Association of eNOS gene polymorphisms and systemic lupus erythematosus in southeast Iran

Background and objectives Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with unknown etiology. Genetic and environmental factors play important roles in the pathogenesis of SLE. The primary objective of this study was to investigate the possible association of eNOS gene intron 4b/a, Glu298Asp and T‐786C polymorphisms with SLE in southeast Iran populations. Patients and methods This was a case‐control study comparing eNOS polymorphisms in 106 SLE patients and 196 age‐ and sex‐matched healthy controls. The 4b/a, Glu298Asp and T‐786C polymorphisms were analyzed using polymerase chain reaction and restriction fragment length polymorphism. Results Our findings indicated that the 4b/a polymorphism was associated with SLE, and the risk of SLE was 3.5‐ and 1.75‐fold higher in patients with aa and ba genotypes than in patients with bb genotype. No association was observed between Glu298Asp and T‐786C polymorphisms and SLE. There were no differences in eNOS gene polymorphisms between the Balouch and Fars population. Conclusion Statistically significant differences were observed in genotypes and allele frequencies of 4b/a polymorphism between patients with SLE and healthy controls in southeast Iran.