Association analysis of ERAP1 gene single nucleotide polymorphism in susceptibility to ankylosing spondylitis in Iranian population

Background Ankylosing spondylitis (AS) is a debilitating spondyloarthropathy that has been associated with variation in several genes. Human leukocyte antigen (HLA)-B27 constructs an impaired structure, culminating in recognition and activation of immune system. Impaired function of Endoplasmic reticulum aminopeptidase (ERAP) 1, which primes peptides to be loaded in HLA molecules, has strongly been associated with AS proneness. Here, we intended to investigate the possible association of ERAP1 gene single nucleotide polymorphisms (SNPs) with AS susceptibility in Iranian patients. Methods Two-hundred and twenty AS patients and 220 healthy controls were enrolled in this study. DNA was extracted from blood samples and then was genotyped for rs27044, rs17482078, and rs10050860 polymorphism by SSP-PCR approach. Results It was seen that G allele and GG genotype of rs27044 SNP significantly increased the risk of AS that was even stronger in HLA-B27 positive patients. Moreover, the T allele and TT genotype of rs10050860 polymorphism were associated with increased risk of the disease in both all and HLA-B27 positive AS group. Two haplotypes were associated with the risk of AS and there was linkage disequilibrium between SNPs. Two SNPs were associated with clinicopathological manifestations of AS subjects. Conclusions This association study replicated the role of ERAP1 gene polymorphisms with the risk of AS in an Iranian population.