This study was conducted to investigate the possible association of the single nucleic polymorphisms (SNPs) in the interleukin-17F precursor gene (IL17A) gene with asthma. This study was conducted to assess the pattern of the genetic polymorphism of the IL17A gene and its possible association with asthma. In this study, the IL17A genetic sequences in chromosome no. 6 were analyzed in sixty-eight samples, forty-eight samples of patients (assigned S1 to S48), and twenty samples of control (S49 to S68). A specific PCR fragment of 526 bp was designed to amplify a specific portion of the IL17A gene. The amplified fragment was specifically designed to incorporate a high-frequency single nucleotide polymorphism (SNP) within the IL17A gene, namely rs2275913. Within the amplified locus of the IL17A gene, the genetic variations of the targeted locus were screened in the selected population. Subsequently, Sanger sequencing method was conducted for the amplified fragment to assess the variations of the observed SNP within the selected population. The observed variations were documented within the corresponding referring genomic DNA sequences. Statistical calculations were performed to assess the possible association between the observed SNP and the development of asthma. The conducted sequencing reactions confirmed the presence of the targeted high-frequency variant in the amplified fragments of the IL17A gene, namely G271A. The identity of this variant was confirmed as it was deposited as rs2275913. This variant exhibited variable distributions in the investigated samples, a homozygous GG, a heterozygous GA, and a homozygous (AA) pattern in the investigated population. The homozygous GG form was detected in the majority of cases and controls. Results showed that the homozygous AA form was only detected in the samples of patients and no control showed any detection of the homozygous AA. Statistical analyses showed that this homozygous AA pattern tended to exhibit a significant association with the progression of asthma. In conclusion, the investigated IL17A gene has been shown to exhibit informative polymorphic patterns in the investigated population of ThiQar. In the identified rs2275913 SNP of the investigated population, a novel association was found between the AA genotype and the development of asthma. For this reason, it was found that rs2275913 SNP is an interesting marker that can be utilized to diagnose the development of asthma in our investigated samples. Further studies are required using a larger size of samples to explore more details in this suggestive association.

IL-17, Asthmatic, Sequencing, Polymorphism, Thi-Qar Population