My question involves medical malpractice in the state of: IL

I recently requested my daughter and son's medical records from our current family physician whom they've both seen since birth. My son is 3 mos old and my daughter is 2. My daughter has terrible breathing problems and I am unsatisfied with the attempts to rectify this. While reading through my son's records I found a letter from the State of IL stating my son was a carrier for sickel cell anemia. My doctor has NEVER told me about my son being a carrier, I never even knew he was tested, nor did I know anything about this letter. I feel like my doctor neglected to tell me what is very important info about my son.

What should I do about this situation?