Polymorphism of FOXO3a Gene and Its Association with Incidence of Asthma in Iraqi Patients

Abstract

Asthma is common polygenic multifactorial inflammatory disorder influenced by genetic and environmental factors characterized by inflammation of airways leading to obstruction, coughing and wheezing in response to an allergen or inorganic pollutions. FOXO3a (Forkhead Box O3) is a gene plays a vital role in the etiology of asthma disease. The objective of this study is to investigate an association of single nucleotide polymorphism SNP of the FOXO3a (rs 13217795, C˃T transition) gene with asthma susceptibility in adults of some Iraqi patients. study consists of two groups: fifty asthma patients (28 female and 22 male) and twenty five apparently healthy as a control group (9 female and 16 male). The age of the samples ranged from 20-60 years old. Recruited from the Alzahra’a Center for Asthma Allergy in Baghdad during the period extended from October /2017 to last February /2018. The DNA purity ranged between 1.8-1.9 and the concentration of DNA between 40-120 ng / μl. Then fragments targeted of FOXO3a gene (rs13217795 C>T) were amplified by polymerase chain reaction (PCR). Then Restriction Fragment Length Polymorphism (RFLP) technique was used to determined SNP (rs13217795) polymorphism by using Cci I restriction enzyme. Samples from control and patients group were sent for DNA analysis sequencing. TT not appeared in the sequencing.The highest rate of asthma was in the 40 to 60 age group. As for gender, the females ratio was higher than the males. Most patients have a family history of asthma. Most patients with asthma were in the autumn. The results were revealed that SNP (rs 13217795) of FOXO3a gene with Polymorphism of CT genotype in the control group was significantly higher than in patients group (80 % versus 50%, respectively). And persons with the CT genotype in the patient group were significantly higher than those with the CC genotype. While, the percentage of those with TT Polymorphism genotype in the patient’s group were showed highly significant difference as compared with control group (28 % versus 0 %, respectively). The Allele frequency C in the patients and control group shows 47.00% versus 60.00%, respectively. While Allele frequency T in the patients and control group shows 53.00% versus 40.00%, respectively. These results indicated that the polymorphism of C˃T (rs 13217795) of FOXO3a gene was associated with the developing Asthma in this studied sample. In conclusion, the T allele variant of FOXO3a gene (rs 13217795) polymorphism may be associated with increased susceptibility of the development of asthma in Iraqi patients.