Sunday, September 9, 2012

Scanning the genome for disease in unborn children

Some people have the misfortune to be born with a disease or disability. Such congenital diseases are often of a genetic origin, which means there is something wrong on the DNA. This results in an incorrect blueprint for certain proteins and that can cause life-long problems. With congenital diseases, things go wrong in an early stage: during the embryonic phase of life. While most genetic mistakes result in, often unnoticed, abortions, some children are born with the most horrible dysfunctions. It can be argued that in such cases, it is better to opt for an abortion before an unborn foetus gets the potential to live, although this is still highly controversial. Nevertheless, genetic techniques have made it possible to scan for various of the most life-impeding disabilities, allowing parents to terminate such pregnancies. A review in New Scientist discusses the current state of research in this particular field.

About a decade ago, it took years before all building blocks of the human genome were analysed. New techniques have greatly sped up this process, and we are getting closer to the situation where geneticists scan all of a patient's DNA in order to establish disease. We can do the same for unborn children, as it is possible to derive a DNA sample from an unborn child from the mother's blood. This means such tests are fairly non-invasive, which means, aside from medical costs and the required time, the procedure is fairly simple and thus desirable.

Foetal scanning
New Scientists discusses various recent developments in the field of genome scanning. For example, scientists from the University of Washington managed to devise a technique that allows for analysis of all the DNA an unborn child possesses. It is possible to set up an analysis from the first trimester, which means any serious defects will be known fairly early in pregnancy. In addition, researchers from the Stanford University in California have done pretty much the same. Such whole genome scanning techniques could be available in the clinic in the next five years.

Knowing what defects a child will be born with helps prospective parents prepare, both mentally and practically. They may also opt to terminate the pregnancy early if they feel a particular diagnosis is too much to handle for them. Better genetic analysis also helps women that opt for IVF treatment in order to get pregnant. Being able to exclude serious life-impeding diseases would be a great help.

There is a great debate surrounding a woman's right on abortion. It can be argued that there is no biological reason to regard a foetus in its early stages as an actual organism: during the first period, a foetus is not much more than a clump of cells that does not show much sign of life. The question is when an unborn child can be regarded as an actual being entitled to not be harmed, and this debate is far from over. In addition, it is necessary to debate the question of what is a valid medical reason to terminate pregnancy. How bad does a genetic defect need to be before an abortion is warranted? For some conditions life is not practically feasible, such as for babies born with anencephaly: such children are born without a brain and are therefore unable to function, while 'technically' being alive. 

Although the ethical debate is far from over, and may likely never be settled, we are continuously improving our genome scanning techniques. This means we are getting better at predicting the impairments that a child will be born with. Because of the severe conditions that a baby with genetic defects can acquire, it is immoral in my opinion to prohibit pre-birth genome scanning. The question is, how far are we willing to go? That is a difficult question, but being able to better predict the effect of genetic defects is a promising development that could prevent a lot of harm being done, to an unborn child as well as its parents.

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