Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by aberrant vascular development. Mutations in two genes, endoglin (ENG) and activin receptor-like kinase 1 (ACVRL1) are associated with HHT. The present case study revealed the molecular diagnosis in a family exhibiting the clinical features of HHT disease. The coding exon and flanking intronic regions of the ENG and ACVRL1 genes were sequenced and a novel mutation in exon 10 of ENG was observed in the family. The mutation (c.1426C>T) in exon 10 of the ENG gene caused a G476X mutation, which results in a premature stop codon and a truncated ENG protein. This finding demonstrated a novel mutation in the ENG gene in a Chinese family, which suggested that a truncated ENG protein may cause HHT. The present study established a genetic test to confirm the clinical diagnosis in individuals and provide an opportunity for early detection and management of the disease.