There are also multiple types of Ehlers-Danloss syndrome, there are multiple genetic loci which can bear a mutant allele for various genes involved in for the most part, collagen formation. And one doesn't have to have EVERY sign possible in a diagnostic manual for ED to be present. Double-jointed bits are common, and so are joint dislocations. Its best to keep as fit as possible to help provide muscular support to the joints.
And heh, talking of freaky stuff, I know someone with it, that can kick themselves in the forehead. Backwards. I really wonder what kind of kinky stuff that kind of flexibility would make possible that just couldn't happen otherwise
(she is pretty damn fine)