Board Thread:Theories and Speculation/@comment-5012682-20150620162706/@comment-5936871-20150622175530

@Omojuze Show me proof of that then, and show me an example of when Sasuke and Itachi learned how to use it, rather than awakening it upon achieving MS. Also the fact that it requires Mangekyo is proof that it is genetic, since MS is a kekkei genkai.

@Minamoto You may have to train to obtain the techniques, but you're already born with the potential to use them. That's how kekkei genkai work, they're abilities passed down through the blood. Hence when you steal someone else's DNA, you can use their kekkei genkai as seen in Danzo, Obito, Madara, and Kabuto's case.