目的:探讨一个遗传性出血性毛细血管扩张症家系的临床特点及遗传学病因。方法:对13名家系成员进行详细的临床检查、耳鼻咽喉科专科检查及实验室检查,用聚合酶链反应(PCR)扩增13名家系成员和2名健康对照者的ALK-1基因3,4,7,8号外显子。用单链构象多态性(SSCP)进行ALK-1基因的突变分析。结果:13名家系成员中在3号外显子上PCR-SSCP呈明显异常带型者有4例,与正常对照者比较于大约700 bp处多出一条带,包括先证者及先证者的父亲、姑姑及叔辈姑姑。结论:该家系遗传性出血性毛细血管扩张症是由于ALK-1基因突变引起,突变位点位于3号外显子。 Objective: To investigate the clinical features and genetic causes of a hereditary hemorrhagic telangiectasia pedigree. Methods: Thirteen pedigree members were subjected to detailed clinical examination, otolaryngology specialist examination and laboratory examination. The ALK-1 gene of 13 family members and two healthy controls were amplified by polymerase chain reaction (PCR) Exons 4,7,8. ALK-1 gene mutation analysis was performed using single-stranded conformational polymorphism (SSCP). Results: Among the 13 pedigree members, there were 4 cases with obvious abnormal bands in exon 3 and more than 700 bp in normal controls, including probands and probands Father, aunt and aunt aunt. CONCLUSIONS: Hereditary hemorrhagic telangiectasia in this pedigree is caused by a mutation in ALK-1 gene, with the mutation located on exon 3.