The Downside of Human Genetic Engineering

Part one of this article looked at the pros of genetic engineering in humans. Now, we look at the cons. As with any new technology, there are some downsides.

There's a big question mark over safety

There are risks associated with getting genes into a human body and having them carry out the desired function. Some genes are carried in on viral vectors and these bugs have been altered so as not to infect a patient with a disease. However, a small number of gene therapy trials have resulted in the deaths of some subjects.

Also, we simply do not know long term the potential ramifications of altering genes. For example, if you were to stop telomeres from shortening would this have negative knock-on effects elsewhere in the genome? The human genome and our whole bodies are a maze of complicated biological signals, pathways and interrelationships. A positive change upstream could cause a negative effect downstream.

Genetic diversity

If we were all to undergo genetic modification would this limit our genetic diversity? Could there be a danger that our gene pool diminishes and that as a population we become more susceptible to being wiped out by a hitherto unknown disease threat?

To say that genetic engineering has attracted some controversy would be an understatement. There are many cries that scientists are 'playing God' and that it will lead to a two-tier society - the genetically haves and the have-nots. But is this any different to the cries of horror and fears of Frankenstein's monster that greeted Louise Brown, the first child to be born by IVF treatment? There was great uproar in the late 1970's but IVF is now a common, if expensive, fertility treatment. And there aren't any monsters stalking the Earth.

Having said that, genetic engineering does hold the potential that parents could (if the technology worked) assemble their kids genetically, to be smarter, to be more athletic or have a particular hair or eye colour. Though it's rather fanciful to suggest that intelligence could be improved by the substitution of a gene, it may be found that there are several genes that are more commonly expressed in the genomes of intelligent people than those with more limited intellectual capacity. And parents might want to engineer an embryo to house a greater number of these genes. It is this genetic engineering of humans that so frightens people, that we could somehow design the human race. Though some people point out other potential benefits. What if it turned out that there were sets of genes that were commonly expressed in criminals - could we tackle crime by weeding out those genes?

The technology is nowhere near there yet, but a tiny number of parents undergoing IVF have selected their embryos to be free from genetic mutations that have blighted generations of their family. In the UK in January 2009 a mother gave birth to a girl whose embryo had been selected to be free from a genetic form of breast cancer. Some see this as a slippery slope towards a eugenic future, others view it as a valuable use of genetic engineering to prevent disease from striking someone down.

Society will decide how it uses this technology, and it is for governments to weigh up the pros and cons of genetic engineering in humans to see what may be carried out and what should be illegal. They will be prompted by public understanding, desire and concern. It therefore behoves all of us to understand what scientists are trying to accomplish and what they are not trying to do. We must all become better informed, to equip ourselves with more information and to know the difference between science fiction and science fact.