Supplementary evidence from the Department
of Health following the evidence session on 28 February 2007
RE: SCIENCE AND TECHNOLOGY COMMITTEE INQUIRY
INTO GOVERNMENT PROPOSALS ON THE REGULATION OF HUMAN-ANIMAL CHIMERA
OR HYBRID EMBRYOS
1) POINTS RAISED
a) Definitions and terminology: i) what definitions
for human-animal chimera or hybrid embryos were used in drawing
up the Government proposals; and ii) what sources of information
underpinned the definitions used by Caroline Flint MP when describing
the terminology used in drafting the Government proposals (as
referred to in question 269 of the session transcript)
In the context of the Human Fertilisation and
Embryology Act 1990, the terms "hybrid" and "chimera"
both appear in the 1987 white paper Human Fertilisation and Embryology:
A Framework for Legislation. The former term is there used to
describe the product of trans-species fertilisation, and follows
the earlier report of the Warnock Committee of Inquiry in proposing
that penetration of a hamster egg by human sperm should be permissible
under licence for testing the capacity of human sperm in fertility
treatment, provided that the product is destroyed at the two-cell
stage. (Accordingly, other mixing of human and animal gametes
is banned by the 1990 Act). The term "chimera" is used
in reference to "procedures involving the fusion of cells
of a human embryo with cells of the embryo of another species".
Embryos created by the mixing of animal eggs
with other human cells [ie other than gametes] are described in
the 2000 report from the Chief Medical Officer's expert group
on stem cell research as "hybrids".
Usage of the terms "hybrid" and "chimera"
in the Government's 2006 White Paper built on those earlier uses.
Further, the Government's proposals were drawn up following consultation
in the context of the 2005 report from the Science and Technology
Committee, Human Reproductive Technologies and the Law. As you
will be aware, the Committee, in making recommendations under
the heading "Chimeras and hybrids", had employed the
definitions found in the Canadian Assisted Human Reproduction
Act 2004. Those
definitions share several points of commonality with legislation
from other Commonwealth countries.
In response to question 269 on 28 February,
the descriptor "human" was added in order to distinguish
hybrids and chimeras that may be considered, if there were imagined
to be a spectrum of such entities running from a fully human to
a fully animal embryo, to be closer to the former end of that
spectrum, and therefore arguably more appropriately within the
purview of an Authority primarily dealing with human fertilisation
and embryology, as opposed to regulation under legislation relating
to animals in scientific procedures. The term "cybrid"
(or cytoplasmic hybrid) was used following the usage of that term
by a range of earlier witnesses including the Government's Chief
Scientific Advisor, Sir David King.
b) A breakdown of responses to the Department
of Health 2005 public consultation on review of the Human Fertilisation
and Embryology Act 1990 to indicate (i) what proportion of responses
came from the scientific community (as referred to in question
297 of the session transcript); and ii) how many of the respondents
opposed to the creation of human-animal chimera or hybrid embryos
for research were also against use of human embryos for research
purposes (as referred to in questions 298-299 of the session transcript)
Whereas respondents to the Department of Health's
consultation were not asked to identify themselves as "scientists"
or otherwise, the Committee may wish to note that responses were
received from the following bodies, expressing a range of views
in relation to human-animal chimera and hybrid embryos:
The Academy of Medical Sciences.
The Medical Research Council.
The Economic and Social Research
The Wellcome Trust/Cancer Research
UK Gurdon Institute.
East of England Stem Cell Network.
Cambridge Genetics Knowledge Park
Public Health Genetics Unit.
University of Newcastle.
The BioIndustry Association.
Of 336 responses that specifically addressed
the question, 277 were opposed to the creation of human-animal
chimera and hybrid embryos. The consultation document did not
seek views on embryo research per se, as the Government had made
clear its intention not to propose changes to the fundamental
aspects of the current law, including the permissibility of embryo
research. However, 227 of the respondents opposed to hybrids and
chimeras also stated opposition to embryo research, or such opposition
may reasonably be inferred.
2) THE COMMITTEE
a) Whether the Department has consulted scientists
who are specifically against allowing the creation of human-animal
chimera or hybrid embryos for research purposes?
A number of responses to the Department's consultation
were received from the scientific community, as indicated above.
These express a range of views about the potential value for research
of different types of creation or entity combining human and animal
genetic material. The full text of the responses is available
on the Department of Health's website.
b) Whether recent moves by the HFEA to allow
stem cell researchers to recruit egg donors have influenced the
Government's proposal; and if so, how?
No. However it is clear that egg donation is
part of a wider issue of the availability, procurement and use
of eggs for (human) embryo research, whilst also raising a number
of distinct ethical issues.
c) Whether the Government has assessed the
potential impact upon medical research of the proposed ban for
the creation of human-animal chimera or hybrid embryos for research
upon medical research (for example, in development of cell-based
therapies for treatment of disease); and if so, how?
d) How the Government aims to balance scientific
development with ethical and moral concerns in an area such as
If I may respond to the related points in (c)
and (d) together, the Government's White Paper set out our principal
aims in proposing revisions to the existing legal and regulatory
framework. These are:
to ensure that legitimate medical
and scientific applications of human reproductive technologies
can continue to flourish,
to promote public confidence in the
development and use of human reproductive technologies through
effective regulatory controls applicable to them, and
to secure that regulatory controls
accord with better regulation principles and encourage best regulatory
The Government has made clear its support for
legitimate medical research that promises advances in knowledge
about, and treatment of diseases and disorders, including through
embryonic stem cell research. This remains our position, and we
believe it is the sum effect of the policy proposals contained
in the White Paper. Those proposals will be subject to democratic
scrutiny via the Parliamentary process including pre-legislative
We have also made clear, throughout the current
review of the law, that we believe its foundations remain sound.
In its simplest terms, this model comprises boundaries set by
Parliament together with active monitoring and regulation by an
independent statutory body. We believe that this model remains
appropriate and effective, and is conducive to achieving the aims
set out above.
With regard to the potential impact of the White
Paper proposal on hybrid and chimera embryos, it must be pointed
out first and foremost that the proposal is not for an absolute
ban without possibility of exceptions, but is conjoined with a
proposed secondary legislative power, to be exercised via regulations
with the approval of Parliament, to allow such creations for research
under licence. At present the law is not sufficiently clear on
this matter, other than to ban the mixing of human and animal
Further, the Government's expressed position
prior to the current review, in response to the Chief Medical
Officer's Expert Group report, was for a total ban on the mixing
of human adult cells with the live eggs of any animal species,
without the possibility of exceptions. Moreover the Government
had echoed the Expert Group's call to bodies funding research
to make clear that they would not fund or support such research.
it can be seen that, as a result of the current review, the Government
is proposing to build more flexibility into the law, not less,
and putting the matter to Parliament for scrutiny and decision.
In addition, we welcome the move by Research
Councils UK to stimulate public engagement and debate on the future
of stem cell research. The Government believes that open, constructive
and informed dialogue on key scientific challenges is an important
part of its approach to science and looks forward to seeing the
outcomes of the debate.
e) Which areas of research requiring the
creation of entities falling within the overarching heading of
"human-animal chimera or hybrid embryos" would the Government
like to see permitted? It would be helpful if this could be presented
in the form of a list of the range of creations falling within
this terminology, with an indication of which of these creations
the Government believes should be permitted or prohibited for
The Government has made its proposals for revised
legislation, including in relation to human-animal chimera and
hybrid embryos, as described above. As mentioned in response to
question 2(a) above, we are aware of a variety of views from the
scientific community about which creations or entities may be
of potential value in research, and there will be a number of
further opportunities for stakeholders to make their views known
as the proposed legislation progresses through scrutiny and pre-legislative
scrutiny. Outside of the Parliamentary process we are aware of,
as an example, the working group set up under the aegis of the
Academy of Medical Sciences to consider research opportunities
and appropriate terminology.
In terms of the scope of the Government's proposals,
drafting of the relevant Bill is underway, and, whilst the following
list is not necessarily exhaustive, we expect the revised legislation
mixing of human and non-human gametes;
embryos resulting from combination
of haploid sets of human and animal chromosomes;
embryos created by placing a human
cell or cell nucleus in an enucleated animal egg;
fusing of a human embryo with animal
creation of a "transgenic"
human embryo (eg by addition of a non-human gene or genes).
The scope of the legislation will not, however,
extend to entities which fall to be considered by the regulatory
controls relating to animals in scientific procedures, overseen
by the Home Office. For example, the revised legislation will
not apply to transgenic mice such as those currently used in the
study of Down's Syndrome.
We look forward to receiving the Committee's
78 Cm 259. See paragraphs 39-42. Back
Stem Cell Research: Medical Progress with Responsibility,
Department of Health, June 2000. See page 47, recommendation 6. Back
HC 7-1. See pages 31-32. "Chimera", in Canadian law,
also refers to an embryo consisting of the cells of more than
one human being, embryo or foetus. Back
Government response to the recommendations made in the Chief
Medical Officer's Expert Group Report "Stem Cell Research:
Medical Progress with Responsibility". Cm 4833, August 2000. Back