SMAD4 loss-of-function mutations are associated with juvenile polyposis syndrome (JPS) and a combined JPS-hereditary hemorrhagic telangiectasia (HHT) known as “JPS-HHT syndrome”, and some affected individuals present with aortic dilatation (Larsen Haidle et al., 1993; Jelsig et al., 2016). The gene discussed is SMAD4; the disease is juvenile polyposis syndrome.