It could just be a genetic muctation. I'm pretty sure that's how the munchkin breed started out, they weren't bred to be short it just naturally appeared in a regular sized kitty. My grandfather had a barn cat that had really short legs like a Munchkin, but I know it wasn't a purebred or even a mix because it was just a barn cat. It was just a genetic mutation, but I think the short legs make her cute and special