Does every person with a germ-line mutation in a GIST- susceptibility gene develop GIST?
No, not everyone with a germ-line mutation in a GIST susceptibility gene 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 GIST susceptibility genes, and 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. While the overall risk for an individual who carries a germ-line mutation in a GIST-susceptibility gene to develop GIST is not certain
