Board Thread:Naruto Gaiden/@comment-4271790-20150625052107/@comment-1043414-20150701165914

I know, and I admitted that. My point is that his DNA was altered to match Hashirama's to obtain the Hokage's abilities even in a diluted state. Plus, for all we know, the process could have been improved as later Madara performed a Wood Release of comparable to his old rival.

But that's irrelevant the question is the nature of Sarada's DNA matching to Karin. We'll just have to wait and see because all I have to go on is theory.