Human Genetic Engineering: A Very Brief Introduction
Rayshell Clapper for redOrbit.com – Your Universe Online
What, Why and How?
What exactly is human genetic engineering (HGE or HGM)? It´s a simple question with a complex answer. According to the Association of Reproductive Health Professionals (ARHP), HGM is a process by which scientists and medical professionals alter the genetic makeup, or DNA, in a living human cell. Ideally, HGM would be used to fix defective genes that cause diseases and other genetic complications.
In one method of altering the genes of living cells, scientists insert a new gene into a virus-like organism. This organism is then allowed to enter the cells and insert the new gene into the genome. Human genetic engineering uses two applications to do this: somatic and germline. It is important to note the distinction between these two applications.
Somatic engineering (from the Greek word “soma,” which means “body”) targets specific genes in specific organs and tissues without affecting the genes in the eggs or sperm (depending upon the gender of the person). The aim of this type of human genetic engineering is to treat or cure an existing condition. It does not alter the individual´s entire genetic makeup as a report for the Genetics and Public Policy Center explains.
The other type of human genetic engineering is germline, which targets the genes in eggs, sperm, or embryos in very early stages of development. This means that the genetic modifications that take place affect every cell created afterwards in the developing embryo´s body. Germline HGM also means that the modifications are passed on to all future generations if the individual goes on to have offspring. Obviously, germline HGM tends to be more controversial because the introduction of the gene alters future reproduction, whereas somatic HGM only affects the individual on which it is performed.
Finally, cloning can be considered as a third method of HGM. The US Department of Energy´s genomics website explains that there are three main types of cloning: recombinant DNA technology or DNA cloning, reproductive cloning, and therapeutic cloning. DNA cloning is the transfer of a DNA fragment from one organism to a self-replicating genetic element in order for the DNA to replicate itself in a foreign host cell. Reproductive cloning, on the other hand, is used to generate an organism that has the same nuclear DNA as another currently or previously existing organism (think of Dolly the sheep). Finally, therapeutic cloning — also known as embryo cloning — involves the production of human embryos for use in research.
On February 13, 2013, experts debated whether the US should ban specifically prenatal engineering. Livescience.com reported about this debate over HGM as the concern turned from empowering parents to give their children the best start possible to creating designer babies who may encounter genetic problems as a result of the genetic engineering of humans.
The ARHP noted that though many assume that germline engineering is necessary to allow parents to avoid passing on deficient DNA, other options do exist, including adoption, gamete and embryo donation, and even pre-implantation diagnosis and selection. The latter allows couples to have a child that is genetically related to both parents yet does not carry the genetic disease of concern.
A number of experts have focused on the possible unknown consequences of human genetic engineering and highlight the problems created by plant and animal genetic modifications. In the case of mishaps in plant or animal genetic experiments, scientists are able to discard the failed subjects, whereas doing so with a human who has been genetically engineered would be considered highly unethical.
Those in support of human genetic engineering often believe that parents should have the power to ensure that their children have a healthy life. On this side of the debate, the focus has often been on the protection of the unborn child. And many respond to the argument that HGM is dangerous and uncertain by pointing out that reproduction itself is uncertain and often leads to congenital diseases and death.
Another common ethical concern is the fear that human genetic engineering might lead to eugenics — the deliberate attempt to improve the human race through artificial genetic selection or selective breeding. Although the idea of eugenics calls to mind for many the horrors of the Nazi regime, both sides of this debate have legitimate arguments highlighting both the pros and cons of attempting to create a stronger, healthier race of human beings.
Both technologically and morally, human genetic engineering has a number of hurdles that it must overcome before it makes its way into mainstream acceptance and medical practice. With more education and research will come better understanding and better decisions.