Well, there is a genetic component to anxiety, and I would suspect that anxious parents could also create anxiety. But, I think, from all I have read that ADHD is the biggest cause as the person tries to cope with the ADHD. And frankly, if you were a part of it or not, doesn't matter. What does matter is that you are a part of helping him deal with it.
In terms of your anxiety question. My go-to-guy for this is Dr. Charles Parker at Corepsyc.