中文摘要：

目的：探讨一个遗传性出血性毛细血管扩张症（hereditary hemorrhagic telangiectasia,HHT）家系的临床特征及基因诊断的可行性。方法：收集先证者及家系成员的病史资料并进行临床诊断。同时,对先证者进行致病基因突变检测;鉴定出可能致病性变异后,对家系成员进行特定致病基因突变检测及基因诊断。结果：该家系中4代有5例个体以鼻衄为突出临床表现。先证者临床诊断为HHT;2例在世家系成员为临床疑诊个体。ENG（endoglin）基因5＇非编码区c.1-127C〉T突变见于先证者和2例临床疑诊个体,未见于其他家系成员;综合临床与基因突变分析2例临床疑诊个体确诊为HHT。结论：HHT临床表现个体差异大,ENG基因c.1-127C〉T突变是此HHT家系的可能致病性变异。临床与基因诊断相结合可提高HHT的诊治水平。

英文摘要：

Objective： To investigate the clinical features and feasibility genetic diagnosis in a hereditary hemorrhagic telangiectasia （HHT） family, and to explore the application ofgene mutation testing in HHT diagnosis. Methods： Medical histories and clinical features of a family were analyzed to diagnose HHT patients and suspected individuals according to the clinical diagnostic criteria. Sequence analysis of endoglin （ENG） and activin A receptor like type 1 （ACVRL1） gene in the proband was performed with PCR and Sanger sequencing technology. After the possible pathogenic mutation was identified in the proband, the specific mutation was detected in the suspected individuals and part of other family members. Then the genetic diagnoses were concluded.Results： There were 5 family members in 4 generations manifested with epistaxis. According to the clinical diagnosis criteria, the proband with epistaxis, mucocutaneous telangiectases, visceral arteriovenous malformation and family history was diagnosed as HHT; while 2 survival family members with epistaxis and family history were suspected individuals. A substitution mutation in the 5＇-untranslated region（5＇-UTR） of ENG c.1-127 C〉T was detected in the proband and the 2 suspected individuals, which did not exist in other family members. Based on the clinical and genetic findings, the 2 clinically suspected individuals were diagnosed as HHT. Conclusion： There is great variability of the clinical manifestations among HHT patients. ENG c. 1- 127 C〉T mutation is the possible pathogenic variant of the HHT family. A combination of clinical and genetic diagnosis could improve the diagnosis and treatment of HHT.