Does every person with a germ-line c-kit or PDGFRA mutation develop GIST?
No, not everyone with a germ-line c-kit or PDGFRA mutation will develop GIST. A study of one large family with a germ-line c-kit mutation estimated that individuals in the family who carried this alteration might have up to a 90% risk of developing a GIST by age 70. However, more data are needed to determine whether this estimate is true of all possible mutations within the c-kit and PDGFRA genes, and to find out whether anything can increase or reduce these risks. It is also not clear why the symptoms, location, age at diagnosis and clinical course of some GISTs are different from other GISTs, even within the same family in which individuals carry the same germ-line mutation. It is likely that other unknown genetic, environmental and/or lifestyle factors also contribute to the development of a GIST, even in the presence of an inherited susceptibility.
