Association study of AFF1 gene polymorphism (rs340630) with Iranian systemic lupus erythematosus patients

Abstract: Aim: To investigate whether AFF1 polymorphism was associated with susceptibility and clinical features of SLE in Iranian patients. Methods: A total of 320 patients with SLE and 330 age, sex and ethnically matched healthy control subjects were enrolled in the present study. Both cases and healthy controls were genotyped for rs340630 polymorphism located inside the AFF1using Amplification Refractory Mutation System-PCR (ARMS-PCR). In order to investigate the association of this SNP with clinical features of SLE, clinical manifestations of the patients were recorded. The distribution of rs340630 genotypes were tested for deviation from Hardy-Weinberg in healthy controls. Genotypic and allelic distribution between patients and controls were assessed by chi-square test. Major results: Both A and G alleles of rs340630 were seen among our cohort of Iranian SLE and healthy control samples. All three genotypes of rs340630 were found, i.e., homozygous A/A (OR=1/01, 95%CI=%72 – 1/42, P= %99), homozygous G/G (OR=%92, 95% CI= %63 – 1/35, P=%77) and heterozygous A/G (OR=1/03, 95%CI= %76 – 1/41, P=%87). No significant differences were observed between allele frequency of this polymorphism in SLE patients and healthy controls. However, in the SLE group, the number of patients with renal disorder was significantly increased for the AG genotype compared to the other genotypes of AFF1 polymorphism (P= 0.05). Conclusion: There was no association between AFF1 polymorphism (rs340630) and SLE. However, our findings indica ted that the AG genotype of AFF1 polymorphism (rs340630) was significantly (P=0.0045) correlated with renal disorder in Iranian population.