I've read Phenylketonuria is said to cause musty, mousy, or BO smell as well. I could see how this would be a hard one to deal with if everyone is offering you gum that will exacerbate the condition.
Regarding the links: if you mean the link to the big list I posted in this thread - I don't know how many of them cause odors, but there is another link I posted a couple months back that had a list of about 10 specific metabolic disorders that will cause odor.