Gene Editing: Can the Utility Exceed the Fear?

Effective gene editing is becoming closer to reality as scientists develop new tools and methods to change our DNA. Arguably the most promising (and certainly the most well-known) recently developed tool for editing genes is CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), a family of molecules which proven to be effective in controllably modifying specific segments of DNA. However, as the tool has become more known, many fears have arisen, concerning the medical and ethical dangers of gene modification. Do the potential benefits outweigh the potential risks? To answer this question, let’s first address what CRISPR is.

A computer representation of CRISPR in action

CRISPR is a two-part molecule: one part is a guide RNA to locate the desired gene, and the other is a DNA-cutting enzyme that performs the modification once on site. There are different variations being developed, but each one has those two key features. When these pieces work in tandem, they can cut and modify specific genes with a higher rate of precision, accuracy, and success than other methods.

Now, we should examine some of the fears that have risen alongside the popularity of CRISPR. The first is an ethical question on gene modification as a whole. At the most extreme end, some people’s minds jump immediately towards eugenics, the practice of purposefully controlling human reproduction to increase the occurrence of favorable genetic traits. One can see how the fear of effective genetic modification could be a step on a slippery slope in this direction, but again, this is generally the worst-case scenario and seems unlikely in the near future. A more subtle and reasonable fear is the idea that access to tools for choosing genes may lead to widening the gap between economic classes. After all, if a technology can ensure one’s children possess desirable traits, and this health technology is economically restricted (as it very well could be in the US), then new generations of the affluent could receive a measurable genetic advantage over others. This general fear has been characterized with the buzzphrase “designer babies.”

Pictured: Baby, non-designer

Before addressing the second fear, let’s discuss this first one, and why it may not pertain to CRISPR as much as it may seem at first glance. The traits that most are concerned about when discussing “designer babies” are broad, such as height, athletic ability, or intelligence. These kinds of attributes are actually very difficult to define genetically. A recent study attempted to find a genetic link for height and found that 697 genes accounted for only one fifth of height differences between subjects. Intelligence has eluded our attempts to define it sociologically and psychologically, much less quantify it genetically. Traits such as these would be extremely difficult to control, and while it is not off the table, it is certainly a long way off. The potential benefits of CRISPR would mainly be for genetic resistance to diseases, which are easier to quantify. However, if access to this is still economically restricted, it may still cause further class disparity for general health and life expectancy, so we must be wary of this danger as more about CRISPR is discovered. 

The second most common fear about the use of CRISPR is its potential danger when used on humans in general. Some fear that the technology is not efficient enough and may cause unintended cuts. Many also fear “off-target” effects; when one gene is modified for an intended effect, it may change something else unexpectedly. These fears have led many to be cautious about the use of CRISPR on humans, but some recent developments may help eliminate these worries.

A T cell, the supporting character of this CRISPR trial

In one recent trial, CRISPR was used to modify the T cells in 3 different cancer patients at the University of Pennsylvania, in an attempt to make the cells more effective at combating the cancer. The cells did not cure the cancer or become more effective at fighting it, but the trial was far from a failure. The most important result of the tests was that the cells passed the safety bar for clinical trials. The scientists facilitating the trials had a high success rate in gene cuts, the modified T cells survived for several months, and there were no adverse side effects. This is a big step towards further tests for CRISPR, suggesting that the method may be safer than originally thought. 

Recent findings on the safety of CRISPR bring us closer to eliminating the fears about its use. While it is still too early to make a definitive call, and every precaution should still be taken moving forward, it is good early evidence that the potential negative side-effects of CRISPR may be overblown. If development continues down this path, and CRISPR proves itself to be a reliable and effective way to modify genes against disease, its potential for improving human quality of life may outweigh any fears we have about using it sooner than we think.