RESUMEN
Objective A very high prevalence of rheumatoid arthritis (RA) is observed in Minnan population in China.We aimed to explore the genetic characteristics of RA in Minnan population and genetic mechanisms of RA by studying the associations of three single nucleotide polymorphisms (SNPs) of signal transducer and activator of transcription 4 (STAT-4) (rs7574865),the cytotoxic T-lymphocyte antigen-4 (CTLA)-4 (rs3087243) and chromosome 9p21.3(rs1333049) with RA in Minnan population.Methods A case-control study of 119 RA patients and 125 normal controls from Quanzhou were enrolled.SNPs (rs7574865,rs3087243,rs1333049) were genotyped by allele-specific polymerase chain reaction (PCR) and analyzed by SPSS 18.0.x2-test was applied to compare allele and genotype frequeneies betweeen cases and controlsLogistic regression models were used to analyze the SNPs.Results The results showed the genotype distributions of STAT4 genes were significantly different between case and control groups (P＜0.01).Compared with the GT heterozygous genotype,TT and GG homozygosity carriers had a lower risk (OR=0498 and 0.300,P=0.018 and P=0.002 respectively).There was not statistical difference in genotypes and allele in CTLA-4 (rs3087243) between RA patients and healthy controls (x2=4.083,P=0.130),but compared with the AG genotyoe,GG homozygosity carriers had a lower risk on basis of statistics (OR=0.580,P=0.04).There was not statistical difference in genotypes and allele in the chromosome 9p21.3 (rs1333049) (P＞0.05),but compared with the GG genotype carriers,CC and GC genotypes carriers had a lower risk on basis of statistics (OR=0.565,P=0.0495).Conclusion Chromosome 9p21.3 (rs1333049) and CTLA-4 rs3087243 G/A may not be associated with susceptibility to RA in Minnan popula-tions.This replication study confirmes that STAT4 rs7574865 G/T polymorphism is associated with susceptibility to RA in Minnan population.