Embryo editing to make babies would be 'irresponsible,' says DNA summit statement - It would currently be “irresponsible” to use new DNA editing tools to
alter the genomes of human embryos, eggs, or sperm in order to produce a
baby, the organizing committee of an international summit on the issue concluded today in a statement.
But the group did not rule out such embryo editing later, if safety
questions are resolved and society develops a consensus on ethical and
legal issues. And the group said basic, preclinical research involving
human embryos, sperm, and eggs should continue. It did not endorse any
kind of ban or moratorium on such research.
The statement - which differs little from similar previous statements
from prominent groups - came after 3 days of intense discussion among
scientists, government officials, science policy experts, philosophers,
and others in Washington, D.C. The unusual gathering, sponsored by U.S.,
U.K., and Chinese scientific societies, explored the promise and perils
of new methods to alter human DNA, focusing considerable debate on the
prospect for altering the genomes of eggs, sperm, or embryos. This
so-called germline engineering is seen by many as crossing a line,
because it bestows permanent genetic changes on a new individual and any
offspring they may have. Yet there are circumstances in which such DNA
editing could prevent the transmission of genetic diseases, so some
advocate it shouldn't be banned, as it is in many countries.
Here is the complete statement from the organizing committee, which was led by David Baltimore of the California Institute of Technology in Pasadena:
On Human Gene Editing: International Summit Statement
Scientific advances in molecular biology over the past 50 years have
produced remarkable progress in medicine. Some of these advances have
also raised important ethical and societal issues - for example, about
the use of recombinant DNA technologies or embryonic stem cells. The
scientific community has consistently recognized its responsibility to
identify and confront these issues. In these cases, engagement by a
range of stakeholders has led to solutions that have made it possible to
obtain major benefits for human health while appropriately addressing
societal issues.
Fundamental research into the ways by which bacteria defend
themselves against viruses has recently led to the development of
powerful new techniques that make it possible to perform gene editing -
that is, precisely altering genetic sequences - in living cells,
including those of humans, at much higher accuracy and efficiency than
ever before possible. These techniques are already in broad use in
biomedical research. They may also enable wide-ranging clinical
applications in medicine. At the same time, the prospect of human genome
editing raises many important scientific, ethical, and societal
questions.
After three days of thoughtful discussion of these issues, the
members of the Organizing Committee for the International Summit on
Human Gene Editing have reached the following conclusions:
1. Basic and Preclinical Research. Intensive basic
and preclinical research is clearly needed and should proceed, subject
to appropriate legal and ethical rules and oversight, on (i)
technologies for editing genetic sequences in human cells, (ii) the
potential benefits and risks of proposed clinical uses, and (iii)
understanding the biology of human embryos and germline cells. If, in
the process of research, early human embryos or germline cells undergo
gene editing, the modified cells should not be used to establish a
pregnancy.
2. Clinical Use: Somatic. Many promising and
valuable clinical applications of gene editing are directed at altering
genetic sequences only in somatic cells – that is, cells whose genomes
are not transmitted to the next generation. Examples that have been
proposed include editing genes for sickle-cell anemia in blood cells or
for improving the ability of immune cells to target cancer. There is a
need to understand the risks, such as inaccurate editing, and the
potential benefits of each proposed genetic modification. Because
proposed clinical uses are intended to affect only the individual who
receives them, they can be appropriately and rigorously evaluated within
existing and evolving regulatory frameworks for gene therapy, and
regulators can weigh risks and potential benefits in approving clinical
trials and therapies.
3. Clinical Use: Germline. Gene editing might also
be used, in principle, to make genetic alterations in gametes or
embryos, which will be carried by all of the cells of a resulting child
and will be passed on to subsequent generations as part of the human
gene pool. Examples that have been proposed range from avoidance of
severe inherited diseases to ‘enhancement’ of human capabilities. Such
modifications of human genomes might include the introduction of
naturally occurring variants or totally novel genetic changes thought to
be beneficial.
Germline editing poses many important issues, including: (i) the
risks of inaccurate editing (such as off-target mutations) and
incomplete editing of the cells of early-stage embryos (mosaicism); (ii)
the difficulty of predicting harmful effects that genetic changes may
have under the wide range of circumstances experienced by the human
population, including interactions with other genetic variants and with
the environment; (iii) the obligation to consider implications for both
the individual and the future generations who will carry the genetic
alterations; (iv) the fact that, once introduced into the human
population, genetic alterations would be difficult to remove and would
not remain within any single community or country; (v) the possibility
that permanent genetic ‘enhancements’ to subsets of the population could
exacerbate social inequities or be used coercively; and (vi) the moral
and ethical considerations in purposefully altering human evolution
using this technology.
It would be irresponsible to proceed with any clinical use of
germline editing unless and until (i) the relevant safety and efficacy
issues have been resolved, based on appropriate understanding and
balancing of risks, potential benefits, and alternatives, and (ii) there
is broad societal consensus about the appropriateness of the proposed
application. Moreover, any clinical use should proceed only under
appropriate regulatory oversight. At present, these criteria have not
been met for any proposed clinical use: the safety issues have not yet
been adequately explored; the cases of most compelling benefit are
limited; and many nations have legislative or regulatory bans on
germline modification. However, as scientific knowledge advances and
societal views evolve, the clinical use of germline editing should be
revisited on a regular basis.
4. Need for an Ongoing Forum. While each nation
ultimately has the authority to regulate activities under its
jurisdiction, the human genome is shared among all nations. The
international community should strive to establish norms concerning
acceptable uses of human germline editing and to harmonize regulations,
in order to discourage unacceptable activities while advancing human
health and welfare.
We therefore call upon the national academies that co-hosted the
summit - the U.S. National Academy of Sciences and U.S. National Academy
of Medicine; the Royal Society; and the Chinese Academy of Sciences -
to take the lead in creating an ongoing international forum to discuss
potential clinical uses of gene editing; help inform decisions by
national policymakers and others; formulate recommendations and
guidelines; and promote coordination among nations.
The forum should be inclusive among nations and engage a wide range
of perspectives and expertise - including from biomedical scientists,
social scientists, ethicists, health care providers, patients and their
families, people with disabilities, policymakers, regulators, research
funders, faith leaders, public interest advocates, industry
representatives, and members of the general public. Source: Sciencemag
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