Human Genome Editing Science, Ethics, and Governance (2017) / Chapter Skim
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6 Enhancement
6 Enhancement
Pages 137-162
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From page 137... ...
Genome editing is playing an increasing part in somatic gene therapy to treat and prevent disease (see Chapter 4)
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From page 138... ...
The chapter ends with conclusions and recommendations. HUMAN GENETIC VARIATION AND DEFINING "NORMAL" AND "NATURAL" Before beginning to discuss so-called enhancement, it is important to explore how terminology related to human gene therapy and genome editing has the potential to bias judgments unconsciously.
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From page 139... ...
in the human gene pool but has some property that could be viewed as an "enhancement" since it is predicted to have a beneficial effect. Such a change is a more radical step than that of replacing a disease-causing variant with a common human variant known not to cause disease.
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From page 140... ...
Although surveys indicate significant support for gene therapy and genetic engineering to improve the health of both existing individuals and unborn children (see Table 6-1) , the possibility of "enhancement" in new and potentially more wide-ranging ways can engender anxiety as well as TABLE 6-1 Summary of Public Attitudes Toward Aspects of Gene Therapy or Genome Editing as Revealed by a Selection of Surveys Percent Question Poll (Year)
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From page 141... ...
59 to change their own genes to prevent their children from having a genetic disease Approve of scientists changing the March of Dimes-Harris 84 makeup of human cells to stop (1992) children from inheriting a usually fatal OTA-Harris (1986)
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From page 142... ...
11 improve their intelligence or physical characteristics should be legal Changing a baby's genetic characteristics Pew (2014) 15 to make the baby more intelligent is an appropriate use of medical advances If future science developed the ability ABC (1990)
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From page 143... ...
In 2016, a Pew study of surveys of more than 4,000 individuals revealed that anxiety outpaced enthusiasm not only for enhancement through somatic genome editing, but also for mechanical and transplantrelated enhancement (Pew Research Center, 2016)
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From page 144... ...
"Status quo bias" is a phenomenon in which the preference for what is familiar can affect the way people form judgments about the merits of an innovation. The predisposition toward the status quo may arise from concerns about transition costs (i.e., how people adapt to the circumstances arising from an innovation)
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From page 145... ...
To reduce the risk of breast cancer in a person of average health and with nondeleterious variants, for example, is not to cure a disease or even to prevent one that is likely to occur, but this boosted resistance is often viewed as therapeutic prevention, akin to immunization against infectious diseases. A similar point pertains with respect to reducing cholesterol in persons at no more than average risk for heart disease; this is already a widespread practice in American society, and statins and aspirin are widely used to enhance resistance to heart disease pharmacologically even for those not at high risk.
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From page 146... ...
. In 1991, as the first three somatic gene therapy trials were under way, the chair of the Human Gene Therapy Subcommit tee of NIH's Recombinant DNA Advisory Committee (RAC)
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From page 147... ...
Government-supported research also has been conducted in many countries to advance the fields of gene therapy and regenerative medicine and, more recently, human genome editing to modify the DNA in the bloodforming cells of patients with sickle-cell disease and other blood disorders and some forms of cancer. These precedents, and many others like them, have built robust scientific, regulatory, and ethical oversight structures (see Chapter 4)
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From page 148... ...
The discovery of variants that simply increase the odds of developing a disease and others that are associated with diseases whose onset is in later life also has blurred the previously bright line demarcating "disease." Early ethical debate built on language used by the pioneers in human genetics, who referred to "inborn errors," noting that most traits targeted for modification were called "errors," as in mistakes from what was supposed to be. The greatest challenge for the normality standard came from some researchers considering what might best be called enhancements for the purpose of relieving disease.
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From page 149... ...
Externally induced changes that offer more significant or unusual advantages, such as those providing greater muscle mass or more acute vision or obviating the need for sleep, raise questions about the authenticity of the resulting capacity and whether the individual newly endowed with these capabilities is somehow diminished by having failed to earn them. Yet people are born with unearned varying capacities, some markedly superior to the norm, which raises the question of whether and when an advantage becomes "unfair." This is a difficult question to answer precisely because of the highly uneven distribution of abilities in the human population.
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From page 150... ...
Of course, somatic or germline genome editing for enhancement is very unlikely to be the most profound source of inequality in any setting. But those most uncomfortable with using genome editing for enhancement will likely still be concerned regardless of the size of its contribution.
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From page 151... ...
In the United States, governance of enhancement applications of genome editing would fall, as with other gene therapy, to the FDA, the Recombinant DNA Advisory Committee (RAC) , institutional biosafety committees (IBCs)
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From page 152... ...
In addition, the FDA has some authority to restrict off-label uses -- for example, through requirements for special patient testing or adverse event reporting -- and the U.S. Congress can pass legislation to specifically prohibit certain uses, as has been the case for human growth hormone (see Box 6-2)
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From page 153... ...
This disquiet is influenced not only by the concerns outlined above with respect to somatic genome editing but also by the long and troubling history of eugenics, a history that included coercive measures and even genocide. This history is replete with dogma that creates hierarchies of human quality based on race, religion, national origin, and economic status, and it demonstrates how scientific concepts, such as natural selection, and public welfare measures, such as public hygiene, can be subverted for purposes of cruel and destructive social policies.
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From page 154... ...
Three generations of imbeciles are enough."3 Eugenics programs were part of progressive social reforms and were thought to uplift the population by improving genetic qualities (Lombardo, 2008)
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From page 155... ...
It was impossible to imagine somatic enhancements when somatic therapy was not yet successful, so any claim of a somatic enhancement would have been considered too risky, with very little benefit. Similarly, if early attempts at modifying somatic cells through viral vectors were successful in only a small number of the cells, how could sperm, eggs, or zygotes be changed?
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From page 156... ...
. The report established a framework of risks and benefits and the rights of individuals that would serve as a framework for government regulation of this new science, such as through the human gene therapy subcommittee of the RAC.
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From page 157... ...
society viewed germline genetic modification through this particular ethical lens. The concern of the Bush-era commission that germline enhancement might encourage people to view children as something to be designed and manipulated has long been a concern of some social scientists and humanists.
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From page 158... ...
It encompasses not only the concerns raised about germline editing in general, as described in Chapter 5, but also concerns about altering how children are viewed and about creating or increasing social inequities in a multigenerational fashion as a result of the heritability of the enhancement. Even where the benefits of an individual enhancement might be regarded as justification for an individual intervention, these analyses often feature a concern about the slippery slope and an echo of eugenics movements of the past.
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From page 159... ...
Given that human germline genome editing has not yet been tested clinically for therapeutic or preventive purposes, it appears clear that germline genome editing for purposes of enhancement -- that is, not clearly intended to cure or combat disease and disability -- is very unlikely at this time to meet the standard of possible benefit and tolerable risk as required to initiate clinical trials. Even as risks recede with greater experience and information, truly discretionary and elective germline edits would be unlikely to have benefits outweighing even minor health risks.
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From page 160... ...
The risks and possible benefits of hGH administration were uncertain in the 1980s and 1990s, and the drug was approved only for severe cases of growth hormone deficiency in children. But over time growth hormone therapy was shown to be reasonably safe and effective for patients who had low levels of the hor mone in their blood or who experienced severely stunted growth despite normal levels of the hormone; studies showed it bringing children up to the 10th to 25th percentile, depending on dosage and timing of treatment (Allen and Cuttler, 2013; Maiorana and Cianfarani, 2009)
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From page 161... ...
Prohibited distribution of human growth hormone ( 1) Except as provided in paragraph (2)
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