An error in the blueprint
Does it run in the family?
The basis of gene therapy
A very special vehicle
Back to basics
Knowledge and possibilities increase
Gene therapy: the object of discussion
What does the future offer us?
Biomedical research currently receives much attention from business, scientists and the media. Major 'breakthroughs' are reported daily and scientific developments are moving fast. Gene therapy is a promising technique in the world of life sciences. But is gene therapy hype or does it already exist right now?
An error in the blueprint
Does it run in the family?
The basis of gene therapy
A very special vehicle
Back to basics
Knowledge and possibilities increase
Gene therapy: the object of discussion
What does the future offer us?
What are genes exactly? Can scientists alter genetic conditions in humans using gene therapy? What can we expect from gene therapy? Is gene therapy hype or does it already exist right now? There are many questions. Time to learn a little bit more about them.
An error in the blueprint
So what are some of the potential benefits to the use of gene therapy? Proteins have a lot of important functions in our body. For example, they function as building blocks, they transfer messages and break down waste materials. The blueprints of proteins are written in our genetic material, the DNA.
We call these blue prints ‘genes’. When something’s wrong with a blue print, or gene, properly functioning proteins cannot be produced. This can have far reaching effects. Illnesses like haemophilia (an hereditary disorder of blood clothing) and cystic fibrosis are examples.
Does it run in the family?
You inherit many things from your parents including some of your features such as eye colour and hair colour, it is often said that these things “run in the family”. When we look at inherited characteristics such as these it’s not only genes that play a role, but also a persons lifestyle choices.
For example a person can have a lot of talent for playing the piano. But if this person never takes lessons, it would be very hard for them to become the second Beethoven.
Multifactorial
This is the same for a lot of diseases and disorders. In most cases it’s not only your genes that determine whether or not you will become ill. It also depends on what you eat, how much exercise you have, where you live and what you go through in general. Many genetic conditions are what we call, multifactorial, meaning there are many different things both genetic and environmental that affect a persons chances or risk of being affected.
However for some diseases it is certain that you will get them, when you have a faulty gene for a certain protein. It is diseases like this that scientists hope to cure with gene therapy.
The basis of gene therapy
The basic idea for gene therapy has existed since 1989. The idea is that when genes contain certain faults which make proteins work less, or not at all, we should be able to do something about it. When we replace or repair the gene, this should make things right! Sounds good, doesn’t it?
A very special vehicle
But how do we get the new gene to the right destination in the cells’ DNA? To do so, we need a vehicle: the gene cannot travel there on its own. Viruses are often used as a transportation vehicle. Viruses naturally deliver their own genes in cells, which can sometimes make you ill.
Cripled viruses
The viruses that are used for gene therapy are made harmless by scientists. They replace the viral genes that cause disease with the genes that need to be delivered. These modified viruses do not make you ill, but they are able to deliver the gene to the right place in the DNA. At least, that is the idea in principle.
Back to basics
In practice, this has been a bit more complicated than was originally thought. In one research project, investigating gene therapy for a severe immune disease, the gene was sometimes delivered to the wrong spot. This resulted in three patients developing leukaemia. Two of whom fortunately recovered and for the rest of the patients on the trial the therapy worked well.
They can now live normal, healthy lives without medication. Nevertheless, the risk of developing leukaemia was so great that research into gene therapy was set back quite a few years. Scientists had to pay more attention to the basics of the therapy in order to make it safer for future patients.
Knowledge and possibilities increase
In recent years better modified viruses were investigated, viruses which were more stable and able to transport and deliver genes more precisely. Scientists now claim they have safer transportation methods for certain diseases.
People are now yearning for the results of new research programmes. The first results that can give perspectives on a cure, are expected for haemophilia, cystic fibrosis, some immune diseases, metabolic disorders, eye diseases and also cancer.
Gene therapy: the object of discussion
There are some people who think that genetic material should not be modified under any circumstances, even if this research has the potential to find a cure for many long term and potentially fatal conditions.
For those who stand to benefit from the results of gene therapy research it means that their health could be improved dramatically. For many of the conditions being researched for gene therapy there are no treatments at present.
What does the future offer us?
At the moment gene therapy has the potential to be very useful when a disease is caused by an error in one gene eg conditions such as Cystic Fibrosis and Chronic Granulomatous Disease.
However a lot of genetic disorders exist as a result of errors in multiple genes (sometimes hundreds of genes) and for other genetic conditions, the chance of becoming ill also depends on a person’s lifestyle. In that case gene therapy is very complicated, if not impossible because it only works to correct one faulty gene.
Bone marrow stemcells
Other research groups focus on adding genetic material to bone marrow cells in order to make transplantation more safe. Futhermore progress is made in the treatment of various cancers with gene therapy.
What the future will bring us is hard to say. Expectations are high. The results so far are very promising, developments are coming quickly. One thing is for sure: a lot more work has to be done.
Last updated december 3, 2007
This information was realised by EGAN in the context of CONSERT.
EGAN is the European alliance of national genetic alliances and European disease specific patient groups with a special interest in genetics, genomics and biotechnology.
CONSERT is a consortium of European research and clinical institutions cooperating to develop gene therapy for inherited diseases