When gene editing turns up in news headlines, most people’s minds instantly turn to such outlandish concepts as designer babies. In reality, though scientists have developed multiple approaches to gene editing, the uses for the technology remain severely limited.
Down the road a little further, certain scientists predict nearly 90% of genetic diseases could be treated using gene editing, but so far the techniques appear to present at least as much risk as potential rewards.
CRISPR, Prime, Nanoparticles, and More
For decades now, scientists have been developing gene editing tools, from the rudimentary to the complex, starting with procedures for modifying the extremely simple genetic material inside of bacteria. More recently, however, the scientists behind CRISPR won the Nobel Prize for technology that has made its way into early human trials for treating a condition that causes a dangerous buildup of an abnormal protein in the liver.
In the small trial, the gene therapy bested the current standard of care, but its potential hasn’t been gauged beyond a one-time treatment.
Another potentially powerful approach to gene editing in single-gene disorders involves the use of nanoparticles. In research supported by the Brain Research Foundation, scientists explored the use of synthetic nanoparticles that could be administered via intrauterine injection into the fetal brain.
Such interventions are closer to a pharmaceutical than to what people envision when they think about gene editing, however, because they do not entail germ-level modifications.
The Problem of Germline Modification
As should be clear from the above examples, the forms of gene editing scientists are testing currently focus on later interventions – which is to say, those that do not have a direct impact on the transmissible genetic material of the individual. That means that, for conditions passed from parent to child, each new generation would need to receive the treatment.
Keep in mind that the technology is so unproven and even risky right now that the WHO has officially stated its opposition to embryo editing, never mind germline forms of editing, despite generally endorsing genome modification as a form of treatment otherwise.
One of the concerns with regard to genome editing, particularly at the embryo level (which in fact has been performed at least once by a Chinese lab without appropriate authorization or oversight) is that CRISPR, the best recognized tool, has the potential to cause unintended modifications during the editing process. In essence, the tool can create and insert new DNA elements, but where it places them is unpredictable, which can pose the specter of unintended consequences.
That being said, for many, the risks are acceptable given the potential benefits. An improved version of CRISPR has already shown promise in treating sickle cell anemia, as well as Tay-Sachs, a deadly neurodegenerative condition. Other single-gene mutations could follow, and lead to improved quality of life and extended survival for millions.
Although gene editing has generated a lot of understandable excitement, since well before it was a practical goal, we’re really still in the earliest days of this technology. For most people, it will remain out of reach for decades, if not our entire lifetimes.
Still, where it has the potential to be a tenable, safe choice, gene editing is cause for as much excitement as – and likely more than – it has generated already. We should embrace the promise, but remain aware of the risks. As with so much scientific innovation, cautious hope is the best way forward.