From animals and plants, the DNA altering has now caught up with human beings. Soon, we would see genetically modified human beings.
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is a new genetic editing tool, which scientists claim could transform the field of biology. In fact, for many years now, scientists have been experimenting on gene editing techniques in order to find the best tool to alter the DNA of human beings. It is through this search that animal and plant genes were altered by scientists.
With the discovery of CRISPR, it allows scientists to edit human genes with unprecedented precision, efficiency, and flexibility. So far, scientists claim to have successfully used CRISPR to create monkeys with targeted mutations to prevent HIV infection in human cells.
In 2015, Chinese scientists announced they successfully used CRISPR to create a genetically modified human embryo. In April 2016, the same Chinese researchers announced they have genetically modified another human embryo.
But even before the Chinese announcement of the second modified embryo, in February 2016, British scientists were given permission by the country's regulators to genetically modify human embryos by using CRISPR-Cas9 and related techniques. The embryos were to be destroyed after seven days due to ethical and legal restrictions.
These developments showed clearly that soon, scientists will start editing the human gene, if permitted by governments.
Comment: And it is likely that they will do it, and already have, without the government's permission.
A private biotechnology company in the United States called Editas Medicine, has announced that by 2017, it will produce the first genetically modified human beingson Earth. The company plans to start the first trials soon.
According to Editas Medicine, it is poised to become the first lab in the world to 'genetically edit' the DNA of patients suffering from a genetic condition. Specifically, the company is concentrating on a blinding disorder known as 'leber congenital amaurosis'. The disorder prevents normal function of the retina; the light-sensitive layer of cells at the back of the eye. It appears at birth or in the first months of life and eventually, sufferers can go completely blind.
Experts say the disease is inherited and is caused by defects in a gene that instructs the creation of a protein essential to vision.
By using the CRISPR editing technique, scientists at Editas Medicine believe they can fix the mutated DNA.
The Chief Executive of Editas Medicine, Katrine Bosley told a conference in the United States that the company hopes to start trial of the technology on blind patients in 2017. Although human gene editing is currently banned in the United States, Bosley said the company has applied for a special permission from the country's health regulators.
However, despite Editas Medicine's hope to start using the technology on humans, some concerned scientists and observers have expressed worry on the technology. This is because the technology fundamentally changes a person's genetic code, which can then be passed down to offspring. Even CRISPR advocates have admitted that it could have unintended consequences for other parts of the genome, and could lead to designer babies. Designer babies are babies whose genetic make-up has been selected, in order to eradicate a particular defect, or to ensure that a particular gene is present.
"CRISPR is a hugely exciting technology and it undoubtedly has great potential that is attracting the attention of researchers around the world. If the potential of CRISPR is to be realized then the technology needs to be thoroughly explored through high quality biomedical research that is subjected to ethical approval and peer review. Otherwise there is a risk that families desperate for cures will be vulnerable to plausible offers from over-enthusiastic advocates for the technology," Alastair Kent of the Genetic Alliance said.
Some observers also say scientists should avoid even attempting to lax jurisdictions - the technology for clinical application in humans - until the full implications of the technology are discussed among scientific and governmental organizations.
Also, some scientists who support basic research on CRISPR say they do not see the technology as developed enough for any clinical use in making heritable changes to humans.
"Think of the CRISPR-Cas9 gene editing technique as a nanoscissors. Put some of these nanoscissors into a cell and they will make cuts near the gene defects you want to alter, which can then be replaced by a properly functioning gene segment. But the nanoscissors can also cut other genes in a somewhat unpredictable fashion. This could change the function of a gene responsible for keeping a cell from becoming cancerous, for example, or causing other diseases.
These unwanted edits are called off-target effects. Even if on-target gene editing is accurate, the off-target effects could influence the function of many genes, possibly posing serious health problems. In the germline, off-target effects might persist for generations and could lead to long-term changes in the genome.
Until we know the full consequences of gene editing, it would be a huge mistake to use it to modify the germline."
Gang Bao, PhD, is professor of bioengineering at Rice University in Houston, where he directs the Nanomedicine Center for Nucleoprotein Machines
"Although I believe that germline gene editing may soon be of great value, we need to better understand and manage the risks that could arise before moving forward with it, as we do with all new medical technologies. That is why I joined 17 other investigators calling for a moratorium on the clinical use of germline gene editing while diverse groups of citizens examine emerging data on this technology and evaluate its risks and rewards."
George Church, PhD, is professor of genetics at Harvard Medical School
"Those who support gene editing often describe it as molecular scissors that cut out harmful DNA sequences on a chromosome and thus “edit out” disease. They sometimes use the image of a red pen, or the “undo” function on a computer, only applied to the book of life. These images make the gene editing process seem easier and cleaner than it really is, and assume a control over our germline we have not yet mastered. This reinforces the hype and glosses over the potential for off-target edits, which can create unintended mutations in the genome."
Eleonore Pauwels is a scholar with the Science and Technology Innovation Program at the Wilson Center in Washington, D.C.
"Evolution has been working toward optimizing the human genome for 3.85 billion years. Do we really think that some small group of human genome tinkerers could do better without all sorts of unintended consequences?
The ethical arguments against human germline engineering are significant. A most compelling one is that medical research should always seek to balance benefits and risks, with individuals who are participating in research giving fully informed consent. But the individuals whose lives are potentially affected by germline manipulation could extend many generations into the future. They can’t give consent to having their genomes altered from what nature would have made possible.
There’s also a concern about human hubris. Who gets to decide what’s an improvement on the genome?
Gene editing potentially holds great promise, and equally great peril. Today, there are too many unknowns about this technique to apply it to the germline of humans and other species."
Francis S. Collins, MD, is the director of the National Institutes of Health.