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.