What CRISPR enables, say its proponents, is a quick, easy and effective way to edit the genes of any species – including humans. Other methods take months or years, while CRISPR speeds that time up to mere weeks. The ability to cut and splice genes so quickly and so precisely has potential applications for the ability to create new biofuels, materials, drugs and foods within much shorter time frames at a relatively low cost.
In a nutshell, CRISPR is a synthetic biology technique that takes advantage of the sophisticated immune systems of bacteria. Researchers essentially trick bacteria into cutting strands of DNA at a precise spot, where they can then replace, change or disable a gene. While scientific research into the CRISPR microbial defense mechanism dates back to the late 1980s, it was not until 2012 that the immense genetic implications became clear.
CRISPR essentially enables researchers to edit the DNA of any species at a precise location. Once you can locate the “interspacers” (the I in CRISPR) separating the “palindromic repeats” (the P and R in CRISPR), you can cut and change genes nearly anywhere in the genome. In the most exciting scenario, CRISPR would make it possible to treat genetic diseases such as sickle-cell anemia and muscular dystrophy.
Despite its rather innocuous-sounding name (pronounced “crisper”) and its potential life-changing medical applications, CRISPR has become the center of an intense debate about the future of synthetic biology. Some, such as my colleague Vivek Wadhwa, have called for a global moratorium on the gene-editing technology, due to ethical and safety concerns. From editing microbial DNA in lab test tubes, it’s a slippery slope to editing human DNA in living cells. “No one is prepared for an era when editing DNA is as easy as editing a Microsoft Word document,” says Wadhwa.
In one controversial scenario, it might be theoretically possible to alter the genetic material that controls hereditary characteristics, not just the genetic material of somatic cells. At some point, fear researchers, it might be possible to control the specific traits that we pass on to our offspring by tinkering with the genes in a human embryo. That’s the classic “Frankenbabies” scenario, in which tinkering with a few genes to create a “designer baby” leads to a whole host of irreversible genetic consequences.
That’s not just science fiction. Earlier this year, Chinese researchers showed how CRISPR techniques might be theoretically possible to utilize on a non-viable human embryo – and set off a firestorm of debate about the ethics involved. Mainstream scientific publications refused to publish the results, citing ethical and safety concerns about creating genetically modified humans.
The Center for Genetics and Society has even put together a briefing of seven key reasons why genetically modified humans could be so dangerous. Point No. 1? “Profound health risks to future children.” Messing around with the genetics of an unborn child is serious business. Even tinkering with a single gene (e.g. “eye color”) could have unforeseen implications: “Altering the genomes of our offspring — not just the first generation but all later ones as well — means irreversibly changing every cell in their bodies, forever.”
That’s why venture capitalists have focused on companies within the much safer area of genomic medicine, where CRISPR can address genetically driven diseases without the risk of tinkering with hereditary characteristics. The big deal that pushed CRISPR into the mainstream was the blockbuster $120 million Series B round this summer for Editas Medicine, which is led by some of the biggest names in the CRISPR world: Feng Zhang, a researcher at the Broad Institute, Jennifer Doudna and David Liu from Howard Hughes Medical Institute, and George Church and J. Keith Joung from Harvard Medical School.
Of course, it could be the case that CRISPR is getting overhyped. After all, it’s not so much a product or service as it is a tool or technique. That means that competitors could one day come up with another tool or technique that’s cheaper, better or faster than CRISPR in the same way that CRISPR has rapidly eclipsed other gene-editing techniques, such as TALENs and zinc fingers.
Keep your eye on this space. Big international proceedings are set to take place later this year to discuss gene-editing, and there’s sure to be greater guidance and debate as to what’s possible and what next steps should be when it comes to editing genes. However, despite the justified concerns about the potential applications of gene-editing technologies, it’s hard not to acknowledge that the gene is already out of the bottle when it comes to CRISPR.