Yes, but unless the user says so, how can you be sure that it's typo and not an intended mistype? Ie, I've seen usernames on LJ that have two words stuck together, and because the two words would be one or two characters too long, the person would take out one of the letters. For instance, "mitarashi dango", a japanese sweet: the person in this case used the nick "mtarashidango".

I know maybe two people who have had a rename, and my list is pretty full.