摘要
目的对1例遗传性异常纤维蛋白原血症家系进行表型、基因型分析,并研究其致病机制。方法采集先证者及其父母的外周血并进行常规出凝血、血浆纤维蛋白原(Fib)活性和抗原检测。对Fib的基因FGA、FGB和FGG的所有外显子及其侧翼序列进行PCR扩增及测序。采用Fib凝固率测定、纤维蛋白聚集曲线和电镜扫描纤维蛋白凝块等方法研究其致病机制。结果先证者活化部分凝血酶原时间、凝血酶原时间正常,凝血酶时间延长,Fib抗原正常、活性降低;其父亲表型与之相似。先证者及其父亲FGA基因第2外显子均存在A1211G杂合碱基置换,导致Fibα链Arg19Gly错义突变。western-blot检测显示,先证者及其父亲血浆Fib无异常条带出现。先证者血浆Fib凝固率为20.8%,凝血酶或爬虫酶诱导的聚集曲线严重受损,纤维蛋白凝块的纤丝直径大于健康人对照(P<0.001),密度小于健康人对照。结论鉴定该病例为遗传性异常纤维蛋白原血症,Fibα链Arg19Gly杂合错义突变导致Fib功能受损,为该病例及相应临床症状的原因。
Objective To analyze the phenotype and genotype of a Chinese pedigree with inherited dysfibrinogenaemia and investigate the molecular mechanism of the disease.Methods Venous blood samples were collected from all family members,and routine coagu-lation tests were conducted.Functional fibrinogen in venous blood samples was measured by Clauss method,and the antigen level of fibrinogen in plasma was measured by immunoturbidimetry assay.All the exons and exonintron boundaries of the three fibrinogen genes were analyzed by direct sequencing.Fibrinogen electrophoresis,fibrinogen clottability measurement,fibrin polymerisation measurement and electron microscopy scanning were also used to investigate the molecular characteristics and pathogenesis.Results The proband had normal activated partial thromboplastin time,prothrombin time and plasma fibrinogen antigen,but prolonged thrombin time,pro-longed reptilase time and reduced fibrinogen activity level,which were also found in his father.The sequencing results of the proband revealed heterozygous A1211G in the exon 2 of FGA gene originating from his father,which caused Arg19Gly missense mutation.The western-blot results showed that no abnormal bands of plasma fibrinogen were found in the proband and his father.Both thrombin-in-duced fibrin polymerisation and reptilase induced fibrin polymerisation were significantly impaired compared to normal control.Fibrinogen clottability measurement showed that only about 20.8%molecules of plasma fibrinogen in the proband were involved in the clot formation.Scanning electron microscopy revealed that the proband′s average fibre diameters were found to be significantly thicker than that of the control(P<0.001),and the density was smaller than that of normal control.Conclusion The Arg19Gly mutation should be re-sponsible for the proband′s dysfibrinogenaemia and the relevant clinical symptoms.
作者
黄丹丹
蔡挺
张顺
黄左安
郭莳雨
丁秋兰
戴菁
王学锋
HUANG Dandan;CAI Ting;ZHANG Shun;HUANG Zuoan;GUO Shiyu;DING Qiulan;DAI Jing;WANG Xuefeng(Medical Laboratory Department,HwaMei Hospital,University of Chinese Academy of Sciences,Ningbo 315010,Zhejiang;Key Laboratory of Diagnosis and Treatment of Digestive System Tumors of Zhejiang Province,Ningbo 315010,Zhejiang;Clinical Laboratory Department,Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200025,China)
出处
《临床检验杂志》
CAS
2019年第9期675-679,共5页
Chinese Journal of Clinical Laboratory Science
基金
浙江省消化系统肿瘤诊治及研究重点实验室(2019E10020)
