how to get EP test when teenager

My son had CP from his very premature, birth but i was not told this until he was 5 and a half years old,he is now 17,so my question is two-fold-first,how do i ask for tests for autistic spectrum(as this runs in our family,and some of his behaviours are more akin to that than cerebral palsy)and also,do i have any claim from the hospital for not actually telling me he had CP for all those years?(it only came out in a routine clinic visit for my younger,also very premature child.)although he had been having physio,and regular clinic visits  from birth.he also had psychology assessments aged 7.