FOXO3a gene polymorphism and bronchial asthma in Egyptian children

Background: FOXO3a proteins play multiple crucial roles in immune response. FOXO3 inhibits T cell proliferation, induces T cell apoptosis via upregulation of proapoptotic proteins and it suppresses T cell activation preventing autoimmunity. The role of FOXO3a gene in the pathogenesis of bronchial asthma has been studied in few ethnic groups and revealed its implication in asthma pathogenesis. Objectives: The aim of the current study is to detect the association between single nucleotide polymorphism of the FOXO3a gene (rs13217795) and bronchial asthma, atopy and asthma severity in Egyptian children. Methods: The current cross-sectional case-control study was performed on 75 asthmatic children aged 2 to 12 years following up in the pulmonology outpatient clinic in Children's hospital, Cairo University and 75 age and sex matched healthy controls. Candidates were subjected to clinical evaluation in addition to genotyping for the FOXO3a gene polymorphism using PCR-RFLP technique. Results: The highest frequency was for the heterozygous type CT in both cases and controls groups. The genotype frequencies of mutant type TT for cases and controls were 12 % and 16% respectively, and the T allele frequencies were 37.2% in cases and 46.7% in the control group while CC genotype was present in 37.3% of asthmatic patients and 22.6% in the controls and the C allele was detected in 62.8% and 53.3% for cases and controls respectively. No statistically significant differences were observed between asthmatic patients and controls regarding the different genotypes of the FOXO3a gene polymorphism (p=0.161). No significant association was detected between the different genotypes of the FOXO3a gene polymorphism and the atopic status (p=0.536) or the different grades of asthma severity (p= 0.545). Conclusions: The study of FOXO3a gene polymorphism (rs13217795) in asthmatic Egyptian children revealed low frequency of the mutant TT genotype among cases and controls. In the current study, FOXO3a polymorphism has no role in the pathogenesis of asthma or atopy. Moreover, it has no relation to degree of disease severity. Keywords: Asthma, FOXO3a, gene, children, Egyptian, polymorphism