ENG and hereditary hemorrhagic telangiectasia: In addition, mutations in the human endoglin gene (ENG) are the underlying cause of hereditary hemorrhagic telangiectasia (HHT) type 1 (HHT1), an autosomal-dominant disorder characterized by the presence of arteriovenous malformations (AVMs) in different organs (McAllister et al., 1994; Abdalla and Letarte, 2006; Shovlin, 2010).