We could have studied Hd together, and researched the lastest info, and talked with other families that had the same problem. That's why I think this forum is so wonderful when used for the right reasons and not abused. When I went through a period of believing I had HD, I thought long and hard about what to tell my sons. I decided the truth was the best way, and kids now days are so much more knowledgeble about everything. I had decided on an analogy.
Analogies are never the same as the exact situation, but points can be made.
I would pick a calm time and feel them out first. You might be surprised at their wisdom. They are not blind to obvious things. I think you need to know and have a right to know what is happening in our family. Focus on the positive, and don't get bogged down in the down side.