rph3664, when I read something like that, I think, dear God, we got off easy. And it has been hard taking care of a child with Asperger's, and the damage goes out in ripples, but we got off easy.
There is no one thing to say to the parents of special needs children, just as there is no one thing to say to someone dying or someone grieving.
Listen close, feel your way, don't think you have the answers. The things to say can range: "It must be hard." "How are you coping?" "You're doing a fantastic job." "You sound like you're at the end of your rope."