The Role of the ADRB2 rs1042713 Polymorphism in Bronchial Asthma Susceptibility and Its Pharmacogenetic Implications

Introduction. Bronchial asthma (BA) is a multifactorial pathology of the respiratory system, in the development of which the variability of genes regulating the tone of the bronchial smooth muscles plays an important role. One key candidate is the β2-adrenoreceptor gene (ADRB2). Purpose of the study. To study the distribution features of genotypes and alleles of the rs1042713 (Arg16Gly) polymorphism of the ADRB2 gene in BA patients and control group individuals, as well as to evaluate their association with the risk of disease development. Materials and methods. 100 BA patients and 100 conditionally healthy individuals (control) were examined. Genotyping of the rs1042713 locus was performed using the PCR method. The compliance of genotype distribution with the HWE equilibrium was evaluated. Statistical analysis included calculations of the χ2 criterion, Fisher's exact criterion, odds ratio (OR), and 95% confidence interval (CI). Results. The frequency of the Arg/Arg genotype in BA patients was 79.0%, which is significantly higher than in the control group (39.0%) (χ2 = 33.24; p = 6.04 × 10 − 8; (pFisher = 1.79 times 10 − 8). The frequency of the Gly allele in the BA group was significantly lower compared to the control (14.0% vs. 39.0%; χ2 = 30.82; p = 2.83 × 10 − 8). For the Gly allele, OR = 0.255 (95% CI: 0.156–0.416) was calculated. In the patient group, a pronounced deviation from HWE was identified (χ2 = 17.52; p = 2.84 × 10 − 5), while in the control group, the equilibrium was maintained (χ2 = 0.57; p = 0.452). Conclusion. The homozygous Arg/Arg genotype is associated with a high risk of BA development, which is due to functional changes in β2-adrenoreceptors and their accelerated desensitization. The Gly allele performs a strong protective function. Disruption of HWE in patients indicates a pronounced selective pressure of the disease on genotypic distribution in the population. The obtained results are of great importance for developing systems for the pharmacogenetic prediction of β-agonist efficacy.