Sunday, 24 May 2015

Thirteen ‘solutions’ to mitochondrial disease assessed

Mitochondrial disorders are passed on through a mother’s mitochondrial DNA. They are progressive and can be very disabling but are thankfully relatively rare. They can cause stillbirth, death in babies and children, or may onset with severe effects in adulthood, such as blindness or heart failure.

As there is currently no treatment for most of them the majority of ‘solutions’ are aimed at prevention.

1. Hitler’s solution would have been euthanasia. His chief physician, Karl Brandt, believed that killing disabled people not only relieved the burden their lives imposed on the state, but also released them from lives that were not worth living: 'My underlying motive was the desire to help individuals who could not help themselves...such considerations should not be regarded as inhuman.’

2. Infanticide would be the answer of Watson and Crick, the scientists who discovered the molecular structure of DNA. Along with eugenicist Margaret Sanger and bioethicist Michael Tooley they advocated killing disabled neonates on the grounds that they were not fully human. Dutch doctors do the same today under the Groningen Protocol.

3. Prenatal diagnosis and abortion is the choice of most British mothers carrying a disabled baby. The fetal DNA can be examined through chorionic villus biopsy or amniocentesis followed by induced intrauterine death. 91% of babies with Down’s syndrome detected prenatally have their lives ended this way. Whether you see killing a new-born baby in a hospital ward as any different from killing in the womb a few weeks earlier will depend on your view of the unborn child.

4. Pre-implantation genetic diagnosis (PGD) is favoured by those who believe that killing a human embryo is different from killing a fetus. Produce embryos by IVF, examine them in the laboratory, and discard or destroy those which are affected. Then implant only those without a disability.

5. Mitochondrial transplantation (ie. three parent embryo technique) was recently approved by the British parliament. Take an egg with faulty mitochondria before or after fertilisation, shell out the nucleus and then transplant it into a donor egg from which the nucleus has been removed. This is currently untested and may result in worse genetic defects than those one is trying to prevent. But then prenatal diagnosis and abortion can be used as a back-up.

6. Use IVF with an egg from an unaffected donor. The baby would not carry mitochondrial disease as it can only be picked up from the affected mother. But the baby would also not be biologically related to its mother. Also it introduces a third person into the marriage and family tree and in an unnatural way.     

7. DNA editing has been successfully employed in mice. Produce an embryo by IVF. Inject the embryo with a segment of RNA designed to produce DNA-cutting enzymes. Snip out the faulty gene and implant the embryo in its mother’s uterus. Grow to term. An elegant form of molecular microsurgery not yet tested in humans but which runs the risk of passing any introduced genetic errors down the generations. Not yet legal in Britain.

8. Contraception. An affected couple who didn’t feel comfortable with approaches 1-6 above might just choose not to have children and use contraception on every occasion.

9. If they wanted to be absolutely sure (as no method of contraception is 100% foolproof) they might opt for abstinence.

10. Alternatively a woman known to be a carrier of mitochondrial disease might choose to remain single.  

11. Another option might be to adopt a frozen embryo related to neither parent in order both to carry a child to term and to give it chance of life it might not otherwise have. There are over 600,000 embryos in the US alone for which embryo adoption is a possibility.

12. Then there is the possibility of baby or child adoption. This provides an affected couple with a child and a child with a home.

13. Finally, they may opt simply to go ahead and accept the child they are given, whether it has mitochondrial disease or not, and regardless of how badly it is affected. After all, isn’t every human being precious and worthy of the greatest protection, care, respect and the best treatment that is available.

So which of these thirteen options is the best? The answer to that question will depend on one’s fundamental world view including one’s view of the status of the human embryo and fetus and one’s view of the marriage bond.

Most, but by no means all, would be repulsed by options 1 and 2 – euthanasia and infanticide.
Those who do not see the fetus as a human being with rights would opt for 3 – prenatal screening and abortion. 

If they are squeamish about abortion but happy with embryo disposal they might opt for option 4 – pre-implantation genetic diagnosis (PGD).

If they are desperate to have a child genetically related to both parents they might risk 5 – the three parent embryo - or 7 – DNA editing. On the other hand if they are happy for the baby to be related just to the father they might opt for 6 – IVF with an egg donor.

Those who cannot contemplate 1-6 for whatever reasons have three options: choosing not to conceive either through contraception, abstinence or remaining single; adopting an embryo, baby or child; or going ahead and having the baby anyway.

What do I think myself?

For me three crucial ethical principles come to bear.

The first is the status of the human embryo. As I have previously argued I see the human embryo as a living person worthy of the utmost respect, empathy, protection and wonder. So that rules out options 1 to 4. The end of having an unaffected baby does not justify the means of taking human life, at any stage.

Second is the inviolability of the marriage bond (dealt with in more detail here). To me introducing a third person into the marriage bond violates the biblical principle of one man, one woman, for life. Although the lust and cheating elements of adultery may not be present, the use of donor gametes still constitutes a form of biological adultery. So option 6 is out. 

Third I don’t have an absolute objection to IVF per se (provided that the couple is married, all embryos are re-implanted and that there are no donor gametes) but I do think that the creator designed human reproduction to occur as a result of the union of egg and sperm. So, even apart from concerns about safety and germ-line manipulation, the act of cobbling together a human being using organelles from three different individuals (the three parent embryo) not only introduces a third person into the marriage bond but disrupts the divinely designed reproductive process. This, for me, rules out option 5.

Of the remainder DNA editing (7) is most interesting. I do not have an a priori objection to germ-line gene therapy but I do have serious concerns about its safety. Its attractiveness is that, unlike the three parent embryo solution, it offers the possibility of restoring a whole embryo to health. But it could only be considered if was shown to be absolutely safe and effective in non-human primate studies and this has not thus far been done.

So I am left with options 8-13. 8-10 are feasible but rule out parenthood unless accompanied by adoption. Embryo adoption (11) makes parenthood possible and saves a life. But only if that embryo is already in existence and would otherwise perish. I do not believe that it is right to create embryos that are not going to be implanted and I do not support surrogacy (which is what this essentially is) other than to save an existing embryo. Baby or child adoption (12) may not save a life but it does potentially give a child in care or in fostering a loving home.

Having a baby regardless knowing that it could be affected (13) will require a great degree of both courage and love, and is perhaps the costliest solution of all.

God shows his compassion toward us through loving care given at great personal cost. He adopts us into his family. He loves us in spite of the fact that we are disabled by sin. He seeks to bring us back into a loving relationship with himself. So for me, options 11-13 most closely resonate with the heart of God himself. 

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