Vague Descriptions

[Gollum the Great]

You've got to be making this up, Legate.

[Legate of Amon Lanc]

No way, my good Gollum. Okay, another hint. One of the group mentioned above died recently before the person in question left its home place. These events were closely related (not totally, like one being consequence of the other, but simply related to each other). And, to add, the death of this one mentioned above was not a result of the disease. The disease itself is not lethal. But very often throughout the history of M-E, somebody died as an outcome of that disease. However, it was not the disease itself that killed them.

That's a lot of hints, I'd say. Try to put all the evidence together and try to think.

And remember, still: we are looking for one certain person about whom we read as being vulnerable to this disease. (Like I said, there were many who had this disease, and probably also some who were vulnerable to it, but about this one we know because the book says it.)

[Thinlómien]

I can only think of the Sackville-Bagginses and their sort of cleptomania , but that does not fit more than maybe half of the hints...

[Legate of Amon Lanc]

No, but actually, you are far, far closer to the correct answer than all of those who posted here this far have been. You are very, very close, from several aspects.

[The Might]

Cleptomania?

Well, actually I was going to say Sméagol curious "disease" of greedily wanting mroe presents for himself.

After all this affected all Hobbits, and because of it he eventually had to move far away from his home place, but did not die because of it... well ok, maybe he did.

But anyway, since you said the person did not belong to the group of people affected by it by default it cannon be right...

[Legate of Amon Lanc]

Indeed, it isn't Sméagol. You are heading in the right direction, though. Now I think this is the time to emphasise the important thing from the original question: it is really explicitely said in the book that this person was vulnerable to some sort of disease. In the italicised part, I am not making up any metaphores of my own, I am merely recounting what the book says at some point.

And the person about whom this whole question is, just to remind of it because all the hints may have created a bit of confusing atmosphere, did not die because of this disease - at least it is not said in the books.

[The Might]

Wait, wait, you're tricky.
Looking for what you speak of, I cam across this quote from the UT:

In a letter written in September 1954 my father said: "At the beginning of the Second Age he [Sauron] was still beautiful to look at, or could still assume a beautiful visible shape – and was not indeed wholly evil, not unless all 'reformers' who want to hurry up with 'reconstruction' and 'reorganization' are wholly evil, even before pride and the lust to exert their will eat them up. The particular branch of the High Elves concerned, the Noldor or Loremasters, were always vulnerable on the side of 'science and technology,' as we should call it: they wanted to have the knowledge that Sauron genuinely had, and those of Eregion refused the warnings of Gil-galad and Elrond. The particular 'desire' of the Eregion Elves – an 'allegory' if you like of a love of machinery, and technical devices – is also symbolized by their special friendship with the Dwarves of Moria." ~ note 8 of Concerning Galadriel and Celeborn

Ok, so this a kind of "disease", somewhat like Sméagol's greed for treasure, their greed for knowledge.

Now, who could still be like that... Saruman?