Because I don’t have children, I’ve never been burdened with deciding if, when, and how to tell them that I have the Lynch mutation…
… and that they may also have it (a 50% chance).
Of course, this begs the question: What are the ethics of having your kids tested for the Lynch mutation without their knowledge? The rationale for doing so is that, if they test negative, you can avoid all the anxiety and stress involved with being open about it all.
Of course, if they test positive, the question of “if” no longer matters. But you are left with the heavy questions of when and how to tell them and deciding what surveillance is appropriate.
Again, I wouldn’t dare to give specific advice in this area. Instead, seek the guidance from your doctors and genetics professionals who will help you make ethical and rational decisions regarding such matters.