I have worked with many autistic children and God is giving him a unique way to communicate. You have to just open your heart and hear in a different way...more meaningful. Patience is your work and you can get this patience from a compassionate heart. Smile at him, make codes for things he needs or what he wants to share with happiness he feels and in between moments and sadness to share. He can speak, just in the way that God has given him. Find help in his school...fight for his rights and keep a calm, loving and peaceful heart filled with joy WITH him...it is a gift in disguise. You got this. I mean it.