Human Genetic Engineering Research Forges Ahead
A few months ago, we wrote about research underway in China that involved modifying human DNA in fetuses in order to eliminate a blood disease called beta thalassemia. The experiments didn't go as well as the scientists had hoped, and that particular study was put on hold; but scientists in China have continued DNA experimentation, pushing the boundaries of what many around the globe consider ethical. For instance, just last month, researchers at the Guangzhou Institute of Biomedicine and Health created two designer Beagle puppies with twice the normal amount of muscle.1 The scientists also created designer monkeys, as well as micropigs that they intend to sell as pets for $1600 apiece.
Many researchers defend efforts to alter human DNA as the frontier where hereditary diseases may finally be wiped out. As we said in a previous article, "In the best of all worlds, the technique and others like it could be used to eradicate genetically based diseases and would be a boon to human health. In the worst case scenario, though, it's the stuff of Gattacan nightmares.2 Once you can alter one strand of DNA, you can alter others, as well. Many fear that pursuing this work opens the door to creating humans in labs and government-sponsored eugenics, and the alarms have been sounded."
For anyone who has read the science fiction novel Oryx and Crake by Margaret Atwood, the Chinese pig development is particularly chilling. In Atwood's book, scientists create designer pigs (pigoons) that host multitudes of human organs for transplanting (six kidneys per pigoon), and that's what marks the ‘beginning of the end' of the human race. After perfecting the pigs, the fictional scientists create designer babies and in short order, only simple-minded but beautiful automatons programmed to self-destruct at age 30 are left on earth. But is that what we'd really choose? Isn't it more likely that we'd choose to create brilliant babies that live forever? Now what could go wrong with that?
Such scary scenarios haven't deterred the researchers, and so the race is on to modify human and animal DNA not only in China, but around the globe. The leading technology right now is a gene editing technique developed at MIT called CRISPR-cas9. While CRISPR-cas9 isn't the only type of genetic modifier being tested on humans, it's the most precise and the one many scientists think may prove the most useful. Apparently, the CRISPR-cas9 technology is easy to use and relatively cheap. The technology relies on bacteria that have an inbuilt defense mechanism against viruses. When the bacteria are injected into a host and they encounter a virus, they eliminate it. In CRISPR-cas9, these bacteria are programmed to mistake genetic mutations for viruses so that they go to work cutting out the targeted elements of DNA.
Here in the US, a company called Editas recently threw its hat into the gene-editing ring, announcing that it's using genetic modification to try to eradicate an inherited vision impairment called leber congenital amaurosis, which can lead to blindness.3 The company plans to inject a soup of bacteria directly into affected patient's eyes, expecting the CRISPR technology to eradicate around 1,000 DNA letters from a gene called CEP290, thus reversing the genetic mutation that causes the visual impairment.
Gene editing isn't actually legal in the US, at least not so far. Editas is asking for special permission to forge ahead with its research and hopes to have human trials underway by 2017.
Those in favor of continuing human gene editing research, like Editas CEO Katrine Bosley, say that the technology has the capacity to heal thousands of inherited genetic conditions like Huntington's disease and cystic fibrosis.4 Professor Darren Griffin of the University of Kent agrees: "The ‘engineering the perfect baby' argument is, in my opinion, a red herring when the alternative is children losing their sight," he says. "Certainly, the 600 patients in the US suffering from blindness caused by leber congenital amaurosis have much to gain."
Dr. Griffin's argument is supported by another related incident that was reported just last week, when a British baby with virulent leukemia was injected with genetically modified immune cells from a donor.5 The immune cells were edited using a technique called TALEN so that they would target and eliminate only leukemia cells. Although the infant's condition hadn't responded to any traditional treatments and her doctors had given up hope for the baby's survival, the 10-minute treatment actually wiped out the cancer cells, and she's now cancer free. Of course, it's a bit different to inject a patient with modified cells than to actually alter the patient's own DNA, but the point is, DNA modification has incredible potential to cure disease, and scientists say other cancers might soon be wiped out using this approach.
It's hard to argue with such startling success, but the problem, as we've discussed before, is that once we start editing human genes, we don't know how the human body will compensate. There could be a cascade of other, unintended effects, particularly when the altered genes are passed on to offspring. And once again, there is that "designer baby" fear--the worry that some unethical group will get hold of the technology and try to create a super-race to control the rest of humanity. Judging by comments in response to articles about CRISPR on the internet, a large number of people do harbor such fears. For instance, reader VinceGlortho, in his response to an article about CRISPR in the Telegraph, encapsulates the sentiment expressed by many other readers:
"Now it is an inevitability that we will be altered as a species, under the guise that it will help humanity," he says. "It will only help the elite-- the rest of us are the guinea pigs, the canaries in the coal mine."
Then again, it's probably worth noting that VinceGlortho took his nom de plume from a character in the movie Ghostbusters. In any event, we certainly live in interesting times.
- 1. Murdia, Madhumita. "Chinese scientists create ‘designer dogs' by genetic engineering." 20 October 2015. The Telegraph. 13 November 2015. http://www.telegraph.co.uk/technology/news/11943103/Chinese-scientists-create-designer-dogs-by-genetic-engineering.html
- 2. https://www.youtube.com/watch?v=WAdMyHnFSbg
- 3. Knapton, Sarah. "First genetically modified humans could exist within two years." 12 November 2015. The Telegraph. 13 November 2015. http://www.telegraph.co.uk/news/science/science-news/11991905/First-genetically-modified-humans-could-exist-within-two-years.html
- 4. Regalado, Antonio. "CRISPR gene editing to be tested on people by 2017, says Editas." 5 November 2015. MIT Technology Review. 13 November 2015. http://www.technologyreview.com/news/543181/crispr-gene-editing-to-be-tested-on-people-by-2017-says-editas/
- 5. Knapton, Sarah. "British baby given genetically-edited immune cells to beat cancer in world's first." 5 November 2015. The Telegraph. 13 November 2015. http://www.telegraph.co.uk/news/science/science-news/11978223/British-baby-given-genetically-edited-immune-cells-to-beat-cancer-in-world-first.html