It really doesn't look like anything to be worried about. There is a bit of discoloration on the middle tip, but I'm too much of a n00b to tell what it could be at such an early stage if its anything at all. I'd say keep an eye on it and see what happens and if it seems to progress, post more pics. Its possible that it could be some kind of natural defect in the leaf. The rest of the leaves look healthy so I really doubt that you have anything major to worry about. :thumbsup: