2019-02-20
Pixabay.com

Genetic engineering has been a topic of varying contention for years. Recently, though, there was new fuel thrown on the fire with a series of experiments done with Clustered Regularly Interspaced Short Palindromic Repeats or CRISPR. CRISPER is commonly used to refer to a variety of systems that can target specific stretches of DNA allowing scientists to delete particular portions of the genetic code or insert new genetic material into a previously existing genome. The precision of CRISPR allows geneticists to permanently modify an organism’s genetic code with previously unheard of accuracy. This technology is based on the naturally occurring abilities of some bacteria.

Even though debate has surrounded genetically engineered crops and genetic experiments in animals, for most people, the controversy surrounding genetic experimentation has been largely ignored. The ethics of genetic engineering, however, are back in the spotlight.

Early this year, a team of scientists successfully performed genetic modification on a fertilized human embryo using CRISPR. In vitro fertilization and gene therapy have involved elements of genetic engineering nearly since their conception, but the CRISPR experiments are the first time humanity has been confronted with human germline genetic modification. Germline modification is used to refer to genetic changes that would be passed down to an organism’s offspring. Any genetic alterations done to a parent would appear in children and grandchildren. Naturally, this has once again raised the question of whether genetic engineering is ethical.

Books have been written on the ethics of all sorts of genetic engineering, but the controversy reignited by the CRISPR studies focuses on genetic modification of humans. For decades, accurate and feasible human genetic engineering was something out of a science fiction novel. Depending on a person’s opinion on genetic modification, genetically engineered humans were a distant fantasy or specter that loomed centuries down the road.

The CRISPR experiments did not use viable embryos and so no child has resulted from the study, but the CRISPR team proved that genetically modified humans were possible. The ethics of human genetic engineering is no longer a question to be dealt with in some remote future, but a debate that is very relevant now. So, what are the benefits and dangers of human genetic engineering?

Testing For Genetic Diseases

Genetic testing is not terribly new. Amniocentesis has been a staple of modern pregnancies for many years, and many at-risk people choose to be tested for genetic diseases such as Huntington’s disease. Improved genetic testing would lead to earlier diagnosis of such diseases. Earlier diagnoses would allow people destined to develop genetic diseases to make the most of their healthy years. Those who did not carry a genetic disease would be able to set their minds at ease.

Human genetic engineering has the potential to do more than identify a faulty gene. Improvements in technologies such as those used in CRISPR have the potential to correct the genetic errors that cause genetic diseases in the first place. Furthermore, germline genetic engineering could lead to the eradication of certain genetic diseases all-together.

Opponents of human genetic engineering argue that some faulty genes actually serve important purposes. The classic example of a useful genetic “defect” is sickle cell disease. Sickle cell disease, also known as sickle cell anemia, is caused by a genetic flaw that causes some red blood cells to be sickle shaped. The sickle shaped cells are prone to causing blockages in the circulatory system resulting in pain, stroke, cardiac arrest and death. Sickle cell disease, though, only presents if a person carries two copies of the sickle cell gene. If a person only has one copy, they have normal red blood cells and some protection against malaria. Were the sickle cell gene to be universally corrected, malaria-related deaths would increase dramatically.

Critics of genetic modification in humans also point out that genetic engineering is still relatively new. The potential long-term consequences of altering the human genome are still unknown. Changes to the human genetic code could potentially create new genetic diseases or genetic defects that, in the case of germline engineering, would persist for generations.

Designer Babies

The specter of designer babies is commonly raised by opponents of human genetic engineering. Advancement in genetic modification techniques could allow parents to influence their child’s eye color, hair color, height, intelligence and athleticism. It sounds like something out of a dystopian sci-fi story, but the possibility of designer babies is not as far-fetched as it sounds. Researchers have isolated genes that influence a person’s ability to gain muscle mass, and professional athletic associations have struggled to control “gene-doping,” the non-therapeutic use of cells, genes or genetic elements to enhance performance. Parents can already select the sex of their child in certain areas of the world and, while the genetics of intelligence have not yet been determined, they have long been a topic of interest in the scientific community.

This ability to “design” a child, genetic engineering critics argue, would lead to a generation of children whose very make-up was shaped by parental whims, market forces, constantly shifting standards of beauty and societal preferences. It could lead to a constantly deepening divide between those who were genetically enhanced or improved and those who were not. This divide might follow current class lines depending on the monetary cost of genetic engineering. This incorporation of a genetic component to the “haves” and “have nots” could also lead to a new form of eugenics or even the split of humanity into two distinct species.

Proponents of genetic engineering, however, argue that such claims have little basis in fact. Sex is based entirely on the presence or absence of the Y chromosome while traits such as hair and eye color are controlled by many different genes. Furthermore, the genetics of intelligence are still something of a mystery.

Lowering Hazards For High Risk Parents

Some genetic diseases have a very high potential of being inherited. A person with Huntington’s disease, for example, has a 50 percent chance of passing the faulty gene on to their child. In such situations, parents may decide not to have children due to a fear of passing on the genetic disorder regardless of how much they wish to have a child. Human genetic engineering has the potential to lower the risks for such couples. Improvements in technology such as CRISPR could allow scientists to correct a faulty gene. Genetic engineering could also be used to lower the dangers of high-risk pregnancies by insuring the genetic health of the fetus.

Those who are against human genetic engineering argue that alternatives exist for parents with a highly inheritable genetic disease. Surrogacy and adoption are options that do not involve invasive changes to an embryos genome.

Testing For Socially Undesirable Traits

Opponents of human genetic engineering claim that genetic modification could eventually become a tool of discrimination and prejudice. Researchers have long been curious what genetic predispositions, if any, influence a person’s tendency toward anger, violence, hatred and addiction. Genetic tests for such undesirable, but non-medical, traits could lead to discrimination against a person who carried a “violence” gene, regardless of whether or not the person has ever acted in a violent manner. Furthermore, if genes linked to such social undesirables were found in higher concentrations in certain ethnic groups, racial prejudice would suddenly have a genetic rationalization.

Proponents of human genetic modification argue that genetic testing could be kept confidential to avoid discrimination against individuals. Genetic information would be part of a person’s medical record and therefore privileged information.

Despite the potential abuses, those who favor genetic engineering argue that research into genetic influences on violence and addiction should continue. Identifying genetic predispositions towards addiction could help people with a high likelihood of developing a substance abuse problem manage their risks more effectively. Studying genetic links to violence could also lead to the identification of the gene pattern responsible for psychopathy as current research points to the disorder having a hereditary component.

Lengthened Lifespan

Human genetic engineering has the potential to lead to a longer average lifespan. Researchers have identified the portion of human chromosomes responsible for determining how many times a cell can divide and, thus, how long an organism will live. Human genetic modification could alter this portion of the chromosomes, extending a person’s lifespan.

Opponents of human genetic modification point out that the earth is already struggling to support a population of 7.2 billion people. Lengthening the average human lifespan would place even greater stress on an already overburdened planet.

Use of Human Embryos

This is one of the most expected controversies in human genetic research. Human genetic experimentation requires the use of human DNA. As with stem cell research, that DNA is usually found in donated eggs, sperm and embryos. This, naturally, runs headlong into the explosive question that has kept the debate over abortion raging for years: when does human life begin?

People who believe that human life begins at conception see the use of fertilized human embryos in medical research, such as the CRISPR study, as abhorrent. To those who hold that life begins at conception, experimentation on a fertilized human embryo is nothing short of sickening violation if not torture.

The use of human embryos in genetic experiments is not universally supported by those who believe that an embryo cannot be considered human until later in development. As of now, embryos used in genetic research are destroyed when the study is complete. This is in part because the scientists working on such research recognize that the long-term consequences of genetic modification are not yet understood. The knowledge required for a woman to safely carry a genetically engineered child to term simply does not exist yet. Still, the waste of human embryos or donated eggs grates on people, especially those who struggle to conceive. Some who rely on fertility treatments or in vitro fertilization see the use of embryos in medical research as a waste of viable eggs.

Proponents of genetic research are quick to point out that the embryos used in the CRISPR experiments were not truly viable. Had any one of the embryos been implanted in a woman’s womb, the embryo would not have survived to term. Some scientists argue that healthy, viable embryos would not be involved in such genetic modification research until closer to clinical trials. The waste of some viable embryos would be inevitable but would not seriously begin until science was preparing to implant a genetically modified embryo in a woman.

Playing God

This comes up in nearly every argument involving genetic engineering, regardless of whether it is corn or cows or children being modified. Some people who believe that human beings especially have a right to be “unmodified,” maintain that altering the human genome is equivalent to “playing God.” “Playing God” has a different meaning to every individual with some people claiming than any genetic modification involves a moral and spiritual trespass. On the other side of the spectrum are religious authorities who claim that genetic experimentation is within God’s gift to mankind of “dominion over the earth.” So far, few religious authorities see the question of genetic engineering as black-and-white. Most allow for genetic engineering that would preserve human life but frown upon the use of genetic modification for non-medically necessary uses such as sex selection.

Genetic Diversity Concerns

The ability to select for or against specific traits could affect the genetic diversity of the human species. Opponents of genetic modification argue that germline human genetic engineering would decrease the genetic diversity of the human species as certain traits would be seen as more desirable than others. This decrease in biodiversity would leave the population as a whole more vulnerable to diseases and changes in the environment.

Supporters of human genetic modification argue that genetic engineering could be used to increase genetic diversity. Geneticists could select for traits that would normally be lost in the random shuffle of genes. Human genetic engineering could also theoretically be used to create entirely new traits thus increasing genetic diversity beyond its original starting point.

Safe Usage of the Technology

Regardless of whether human genetic engineering is a marvel or an abomination, the technology to achieve it exists. Human genetic modification is possible and the world knows it. Proponents of human genetic engineering argue that human genetic modification is now inevitable. Someone, somewhere will improve and use the technology. Banning further research, testing and eventual usage would keep the technology from being done in a safe environment. Genetic modification would be driven underground and sold on the black market. Permitting human genetic engineering would also allow organizations to regulate the technology’s usage rather than leaving it to become part of the medical tourism industry. Men and women already travel internationally to receive risky surgeries, cheaper pharmaceuticals or procedures illegal in their home countries. The same thing would happen to human genetic modification.

Expanded Understanding of Human Genetics

Experiments involving the human genetic modification have revealed information about the human genome that would not have otherwise been discovered. The CRISPR studies, for example, revealed that a human embryo can sometimes repair its own faulty DNA without medical intervention. This phenomenon had never been observed before and scientists had not imagined it was possible. Such discoveries increase geneticists’ understanding of the human species and genetics as a whole. Further studies of the phenomenon of self-repaired DNA alone could lead to revolutionary treatments for diseases such as Huntington’s, Tay-Sachs and dozens of types of cancer. For proponents of genetic engineering, the information gained through human genetic research is invaluable. Opponents of human genetic modification, however, argue that the ends do not always justify the means.

Both opponents and proponents of human genetic engineering have valid points and strong arguments defending their position. There is a great deal of good to be gained from research into human genetic engineering, but there is also enormous potential for abuse. A genetically engineered human being is not yet safely possible, but the CRISPR studies have taken the concept out of science fiction and planted it squarely in today’s reality. What society will decide to do with the potential to modify the human species at its fundamental level has yet to be determined, but the debate over genetic engineering has been reignited, and it suddenly has far more personal consequences for mankind.

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