摘要
目的:对一个遗传性凝血酶原缺陷症家系进行凝血酶原(FII)基因突变的检测。方法:用活化部分凝血活酶时间(APTT),凝血酶原时间(PT)及FII促凝活性(FII:C)、FII抗原(FII:Ag)测定进行表型诊断;用PCR法对先证者的FII基因14个外显子及其侧翼序列和5’端非翻译区(5’UTR)、3’端非翻译区(3’UTR)序列进行扩增,PCR产物纯化后直接测序,检测其基因突变。家系成员DNA在先证者FII基因突变区域扩增后测序。突变位点经限制性内切酶分析证实。103例健康献血者作对照。结果:先证者表型诊断为凝血酶原缺陷症(Ⅰ型);FII外显子区共发现3个与文献报道的FII基因序列不同的位点,其中位于第2外显子区的为纯合突变A601G。家系分析表明先证者父亲、母亲和外祖母均为A601G杂合子。结论:纯合错义突变A601G引起的Glu29→Gly是导致本例遗传性凝血酶原缺陷症的原因。这在国际上首次报道。
objective: To discover the gene mutations of a pedigree with inherited prothrombin (FII) deficiency. Methods: The activated partial thromboplastin time (APTT), prothrombin time (PT), FII activity (FII: C) and FII antigen(FII: Ag) test were adopted for phenotype diagnosis. The genomic DNA was extracted from the peripheral blood of the proposita. All the 14 exons, intron/exon boundaries and the 5' and 3'untranslated regions (UTR) of the prothrombin gene were amplified by polymerase chain reaction (PCR). The PCR products were screened by direct sequencing and the mutations were further confirmed by restricted enzyme digestion. The other 5 persons in the pedigree were examined too. 103 healthy blood donors were used as controls. Results: The phenotype of the proposita was prothrombin deficiency(type Ⅰ). Taking the prothrombin nucleotide sequence published by Degen & Dacie as the reference, totally three variations in the FII gene have been found in the proposita. The novel mutation is a homozygous A601G subtitution on exon 2. Conclutions: The prothrombin deficiency of the proposita is caused by a homozygous Glu29 to Gly mutation in the prothrombin gene, which has not been identified previously.
