Role of endoplasmic reticulum aminopeptidase-1 gene polymorphism (rs13167972) in occurrence susceptibility of ankylosing spondylitis in a sample of Iraqi male patients

Background Ankylosing spondylitis (AS) is a chronic and systemic seronegative inflammatory spondyloarthropathy, an autoimmune disease that has been associated with impaired Endoplasmic Reticulum Aminopeptidase (ERAP)-1 activity, which is involved in priming antigenic peptides. The purpose of this study is to investigate the association of 3 -UTR of ERAP1 gene polymorphism (rs13167972) with the AS occurrence susceptibility in a sample of Iraqi male patients. Methods The AS patients were diagnosed clinically and by magnetic resonance imaging (MRI) and other clinical and laboratory criteria like symptoms, increased C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The blood grouping and Body Mass Index (BMI) were also investigated to be associated with AS occurrence. The genotyping of the 3− UTR region of the ERAP1 gene (rs13167972) was done by Sanger sequencing. Results The results revealed that the AS occurred significantly in the age group of 20–35 years (p = 0.013). The BMI shows that the AS patients were overweighted males (p = 0.013) and the most predominant blood group in AS patients was O- (p = 0.002). The ESR and serum level of CRP were significantly raised in AS patient sera (