Iranian Journal of

Background: IFN-g is one of the most essential and fundamental player in initiation and development of T1DM. This mediator belongs to T Helper-1(Th1) class of cytokines and exerts stimulation and differentiation of naïve T cells towards Th1 cells and meanwhile inhibits differentiation and proliferation of Th2 cells. These effects are highly important in induction and progression of cell-mediated immune responses that is aberrantly operative in development of T1DM. Due to such outstanding role, numerous studies including genetic manipulation have focused on the role of this pro-inflammatory cytokine in T1DM.

 Methods: In a genetic association study the influence of IFN-g gene variation in position +874*T/A on development of T1DM was analysed in 248 British Caucasian T1DM patients in comparison with 119 healthy matched controls. ARMS-PCR procedure was designed for detection of the variants at allele/genotype level. 

Results: No significant association between IFN-g gene polymorphism and T1DM was apparent (P≥ 0.05). The distribution of these polymorphic variants was in Hardy-Weinberg equilibrium.

Conclusion: While some studies have shown an association between the examined polymorphism of IFN-g and T1DM, our data do not support that. According to present study the selected polymorphic marker (+874*T/A) is not among the polymorphisms that governs in part genetic susceptibility to T1DM. That irreproducibility or controversial results is a common observation in genetic studies of complex traits such as T1DM, reflecting a fragile correlation between genotype and phenotype. This study also underlines the importance of replication of association studies to confirm the previous results/interpretations.