Select Committee on Science and Technology Written Evidence

Memorandum 68

Supplementary evidence from the Department of Health following the evidence session on 28 February 2007



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".[78]

  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".[79]

  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. [80]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 Royal Society.

    —  The Academy of Medical Sciences.

    —  The Medical Research Council.

    —  The Economic and Social Research Council.

    —  The Wellcome Trust.

    —  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.


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 this?

  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 practice.

  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 scrutiny.

  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 gametes.

  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. [81]Therefore 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 research purposes

  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 to cover:

    —  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 cells; and

    —  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 recommendations.

March 2007

78   Cm 259. See paragraphs 39-42. Back

79   Stem Cell Research: Medical Progress with Responsibility, Department of Health, June 2000. See page 47, recommendation 6. Back

80   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

81   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

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