Sin enters creation in the garden, and death and decay enter with it. Man attempts to compensate, but lacking the wisdom and knowledge of the original Designer, this sort of thing is the result. Natural unregenerate man thinks himself wiser than he is. –STL

The mother’s DNA tests showed that she’s also the uncle of her daughter. Doctors realized that the mom was a human chimera with DNA from more than one fetus.

Source: Woman finds out she is her daughter’s mother – and uncle