What are the genetic changes related to gastrointestinal stromal tumor ?
Genetic changes in one of several genes are involved in the formation of GISTs. About 80 percent of cases are associated with a mutation in the KIT gene, and about 10 percent of cases are associated with a mutation in the PDGFRA gene. Mutations in the KIT and PDGFRA genes are associated with both familial and sporadic GISTs. A small number of affected individuals have mutations in other genes.  The KIT and PDGFRA genes provide instructions for making receptor proteins that are found in the cell membrane of certain cell types and stimulate signaling pathways inside the cell. Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. When the ligand attaches (binds), the KIT or PDGFRA receptor protein is turned on (activated), which leads to activation of a series of proteins in multiple signaling pathways. These signaling pathways control many important cellular processes, such as cell growth and division (proliferation) and survival.  Mutations in the KIT and PDGFRA genes lead to proteins that no longer require ligand binding to be activated. As a result, the proteins and the signaling pathways are constantly turned on (constitutively activated), which increases the proliferation and survival of cells. When these mutations occur in ICCs or their precursors, the uncontrolled cell growth leads to GIST formation.