No need to guess, colorcountry. The issue has been discussed at length by LDS scholars and scientists. A readable summary is to be found here. Other articles are linked here.
The short answer is that DNA does not (and probably cannot) "disprove" the Book of Mormon.
Not yet! The study has not been released.
But will they believe it when it happens, or will they issue the same type statement as always, that all one requires is faith.....that science, reason, and God have not suceeded in revealing the untruthfulness of the Isrealite migration?
I'm sure Jeff Lindsey, FARMS and FAIR already have a press release prepared.