Population frequency, mutation linkage and analytical methodology for the Arg16Gly, Gln27Glu and Thr164Ile polymorphisms in the β 2 -adrenergic receptor among Turks

Abstract

Aims Inherited polymorphisms of codons 16, 27, and 164 of the β₂-adrenergic receptor (B2AR) gene may result in significantly changed functions of this receptor. The aim of the present study was to investigate the frequencies of the main mutations of the B2AR gene in Turks. Methods A group of 104 unrelated Turkish subjects were analysed for the Arg16Gly, Gln27Glu, and Thr164Leu polymorphisms of B2AR by a newly designed polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assay. A 242-bp amplicon including the Arg16Gly and Gln27Glu polymorphisms was generated including an arbitrary restriction site, allowing the cleavage with Eco130I or Fnu4HI for analysis of the two polymorphic sites, respectively. For the amino acid polymorphism at codon 164 a 280-bp fragment was generated and digested by MnlI. Results The allelic frequencies of mutated Gly16, Glu27, and Ile164 alleles were found as 59.6%, 31.7%, and 0.5%, respectively. Although, the frequencies of the polymorphisms at codon 16 and 164 were found similar as in various Caucasian populations, the frequency of the Glu27 variant was found significantly lower than these populations. Conclusions Obviously there are interethnic differences in functionally relevant B2AR variants which may have implications for drug treatment and disease susceptibility.