Wow, I lived what you are going through. My son was reading by the time he turned 2. He was obsessed with letters and numbers....it would take us forever to walk through a parking lot because he needed to obsess over every license plate. His speech therapist picked up on it before we did and mentioned hyperlexia. It is my understanding that hyperlexia is not a medical diagnosis, but if you google it, you will find a lot of info about kids like your son and give you ideas about ways to work with him and what his future challenges may be (so you can work on them).
My son is now 10 and doing well. My advice to you is to focus on the delays and issues that your child is dealing with now. I know it is hard to ignore the genius qualities that he is showing, but if he is a genius, he will remain a genius. Kids that read extremely early tend to have a lot of communication and social issues. Many of these issues can be worked out if the child is worked with at an early age. I feel so fortunate that we were involved with Early Intervention (also in Illinois) and my son did 2 years at our District's preschool(Dist. 204) with an IEP because he had a lot of autism red flags and was "at risk". His speech therapy consisted of teaching him how to handle himself in social situations. For example, the speech therapist would sit next to him at snack time and coach him to ask his friends what their snack was, or what cartoon they liked, etc. That therapy, at age 3, was so valuable in teaching him skills that he will need to be a well-rounded person. I often think about what kind of issues we would have with him now if he had not had those opportunities when he was so little.
The rest of the story is that my son dropped his IEP when he started kindergarten and he tested into gifted in 3rd grade. I still see his quirkiness now and then, but nobody else really sees it. He is social, has friends, loves school, does really well in school and is HAPPY!
Please don't ignore the delays and issues that your son is experiencing. Therapy and school does help and will actually open his world more by making him develop areas that are not natural to him. The genius in him can be developed when it is more age appropriate, but these life/people skills that he is probably lacking have a small window and should be developed asap.
Good luck!!
Kelly