GIST Support WikiQUESTION: Has anyone ever heard of GIST cases in members of the same family?
ANSWER: "yes"
You might want to read up more about GIST here http://www.gistsupport.org/about-gist.php
Two possibilities...one is that the family carries what is called neurofibromatosis-1, which is a fairly common defect in a tumor suppressor.
This leads to increased risk of GIST-like tumors in those with NF-1. However, the GIST is genetically different than the usual adult sporadic GIST. NF-1 GIST is slower growing, less likely to metastasize, and does NOT carry mutations in the KIT or PDGFR A proteins--which are the targets of Gleevec in regular adult GIST. NF-1 patients may tend to grow multiple new primary tumors along their GI tract.
You might want to read up on Google for neurofibromatosis-1 to learn more. These patients may have many brown spots on their skin (cafe au lait marks) or rubbery superficial skin growths.
Secondly, there are EXTREMELY rare situations in which the family germ line (egg or sperm) contain mutations in the c-kit gene, and this leads to GISTs that are like the adult sporadic variety. They act in a more aggressive fashion as does sporadic GIST, and they are responsive to Gleevec.
If your husband and his brother both have true GISTs, then that is not likely to be random chance. Rather there is likely a genetic predisposition/weakness in that family. I would suggest in this case that the family seeks consultation with sarcoma experts to determine what exactly is going on.
There are other types of tumors that form on the GI tract, other types of gastrointestinal soft tissue sarcomas too, so without further information, we don't know if the brother-in-law has GIST also.
Marina