Association between Arginine 16 Polymorphism of B2 Adrenergic Receptor and Bronchial Asthma in Children

Background: Asthma is one of the most prevalent health problems. The relationship between β2AR genotypes and response to β2AR agonist therapy is controversial. Some studies have found that the Arg-16 genotype is associated with reduced response to β2AR agonists, whereas others have found that the Gly-16 genotype is associated with reduced response. Objective: to detect gene polymorphism and to determine the association between gene polymorphism and bronchial asthma susceptibility as a risk factor, and to evaluate of the degree of severity of bronchial asthma among cases having a defect in studied gene and those without defect, and also to assess of drug response to β2 agonists concerning gene polymorphism. Methods: This study was carried out at Zagazig university hospitals. 100 Egyptian children with ages ranging from 5 to 12 years were enrolled. They were divided into 2 groups, the asthmatic group included 50 asthmatic children who were diagnosed according to GINA guidelines (2016), and a control group of 50 age and sex-matched healthy children. Results: Arg16Gly heterozygous represents 48%, Arg16 homozygous represents 38% and Gly16 homozygous represents 16% of asthmatic patients, while among the control group Arg16heterozygous represents 38%, homozygous represents 14% and 48% for Gly16 homozygous. There was no significant difference between Arg16Gly genotypes and asthma severity. Also, Arg 16 homozygous showed the best response to treatment with inhaled shortacting beta 2 agonists. Conclusion: there is an association between beta 2 adrenergic receptor polymorphism and the occurrence of bronchial asthma and also between this polymorphism and response to treatment. Also that the polymorphism at codon 16 of the β2 adrenergic receptor gene not a determinant of asthma severity in the Egyptian children.