To be fair, the disable were the first people they sought to either sterilize or eliminate from the German body politic altogether - but again, as horrifying as that is (and very much derived from mainstream eugenics ideology), it was not an attempt as mass murder of an entire people.
I’m not a big fan of the German sonderweg view, but I am interested in understanding how such a thing can happen, because if we understand that, we can hopefully avoid it in the future - which we’ve done a pisspoor job of doing, with regards to attempted genocides and ethnic cleansing since the second world war.