The Risks of Gene Editing

In response to: Editing Humanity’s Future from the April 29, 2021 issue

In her recent review of four books on the prospects of applying CRISPR and related gene modification technologies to the improvement of human biology [“Editing Humanity’s Future,” NYR, April 29], Natalie de Souza appropriately emphasizes the safety of such manipulations as a fundamental requirement, as well as the profound social ramifications of decisions to use these technologies. What de Souza, in common with the authors of all the books under review, sidesteps, however, is that “safety” means entirely different things when therapeutic alterations of the tissues of a mature body are considered, in contrast to those that are administered at early embryonic stages. The engineering of retinal cells to relieve blindness, for example, is not comparable to ridding embryos of genes associated with cystic fibrosis, HIV susceptibility, or sickle cell disease.

Body cell, or “somatic,” modification is in line with traditional medical practice, where a sick person undergoes a procedure or takes a drug that may be the best means for saving their life or sparing them...