Basically, there is a dude in China who claims that he was able to modify the genetic code of 2 babies that were just born using a technology called Crisper. Using that particular tech, you can cut out unwanted genetic code and modify how the embryo will develop.
Apparently, this guy claims to have done a Crisper on 2 young girls that makes them resistant to HIV, and it was done because the father was HIV positive and didn't want to pass it on to his kids.
The thing that makes this news? Because using this technology, scientists think it may be possible to edit the DNA for children with certain traits like eye color, body makeup, intelligence, etc.