In early December, scientists from around the world gathered in Washington to discuss a revolutionary subject for the future of the human species, but very controversial from an ethical point of view. The meeting, led by the American Society of Sciences, analyzed the risks of experimenting with a new technique known by the acronym CRISPR, discovered three years ago to edit the DNA of any kind.
The human genome is a book written with four letters and the combination of these are the 20,000 genes, which are the recipes for making proteins in the body. Since 2003, when they managed to decode the genome, scientists have identified nearly 6,000 hereditary diseases that are caused by a typo in the great book of life. The CRISPR technique is a kind of word processor that detects errors and cut or changed to the correct version. It is what makes the find and replace feature in Word. It counts with two tools: a segment of RNA, a chemical messenger able to identify any part of the genetic code, and an enzyme that can cut and replace it. The system is so revolutionary that appeared on the cover of The Economist, and considered the journal Science the discovery of the year.
Although there are other methods to genetic edition, the CRISPR technique makes it simpler, faster and more accurately, which in turn makes it a very economical tool. “In the past, changing a gene or add it to a complete genome was the thesis of a doctoral student,” he told The New York Times Bruce Conklin, a genetics lab in San Francisco Gladstone. Under the new system a high school student can do in just an hour.
With CRISPR scientists have been correct in their laboratories mutation that causes cystic fibrosis. In October, researchers at Harvard University 62 genes modified pig embryos. Thanks to its ease and efficiency is increasingly used in laboratories around the world where it is applied in dozens of species, from fruit flies, rabbits, rats, to macaques. The technique has been cured version of muscular dystrophy affecting rodents. It has also been used in almost all cell types, from the heart to the immune system.
In theory, the scope of prevention is enormous and diseases caused by one faulty gene could be corrected, as Huntington’s disease, a degenerative neurological disease. Currently the children of a person with this defective gene are exposed to 50 percent chance of having it.
But simultaneously, experts have managed to make the most accurate and versatile technique and expand its capabilities so that not only You can insert and remove a but several at once gene, which is essential for many diseases whose origin is written in different parts of the genome, such as diabetes, heart disease and autism.
Researchers hope CRISPR that are achieved through developing gene therapies for diseases such as HIV, to create a more powerful immune system the virus; or malaria and dengue by modifying the mosquito’s ability to transmit; or cancer cells to make them more adept at recognizing tumors or Alzheimer’s, speaking the genes that create a predisposition to the disease.
The agricultural industry will also see great potential and as giants like Dannon CRISPR used to create types of bacteria that produce tastier yogurt. Monsanto used to create plants with improved characteristics and in the future is speculation that she could make it less harmful red meat. “With the technical range of potential uses is so great that everyone is using it,” says Rodolphe Barrangou a biologist at North Carolina State University who participated in the discovery.
But an application He created controversy. In April this year, researchers at Sun Yat Sen University in China have announced genetically modified human embryos to repair the gene responsible for a deadly blood disease. While these were not viable embryos to be implanted and brought to term, alarms sounded in the world.
One of the concerns is that in the process of cutting and pasting other genes are modified, which would cause unwanted effects. And if those changes are made in the germ cells, egg and sperm, they could have repercussions throughout the body. Not only that, such changes would be passed from generation to generation so that the golden rule of not scientists playing God would break.
This does not concern those in favor of research with The technique. The expert John Harris, who promotes the procedure, arguing that the rate of children each year are born with a serious genetic defect is 6 percent, so consider that nature is not a more accurate system. “If scientists had invented sexual reproduction never been allowed,” he said in a column published in The Guardian.
In addition there is no consensus on which diseases run these risks warrant. Some believe that when it comes to catastrophic conditions may be valid, but a very different thing would be to modify embryos and stem cells to cure myopia or to increase the height of an individual. Some even say that deafness or autism are part of human diversity and should be excluded from this type of gene therapy.
Even more controversial is that the technique could be the gateway for babies Chart: flawless, smarter, more beautiful. Although experts say that such improvements are not so easy because those traits do not respond to a specific gene but a group of them, advances in this field are so fast that already worth raising that possibility.
As CRISPR a technique for their facility is available to all concerned that fall into unscrupulous hands. In March, scientists managed to create a chain reaction to accelerate the process of producing a species with a mutation that would be inherited. If the system is used without control could alter animals and plants outside the laboratory.
Those in favor of continuing the investigation indicate that science has crossed the line not play God. The closest example is what happened in Britain recently when the technique of modifying embryos with defective mitochondrial DNA is passed. Scientists meeting in Washington called for suspending the technique in human embryos until they know for sure their risks and benefits. But the thought of curing diseases like cancer and Alzheimer’s, costly for society and debilitating for families, makes it difficult to stop this revolution. “When they could not do was easy to say that we should not,” said one of the experts of the Washington meeting.
But in general there is consensus that the ethical dilemmas hopefully not overshadow the benefits for CRISPR health. For as editorial says The Economist, “a tool that allows prolong life and improve its quality should be welcomed.”
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