Williams syndrome is only in humans. It's not even a particularly hereditary condition. If what you said was true, we would expect to see modern day wild Wolves

Williams syndrome is only in humans. It's not even a particularly hereditary condition. If what you said was true, we would expect to see modern day wild Wolves with this same genetic abnormality. Or we would expect to see wolves (and other predators, too) domesticated many different times in many different places, whenever this animal version of "Williams Syndrome" naturally occurred. We don't see that. There are plenty of other genetically similar canine species that aren't domesticated. There are plenty of related animal (seals, ferrets, skunks) that aren't been widely domesticated, but are completely capable of being domesticated on an individual level, and none of them possess genetic abnormalities One thing that many of these animals have in common is that they are fairly comfortable and adaptable to living in very close proximity to humans. That's true of modern day coyotes, raccoons, etc. Humans have 99.9% identical DNA. All the variation you see in humans is explained by just 0.1% genetic differences. There's no reason to believe that the same isn't true for dogs without having to resort to a rare genetic deformity.