ABSTRACT
Objective To investigate the correlation between the single nucleotide polymorphism(SNP) of macrophage migration inhibitory factor(MIF) gene -173G/C and the susceptibility in patients with juvenile idiopathic arthritis(JIA).Methods Study group consisted of 97 children of JIA.All patients included in this study met the International League of Associations for Rheumatology criteria for JIA.Control group consisted of 102 healthy individuals.Germline DNA was extracted from peripheral blood by AxyPrep blood genomic DNA miniprep kit.Polymerase chain reaction-restrictivon fragment length polymorphism(PCR-RFLP) was used for genotyping the -173G/C polymorphism of MIF.Genotype distribution and allele frequencies were obtained by direct counting.Statistical analysis was performed by using SPSS Bosoftware.Allele and genotype distributions were compared using the chi-square test.The relative risk of alleles was described by odds ratios (OR) and 95% confidence intervals (95%CI).Hardy-weinberg equilibrium was confirmed with the chi-square test.Results We detected 3 kinds of genotypes at the MIF-173 locus.The frequency of each genotype was 54.6%(GG),42.3%(GC),3.1%(CC) in JIA group,and 79.4%(GG),20.6%(GC),0(CC) in control group.The C allele frequencies in the JIA and control group were 24.7% and 10.3%,respectively.There was significant difference was observed between the JIA and control group in the frequencies of mutant genotype(GC and CC) of MIF-173G/C polymorphism(?2=13.872 P=0).Individuals possessing a MIF-173C allele did have an increased risk of JIA(OR=2.79,95% CI 1.62-4.81 P=0).When the genotype and allele distributions of the MIF-173 gene in the subtypes of JIA and contronl group were compared,a significant difference wad found in the systemic JIA and control group (P0.05).Conclusions MIF-173G/C SNP may be associated with the sensitivity of JIA.MIF-173 C allele may increase susceptibility to JIA.