November 20, 2019

Unnatural Selection VI: Genetic Ethics


Ethical Implications of Application

The next two posts identify some of the weightier ethical issues arising from the application of biohacks to humans – the detection and cure of disease. There are about 5,000 different inborn diseases which are due to genetic mutations. It is speculated that we all carry at least one lethal gene, but fortunately most of our genes come in pairs and usually both members of the pair need to be defective for a disease to develop.

Genetic Screening

The earliest immediate practical application of the genome tinkering is likely to be an increase in the number of tests available for screening defective genes. But as Jesus asked the cripple at the Pool at Bethesda…

"Now a certain man was there who had an infirmity thirty-eight years.  When Jesus saw him lying there, and knew that he already had been in that condition a long time, He said to him, “Do you want to be made well?” John 5:5-6

Do you want to be made well? That is a really heavy question that warrants deep examination both theologically and ethically.

Mass screening has usually been counterproductive, unless a population has a very high prevalence of a defective gene. More usually screening is carried out for families where a risk of genetic disease is already established. Different ethical issues are raised depending on whether screening is prenatal or postnatal.

Prenatal screening of fetuses via Amniocentesis can involve abortion, a thorny question about which Christians have disagreements with the culture and even their own brethren. Prenatal screening does not necessarily depend on genetic engineering and has been carried out since the 1970s. Typically it is offered to a pregnant mother in cases where both parents are known to be heterozygous (‘carriers’) for a specific lethal genetic disease. This means that any child born in that family has a 1 in 4 chance of being affected by that disease. Tests are carried out using a tiny sample of cells obtained from the fetus. If the fetus is found to carry disease, then the pregnancy may be terminated. Such terminations comprise less than 3 per cent of abortions performed annually. Although I am not going to argue the abortion issue, I needed to raise the topic of Amniocentesis and similar screenings. Should they be done?

Ethical issues are also raised by preimplantation diagnosis (PD). As with other forms of prenatal diagnosis, this procedure is usually carried out when both parents are known carriers of a lethal disease. PD involves in-vitro fertilization (IVF)[9] followed by growth of the embryo to the stage at which it contains 4-8 cells. One or two cells can then be removed without damaging the embryo, and defective genes identified. Clearly defective embryos are discarded and only the healthy embryo is implanted in the mother. Only a few hundred PDs have been carried out so far, but this number is likely to increase markedly as more DNA tests become available.

The procedure has the great advantage that it avoids the need for aborting an affected fetus post-implantation, as required by current prenatal diagnostic procedures. In assessing the ethical implications involved, it should also be kept in mind that more than 80 per cent of all embryos fail to implant following IVF or natural fertilization. Some of these embryos demonstrate severe chromosomal abnormalities, apparently ‘nature’s way’ of preventing the birth of children carrying genetic defects. It could therefore be argued that in PD, human intervention is merely refining this natural process of viable embryo selection.

Postnatal screening raises rather different issues. Where prevention or treatment of diseases is possible, there seems every reason to proceed. Every baby born in the UK, as in many other countries, is screened for the genetic disease phenylketonuria. If untreated this disease results in severe mental retardation, but once detected is easily prevented by minor dietary adjustments. This is a good example of a genetic outcome being radically altered by a small change of environment. Knowing that defective genes are present can enable affected individuals to change diet and lifestyle in attempts to counteract their effects. Is this unbiblical?

Where no treatment is available, different issues arise. Receiving general information about the genetic basis for human disease is very different from the momentous implications of hearing that you personally carry a defective gene. For example, Huntington’s Disease develops in people aged 40 to 50. After some years of increasing loss of motor control, death occurs 10-15 years after the first onset of symptoms. A DNA test can now tell a person at risk that they carry the defective gene. Some might conclude that such information is too heavy a load for anyone to bear. However, Christians in particular might view the situation differently. Knowledge that one is under a death sentence by carrying a lethal gene could enable a choice not to have children and the pursuit of a different life path. Utilize their remaining time in pursuit of spreading the Gospel perhaps??

In postnatal screening two urgent ethical issues arise. First, screening may lead to people having information about their lives about which they can do nothing. The right NOT to know one’s genetic errors is as important sometimes as the right to know. Second, screening may create an inferior subhuman classification of carriers of deleterious genes. A form of diagnostic eugenics. Those who are carriers are then marginalized from the benefits of society. They likely wouldn’t be able to obtain mortgages or life insurance. Christians though, will need to view all people as having equal value, irrespective of their genetic inheritance, and should press for insurance practices which allow the equitable pooling of risk.

Regardless, some should be allowed to choose to do nothing or know nothing. Purposely chose genetic ignorance. By not choosing, they chose anyway. To answer Jesus’ question, “Do you wished to be healed?”

Some people's answer will be no.

No comments:

Related Posts Plugin for WordPress, Blogger...
Related Posts Plugin for WordPress, Blogger...