I first spoke at age 5 1/2. It was at some kind of experimental camp: name of Harrelson, I believe. The word was "pig." After I spoke, my memories became clear. I remember the camp: the greenery, the smell of mowed grass, the swimming pool, wanting an orange soda, enjoying the trampoline. This was in 1966.
I read very early. I counted very early. I couldn't write until I was 6. Before that, I would play at writing, just scribbling on a piece of paper. In the fall after I started to speak (I guess age 5 3/4), I picked up a book, "Green Eggs and Ham," by Dr. Seuss. I knew how to read all the words with comprehension. I was also able to buy things for my parents, and receive the correct change. I was told that I skipped lots of stages, speaking like a "normal" kid by the age of 6.
I did okay in life. I went to special schools---except grades 6 to 8, when I was in normal classes (when I should have been in "Special Progress" classes based on my reading ability). It was stated that I didn't have enough "maturity" for the SP classes.
I graduated high school on time. I started working during high school, but had a "real" job at 18. I got my present job at 19. I left home at 20. I learned to drive at 37. I graduated college at 45. I have Asperger's-type symptoms-but I'm undiagnosed.
I hope everything comes together for you son, like it did for me. I had severe neurological symptoms until age 5. It's almost like I went from Classic Autism to Asperger's. I hope this is true for your son.