CRISPR: Considering (What May Be) the World's First Designer Babies

By Shannon Trujillo · Dec 2018

On November 25, 2018, a Chinese researcher claimed to have been the first person to successfully use CRISPR-Cas9 on human embryos — applied to twin girls born earlier that month. The announcement sparked immediate and widespread outrage in the scientific community.

What Is CRISPR?

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a gene-editing technology designed to target a specific region of the genome and cut out a stretch of DNA. In Dr. He Jiankui's experiment, he targeted CCR5 — a protein on white blood cells and a binding site for HIV — with the stated intention of conferring immunity to HIV in the two girls.

Why the Outrage?

Dr. He appears to have bypassed virtually every community guideline for human germline editing, conducting the experiment in secrecy and concealing it from his own institution. He used gene editing not to address an actual disease with no alternatives, but to reduce an already-low risk of HIV infection. Preliminary findings were also questionable — only about half of each girl's CCR5 genes appeared edited, and the edits differed from the naturally occurring mutation known to confer HIV resistance. The longer-term consequences of novel mutations introduced into the germline are unknown.

Could CRISPR Work on Everyone?

A Stanford study found that the majority of participants already had antibodies against the Cas9 proteins used in CRISPR — suggesting many people might mount an immune response to the therapy. This is seen by some researchers as a reason to study the technique further and explore alternative proteins, rather than a dead end. As with most significant scientific advances, CRISPR will require many iterations before its potential — and its risks — are fully understood.