Any Success Stories out there?

I guess I just need some 'pie in the sky' hope for my son. He is nine and has been with us for almost a year. He has been diagnosed as borderline MR with an IQ of 70. He has a horrible abuse/neglect past with some possible sexual abuse as well. He's been diagnosed with PTSD and ADHD. (Also has a RAD dx but I disagree there) He has bonded wonderfully with our family. The thing I'd like to know is are there stories out there of kids that had been diagnosed learning disabled, low IQ, etc and 'caught' back up so to say with there grade level/improved IQ or the like. What I see is a really smart boy but I've been working with him with reading and we can't seem to make much gains. In day to day functioning he is at or above normal. He is a great kid, makes friends well, plays well, does chores around the house with minimal instruction. I just feel like there is a big 'block' there for learning reading/math and once we can get past that I think he'll improve leaps and bounds. I'd love to hear any stories of similar cases that went on to prove everyone wrong...