遗传性凝血因子Ⅶ缺陷症伴组织因子异常的研究

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FⅦ cDNA，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（Arg131Trp）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。

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

OBJECTIVE: To investigate the mechanism of clinical haemorrhage in an inherited coagulation factor VII (FVII) 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 (Arg131Trp) heterozygous polymorphism in TF gene, which was 2.63% frequency 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 Arg131Trp heterozygous polymorphism in TF gene explained the clinical symptom of the proband.