Background: Bronchial asthma is one of the most prevailed non-communicable diseases among Egyptian children and all over the world. Genetic-environmental interaction can influence the nature of many diseases including asthma and considering β2 agonists as one of the most commonly prescribed bronchodilators for relieving asthma symptoms, so this study was conducted to investigate the possible relationship between Gln27/Glu polymorphism of ADRβ2 from one side and bronchial asthma susceptibility, severity and responsiveness to Albuterol (short-acting ADRβ2 agonist) from the other side.
Subjects and methods: A case control study of one hundred Egyptian children was designed. All participants were genotyped using allele-specific Polymerase chain reaction (PCR) to assess single nucleotide polymorphism (SNPs) of ADRβ2. Fifty asthmatics, their mean age was (8.10+2.52), who were selected and classified according to GINA guidelines, 2017 and spirometerically assessed to evaluate pulmonary functions. Another fifty matched healthy participants were selected as a control group with a mean age of (8.44+2.40).
Results: Gln allele frequency = 0.59 and Glu allele frequency = 0.41 for cases with Chi- squared X2 = 0.12 and Gln allele frequency = 0.56 and Glu allele frequency = 0.44 for control participants with X2 = 0.93. There were no statistically significant differences between patients and control regarding Gln27/Glu polymorphism. Gln27 was the only genotype having positive association with both asthma severity and drug response, as it represents only 17.2% of all mild cases, 56.3% of all moderate cases and about 80.0% of all sever studied cases; P value (0.003).
Conclusion: B2 adrenergic receptor polymorphism at codon 27 is not associated with asthma susceptibility; however it can be a determinant factor for asthma severity and bronchodilating response to B2 agonists in Egyptian asthmatic children, to be confirmed by further Pharmacogenomic studies