Juvenile polyposis, hereditary hemorrhagic telangiectasia, and early onset colorectal cancer in patients with SMAD4 mutation

Background Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder most often caused by mutation in the endoglin or ALK1 genes. A distinct syndrome combines the clinical features of HHT and juvenile polyposis (JP) and has been associated with SMAD4 mutation. The aim of this study was to describe the phenotype of patients with JP–HHT and SMAD4 mutations and to compare this phenotype with HHT or JP patients with mutations other than SMAD4.