Genetic susceptibility to Behçet's syndrome is associated with NRAMP1 (SLC11A1) polymorphism in Turkish patients

Natural resistance associated macrophage protein 1 (NRAMP1), also named as solute carrier family 11 member A1 gene (SLC11A1), has multiple pleiotropic effects on macrophage activation pathways such as up-regulation of the CXC chemokine KC, tumor necrosis factor alpha (TNF-alpha), interleukin-1 b (IL-1 b), inducible nitric oxide syntase (iNOS), and major histocompatibility complex (MHC) class II expression. Since NRAMP1 plays a role in the up-regulation of the TNF-alpha, iNOS and MHC expression, it may also be a candidate gene for Behçet's syndrome (BS). We analyzed the association of NRAMP1 polymorphisms [(GT)( n ), INT4, 3'UTR and D543N] in 102 Turkish patients with BS and 102 healthy subjects by using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). We found a significant association between BS and NRAMP1 INT4 G/C allele frequency (p = 0.004, OR = 1.88, 95% CI = 1.21-2.93). However, there were no significant differences in the distribution of allele frequencies of NRAMP1 (GT)( n ), 3'UTR, D543N polymorphisms between BS patients and healthy controls. There was also no correlation between NRAMP1 polymorphisms and clinical manifestations of BS. Our study suggests that NRAMP1 may be one of the plausible candidate genes for BS. However, it is likely that INT4 polymorphism is not disease-specific and seems to be common to immune-mediated diseases.