The way I understand it is that even if they can fire you for no reason, that is different from discriminating against you because of a disability. If it keeps you from being able to do the job that may be another story, as they do have to be able to get employees who can do the job. You may want to talk to someone about it. I don't have any legal background.

<font color=purple>"The real problem of mental life is not why some people become insane, but rather why most avoid insanity." -Erich Fromm</font color=purple>