Hereditary Hemorrhagic Telangiectasia (HHT, or Osler Weber Rendu syndrome) is an inherited disorder characterized by the development of arteriovenous malformations (AVMs) in visceral organs (brain, lungs, spinal cord and liver) and on mucocutaneous surfaces (skin, lips, nasal and buccal mucosa, gastrointestinal mucosa) where they are called telangiectasias 1. HHT is caused by mutations in endoglin (ENG) and activin A receptor-like kinase 1 (ACVRL-1), which account for over 80% of cases 1. A small number (~ 3–5%) result from mutations in the SMAD4 gene and present with features of both HHT and juvenile polyposis