摘要
目的 探讨遗传性凝血因子Ⅶ (FⅦ )缺陷症分子发病机制。方法 检测凝血指标以明确诊断 ;用DNA直接测序法对患者FⅦ基因的全部外显子和其侧翼以及 3′ ,5′非翻译区进行分析 ,寻找基因突变 ,对有突变的序列反向测序证实 ;发生在非经典的剪接位点突变用外周血单个核细胞异位转录的RT PCR方法确定其剪接方式。结果 患者在 8号外显子 10 96 1位发生T→G杂合突变 ,导致 348位His被Gln替代 ;在 1号内含子 5′端的非经典的剪接位点有Ggtgcg >Ggtgca(IVS1a+5g >a)杂合突变 ,RT PCR结果揭示剪接过程中去除了 2号外显子 ,却把 3号内含子包含进去 ,在 3号外显子起始处出现了移码突变 ,编码与原来氨基酸完全不同的 9个氨基酸后出现了终止信号 ,产生了一个只有 30个氨基酸组成的截短型蛋白。结论 患者FⅦ基因中发现了两种杂合突变 (10 96 1位T→G、IVS1a +5g >a) ,其中后一种非经典的剪接位点突变导致的异常剪接方式为国际首次报道。
Objective To investigate the pathogenesis of inherited coagulation factor Ⅶ (FⅦ) deficiency. Methods The diagnosis was validated by coagulant parameter assay. FⅦ gene mutations were analysed in the proband by DNA direct sequencing of PCR products of all exons,exon-intron boundaries and the 3′,5′untranslated sequences. The mutations were confirmed by reverse sequencing. The ectopic transcripts of RT-PCR were used to confirm the characteristics of the mutation in non-canonical splice site (IVS1a+5g>a). Results Double heterozygous mutations in the propositus were identified:a T to G mutation at position 10961,resulting in His348Gln substitution,a non-canonical splice site (IVS1a+5g>a) mutation,causing the new model of splice and frameshift mutation. Conclusion Double heterozygous mutations of His348Gln and IVS1a+5g>a were identified in a propositus,the splicing pattern of the IVS1a+5g>a mutation was repored for the first time.
出处
《中华血液学杂志》
CAS
CSCD
北大核心
2004年第3期139-142,共4页
Chinese Journal of Hematology
基金
上海市科委科技发展基金资助项目 (0 12 0 3 5 )
