I have 3 years old son. He doesn’t walk and talk either. He can spell only AAAAA, BBBBB, and OOOOAAOOA. He can sit almost all day long with no problem, and can grab things near. I went to many different doctors (neurologist, psychologist, podiatrist, orthopedist. Muscle test, and still same answer: We can not find anything strange, except that he is going up very slow, but without reason. He is very lovely and smiles very much, and likes to play with him. Loves to watch soccer games on TV and cartoons. Help please.