Preimplantation Genetic Diagnosis: Advantages & Future Consequences

Transcription

1 Preimplantation Genetic Diagnosis: Advantages & Future Consequences Charlyn Gonda Kevin Liu ECS 188 Winter 2014 Final Paper WORD COUNT: 2267

2 Gonda, Liu 1 An emerging technological issue in modern society is the rise of human genetic engineering. A complex and controversial topic on multiple levels, human genetic engineering ranges across a broad variety of individual points. Humanity has altered the genetics of other species for millennia through methods such as selective breeding however, advances in biotechnology have allowed humans to make more direct changes on humans themselves. Methods in this field range from gene therapy to genetic enhancement. A prominent technique under controversy is preimplantation genetic diagnosis (PGD), used to create designer babies essentially creating babies with specific desired qualities. PGD, in contrast to other methods such as germline engineering, which seeks to make enhancements in cells, uses the method of discarding embryos that have certain undesirable traits, Proponents of PGD argue that there are many medical and financial benefits, but opponents contend that there are a variety of moral and social problems. Preimplantation genetic diagnosis is a process of profiling the genes of an embryo mostly utilized for the prevention of pregnancy termination. When an embryo forms after fertilization, a single cell is taken and analyzed to ensure that either there are no genetic abnormalities that may have been inherited from the parents, or to test for aneuploidy an abnormal number of chromosomes which will cause birth defects or even miscarriage (O Connor). This process mitigates the need for postconception diagnostic procedures which may require the difficult decision of pregnancy termination when yielding undesirable results (Dayal). Currently, PGD is mostly used for determining whether the embryo has an increased risk of having genetic disease, and only embryos that show no indication of a predisposition to certain genetic diseases are implanted in the womb. But PGD can also be used to test for non-disease related traits, such as cosmetic traits or sex determination. There are several issues raised when discussing any

3 Gonda, Liu 2 application of PGD, including concerns about the safety and reliability of disease selection, and the slippery slope of selecting traits for non-medical reasons. On December 2008, Rupert Neate from Telegraph wrote about a British couple who has successfully used PGD to screen for neurofibromatosis, a potentially serious genetic condition (Neate). This was the first time that a baby was screened with PGD and was born free of this genetic condition, and according to the article, the risk that the baby would have had the disease without undergoing PGD was 50%. Neate reports that this procedure was funded from a local primary care trust grant of 7,000. Since this was the first time PGD was employed for this purpose, there were several concerns regarding its use. Some people expressed fear of eugenics and designer babies, and argued that this was simply too much of an intervention for little benefit. Another case involving screening for a particular disease involves a couple who decided to go through the process of PGD to ensure that their daughter did not have a particular gene, BRCA1 or BRCA2, which is known to increase the risk of breast cancer in women over 40 (Telegraph). The father s family had a history of breast cancer, which fueled the motivation for utilizing PGD. 6 out of 11 embryos tested were found to have the offending gene, and two were found to be free of it and were thus implanted, resulting in one healthy baby. Because both of these cases were in the United Kingdom, permission from the Human Fertilisation Embryology Authority (HFEA) had to be granted in order to implement the procedure legally. HFEA states on their website that embryos that had a copy of the faulty gene are not used, and this practice is a standard procedure when screening for genetic diseases. Sarah Alsamarai, in the Boston College Student Bioethics Research Journal, writes about how this standard procedure angers members of the disabled community (Alsamarai). Activists argue that disposing embryos who would possibly be born disabled is offensive and is akin to saying

4 Gonda, Liu 3 that it would be better for disabled people to not be born. To illustrate the extreme opinion on this matter, one uncommon usage of PGD is to specifically select a child to have a particular disability, for parents with that disability who wish to share it with their child. In a survey of US IVF (in-vitro fertilization) clinics that provide PGD, only 3% have reported providing this service (Baruch). Besides using PGD to screen for specific medical conditions or diseases, PGD can be used to select traits in a baby such as gender or other characteristics such as eye color, handedness, addictive behavior, nutritional background, and athleticism (Simmons). According to the aforementioned survey, 42% of PGD clinics have provided services for sex selection (Baruch). However, ethical dilemmas have been brought up over these non-medical issues. Allowing parents to select the sex of their child could create large gender imbalances, especially in certain cultural contexts, a phenomenon which has historically happened in countries such as China and India. Yet, it has been less controversial to allow parents to select the gender of their baby when they already have a number of children in the opposite gender. Another positive argument for sex selection says that it prevents potential abortions. This has been reported in Bombay, where IVF clinics have used PGD to allow couples who first child is female to ensure that their next child is male, due to the cultural importance of having a male heir (Robertson). Thus in certain contexts using sex selection has more justification. However, usage of PGD for other cosmetic traits has brought up other concerns. Some people fear that they are playing God, and proponents of PGD for medical purposes have called it a corruption to use the technology to test for cosmetic characteristics (Abraham). Allen Goldberg, who attempted to save his son Henry via PGD to create a donor child, writes What I now fear,

5 Gonda, Liu 4 though, is that clinics offering trait selection to satisfy the whims of parents will turn people against a procedure that can save lives (Goldberg). Clearly, the use of PGD brings up a wide range of possibilities for the future of human society, and immediate consequences in the present as well. As mentioned earlier, defective embryos are discarded as an accepted procedure of PGD, and in addition to the previously mentioned issue about the stigma against disabled people, other notable ethical dilemmas follow. For instance, some religions believe that life begins after fertilization, and so discarding these embryos would be abhorrent, just as abortion is abhorrent according to these religions. Supporters of PGD, however, point out that embryos are early enough in the development stage to not have interests and rights, but also state that PGD is only morally acceptable when preventing serious genetic diseases (Robertson). It is worth noting that PGD is not a perfect procedure, since it involves taking out one or two cells from a total of 8 from the embryo, creating concerns that the embryo may not fully develop all biological parts correctly. However, since the technology is so young, there is currently no substantial data to support or refute this theory (Agar). The clearest positive argument for PGD is its usage to prevent disease. Parents do not have to worry about passing a particular disease onto their children. One of the most common uses is to test for Huntington s Disease. Allowing parents to use PGD will prevent them from having to worry about their child inheriting Huntington s, essentially improving their quality of life. This also prevents potential abortions if Huntington s is positively tested for during pregnancies (Lahiri). Allowing PGD would prevent parents from passing on genetic diseases, and thus relieving a great deal of emotional stress for the parents, but also would safeguard children from having to live with a crippling or painful disease. On top of that, PGD could

6 Gonda, Liu 5 potentially also alleviate financial burdens, as parents would potentially not have to pay for treatments for genetic diseases (Baird). Such diseases could essentially be eliminated from the family line. The implications of picking and choosing traits of children come up quite often in various debates surrounding PGD and genetic engineering in general. There are several theories about what will happen in a society that is able to choose the traits of their offspring. Several sources point to PGD being quite similar to eugenics, a practice infamously employed by the Nazis in a misguided attempt to improve the human race by encouraging those they deem their betters to reproduce and killing those who they deem are not (Parry). Social stratification is also a major issue in the realm of possibilities, both in financial and human relationship aspects of society. PGD procedures are costly, as evidenced by the need for a 7,000 grant as mentioned in the case of detecting neurofibromatosis. Thus, while it was mentioned earlier that there is a financial benefit in the long run for having a healthy baby as opposed to a child that would consistently need medical care, the upfront cost may just offset that benefit. Indeed, because of this large cost, only families who are wealthy and have enough resources and connections can afford to undergo this procedure. Alsamarai asks the poignant question of whether genetic diseases would eventually become a mark of the economically underprivileged, and that children will then be cherished more for their genotype than their intrinsic value (Alsamarai). Another concern is the stratification of human society itself. A new type of super humans might arise from the wealthy, and this may lead to these super humans getting better medical treatment and better social status who would look down upon the class of humans who have not been genetically enhanced, much like the novel Brave New World (Han). Worse, Ronald Green in his article, Building Baby From the Genes Up, mentions the question

7 Gonda, Liu 6 of whether we would actually split off into two races and not even breed with each other. Green is widely quoted as a proponent of PGD and human genetic engineering in general. He concedes that, yes, the social implications of genetic overlords is worrisome, but counters that rather than increasing class divisions, the technology might even reduce it because every child might one day never have to risk being born with certain genetic diseases, like a genetic vaccination against dyslexia, for instance (Green). A final major concern with PGD is that continuously using the selection process to remove undesirable traits could potentially, in the long run, cause a loss of diversity in the human gene pool (Naik). This could expose the entirety of the human race to unintended side effects, although the true effects and results of this are very speculative (Boyle). Genetic diversity is certainly related to adaptability and survival for example, disease susceptibility may increase (Wolfe). It has been shown in other species that having higher levels of diversity led to higher chances of survival. Honeybee colonies, in a study from North Carolina State University, have been observed and recorded to have a much higher rate of survival when there was a much greater deal of genetic variation in the colony (ScienceDaily). On the other hand, a variety of Australian marsupials, including the black-footed rock wallaby and the northern hairy-nosed wombat, were endangered due to their lack of genetic diversity. This lack of diversity meant a limited ability to adapt to environmental factors, as well as an inadequate ability to combat certain diseases (Furlan). Thus, PGD could potentially have disastrous long term effects on the human gene pool and our survivability as a species. However, Green contends that the human genome is not a perfect finished product, and that we should be open to exploring all possibilities regarding its development (Green).

8 Gonda, Liu 7 The advent of PGD has certainly been a momentous advance in medical science. And as with all major innovations, there are risks and consequences associated with it. Though it is mostly used for prevention of early or mid pregnancy termination, it is increasingly being used to prevent certain genetic diseases and perhaps even select traits that are not medically necessary. The technical process to execute PGD is also far from perfect, resulting in many discarded embryos and possibly even malformations in the body that are yet undetectable because of its nascent stage of development. Nevertheless, numerous families have been benefitted by PGD, resulting in healthy babies who do not have to worry about the future of their health, and families who can be rest assured that not only will their child have a high chance of not contracting a specific genetic disease, that particular disease in their lineage will not be passed on, at least not through this one child. Some people insist on using the technology to enhance the cosmetic traits of their babies, or even negatively enhance them, and these lead to a discussion about the dangerous slippery slope society could tumble into. The fact that the procedure is extremely costly would, perhaps only initially or maybe even permanently, lead to the wealthy exclusively taking advantage of the technology and increasing social divides. Proponent like Green would like to allay these fears however, stating that human compassion would always triumph, and that this technology might even narrow the gap between classes because of the tremendous medical advantages PGD confers. Finally, there is a speculative fear about emptying the human gene pool of its rich diversity, thus putting our survivability as a species at risk. All of these advantages, present and future concerns merit further debate and research into each issue, and while the technology will inevitably advance, a continued discussion must persist in order to provide a modicum of security for the lives that are at stake.

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