中国人获得性血友病A患者中一个FⅧ基因多态性位点的发现

A polymorphism site of FⅧ gene found in Chinese acquired hemophilia A patients

目的研究8例中国人获得性血友病A患者的FⅧ基因变异,尝试寻找与疾病相关的潜在基因位点。方法对患者进行表型检测,包括APTT﹑FⅧ:C和FⅧ抑制物浓度的测定;采用LD-PCR和多重PCR分别检测FⅧ基因内含子22倒位和内含子1倒位,采用PCR产物直接测序的方法对FⅧ基因进行序列分析,寻找突变和多态性位点。结果 8例患者均表现为APTT延长,FⅧ:C降低,并且能够检测出浓度不等的FⅧ抑制物。在FⅧ基因3’UTR区域内发现c.8899G/A(rs1050705)的多态性位点,其等位基因"A"的频率远高于另一等位基因"G"的频率。结论 c.8899 G/A(rs1050705)多态性位点的等位基因频率可能与获得性血友病A患者中FⅧ抑制物的形成存在一定的联系,这对进一步研究该疾病的分子发病机制具有重要意义。

Objective To investigate the FVIII gene variations in 8 Chinese acquired hemophilia A patients, and try to search for the gene site which is potentially related to this disease. Methods The APTT, FVIII： C and FVIII inhibitor were determined for the patients. The LD-PCR and multiplex PCR were applied to detected the intron 22 inversion and intron 1 inversion. The PCR followed by direct DNA sequencing was adopted to analyze the FVIII gene region. Results All the 8 patients showed prolonged APTT, low FVIII：C and different amount of FVIII inhibitors. A polymorphism site of c. 8899 G/A （rs1050705） was identified in 3＇ UTR region of FVIII gene. The frequency of allele ＂A＂ was much higher than the frequency of allele ＂G＂. Conclusion The allele frequency of c. 8899 G/A （rs1050705） was probably related to the formation of FVIII inhibitor in acquired hemophilia A patients, which will be meaningful for the research of the molecular mechanism of genetic flaw in this disease.