Pathogenic variants in the ENG and ACVRL1 genes result in different HHT types, commonly referred to as HHT1 and HHT2, respectively [4,5] Pathogenic variants in the SMAD4 gene give rise to a combined syndrome of HHT and juvenile polyposis (JP): the JP-HHT syndrome [7]. The gene discussed is ACVRL1; the disease is hereditary hemorrhagic telangiectasia.