I'm really not sure what the Malfoys would have thought of the Gaunts. I think that, had they met, the Malfoys would have been disgusted by the filth that the Gaunts lived in and they would have probably thought that it was a shame that they're living like Muggles. After all, they think of all Muggles as scum and the Gaunts weren't much better.
Since it takes generations of inbreeding to cause such askew traits, I don't think they do realize what inbreeding does. And, if they did know, they probably chose to either ignore it or think that it wouldn't happen to them. |