Identification of a Novel ACVRL1 Gene Mutation (c
100T>A, p.Cys34Ser) in a Japanese Patient with Possible Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu Disease). Hereditary hemorrhagic telangiectasia (HHT; also known as Osler-Weber-Rendu disease) is an autosomal dominant genetic disorder that causes frequent epistaxis, mucocutaneous telangiectasia, and visceral arteriovenous malformations. Four genes (ENG, ACVRL1, SMAD4, and GDF2) have been identified as pathogenic in HHT. We describe the case of a 50-year-old Japanese man highly suspected of having HHT due to recurrent epistaxis, mucocutaneous telangiectasia, and a family history. Genomic analysis revealed a novel missense mutation of c.100T>A, p.Cys34Ser in the patient's ACVRL1 gene. We used 6 freeware programs to perform an in silico analysis of this mutation. The results demonstrated the mutation's high pathogenicity.