Wondering why gene therapy is such a hot topic? A doctor breaks it down for us

There is a revolution happening in the world of modern biology. It's called gene therapy and it might soon have the power to change millions of lives forever. New and exciting for sure, but as with anything that is still being developed, it's not without controversy. And while many of us may have heard the term tossed around, we still have no idea what this therapy actually is. So Dr. Vivien Brown stopped by The Goods to explain what we need to know about this new form of treatment and why it's such a buzzy topic.

The basics

Gene therapy is a technique that uses genes to treat or prevent disease. It aims to treat the root cause of a problem by deleting, adding or altering DNA, rather than just treating symptoms that result from the genetic flaw. Doctors want to treat a disorder by putting a gene into a cell to change how that cell is functioning and evolving. Sometimes doctors are using it to replace a gene that has mutated (which causes disease) with a healthy gene. Alternatively, doctors may knock out a mutated gene that is causing disease. They can replace it, knock it out, or introduce a whole new gene, so there are different ways that this technique can alter the evolution of a disease.

Gene editing

If you think about genes as alphabet soup, you can imagine that one of those letters may be in the wrong place. If it's in the wrong place, it's stimulating cells in a negative way and creates a disease. But gene editing allows for the removal of that gene and its replacement with a healthy one. It involves making cuts at specific DNA sequences with enzymes called 'engineered nucleases'. Genome editing can be used to add, remove, or alter DNA in the genome and by editing the genome, the characteristics of a cell or an organism can be changed.

This is a highly specialized form of cut and paste. This means that we can get rid of specific abnormal genes that cause specific diseases. So for example, certain kinds of childhood leukemia, cystic fibrosis, and glioblastoma are all caused by specific genetic abnormalities, and we're getting close to being able to eliminate those conditions in the future.

How it works

Sometimes inactivated viruses or vectors are used to get into the cell to deliver the new copy of the gene into a cell. It may be delivered by a vector, or virus that is not able to cause disease, but can get into cells. There are still lots of challenges, but it's truly a personalized medicine, attacking the cause of an illness, not just treating the symptoms.

The impact of gene therapy

We're starting to see that diseases are being treated from where they originated, directly from the gene that's causing that abnormality. For example, there is a particular gene therapy that's been licensed in the UK used to treat a certain type of blindness and it correcting previously non-correctable blindness. How exciting is that? This is much more advanced than simply treating the symptoms of a disease.

Why it's a hot topic

Gene therapy has been around since the 1980s, but there has been a lot of research and work in this area since. In December 2017 the FDA approved two therapies for actual clinical use, so we're getting closer to these therapies being used in humans on a broader scale. It's taken a while because it's a very precise way of looking at medicine and  between the research dollars, time and effort required, it takes a while for a breakthrough like this to develop.

New but controversial

Despite being an exciting medical advancement, Dr. Brown suggests we still need to be concerned about safety and ethical issues regarding changing DNA. We have to ask the question, "Who is going to have access to gene therapy?" which will be incredibly costly due to the amount of research and dedication involved in the process. We are currently looking at gene therapy for terminal diseases and those that have no cure. At some point, we'll have to decide if it's worth it to spend this amount of health care dollars on a small number of people. 

Ethical concerns

There are also ethical questions surrounding tampering with DNA. Ethicists will have to ask whether we should be using this for any issue, sex choices, intellectual enhancement or only for serious diseases. It's possible that gene therapy could develop to enhance things like athletic ability or intelligence, and while this may sound idyllic, it could become complicated quickly because people will have to decide what traits are abnormal, normal, or borderline which could put people's rights and humanity at risk. So now is the time that we, as a society, need to start having the conversation around the issues attached to a procedure that could be so beneficial, but problematic at the same time.

But it's not ready yet

Although this medical development is not accessible yet, there's a real possibility that it may be readily available for the next generation. There's so much research involved that at this time it's too soon to tell when gene therapy will be accessible for everyone, but developments have started to accelerate so there is hope for major developments over the next five to ten years. 

Safety concerns

Safety is paramount with a new medical treatment like this and there are still a lot of unknowns. There have been some deaths and the FDA and Health Canada monitor trials very closely. There are many levels of regulations and guidelines so before we use it in an average person, it will be very safe. But there are serious risks, such as toxicity, inflammation and cancers. There are many side effects however, it all depends on the gene, the disease and so on. It's still unpredictable so it's currently a research tool. Gene therapy is not a simple process, so clinical trials are ongoing and very closely regulated and monitored, and proper oversight is key to this therapy being safe, effective and revolutionary for people in need.