Abstract
Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, is an autosomal dominant vascular dysplasia associated with frequent episodes of nosebleeds. The majority of HHT patients have mutations in either endoglin (ENG) or activin receptor-like kinase 1 gene (ACVRL 1), which encode proteins that modulate transforming growth factor (TGF)-β superfamily signaling in vascular endothelial cells. ENG mutations are most common among Japanese HHT patients. We report a 39-year-old man who had often had nosebleeds since childhood. He had multiple tiny red papules on the oral mucosa, tongue and lip. A biopsy from the lip showed multiple dilated vessels in the upper dermis. Systemic examinations revealed arteriovenous malformations (AVMs) in the left lung, cerebellum and small intestine. Somatic mutation in the ENG gene was also found, and we therefore diagnosed him as having HHT type 1.
