug responses. In addition, the relevance of SNPs vs. haplotypes for beta(2)-AR functional responsiveness is discussed. (c) 2005 Lippincott Williams & Wilkins.