As all people with down syndrome are a bit off the wall, this means they must be mutants.
Guy 1: Fucking downy bastards over there across the street..
Guy 2: DON'T! WOLVERINE WILL KILL US WITH HIS MIGHTY BLADES OF DOWNY! AND CYCLOPS WITH HIS VISION OF TARD!
Guy 1: OH FUCK YEAH! We'll be infected with Downyness! RUN!