- Using CRISPR, researchers successfully altered DNA in human embryos in a way that would eliminate or correct the genes causing certain inherited diseases
- If the embryos were implanted into a womb and allowed to grow, the process, which is known as germline engineering, would result in the first genetically modified children — and any engineered changes would be passed on to their own children
- In Iceland, Down syndrome births are becoming increasingly rare as women choose to have prenatal testing for chromosome abnormalities, and nearly 100 percent terminate pregnancies with a positive result
- As CRISPR moves ahead, access to accurate and neutral data will be essential and difficult questions relating to eugenics must be asked
By Dr. Mercola
Gene editing was once a very imprecise and expensive process, but today, thanks to the development of CRISPR, or Clustered Regularly Interspaced Short Palindromic Repeat, scientists can go into your DNA and essentially cut and paste it at specified places. Progress is being made in tackling genetic diseases such as sickle-cell anemia and certain forms of blindness and muscular dystrophy.
A CRISPR clinical trial in people with cancer is already underway in China, and the technology has been used to edit human embryos made from sperm from men carrying inherited disease mutations. The researchers successfully altered the DNA in a way that would eliminate or correct the genes causing the inherited disease.1
If the embryos were implanted into a womb and allowed to grow, the process, which is known as germline engineering, would result in the first genetically modified children — and any engineered changes would be passed on to their own children. The technology is moving so fast that innovations like this are occurring before their full implications are known or fully understood.
“Some critics say germline experiments could open the floodgates to a brave new world of ‘designer babies’ engineered with genetic enhancements,” Technology Review reported, bringing up questions of ethics and eugenics.2
Does the Elimination of Down Syndrome in Iceland Point to a Dark Future for CRISPR?
It’s recently been reported that, in Iceland, Down syndrome births are becoming increasingly rare, with just one or two children born with the condition each year. In essence, Down syndrome is disappearing, but not by nature or happenstance. In Iceland, up to 85 percent of pregnant women receive prenatal screening tests to detect chromosome abnormalities, including Down syndrome. Close to 100 percent of women who receive a positive result end up terminating their pregnancy, CBS News reported.3
Other countries also have high termination rates for fetuses with Down syndrome: 67 percent in the U.S.; 77 percent in France; and 98 percent in Denmark, for instance. As for why so many women terminate their Down syndrome pregnancies in Iceland, geneticist Kari Stefansson told CBS News, “It reflects a relatively heavy-handed genetic counseling. And I don’t think that heavy-handed genetic counseling is desirable … You’re having impact on decisions that are not medical, in a way.”4
Writing in The Nation, journalist and historian — and father to a young son with Down syndrome — David Perry noted that “we’re failing our test run for the age of CRISPR.”5 He points out that today children with Down syndrome can lead long, happy and productive lives, but many expectant parents aren’t informed of this reality.
Prenatal testing companies market heavily to physicians but provide little information on the conditions being tested for. As a result, some parents are receiving wrong information about their would-be child’s prognosis. Perry writes:6
“What does all this have to do with CRISPR? Right now, we’re still in a liminal state when it comes to predicting genetic outcomes for fetuses. Our tools, from amniocentesis (developed in the 1950s and ’60s) to contemporary screenings that locate fetal blood cells in the mother’s bloodstream, are reactive and postconception.
Soon, they’ll shift to preconception and proactive. What will the tens of thousands of clinicians tell would-be parents as they get flooded with messaging from companies eager to sell their high-tech CRISPR product lines?”
As it stands, access to information, or lack thereof, may result in physicians providing outdated or biased genetic counseling to patients. As CRISPR moves ahead, access to accurate and neutral data will be essential. Difficult questions — such as, “When does abortion become eugenics?” as posed by The Atlantic7 — must be asked, and answered. The time has come when parents can choose to abort a fetus based on a disability, but soon this may extend into sex, race or even, one day, sexual orientation.
Even now, Miami-based radiologist Dr. Grazie Pozo Christie pointed out that “eugenics and equality can’t mix,” explaining in U.S. News & World Report, “When we do everything in our power to detect the existence of a baby with a special need with the sole purpose of terminating him or her, we create a discriminatory culture, where only perfect humans may apply for entrance.
This is a powerful obstacle against equality and acceptance of the disabled, which a just society must set as its first goal.”8 Perry also notes that access to unbiased, up-to-date information is crucial in an age of genetic testing and CRISPR:9
“Preventing this potentially dystopian future where altered genes separate the haves from the have-nots starts by shifting discourse. A pro-information approach demands that everyone involved in genetic counseling have access to the best data and presents it in a value-neutral way. We must build systems now that grow as our tools evolve. If we do not, genetic diversity will gradually become code for poverty, and new stigmas will run all the way to the DNA.”
Many Countries Have Already Banned Genetic Engineering of Human Embryos, Germ-Line Modification
Whether or not the creation of “designer babies” with a certain eye color or increased intelligence is inevitable remains to be seen, but some regions are not willing to take a wait-and-see approach. About 40 countries have already banned the genetic engineering of human embryos and 15 of 22 European countries prohibit germ line modification.10 Time reported:11
“Using CRISPR on humans is still hugely controversial, in part because it’s so easy. The fact that it allows scientists to efficiently edit any gene — for some cancers, but also potentially for a predisposition for red hair, for being overweight, for being good at math — worries ethicists because of what could happen if it gets into the wrong hands.
… As CRISPR goes mainstream in medicine and agriculture, profound moral and ethical questions will arise. Few would argue against using CRISPR to treat terminal cancer patients, but what about treating chronic diseases? Or disabilities? If sickle-cell anemia can be corrected with CRISPR, should obesity, which drives so many life-threatening illnesses? Who decides where that line ought to be drawn?”
Correcting embryonic DNA to eliminate genetic defects associated with inheritable diseases currently has the greatest support, but some scientists argue that using germ-line gene editing to eliminate genetic disease is unnecessary, since the technology to test and choose embryos free of genetic disease already exists and is regularly used in IVF clinics.
The alteration of genes to protect a person against future disease or diseases is another area of ongoing research, while genetic enhancement, in which genes are installed or modified to change a person’s appearance, or physical or mental potential is most controversial. A top U.S. intelligence official even added gene-editing to a list of potential weapons of mass destruction that pose a threat to national safety.12
As complex and futuristic as it seems, gene editing is inexpensive and easy to do. Killer mosquitoes, agricultural plagues and DNA-targeting viruses have all been suggested as potential bioweapons should CRISPR or other gene-editing tools fall into the wrong hands.13
Gene editing has become so mainstream there are classes on the topic available at community colleges and DIY kits you can order online. Even middle school students may learn the basics of gene editing in science class, with some comparing the new technology to computer coding a few decades ago.
CRISPR May Cause Unexpected Mutations
Gene-editing technology has gotten much more precise over the years, particularly with the invention of CRISPR-Cas9.14 By modifying an enzyme called Cas9, the gene-editing capabilities are significantly improved, in some cases reducing the error rate to “undetectable levels.” It’s not perfect, however, and may accidently hit other parts of the genome.
A recent study searched for unintended mutations, based on a separate study that used CRISPR-Cas9 to restore sight in blind mice by correcting a genetic mutation. The researchers sequenced the entire genome of the CRISPR-edited mice to search for mutations. In addition to the intended genetic edit, they found more than 100 additional deletions and insertions along with more than 1,500 single-nucleotide mutations. Study co-author Dr. Stephen Tsang, of Columbia University Medical Center, told Scienmag:15
“We feel it’s critical that the scientific community consider the potential hazards of all off-target mutations caused by CRISPR, including single nucleotide mutations and mutations in non-coding regions of the genome … Researchers who aren’t using whole genome sequencing to find off-target effects may be missing potentially important mutations. Even a single nucleotide change can have a huge impact.”
It’s too soon to say whether the mutations are a cause for alarm. However, in the recent study in which researchers used CRISPR to edit human embryos, altering the DNA to prevent inherited disease, they claim to have developed a better technique that avoids off-target effects, as well as mosaicism, in which the DNA changes are taken up by some of the embryo’s cells instead of all of them.16
Meanwhile, a February 2017 report issued by the U.S. National Academies of Sciences (NAS) basically set the stage for allowing research on germline modification and CRISPR, but only for the purpose of eliminating serious diseases — not for “enhancing traits or abilities beyond ordinary health.” The latter would raise concerns “about whether the benefits can outweigh the risks, and about fairness if available only to some people,” NAS noted.17
According to Technology Review, however, “Despite such barriers, the creation of a gene-edited person could be attempted at any moment, including by IVF clinics operating facilities in countries where there are no such legal restrictions.”18
With the technology becoming increasingly accessible to anyone with an interest, it’s probably going to be a matter of when, not if, this boundary is crossed, with unknown consequences. While gene-editing technology has the potential to be great, it could also be easily, and seriously, misused and abused.
– Sources and References
- 1, 2, 16, 17, 18 Technology Review July 26, 2017
- 3, 4 CBS News August 14, 2017
- 5, 6, 9 The Nation August 29, 2017
- 7 The Atlantic May 24, 2016
- 8 U.S. News & World Report August 26, 2016
- 10 Institute of Science in Society January 12, 2016
- 11 Time
- 12, 13 Technology Review February 9, 2016
- 14 Nature Methods 14, 547–548 (2017)
- 15 Scienmag May 29, 2017