I’m hoping someone can help me get some clarification regarding Lynch Syndrome. I’ll give you some background first: both my grandmother and mother had colon cancer. My grandmother was 55, my mother was 43. We’ve always assumed it was hereditary. But my grandmother had genetic testing done while she was being treated for pancreatic cancer much later in 2013 for all of the colon related things using the colonext 17 gene panel (including lynch) and they were all negative. My question is this — if my grandmother tested negative for Lynch is it possible for my mom to test positive? (There are no instances of colon cancer on the other side of the family or the other cancers associated with Lynch Syndrome) It would mean my grandmothers colon cancer would just be a coincidence? Am I right in assuming the chances of that are pretty low? I know that it cannot skip generations. I ask because at 34 I just had my second colonoscopy as advised after the first found polyps and beforehand my dr launched into a rather passionate discussion suggesting or outright assuming really that I have Lynch Syndrome and will need a hysterectomy which has left me deeply disturbed. Both because the thought of that scares me of course but also because I found her bedside manner awful and inappropriate right before a procedure and because I repeatedly told her that my grandmother had been tested. She wants and has wanted my mother tested and seems to be treating me as if she is assuming I have it. I’m sure she wants me tested too but I don’t qualify. I told her before my FIRST colonoscopy that my grandmother came up negative. Also my mothers dr has never requested her to do the same tests as my grandmother and the write up on the genetic testing results for my grandmother did not say to do it. It said to do colonoscopies at the advised times as we have both been doing. The implication is that because my grandmother was negative for those my mother will be too, right? MY doctor seems to be thinking otherwise. Is somebody wrong?
Any input or experience with this would be greatly appreciated!! Thank you so much!