SMAD4 and hereditary hemorrhagic telangiectasia: Nearly 60% of JPS patients could identify causative variants in either of them.[4]SMAD4 is the first gene reported to cause JPS.[6]SMAD4 mutation carriers often present variable combined features of JPS and hereditary hemorrhagic telangiectasia (HHT), also called JPS/HHT syndrome.[7] The clinical features of SMAD4 -related disorders are well established.[7] By contrast, most BMPR1A-related JPS patients are asymptomatic or have nonspecific symptoms difficultly differentiated with other GI diseases.