UGH! Genetic Engineering using Crispr Technology & Covid-19 (6/25/2020)

Three studies showing large DNA deletions and reshuffling heighten safety concerns about heritable genome editing.

Excerpts: 

Unpredictable repair

The changes are the result of DNA-repair processes harnessed by genome-editing tools. CRISPR–Cas9 uses a small strand of RNA to direct the Cas9 enzyme to a site in the genome with a similar sequence. The enzyme then cuts both strands of DNA at that site, and the cell’s repair systems heal the gap.

The researchers used CRISPR–Cas9 to create mutations in the POU5F1 gene, which is important for embryonic development. Of 18 genome-edited embryos, about 22% contained unwanted changes affecting large swathes of the DNA surrounding POU5F1. They included DNA rearrangements and large deletions of several thousand DNA letters — much greater than typically intended by researchers using this approach.