The human body is not perfect. Some are created with inherent faults and others break down before their time. Science has the potential to make good these problems by altering how humans are made. This is genetic engineering, and this article looks at the pros and cons of the technology in humans
This is part one of a two-part series. Here I will look at a defintion of genetic engineering and the pros of human genetic engineering. In part two the cons and the ethics of human genetic engineering are discussed.
Before weighing up the pros and cons of genetic engineering in humans, it's worth taking the time to understand just what is meant by the idea. Simply put, it's a way of manipulating our genes in such a way as to make our bodies better. This alteration of a genome could take place in the sperm and egg cells. This is known as germline gene therapy and would alter the traits that a child is born with. The changes would be inheritable and passed down through the generations. It is currently illegal in many countries.
The other way to change our genome is to swap our bad genes for good ones - in cells other than the sex cells. This is known as somatic cell gene therapy. This is where a functioning gene could be fired into our bodies on a viral vector to carry out the functions that a faulty gene is unable to. This technology is permitted, though it has enjoyed a very limited success rate so far (largely because it is technically very difficult). Nonetheless, it still holds out a great deal of promise.
There are many potential advantages to being able to alter the cells in our bodies genetically.
To make disease a thing of the past
Most people on the planet die of disease or have family members that do. Very few of us will just pop up to bed one night and gently close our eyes for the last time. Our genomes are not as robust as we would like them to be and genetic mutations either directly cause a disease such as Cystic fibrosis, or they contribute to it greatly i.e. Alzheimer's. Or in the case of some conditions such as the heart disease Cardiomyopathy, genetic mutations can make our bodies more susceptible to attack from viruses or our own immune system. If the full benefits of gene therapy are ever realised we can replace the dud genes with correctly functioning copies.
To extend life spans
Having enjoyed life, most of us want to cling on to it for as long as possible. The genetic engineering of humans has the potential to greatly increase our life spans. Some estimates reckon that 100-150 years could be the norm. Of course gene therapy for a fatal condition will increase the lifespan of the patient but we're also talking about genetic modifications of healthy people to give them a longer life. Once we fully understand the genetics of ageing it may be possible to slow down or reverse some of the cellular mechanisms that lead to our decline - for example by preventing telomeres at the ends of chromosomes from shortening. Telomere shortening is known to contribute to cell senescence.
Better pharmaceuticals
The knowledge gained by working out genetic solutions for the above could help with the design of better pharmaceutical products that are able to target specifically genetic mutations in each individual.
As deliriously exciting as some people believe genetic engineerng to be - there are several downsides and ethical dilemmas which will be discussed in part two.