Background: Ankylosing spondylitis (AS) is inflammation of the sacroiliac joints and spine, associated with clinical symptoms such as pain and stiffness in the vertebral column, after which, in a considerable number of individuals, new bone growth occurs. Objective: The current research study attempted to find out whether the presence of SNPs in TNF receptor [TNFRSF1A (rs767455), TNFRSF1B (rs1061622)] encoding genes could influence patients' outcomes to etanercept in a specimen of Iraqi AS patients. Patients and methods: Sixty patients with established AS receiving only etanercept were selected to be enrolled in this research with a mean age of 40.75 ± 8.67 years, 51 patients of them were males and only 9 patients were females. Patients were classed as "responders" if just obtained a BASDAI 50 clinical response and as "non-responders" if they can't achieve a BASDAI 50 clinical elaboration after at least 6 months treatment. After PCR products amplification of purified blood DNA, TNF receptor (TNFRSF1A and TNFRSF1B) genes SNPs were established by Sanger sequencing. Results: The analysis of this study expressed that there was a significant incidence of TT genotype of rs1061622 (P = 0.022) in responder group, whereas the TG genotype of the same SNP was considerably present in the group that did not respond (P = 0.002). Finally, a non-significant difference existed in alleles and genotypes frequency between responder and non-responder groups of rs767455 SNP in TNFRSF1A gene. Conclusions: The wild TT genotype of rs1061622 predicts etanercept responsiveness in ankylosing spondylitis patients. The TG genotype of the same SNP increases the probability of non-responding
