先天性凝血因子Ⅴ缺乏症一种新基因突变的鉴定

Identification of a novel mutation of human blood coagulation FⅤ gene associated with congenital FⅤ deficiency

目的 探讨先天性凝血因子Ⅴ (FⅤ )缺乏症的分子发病机制。方法 利用发色底物法检测血浆FⅤ凝血活性 ,采用PCR产物直接测序或T A克隆后测序、限制性酶切分析先证者FⅤ基因 ,并进行家系和FⅤ基因多态性频率研究。结果 先证者 18号外显子存在G5 72 9T(M16 96 7)的纯合子突变 ,相应的氨基酸变异为Gly1880Val,FⅤ分子结构分析表明 ,突变后FⅤ的重链和轻链结合松弛。结论 FⅤ基因G5 72 9T突变与先天性FⅤ缺乏症的发病有关。

Objective To explore the molecular mechanisms involved in the patient with congenital FⅤ deficiency. Methods Activity of FⅤ was determined by biochemical method. The PCR products of FⅤ gene was analysed by directly sequencing or sequencing after cloned into T vector. The mutative FⅤ gene was analysed by restriction enzyme analysis in the proband and her family members. Results A homozygous missense mutation G5729T resulting in Gly1880Val was revealed in the proband and confirmed in the family screening. Structure function studies of the factor Ⅴ mutants (Gly1880Val) demonstrated the importance of Gly1880 for structural stability of the Factor Ⅴ. Conclusion G5729T mutation of FⅤ gene is related to the pathogenesis of congenital FⅤ deficiency.