RTKN2、LDLR、APOB和APOC1基因多态性与类风湿性关节炎的相关性

目的：建立RTKN2基因rs3125734 C＞T、LDLR基因rs688 C＞T、APOB基因rs693 C＞T和APOC1基因rs4420638 A＞G四个SNP位点的PCR-HRM分子诊断方法，并研究其与兰州地区汉族人群类风湿关节炎易感的相关性。方法：通过设计引物和PCR-HRM检测体系优化，建立四个SNP位点的基因分型方法。检测588例RA患者和200例健康对照者标本，通过病例对照研究分析其RA易感性。结果：经测序验证所建PCR-HRM检测方法的正确性。结果显示，rs3125734和rs688位点的基因型和等位基因频率在RA组和对照组间存在统计学差异（P分别为0.046和0.016、0.014和0.02），rs3125734杂合突变型CT在RA组与对照组间差异有统计学意义（χ2=4.013,P=0.045,OR=1.613,95% CI:1.010-2.576），rs688纯合突变型TT在两组间有显著差异（χ2=6.853,P=0.009,OR=0.273,95% CI:0.103-0.721）。rs693和rs4420638位点基因型和等位基因频率在RA组和对照组间差异无统计学意义（P＞0.05）。经RF和anti-CCP将RA组分层后，rs4420638位点基因型和等位基因频率在RF(-)RA组与对照组间有统计学差异（χ2=4.710，P=0.030；χ2=4.110，P=0.043），其杂合突变型AG在两组间存在显著差异（χ2=4.046，P=0.044，OR=1.799，95%CI：1.015-3.186）；rs693在各组间无显著差异（P＞0.05）。构建rs688和rs4420638单倍型，单倍型CA和TA在RA组和对照组间有显著差异(P=0.020，OR=1.408，95%CI：1.054-1.881；P=5.73×10-5，OR=0.443，95%CI：0.295-0.664)。 结论：建立的rs3125734、rs688、rs693和rs4420638位点PCR-HRM分子诊断方法可用于常规化检测。rs3125734、rs688和rs4420638位点是兰州地区汉族人群的RA易感基因，rs3125734位点CT基因型和rs4420638位点AG基因型是RA发病的危险因素，而rs688位点TT基因型是RA的保护性因素。rs688和rs4420638的单倍型CA可显著增加RA的发病风险，TA可降低RA的发病风险。

Correlation between genetic polymorphism of APOB,APOC1,RTKN2 and LDLR gene and rheumatoid arthritis

Objective:To establish PCR-HRM methods for genotyping four SNPs of RTKN2 rs3125734 C>T,LDLR rs688 C>T,APOB rs693 C＞T and APOC1 rs4420638 A＞G;to investigate the relationship of the SNPs with the susceptibility of rheumatoid arthritis in Han Chinese population from Lanzhou region.Methods: The PCR-HRM methods genotyping for the four SNPs were established by designing the specific primers and optimizing the reaction conditions of PCR-HRM.588 RA patients and 200 healthy controls were genotyped and a case-control study was performed for exploring the relationship of the four SNPs with RA risk.Results: The validities of the self-established PCR-HRM methods were proved by sequencing.The result of the study showed that the genotype and allele frequencies of rs3125734 and rs688 loci were found differences between case and control groups (P=0.046 and P=0.016;P=0.014 and P=0.020).The CT genotype of rs3125734 was different between RA cases and controls (χ2=4.011,P=0.045,OR=1.613,95% CI:1.010-2.576),and so did the TT genotype of rs688 (χ2=6.853,P=0.009,OR=0.273,95% CI:0.103-0.721).There was no statistic difference between RA cases and controls in rs693 and rs4420638(P＞0.05).After the stratified analysis of RA cases according to anti-CCP and RF,the genotype and allele frequency of rs4420638 were found difference between RA-RF(-) cases and controls(χ2=4.710,P=0.030;χ2=4.110,P=0.043),and the AG genotype was different between the two groups(χ2=4.046,P=0.044,OR=1.799,95%CI:1.015-3.186).There were no statistic difference between different groups in rs693(P＞0.05).Building the haplotype of rs688 and rs4420638,the haplotypes of CA and TA were markedly different between RA cases and controls (P=0.020，OR=1.408，95%CI1.054-1.881；P=5.73×10-5，OR=0.443，95%CI0.295-0.664).Conclusion: The self-established PCR-HRM methods of rs3125734,rs688,rs693 and rs4420638 can be applied to the routine detection of clinical sample.The SNPs of rs3125734,rs688 and rs4420638 are RA-associated genes in Han Chinese population from Lanzhou region.The CT genotype of rs3125734 and the AG genotype of rs4420638 increase the risk of RA and the TT genotype of rs688 decrease the risk of RA.The haplotype of CA increase the risk of RA and TA decrease it.