He says risks to genetic manipulation are considerable and uncontrollable
By Adelaide Mena
Photo: Liya Graphics / Shutterstock / CNA
Recent American guidelines for human gene modification have raised important ethical questions, especially with regard to modifying the genes of unborn children and of reproductive cells.
The National Academy of Sciences last week released a 261-page report on guidelines for editing the human genome to treat diseases and other applications. The report covers a wide array of topics, from the editing of adult cells for therapies such as cancer treatment, to the editing of embryos and germ cells (reproductive cells, i.e. ova and sperm), to the question of human enhancement.
John DiCamillo, an ethicist at the National Catholic Bioethics Center, spoke to CNA about the perils and promises of gene editing, as well as the oversights contained in the National Academy of Sciences report.
“Gene editing generally can be morally legitimate if it has a directly therapeutic purpose for a particular patient in question, and if we’re sure we’re going to limit whatever changes to this person,” DiCamillo explained.
In this regard, the report’s guidelines for laboratory treatment of somatic – or non-reproductive – cells and human trials of somatic cell treatments were reasonable, he noted.
DiCamillo pointed to upcoming clinical gene therapy trials for cancer and proposed gene therapy treatments for disorders such as sickle cell disease. However, it’s important to limit these trials to non-embryonic persons, to ensure that the modifications – intended as well as unintended – are not carried in the patient’s reproductive cells.
While this would mean that patients treated for inheritable diseases “could still transmit it to their children,” any children who then developed the disease could themselves be treated through the same process.
The question of transmission to descendents opens up two more points discussed in the National Academy of Sciences report: the modification of ova and sperm, as well as edits to the genomes of embryos. Both of these changes would mean that people would maintain these edits in all of their cells for all of their lives – and could pass on these edited genes to new generations.
“There could be limited situations that could exist where the germ line could be legitimately edited. In other words, making changes to sperm, to eggs, or to early embryos as a way of potentially addressing diseases – inheritable diseases and so forth,” DiCamillo stated.
However, permitting edits to germ line cells could also be “very dangerous on multiple levels,” he warned.
There are considerable, and not yet fully controllable, risks to genetic manipulation. A person conceived with edited genes could experience a range of “unintended, perhaps harmful, side effects that can now be transmitted, inherited by other individuals down the line.”
An embryo who experiences gene modification could also carry and pass on edited genes, particularly if edits were performed before his or her reproductive cells began to differentiate themselves.
The National Academy of Sciences regulations surrounding germ cells and embryos are also problematic for what they overlook, DiCamillo said.
Manipulating sperm and ova requires removing them from a person’s body; if conception is achieved with these cells, it is nearly always through in vitro methods. This practice of in vitro fertilization is held by the Church to be ethically unacceptable because it dissociates procreation from the integrally personal context of the conjugal act.
In addition, scientific researchers rarely differentiate between experimentation on sperm or ova – which are cells that come from a human subject – and embryos, which are distinct persons with their own distinct genomes, DiCamillo noted.
The National Academy of Sciences’ guidelines reflect this lack of distinction between cells and embryos. “That’s very misleading because embryos are not germ line cells; they are new human beings,” DiCamillo said.
For research on embryos to be ethical, therapies should be ordered to treating and benefitting “that particular embryo, not just for garnering scientific knowledge or seeing what’s going to happen.”
DiCamillo condemned policies that see destruction of embryonic persons as a back-up if research does not go as planned, as well as current policies that require destruction of embryos as standard procedure.
“We’d be in that area of very dangerous exploitation of human life and destruction of human life,” he warned.
While the guidelines stumble across ethical roadblocks in regards to gamete and embryo research, the new report’s rules regarding human enhancement are strong, DiCamillo said.
The ability to edit genomes could be used for purposes other than medical treatment. A whole host of human traits could be enhanced or changed, such as vision, intelligence, or abilities. “There’s any number of things that we could do to change the qualities of human beings themselves and make them, in a sense, super-humans … this is something that would also be an ethical problem on the horizon,” he warned.
The existence of these gene-altering therapies raises a question of how much modification and enhancement is permissible. DiCamillo praised the report for its recommendation “entirely against enhancement efforts and that these should not be allowed.”
Currently, gene editing of both germ cells and somatic cells is legal in the United States, including on embryos. However, various U.S. government institutions have policies in place prohibiting federal funding of such research efforts on germ cells and on embryos.
Furthermore, Food and Drug Administration regulations prohibit gene modification on viable human embryos – meaning that human embryos who receive gene modification are always destroyed.
The new guidelines from the National Academy of Sciences are significant because they lay a groundwork for future policy on human gene modification. They cautiously welcome the use of gene therapy on human embryos who are not later targeted for destruction after experimentation concludes.
DiCamillo recalled, however, that “they are merely guidelines – they are advice from the National Academy of the Sciences to the government in regards to future policy. This is not itself a new regulation or policy that the government has established.”
The ethics of gene editing has been questioned for several years – the Congregation for the Doctrine of the Faith addressed the issue in Dignitas personae, its 2008 instruction on certain bioethical questions. It has become more pressing recently, however, because a new technique known as CRISPR is easier to use and less expensive than previous means of gene editing.
Although the ethical questions surrounding gene modification are many and there are a number of problematic applications of these technologies, DiCamillo cautioned Catholics not to renounce completely human gene modification: “We don’t want to be hyper-reactive to the dangers. We have to realize there’s a great deal of good that can be done here.”
He pointed again to the kinds of modifications that can treat deadly genetic diseases and treatments in an ethical manner, with full respect to the dignity of human persons.
“We do need to be attentive to where the dangers are,” he warned, “but we don’t want to … automatically consider any kind of gene editing to be automatically a problem.”