"This is an American." You don't need to accept a term you don't like for yourself but others may not mind. Btw, autistic brains exist outside the UK and the US. In German, it's becoming more common to say "Menschen mit Autismus" (people with autism) but I suspect that's actually more to do with an effort to de-gender because constructions like "Autistinnen und Autisten" (female autists and male autists) are clunky. Also, your "blindist" and "deafist" don't exist in English which is why they sound weird, they do exist in German.