As a four-year old in Juneau, Alaska, Nerdette host Greta Johnsen was diagnosed with an eye condition known as "Best disease." That name is a misnomer for several reasons — the big one being that "Best disease" causes premature macular degeneration — but curiously it happens to be among the best diseases for experimenting with CRISPR, a genetic engineering tool that can be used to edit DNA. 

This very special episode of Nerdette follows Greta, her father, and Dr. Bruce Conklin, the scientist who's currently trying to develop the perfect CRISPR system to inject into some Johnsen family eyeballs. Plus, you can't have a conversation about experimental gene editing without discussing the ethical implications of making irreversible changes to human evolution. 

“We’d be permanently altering the course of evolution if we decide that we think it’s OK to edit human embryos," says Megan Hochstrasser, a science communications manager and CRISPR expert. "Is that something we want to be able to do as a society?”

That's a great question. Let's talk about it. 

Special thanks this week to the Innovative Genomics Institute as well as the Institute for Human Genetics at the University of California, San Francisco.