The results of the first gene-editing experiment conducted on a human embryo in the United States were published on Wednesday, and their implications can’t be overstated. A research team was able to erase the gene mutation responsible for a condition causing sudden heart failure from a one-cell human embryo.
Researchers at Oregon Health & Science University, lead by Shoukhrat Mitalipov, used a tool called the Clustered Regularly Interspaced Short Palindromic Repeats, or CRISPR ― a DNA cutting and splicing machine that scientists can “program” to target a specific sequence of our DNA. Think of it as a precise carnival claw machine.
The ability to target and edit deadly gene mutations from a human embryo means diseases could be cured before a pregnancy even starts. Like Jonas Salk’s miracle cure for polio, perhaps embryonic gene editing could be the new vaccination.
But when the scientific journal Nature released the highly anticipated report, it once again raised concern about “designer babies” ― a fear that initially began after scientists successfully transplanted mitochondrial DNA, resulting in a so-called “three-parent baby.” According to some headlines, scientists were “on the verge” of making designer babies.
After all, if science can target a gene mutation for eradication, parents selecting hair and eye color and tweaking for increased intelligence can’t be far off. But while the news is indeed huge, Aldous Huxley’s dystopian “Brave New World” isn’t as close as it might feel.
CRISPR, while incredible, has yet to be perfected to yield real-life results for humans. And it’s less likely to lead to designer-baby kits than to be used to target known genetic disorders. In fact, the editing of a human embryo isn’t even the most exciting application of CRISPR released this summer.
So how will CRISPR’s capabilities affect our lives? The answer lies in the political and technical impediments it faces.
How CRISPR could fight disease
Using CRISPR to experiment successfully on a human embryo is an important scientific advancement, but in the near term the technology is more likely to be used to treat or potentially eradicate genetic diseases in children and adults. One of the diseases currently in CRISPR’s crosshairs is Huntington’s disease: a fatal genetic disease that destroys nerve cells in the brain of the sufferer, leading to mental and physical deterioration.
In June a report was released showing CRISPR had targeted and reversed the occurrence of Huntington’s disease in mice. While this doesn’t sound as exciting as editing the genes of a human embryo, the success of this experiment is a tangible, practical bombshell.
In the world of clinical trials, testing on an animal subject is the step before clinical trials on humans. Although researchers are a few years out from being able to conduct CRISPR trials for Huntington’s disease, other advances with the technology are moving apace.
The summer 2017 edition of Genome magazine reported that a possible therapy using CRISPR technology and targeting a rare immune disorder, granulomatous disease, or CGD, could be used on humans in the next year. Researchers successfully “corrected” the genetic mutation causing CGD by using some of the patient’s own blood-forming stem cells.
Again, mice played a pivotal role: The edited cells were injected into the mice, then as programmed by CRISPR, worked their way into the bone marrow, where neutrophils (the missing defense mechanism in CGD patients) began being produced. Corrected cells programmed to produce normal neutrophils can theoretically be reintroduced into human sufferers with the same results.
But genetic variation in the disparate human population means one CRISPR code doesn’t fit all. As each disease needs its specially designed tool, each person may need additional genetic testing to see if the tool even works for their unique DNA code.
Proposed federal budget cuts might stop CRISPR before it even starts
The National Institutes of Health, nested within the Centers for Disease Control and Prevention, has a tight rein on federal funding for human embryonic stem cell line research, or hES. President Bill Clinton signed a law restricting research on human embryos that resulted in embryos’ destruction. George W. Bush, fueled by his evangelical base, further restricted testing to fewer hES lines.
In 2009, President Barack Obama overturned the Bush-era law and expanded the number of lines that once again could be scientifically studied ― and importantly, funded through the NIH. The Trump administration’s record of rejecting scientific consensus, courting the religious right and slashing the federal budget doesn’t bode well for accelerating hES research, let alone for CRISPR technology.
The successful editing of a human embryo is a breakthrough worthy of celebration, but with proper funding and continued research, equally stunning advancements with CRISPR could help many more people as the technology takes aim at a widening range of genetic diseases.