Genetic polymorphism of FOXO3a (rs13217795) gene and its association with Asthma

Asthma is a chronic inflammatory disorder delineated by a heightened immunological response due to environmental or genetic factors. Single nucleotide polymorphism studies have shown that FOXO3a plays a pivotal role in maintaining immunoregulation. Polymorphism in FOXO3a has been linked to inflammatory diseases such as chronic obstructive pulmonary disease (COPD), Rheumatoid Arthritis, and Crohn’s disease suggesting that FOXO3a may be associated with asthma. Airway inflammation in asthma is characterized by activation of T helper type 2 (Th2) T cells and Foxo family members are reported to play critical roles in the suppression of T cell activation. Thus this study was undertaken to investigate an association between single nucleotide polymorphism of the FOXO3a (rs13217795, C>T transition) gene and asthma in Indian population. To our knowledge we are the first ones reporting an association between FOXO3a and asthma. Significant level of change has been seen in overall distribution of FOXO3a (rs13217795) genotypes in Healthy control group as compared to disease group although Healthy control group showed little increase in ‘CC’ genotype as compared to Patients of Asthma(54.46% vs 35.41%). Similarly, mutant type ‘TT’ genotype was present in low frequency in Asthma patients’ group 12.50% and also in control group 09.82% (χ2 = 7.643, P= 0.0219*). ‘CT’genotype is higher in patients’ group then control group (52.08% vs 35.71%)allele frequency was also significantly different (χ2=5.544, P=0.0185*) whereas carriage rate was not significantly associated (χ2 = 2.513, P= 0.1129ns).