March 29, 2024

NEJM debates repairing human germlines

How will the changes be monitored for generation after generation?

With the rapid advance in gene-editing technology, the time has come to consider how to ethical trials, according to an editorial in the New England Journal of Medicine. Bryan Cwik, a philosopher at Portland State University, in Oregon, zeroes in on some unprecedented difficulties in designing trials of modifying the human germline.

Cwik argues that “intergenerational monitoring” will be needed, not just of the first generation of modified children, but of their children and grandchildren. There could be subtle effects which emerge only after two or three generations. He points out that:

Monitoring for effects of gene editing will require consent and participation from multiple generations of descendants of the original participants. Studies will therefore require researchers to have access to key medical data for entire families over several decades.

But is this compatible with the autonomy of the research subjects? How can unborn grandchildren give consent to a lifetime of monitoring, with blood tests, physical examinations and collection of genetic material. Some descendants may not be aware that their forebears were genetically modified and notifying them may be socially and psychologically distressing. Cwik concludes:

… protection of the dignity, welfare, and privacy of research participants is of the utmost importance, and no amount of therapeutic potential can justify proceeding with human experiments until that protection is secured.

In another editorial in the same issue of the NEJM, Harvard stem cell scientist George Church jeers at such arguments.

… some critics fret about the slippery slope of human enhancement and the impossibility of obtaining consent from future generations. Doing nothing merely for fear of unknown risks is itself risky — greatly restricting the advance of medicine… We already embrace many enhancements inherited over multiple generations — generally without consulting future grandchildren — for example, education, homes, and extinction of pathogens through the use of vaccinations. The issue for many critics lies not in enhancement relative to our ancestors, but rather relative to one another.

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human germline modification