Study of Bcl-1 Single Nucleotide Polymorphism of Glucocorticoid Receptor Gene in Patients with Bronchial Asthma

Abstract

Bronchial asthma is a chronic inflammatory disorder of the airways associated with airway hyper-responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing. Bronchial asthma is a multi-factorial disease process which represents a dysfunctional interaction between genetic and environmental factors. Several environmental risk factors have been identified such as exposure to air pollution, tobaccos smoke as well as occupational risk factors. The genetic association with BA takes 3 major forms which includes candidate gene, positional cloning linkage and single nucleotide polymorphisms. Single nucleotide polymorphisms (SNPs) or specific genetic variations occur across the entire genome. SNPs are currently the preferred method for the identification of genetic determinants in complex multifactorial diseases such as asthma. Glucocorticoids are the main anti-inflammatory and exert their action through Glucocorticoid Receptor. Polymorphisms of Glucocorticoid Receptor (GR) gene lead to alternation in glucocorticoid sensitivity. Bcl-1 is one of the most common gene polymorphisms under research. The present study was conducted to investigate the frequency of the Bcl-1 single nucleotide polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in patients with bronchial asthma (BA) and to evaluate its association with the response to glucocorticoids therapy. The study included 80 adult patients with BA diagnosed according to the Global Initiative for asthma (GINA, 2017) who was recruited from the Chest Medicine Department of Ain Shams University hospitals. Patients were subdivided according to the response to glucocorticoids therapy into glucocorticoids resistant patients and sensitive patients. In addition, 20 apparently healthy age and gender matched served as healthy controls. All individuals in the study were subjected to full medical history and thorough clinical examination with special emphasis on chest examination according to GINA 2017 and thorough clinical examination for BMI as a tool for diagnosis of obesity. Detection of Bcl-1 single nucleotide polymorphism using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) technique.