Last modified on 11 December 2013, at 20:49

Lentis/Gattaca Revisited

OverviewEdit

And keep in mind, this child is still you, simply the best of you. You could conceive naturally a thousand times and never get such a result.

--Gattaca

Eugenics is the practice of attempting to "improve" the quality of genes within a population. Possible goals include reducing risk for various disorders, increasing intelligence, or boosting physical prowess. One way to achieve eugenics is through the related techniques of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS), in which embryos from in vitro fertilization are tested for certain characteristics before implantation into the uterus.[1] This allows the parent(s) and physician to choose an embryo for implantation that is (likely) free from certain genetic or genomic disorders, but can also allow for choice based on other genetic characteristics.

Andrew Niccol's 1997 film Gattaca explored a world in which a complete, probabilistic genetic analysis could be performed near-instantaneously, on any human genetic material. Niccol predicts a societal expectation that parents with sufficient means would with conceive with the aid of PGD, and widespread discrimination arising against individuals who have further-from-perfect genomes as a result of natural conception.

State of the art in choosing traits in babiesEdit

Preimplantation genetic diagnosis (PGD) is a way to screen embryos for genetic traits. First, embryos are created through the process of in vitro fertilization (IVF). A number of egg and a sperm samples are collected from the mother and father. After fertilizing the collected eggs, they are allowed to mature into embryos over the course of several days.[2] At that point, the embryos can be biopsied (by removing single cells), and the samples passed through genetic screening to see what traits and disorders are present or likely to develop. The most desirable embryo can then be selected and implanted back into the mother.[1] PGD informs a choice of which embryo to use for implantation; it does not introduce any new traits into the combined gene pool of the parents. Additionally, PGD does not provide perfect diagnoses or predictions; even for traits for which screening is possible, screening may only indicate an increased likelihood of disease, as with the BRCA-1 gene mentioned in [1].

23andMe logo

By contrast, virus vectors have been proposed as a method of selectively modifying a genome. Virus vectors are human-engineered viruses that change the genetic material in infected cells.[3] This allows for more directed changes, beyond simply choosing among naturally occurring choices. However, virus vectors are more difficult to use and present risk to the patient; as such, their use is still experimental.[4] This article focuses on the currently better-developed technique of PGD.

PGD is able to screen many known genetic disorders; it can also be used to improve the success rate of the IVF process by selecting embryos without chromosomal abnormalities (aneuploidy).[5] However, such analyses do not always imply that an individual developed from the embryo would exhibit the characteristics associated with the disorder. In addition, PGD can be used to select traits that don't have clear medical value. For example, 23andMe has patented technology to match sperm and egg to bring about specific traits, such as sex, weight, height, eye color, and athleticism, though the reliability of this kind of analysis is not yet well-established.[6]


Current usage of PGDEdit

PGD was originally used in the 1980s to screen embryos for deadly diseases.[1] Physicians were able to select against cystic fibrosis (CF) by detecting the most common mutation linked to CF before implanting the embryo.[7] Preimplantation genetic screening allows physicians to choose haploid embryos (those with 23 pairs of chromosomes) for implantation, which are more likely to be viable.[1] PGD has also been used medically for sex selection, as certain genetic disorders are linked to the X or Y chromosomes.[7] The use of PGD has expanded over the decades: it is now used to screen for the risk of adult onset diseases such as heart disease, match so-called "savior siblings" who can provide umbilical cord fluid to a sibling with lymphoma, allow for elective rather than medical sex selection, and select for a much wider range of characteristics. These characteristics have become increasingly "exotic" and now include things such as deafness or dwarfism.[8]

There are several barriers to the use of PGD. First, PGD requires embryos to be created in vitro, which can cause complications. Complications of IVF include multiple births, premature delivery, low birth weight, miscarriage, and ectopic pregnancy.[9] PGD is expensive: a single round of IVF treatment costs around $9,000, and PGD adds $4,000 to $7,500 to the cost. This is compounded by the fact that each round of IVF only has 10-35% chance of success[10], meaning that a patient may need to pay for several rounds. Ultimately, this costly treatment results only in the child having a probability of having certain traits or not having a disorder.

Finally, there are ethical concerns about the use of PGD. Groups such as Humans Genetics Alert advocate against the use of PGD, except to prevent fatal disorders, claiming that it leads to discrimination against people with different traits. For example, they assert that people with disabilities ought not to be seen as second-class, and selecting for the lack of a disability promotes this discriminatory view.[11] The American Society for Reproductive Medicine's ethics committee has declared sex selection to be unacceptable for non-medical reasons, also citing the encouragement of discrimination.[12] Similarly, a clinic offering sex and trait selection was condemned by the Vatican.[13]

Despite these technological shortcomings and ethical concerns, PGD is commonly used as a reproductive technology. About 1% of the approximately four million annual US births are through in vitro fertilization, and PGD is recommended for use in about half of these cases.[14] The number of recommendations does not translate directly to the usage--some parents may ignore the recommendation, and others may elect to use PGD without the need from family history. Still, this gives the approximation that .05% of US births involve PGD. In a survey by Johns Hopkins Genetics and Public Policy Center, 74% of IVF clinics reported offering PGD services;[14] given a total of the 451 IVF clinics in the US,[15], there are, on average, 7 PGD clinics in each state.

Medical technology: made for health, used for lifestyleEdit

Walter Yeo, before and after the first plastic surgery

PGD exemplifies a common pattern in medical technology. Many technologies and treatments are created for strictly life-and-health-preserving purposes. However, after these technologies are established, their scope expands to include elective procedures, which are used for lifestyle choices independent of health. The following examples illustrate this trend.

Harold Gillies, known as the father of plastic surgery, performed the first plastic surgery in 1917 on Walter Yeo, a sailor who had his face badly burned in World War I.[16][17] Notably, Yeo's surgery restored his eyelids and generally reconstructed his face, helping him to function in society. Plastic surgery continued in this way for many years, primarily being used for reconstructive procedures with patients who suffered accidents.[18] Over time, however, cosmetic surgery became more popular: the American Society for Aesthetic Plastic Surgery reports 2 million cosmetic procedures in 1997, increasing to nearly 12 million in 2004.[19]

Another example is the combined oral contraceptive pill (colloquially known as "The Pill), commonly taken as birth control.[20] The pill was originally approved as the drug Enovid by the Food and Drug Administration (FDA) in 1957, to regulate the menstrual cycle and treat several menstrual disorders.[21] The drug was required by the FDA to warn users that taking it would prevent ovulation.[22] Enovid thus became popular for contraception, and was approved for that purpose by the FDA in 1960.[23] Its popularity rapidly increased. It is estimated that 50 to 80 million people regularly used the pill by 1984.[22]

These examples show that medical technologies evolve to include lifestyle uses when possible, and PGD illustrates this point further. As discussed above, PGD originated for avoiding deadly genetic disorders. One of these disorders that can be screened for is dwarfism. The most common gene causing dwarfism is dominant; when one parent passes along the gene, the resulting child will exhibit dwarfism. However, there is an extremely high mortality rate if the child inherits the dwarfism gene from both parents.[24] As such, parents carrying dwarfism can use PGD to avoid having a child with the fatal form of the disorder, but in some instances parents also ensure that the child still carry the dwarfism gene.[25][8] Deaf parents have taken similar practice to ensure that their children could smoothly integrate into the same Deaf community.[8] Thus, the use of PGD technology, originally developed for medical necessity, is already being used to ensure the presence what is normally considered a genetic defect. With the rapid advancing of genetic screening technology allowing for the screening of even more traits not related to disorders, this trend will continue towards the selection of appearance-related genetic traits.

Ethical concerns relating to PGDEdit

As mentioned above, there are several ethical concerns stemming from the use of PGD. Because PGD requires the use of IVF, the same ethical concerns apply--namely, that those who believe that life begins at conception feel that discarding embryos is murder. Another concern stems from using PGD in Human leukocyte antigen (HLA) matching, which can be used to treat a sibling with lymphoma. This can be seen as the "instrumentalization" of human life, where the donor child is simply a tool for the other child's survival. This view is found in popular culture, notably the novel My Sister's Keeper by Jodi Picoult. The cost of these reproductive technologies is prohibitively expensive to many people, which lends credence to the idea expressed in Gattaca that the wealth gap would be exacerbated by a genetic upper-class. Finally, the ethics of using PGD to select based on non-medical factors is questionable.[26]

Despite these ethical concerns, there is evidence that, through its common use, PGD is becoming more accepted. In 2008, George W. Bush signed the Genetic Information Nondiscrimination Act into law.[27] This law makes it illegal for genetic information to be used either in deciding employment or providing insurance, [28] intending to prevent a world like like that of Gattaca where one's life is determined based on their perceived genetic quality. While the law does not directly mention or regulate PGD, its passage shows an awareness of the potential for genetic discrimination. However, as the law does not ban genetic screening in any manner, its passage also reveals an acceptance that PGD and genetic screening technologies are here to stay- they are acceptable in some circumstances. The acceptance of PGD has come so far that even Germany legalized its use in 2011 for screening for certain genetic disorders, albeit under limited circumstances.[29] This is significant because of Germany's national sensitivity towards eugenics, as a rejection of the policies of the Nazi era. This change shows that, as the technology is used, it will continue to gain in social acceptance despite remaining ethical concerns.

ReferencesEdit

  1. a b c d e Molina B. Dayal, Preimplantation Genetic Diagnosis. November 4, 2013. [1].
  2. Mayo Clinic staff. In vitro fertilization (IVF). [2]
  3. J.N. Warnock, C. Daigre, M. Al-Rubeai. Introduction to viral vectors. [3]
  4. JT Auman. Gene therapy: Have the risks associated with viral vectors been solved. [4]
  5. International Working Group on Preimplantation Genetics. Preimplantation Genetic Diagnosis: experience of three thousand clinical cycles. May 15, 2001. Archived at [5]
  6. Dov Fox. 23andMe's designer baby patent. Huffington Post. October 4, 2013. [6]
  7. a b Alan Handyside, John Lesko, Juan Tarin, Robert Winston, and Mark Hughes. Birth of a Normal Girl after in Vitro Fertilization and Preimplantation Diagnostic Testing for Cystic Fibrosis. New England Journal of Medicine. September 24, 1992. [7]
  8. a b c Susannah Baruch. Preimplantation genetic diagnosis and parental preferences: beyond deadly disease. Houston Journal of Health Law & Policy. [8]
  9. Mayo Clinic staff. In vitro fertilization (IVF). Section "Risks": [9]
  10. Pre-implantation Genetic Diagnosis. Reproductive Health Technologies Project. [10]
  11. Human Genetics Alert. The regulation of pre-implantation genetic diagnosis. March 200. [11]
  12. The Ethics Committee of the American Society of Reproductive Medicine. Sex selection and preimplantaiton genetic diagnosis. [12]
  13. Jasmeet Sidhu. Gender selection has become a multimillion-dollar industry. Slate. [13]
  14. a b Phoebe Berman. Genetic testing of embryos: practices and perspectives of U.S. IVF clinics. Fertility and Sterility. September 2006. [14]
  15. Centers for Disease Control and Prevention. 2011 Assisted Reproductive Technology Fertility Clinic Success Rates Report. [15]
  16. Sheila Yeo. Walter Ernest O'Neil Yeo - One of the first people to undergo Plastic Surgery. [16]
  17. Hannah Furness. Pioneering plastic surgery records from First World War published. Telegraph. July 13, 2012. [17]
  18. American Society of Plastic Surgeons. History of plastic surgery. [18]
  19. American Society for Aesthetic Plastic Surgery. 2004 USA cosmetic surgery statistics. [19]
  20. Hayley Willacy. Combined Oral Contraceptive Pill. [20]
  21. Nicholas Bakalar. First mention: birth control pills, 1957. New York Times. [21]
  22. a b PBS. Timeline: The Pill. [22]
  23. Alexandra Nikolchev. A brief history of the birth control pill. Need to Know on PBS. [23]
  24. PBS. What is Dwarfism? 2005. [24]
  25. Darshak Sanghavi. Wanting Babies Like Themselves, Some Parents Choose Genetic Defects. New York Times. December 5, 2006. [25]
  26. Kevin B. O'Reilly. Testing embryos and ethics: where do we draw the line? American Medical News. February 26, 2007. [26]
  27. Brandon Keim. Genetic discrimination by insurers, employers becomes a crime. Wired. May 21, 2008. [27]
  28. US Equal Opportunity Employment Condition. The GEnetic Information Nondiscrimination Act of 2008. [28]
  29. Nishat Hyder. Germany allows PGD for life-threatening genetic defects. BioNews. July 11, 2011. [29]