The combination of polymorphisms within interferon‐γ receptor 1 and receptor 2 associated with the risk of systemic lupus erythematosus

Genetic factors seem to play a significant role in susceptibility to systemic lupus erythematosus (SLE). We previously described the amino acid polymorphism (Val14Met) within the IFN-γ receptor 1 (IFN-γR1), and that the frequency of the Met14 allele in SLE patients was significantly higher than that of the healthy control population [Tanaka et al. (1999) Immunogenetics 49, 266–271]. We also found an amino acid polymorphism (Gln64Arg) within IFN-γ receptor 2 (IFN-γR2). Since the IFN-γ receptor is a complex consisting of IFN-γR1 and IFN-γR2, we searched for the particular combination of two kinds of amino acid polymorphisms found within the IFN-γ receptor which plays a prominent role in susceptibility to SLE. The greatest risk of the development of SLE was detected in the individuals who had the combination of IFNGR1 Met14/Val14 genotype and IFNGR2 Gln64/Gln64 genotype.