It's a neurological issue. I'm sure there are a few cases out there where it effects them enough to have a health decline. Along the same as Spiders.
I'm still hoping it won't come out as much once she settles in.
I didn't know anything about the Jag issue until after I got my girl. So far she has never showed any signs of have a "wobble" or problem.
Another Jag issue. If you breed Jag x Jag all the supers or BELs will be still born or die soon after they hatch.
Good luck with her and keep us updated.