Background Rheumatoid Arthritis (RA) shares some similar clinical and pathological features with juvenile idiopathic arthritis (JIA) , an autoimmune disease characterized by chronic arthritis. The strategy of studying the putative role of RA susceptibility genetic factors in the development of JIA has proved highly successfully so far . Moreover, accumulated evidence indicates that an ethnic heterogeneity of genetic factors exists for rheumatic disorders .
Objectives To investigate whether five single nucleotide polymorphisms (SNPs), found to be associated with JIA in various ethnic populations so far, are also associated with JIA in Greece.
Methods The sample set consisted of 128 Caucasian JIA patients and 221 healthy controls from Northern Greece. Single Nucleotide Polymorphisms (SNPs) markers that showed association previously with both RA and JIA , namely TRAF1/C5 rs10818488, PTPN22 rs2476601, STAT4 rs7574865, CD247 rs1773560 and PTPN2 rs7234029 SNPs were genotyped with Restriction Fragment Length Polymorphisms (RFLPs) or Taqman primer-probe sets. For the investigation of disease susceptibility, odds ratios (OR) and 95% confidence intervals (CI) were calculated. The statistical difference in genotype and allelic distribution was assessed by two-tailed chi-square test.
Results A case–control association study was conducted enrolling 5 successfully genotyped markers. The risk alleles T of the PTPN22 and A of the TRAF1/C5 SNPs analyzed were more common in individuals with JIA than in controls (p=0.043, OR=0.44, 95% CI 0.21-0.97 and p=0.045 OR=1.37, 95% CI 1.01-1.88, respectively). Furthermore, the presence of the risk allele G of the CD247 SNP in the genotype appeared to be associated with JIA (p=0.039, OR=1.88, 95% CI 1.06-3-37).
Conclusions Our findings confirm for the first time in Greece that the PTPN22 rs2476601, TRAF1/C5 rs10818488 and CD247 rs1773560 SNPs are associated with susceptibility to JIA, thus suggesting that the respective risk alleles may confer susceptibility to clinically distinct disorders. Apart from the previously reported evidence for the role of STAT4 and PTPN2 gene polymorphisms in the development of JIA, our results demonstrate no association of these genes with the disease in a Greek population. The results highlight the importance of comparative studies in different ethnic populations in any attempt to confirm previously detected genetic associations.
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Disclosure of Interest None Declared