中国正常人及类风湿关节炎病人MHC－Ⅱ类DR＿4亚型基因核苷酸序列初步分析

A PRELIMINARY STUDY ON THE DNA SEQUENCE OF MHC-IIDR_4 SUBYYPES OF RHEUMATOID ARTHRITIS AND NORMALCHINESE INDIVDUALS.

对中国人群正常人及类风湿关节炎病人ＤＲ＿４亚型基因决定型别特异性的第二个外显子进行体外扩增、克隆及序列分析显示，６例正常人及３例类风湿关节炎病人存在三种ＤＲ＿４亚型（ＤＲＢｌ０４０２，ＤＲＢｌ０４０５，ＤＲＢｌ．０４０６），中国人这三种亚型第二个外显子核苷酸序列与白种人一致。序列分析结果为进一步应用常规ＰＣＲ－ＳＳＯ法及ＰＣＲ－ＲＦＬＰ法进行中国人ＤＲ＿４基因定型提供了依据。此外，还将序列分析结果与ＰＣＲ－ＳＳＯ杂交分析结果进行了比较，具备较全面的覆盖各亚型多态性区域的探针可以减少等位基因同源性干扰。

he nucleotide sequences of MHC-class II DR_4 alleles in six normal chinese and ThreeRheumatoid Ar thritis(RA)patients were studied.three DR_4 subrypes,DRB1 0402,DRB10405 and DRB1 0406 were found in normal individuals and DRB1 0405 were found in RApatients.The sequences of these subtypes were identical to that previously reported in caucasionpopulation,So these alleles may be typed by PCR-sequence specific oligonucleotide typing(PCR-SSO)or PCR-restriction fragment length polymorphism(PCR-RFLP)using conventional probesor restriction enzyme sets as caucasian population. In addition,we also compared the sequencingresults with the PCR-SSO subtyping of these samples. Some PC-SSO subtyping errors werefound,which may be caused by high homologous sequences in these subtypes.The subtyping er-ror may be reduced by using more probes that cover the polymorphism regions of alleles.