一个新的PROC基因突变的检出及其致病机制的研究

Detection of a novel mutation in PROC gene and the mutation-related pathogenic mechanism

目的:鉴定一个遗传性蛋白C缺乏症患者的基因突变,并对该突变的致病机制进行研究。方法:采用血液基因组提取试剂盒获取遗传性蛋白C缺乏症患者的DNA,用聚合酶链反应(PCR)法扩增其PROC基因所有外显子及侧翼序列并测序,应用Chromas软件分析并检出基因突变;将带有突变位点的PROC基因c DNA序列克隆到载体后转染至HEK293细胞,采用定量PCR法检测突变基因m RNA的表达水平。结果:检出一个PROC基因的新突变[c.740G>A(p.Trp247*)],并在细胞水平证明突变基因m RNA的表达水平出现下调。结论 :PROC基因无义突变的m RNA可能通过无义介导的m RNA降解途径快速降解,从而导致遗传性蛋白C缺乏症。

Objective： To identify a novel mutation of PROC gene and study the mutation-related pathogenic mecha- nism in a patient with hereditary protein C deficiency. Methods： DNA sample was obtained from a patient with hereditary protein C deficiency using blood genomic DNA extraction kit. All 9 exons and the flank sequence of PROC gene were am- plified by polymerase chain reaction （PCR） and the sequence was analyzed by Chromas software. Recombinants expressing mutant PROC gene were constructed and transfected into HEK293 cells, and the level of PROC mRNA expression was detected by qPCR. Results： A novel PROC gene mutation p.Trp247＊ was identified, and down-regulation of mutant PROC gene expression at mRNA level was detected. Conclusions： A nonsense mutation in PROC gene is identified, which caus- es rapid degradation by nonsense-mediated mRNA decay （NMD） pathway, resulting in the occurrence of hereditary protein C deficiency.