I don't think it is AS, though it may be a sever form portrayed.
http://www.imdb.com/title/tt1183252/ - Chocolate. It's a very kick ass martial arts film with many fights, shooting, explosions, etc. The main thing though is that Zen, the main character is an Autistic girl.
"When Zin, former girlfriend of a Thai mob boss, falls for Masashi, a Japanese gangster in Thailand, the boss banishes them: Masashi to Japan, and Zin, with her small daughter Zen, to live next to a martial arts school. Zen is autistic, with uncanny swift reflexes. She watches the students next door and Kung Fu movies, absorbing every technique. She's now a teen, and her mother needs chemotherapy. Zin has taken in a chubby kid, Moom, who watches over Zen. Moom finds a ledger listing business men who owe Zin money; he goes to them one at a time to collect in order to pay for Zin's treatment. Zen, with her martial skills, becomes his enforcer. A showdown with the boss is inevitable. "
May sound lame, but really worth a watch.