PDGFRA and neurofibromatosis type 1: Multiplicity is rarely seen except among patients with familial predispositions for germline mutations in KIT, PDGFRA, or SDH [18,19,20] or for multiple small intestinal GISTs in neurofibromatosis type I patients [21,22] When patients have germline mutations in KIT, PDGFRA, or NF1, they may have early onset of GISTs, ICC hyperplasia in the normally appearing GI tract, and characteristic clinical features, such as skin pigmentation, dysphagia, and other tumors, in addition to multiple GISTs.