[deathanatos]

Chimeras: https://en.wikipedia.org/wiki/Chimera_(genetics)

Essentially, people can (sometimes) not have a single set of DNA.

And this has already caused issues:

> In 2002, Lydia Fairchild was denied public assistance in Washington state when DNA evidence showed that she was not related to her children. A lawyer for the prosecution heard of a human chimera in New England, Karen Keegan, and suggested the possibility to the defense, who were able to show that Fairchild, too, was a chimera with two sets of DNA, and that one of those sets could have been the mother of the children.