Just to put you at ease. Don't worry. When I went for my citizenship fingerprinting, they couldn't get clear fingerprints, so they sent me a letter asking me to come again for fingerprinting within a month. I asked the technician then, what would happen if the second set was also rejected. He said don't worry, they have other ways of verifying information about you. So I just let it go and things worked out well. Yours will too. They can't deny you 'coz of an ailment.
