Science and Technology Committee - A new cell for an old egg

A new cell for an old egg

A 40-year-old woman had eggs harvested for IVF but the resulting embryos following IVF proved unsuccessful and the clinic offered the prospect in a subsequent cycle of IVF of extracting the nucleus of her eggs and inserting them into the enucleated eggs donated by a much younger woman. The new eggs (containing almost entirely DNA from the woman) would be fertilised using IVF in the usual manner.

Legal status: Illegal under the 1990 Human Fertilisation and Embryology Act.

Scientific status: Research on animals underway

Scenario 1: use of oocytoplasm of younger woman

posted 27/01/2004 - 14:57 by Richard Fleming

A variation of this procedure, the donation of some younger cytoplasm to older women's eggs has been attempted in the USA. The results were disappointing.
Disruption of the oocyte structure should be kept to a minimum in clinical cases (ICSI may be borderline) until other mammalian experiments have clearly demonstrated safety limits. Clinical cases should then proceed within a research and development framework.
A strict legal structure may have problems coping with this process, but that should be the aim for future legislation - to provide a safe framework for new development

Ethically defensible

posted 02/02/2004 - 14:35 by kjt

Once nuclear transfer has become a procedure that can safely be undertaken with human cells, there seems to be no ethical problem with this scenario. Even though nuclear transfer has so far been chiefly associated with cloning procedures, this would not be true in this case. Also, there is no concern over a possible disparity between biologic and social parenthood. The woman who intends to raise the child is the same woman who carries it to term and also the same woman who is responsible for half of the child's genome (minus a negligible amount of mitochondrial DNA from the donor egg). Further, there is no dilemma over a morally valuable entity having been discarded. Human eggs are generally not considered to have significant moral status.

Nuclear transfer

posted 11/02/2004 - 17:18 by johnmryder

I do not think the safety of this procedure could be ensured (nevermind how successful it is with animals) until a few human examples have matured to adulthood. And what then if problems were discovered?

safety

posted 12/02/2004 - 16:30 by robertsa

This raises an issue of how much we want set out in law and how much should be left to a regulatory authority.

You could argue that it is reasonable to legalise the procedure but leave it within the the jurisdiction of the HFEA. The Authority can then make judgements on the safety of the treatment and license it accordingly.

Dr Alun Roberts
Committee Specialist
Science and Technology Committee

Reproductive cloning universally condemned

posted 12/02/2004 - 21:12 by Fiona

This is reproductive cloning. The child will be a clone of the 40 year old woman.

Why is this not made clear in the question?

This process involves experimentation on at least two women (though in fact it is likely to need more because of the numbers of eggs involved since it took 278 eggs to clone Dolly the sheep). The fact that this involves experimentation on women is why pro-abortion feminists in the States are opposed to cloning. It also involves experimentation on the baby. Our knowledge of cloning means that it will lead to gross deformities and oversized vital organs, it will also endanger the life of the mother. The baby is likely to die soon after birth.

Quite apart from the dangers of the procedure, eminent philosophers have also pointed to why cloning is inherently wrong, however "safe", because part of our essential humanity is the fact that we are all unique personalities, and we haven't been forced to conform to a manufactured design. It also tampers with other features that are basic to our understanding of what it is to be human - for example, the 40 year old woman who mothers the child is also the clone. How can you have a mother who is also your sister?

This should remain illegal, and the creation of human clones should be banned as a safeguard to stop this happening.

This is not cloning

posted 03/03/2004 - 16:59 by jax

To correct Fiona, this will not result in a clone of the 40 year old woman, any more than normal IVF would. The resultant child will still be a result of recombinated DNA from the womans gametes, and sperm from the father. The main anomaly in terms of parenting will be the extra third party (mitochondrial) DNA contributed from the enucleated egg of the younger woman.

My main objection to this scenario is that there is a reason IVF is not working for this woman - SHE IS TOO OLD AND HER EGGS ARE TOO OLD. I do not see that resources should be spent on such technology, or that the NHS has a duty to provide IVF for such patients. Aging and going through the menopause is part of life - not an illness to be medically overcome - and people need to just get on with their lives.

Why are people so desperate to have their 'own' child, as if it's the be all and end all? Why are we developing such an obsessive attitude to childlessness and baby-making in this country? Why isn't adoption made more accessible? Why don't people accept that not all their desires will be fulfilled, and that medicine cannot provide for all their 'ailments'? If people have so much love to give that they will go to all sorts of ends to bear children, why can't they channel that love into other outlets? Do they want children to give love to or to fulfil their own wants and expectations of life? How can a civilised country justify the money, time, discussion, effort, glossy publications, costly committees and paper pushing put into the development and provision of reproductive technologies in the face of so many more immediate needs in the world??

Cloning or not?

posted 09/03/2004 - 01:02 by DrGarethLeyshon

I suppose strictly speaking, this process involves A CLONE OF THE 40 YEAR OLD WOMAN'S EGG, rather than a clone of the woman. As in the case of a naturally fertilised egg, only half the expressing genetic material will come from the woman. So it is a kind of cloning, but without involving most of the issues which arise from the special case of cloning a unique human being.

Apart from that, I largely agree with jax's comments.

Dr Gareth Leyshon - M.A., MInstP, Member of the BAAS

Accepting the limitations of age

posted 09/03/2004 - 02:52 by Dr Neville Cobbe

I essentially agree with the comments already submitted by most other people here. If it could be conclusively shown that this procedure is safe, then there seems to be no ethical dilemma in principal as no lives are deliberately destroyed. However, the practicality of the approach is highly questionable and I also agree with the previous comments regarding the disproportionate use of resources that could be wasted on such cases. The basic assumption underlying this approach is that the cytoplasm in the older woman’s eggs is somehow to blame for the failure of any embryos to develop. However, it is highly probable that the nuclei of the older woman’s eggs may be defective, in which case the procedure would be a complete waste of time. This would be consistent with an increased incidence of chromosomal nondisjunction (resulting in conditions such as Down syndrome) with increased maternal age.

Accepting the limitations of age

posted 09/03/2004 - 15:43 by jules

Medical science invests a great deal in being to extend life spans, treating age related illness (cancer etc) so why should it not help extend the opportunity for women to have a child after the age of 40 or 45? Why should women accept the limitation of age if medical science can help?

Of course men do not have that restriction and I am sure as a result find it difficult to appreciate the 'ticking of the biological clock'.

While there are many issues that older parents should consider (health, finance etc) - which the press has made clear that older women should not be allowed to have children because of these issues - but living as we do in a sexist society - I never see the press challenging older males who choose to have children, about the issues invloved in childrearing at an older age? Just because men may be able to procreate naturally when they are older does not mean the same issues do not exist.

Perhaps the woman in the example should consider using donated eggs, if there is a increased possibility of genetic abnormalities from her own aged aggs.

The limitations of age and medical science

posted 13/03/2004 - 12:29 by Dr Neville Cobbe

Jules has asked why women should accept the limitations of age if medical science can help. I think the real question here is whether or not medical science can actually help in this scenario. As Richard Fleming has mentioned, previous attempts at cytoplasmic transfer have been discouraging due to the dramatically increased risk of offspring with Turner’s syndrome (Human Reproduction, Vol. 17, No. 4, 850-852). Turner’s syndrome also results from non-disjunction, in this case leading to the loss of an X chromosome, so it is possible that the age of the nuclei could be the main problem. It is not entirely clear why non-disjunction should increase exponentially with maternal age, though it is possible that the extended arrest of oocytes at diplotene of meiosis I may result in gradual dissociation of chiasmata.

Consequently, if medical science can’t really help then I think we should just try to accept our biological limitations, rather than insist on attempts to fulfil our fantasies at the expense of others. As regards fathers having children late in life, the suggestion that this may be wrong presupposes that fathers play an important role in raising children. Accepting this premise, I would therefore agree with that it would be inconsiderate for a man to have children at an age that prevents him from playing a responsible role in their upbringing.