Association Study of an AFF1 Gene Polymorphism (rs340630) with Iranian Systemic Lupus Erythematosus Patients

To investigate whether an AFF1 polymorphism was associated with susceptibility and clinical features of SLE in Iranian patients.

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 investigation of SNP association and clinical features of SLE, clinical manifestations of patients were recorded. The distributions of rs340630 genotypes were tested for deviation from Hardy-Weinberg in controls. Genotypic and allelic distribution between patients and controls were assessed by chi-squares test. The Odds Ratio (OR) and 95 % Confidence Intervals were calculated from multiple logistic regression analysis.

Both A and G alleles of rs340630were seen among the Iranian 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). In the SLE group, the number of patients with renal disorder was significantly higher for the AG genotype compared to other genotypes of AFF1 polymorphism (P= 0.05).

There was no association between AFF1 polymorphism (rs340630) and SLE. However, our findings indicated that AFF1 polymorphism (rs340630) was significantly (P=0.0045) correlated with renal disorder in Iranian population.