What is a germ-line mutation and how does it cause familial GIST?
A mutation is a change in the pattern of a gene’s DNA that prevents the gene from working properly. If you think of a gene as similar to a book, DNA is like the letters that make up the words in that book. Just as you can have a misspelling in a word in a book, you can have a misspelling (or “mutation”) in the DNA of one of your genes. Unlike a somatic mutation (which is present only in tumor cells), a germ-line mutation is present in every cell of your body from the time of your conception, so can be passed on or shared among family members. There have been two genes identified to date that are involved in familial GIST. They are called c-kit and PDGFRA (platelet derived growth factor receptor alpha) gene. Mutations in the c-kit gene appear to be more common. If a person has a germ-line mutation in either of these genes, the gene can no longer function properly, which makes it easier for GISTs to develop. There may also be other cancer susceptibility genes that have not been discovere
