Dr. please ready this need your help.

my brother who is now 35 years old .we have been told he was ,mentally challenge and some autism .

But I feel that he he should have been put as Laundaw kleffner syndrome ,because from when I have read about it seems to fit him a lot.Is there anything that can be done to help him at this point.The state has had him and said even if so there is nothing that can be done for him now.because he is over the age of 21.

and the lady who takes care of him doesn't want to here about it or talk about it.can we do anything to test him still at his age and try and help him learn to talk and do other things.

I have prayed for him  and will not give up hope like others have done.

Thank you for reading this and any help you can give me.