遗传性凝血因子Ⅶ缺陷症伴组织因子异常的研究

Studies on inherited coagulation factor Ⅶ deficiency and tissue factor abnormality in a pedigree

目的探讨1个遗传性凝血因子Ⅶ(FⅦ)缺陷症伴组织因子异常家系的临床出血机制。方法用 DNA 直接测序法对先证者 FⅦ及组织因子(TF)基因的全部外显子及其侧翼5′和3′非翻译区进行分析,寻找突变基因。反向测序证实所发现的突变。用 RT-PCR 及筑巢式 PCR 扩增先证者 FⅦcDNA,检测 FⅦ基因大的缺失和(或)插入突变。对其家系成员作突变基因检测。结果在先证者 FⅦ基因启动子区检测到-55C→T 杂合突变。该突变来自先证者的母亲,其姐姐也带有同样的杂合突变。其他家系成员的 FⅦ基因未见突型。在先证者及所有家系成员的 TF 基因中均发现了9363C→T(Argl31Trp)杂合多态性,9363T 基因杂合频率为2.63%。结论首次报道先证者的临床出血与 FⅦ杂合突变及 TF 的杂合多态性有关。

Objective To investigate the mechanism of clinical haemorrhage in an inherited coagulation factor Ⅶ （F Ⅶ ） deficiency and tissue factor abnormality pedigree. Methods All exons, exon-intron boundaries and the 3＇, 5＇ untranslated sequences of FⅦ and tissue factor（TF） genes were amplified by PCR and sequenced directly, Any mutation identified by direct sequencing was confirmed by reverse sequencing. FⅦ cDNA of the proband was synthesized with random primers and amplified by nest PCR. Results 55C→ T heterozygous mutation located in promoter of FⅦ gene was identified in the proband, The heterozygous mutation was derived from his mother. Tracing the other pedigree members found that his sister had the same heterozygous mutation and the others had wild-type FⅦ genes. A 9363 C→T （Argl31Tip） heterozygous polymorphism in TF gene, which was 2.63% frequencey of T allele polymorphism, was found in all of the pedigree members. Conclusion It was the first report that the - 55C→T heterozygous mutation in FⅦ gene and the Argl31Trp heterozygous polymoIphism in TF gene explained the clinical symptom of the proband,