Amanda Perry is a brilliant scientist from Earth in her late 30s.
She has been quadriplegic since her childhood. In 2010, one of the Ancient spaceship Destiny's Faster-Than-Light engines was destroyed and Perry's expertise was required to repair it. In order to do this, she used a Long range communication stone to switch bodies with Camile Wray. This also allowed Perry to be able to walk for the first time in her adult life. (SGU: "Sabotage")
Behind the scenes
The direction towards the character has garnered some controversy. Some were critical of the character's rather insensitive description, particularly that the disabled character "is physically useless" as well as insinuating that disabled peoples are not able to have an intimate relationship.
Producers of SGU have since apologized and clarified that the character description was not their own, but that of an external casting agency and was never meant to be made public.