READ MORE: Genetic science is still a mystery and will produce dangerous, unintended effects.
It is important to note that the content of this website focuses on genetic engineering of human embryos, not of born children or adults. The kind of genetic engineering performed on embryos, which is soon after their creation, is likely to have more fundamental effects on the developing person, and there is more of a chance that genetic mutations, damage to DNA, or environmental factors can cause unpredicted effects during the person’s lifetime. Genetic engineering of embryos is also known as “germline” editing (or “genome” editing) because the changes made in DNA can be inherited by future generations.
Genetic engineering always involves risk. This is not the risk of a medical procedure, which has an immediate effect, but of the future development and health of the person (and of future generations).
In considering the risks of genetic engineering, we need to consider several questions (aside from the moral, psychological, and relationship issues that are even more important):
Can we predict the effects of genetic engineering on the person and on future generations well enough to justify trying to “fix” genetic abnormalities or enhance certain features and capabilities?
Do the current technologies for genetic engineering actually make the changes in DNA that are desired, with extremely high accuracy?
Since there will always be unpredictability and risk, just how much risk is acceptable? Who decides? Who protects the interests of the individual or future generations affected?
Can we trust the researchers, scientists, and clinics to conduct the genetic engineering so that they avoid the risks that society has deemed unacceptable? Who will regulate this? Can it be effectively regulated? Is it worth the risk?
Here are some of the reasons why predicting the unintended effects of genetic engineering and germline editing is enormously complex, and why certainty is impossible:
It is rare to find a single gene that always has a specific effect on an organism. Most characteristics or abilities that we can identify in organisms are “caused” by a number of genes.
The effect of genes often depends on how they interact. Even a basic human characteristic like height is influenced by tens of thousands of genetic variations.
Genes influence multiple characteristics.
It is never possible to know if a gene or combination of genes might have effects that were previously unknown.
The “expression” (active influence) of a gene can be turned on or off, or changed, by the nature of the entire DNA sequence.
It is only recently that scientists realized what 99% of genes do. Previously, scientists thought that these “noncoding” or “junk DNA”, which means they do not instruct the body in the making of proteins, had no purpose. Now they realize that this kind of DNA is actually involved in turning the protein-coding genes “on” or “off”. The research on these genes is just getting underway.
The influence of a single gene on the organism can change depending on the way it interacts with other genes, proteins, and bacteria.
Genes can mutate, which is when random “mistakes”, damage, or interaction with other substances interfere with the process of duplicating DNA in cells. The new DNA is not an exact copy of the original DNA. In order to know whether a gene will have the expected influence, scientists need to know for sure whether the gene has or has not mutated.
The possibilities for gene mutations are unlimited and unpredictable, and scientists do not know what effect most mutations will have on the body.
An individual’s genetic information in DNA can actually change during lifetime through their environment and experiences. These changes may be inherited by children. The rapidly changing field of science that studies these lifetime changes in DNA is called epigenetics.
While most DNA is found in the nucleus of a cell, there is also some DNA in other structures in the cells called mitochondria. Some inherited changes in mitochondrial DNA can cause major problems for the health of a person in their organs and tissues like the heart, brain, kidneys, and muscles, with negative effects on hearing, sight, intellectual function, diabetes, and other disorders.
The changes in mitochondrial DNA can have multiple effects.
Mutation in mitochondrial DNA may or may not be inherited by future generations.
Genes do not entirely determine a person’s nature. Environmental factors, damage, disease, and freely chosen acts of the organism can interfere with genes’ actual control over what the organism looks like or how it acts. None of this is predictable.
Germline editing continues to affect future generations, and the effects will tend to be irreversible. The inheritance over just a few generations involves millions of potential variations, mutations, and scenarios that occur as edited genes are inherited. This number of possibilities makes it highly likely that unintended effects will eventually appear in future human beings.
Biological evolution in the species, whatever the mechanisms for the changes, has caused human beings to become extremely unique and capable animals. Genetic engineering interferes with the natural process of evolution, of which we still have very little understanding as well as extreme differences of opinion and theories.