Besides the "lost civilization" thing, there really are not a lot of similarities at all. And who are the Atlantean refugees who then proceeded to conquer all of Europe? It's not much of a similarity at all except "part of a landmass disappeared a long time ago."
Well, according to the semi-occult theories the Nazi thought up the "Nordic/Germanic" race was descended from Atlanteans. Valyrians are even paler (at least hairwise, though they also have a "special" eye color) than the rest of Westeros, whether intended or not I see a comparison there.