Is gene therapy the future of medicine?

Get ready for a whole new way of preventing or fighting a disease or medical condition.  Gene therapy holds great promise for a healthy future for millions of people suffering from various inherited and immune disorders. 

For years, scientists have been working on ways to modify genes or replace faulty genes with healthy ones.  It looks like their hard work is finally paying off - as of August 2017, the U.S. Food and Drug Administration (FDA) has approved three gene therapy products.  Two of them help to reprogram a patient’s own cells to attack the deadly cancer of leukemia and the third treats children and adults with an inherited form of vision loss caused by mutations in a specific gene.

Gene therapy appears to be a new frontier as an effective treatment option for a variety of diseases.  It is estimated that there are 4,000 medical conditions which are a result of a gene disorder.  By using gene therapy to replace or manipulate a faulty gene, this could end the suffering of many individuals to lead longer, healthier lives, free of symptoms and the medical costs associated with them. 

How does gene therapy work?

To understand gene therapy, one has to understand what each of us is composed of – trillions of cells.  Everything that is alive is composed of these basic building blocks.  Within every single cell are thousands of genes which carry the DNA information needed to make proteins and enzymes of what we are composed of – muscle, bones, and blood. 

From the moment of conception until the day we die, some of these genes can become defective through mutation. It could be just part of the gene or maybe the entire gene that could be defective or missing at birth or genes that can change or mutate at any time during our life. 

Gene therapy is a scientific technique that uses genes to prevent or treat disease in several ways:

·      Replace a damage gene with a healthy copy of the gene

·      Inactivate a gene that is functioning incorrectly

·      Introduce a new gene into a body that may be needed for normal function

Scientists have figured out a way to insert new genes directly into cells by using what is called a “vector” which is genetically engineered to deliver the gene.  Think of a vector as a vehicle used to transport a good or service to a delivery point.  One type of vector researchers have discovered to use is viruses.  Normally we think of viruses as being dangerous which they can be.  In order to prevent a virus from harming a person, the virus is modified first to remove its ability to cause an infectious disease rendering them harmless.  The reason why viruses can be used as a vector is that they have a natural ability to deliver genetic material into cells.  The viruses’ gene can be removed and replaced with the working human gene.  Once the gene is correctly placed, it can be switched on to provide the “working instructions” for correct functioning. 

Gene therapy can modify defective or mutated cells either inside or outside of the body.  If gene therapy is done inside the body, a doctor will inject the vector carrying the gene directly to the area of the body with the defective cells.  If gene therapy is done outside of the body, a patient’s blood, bone marrow or other tissue will be removed first to be taken to a lab to separate out specific cells to be targeted.  These cells will have the vector containing the correct gene inserted into them.  At the lab, the cells will be allowed to multiply and then injected back into the patient, where they continue to multiply to achieve the desired goal.

What conditions are being treated with gene therapy?

Currently, gene therapy is being used to correct deficiencies in the production of dopamine, such as in Parkinson’s disease, to correct some immune system problems, and to restore components needed for normal blood cell function in people with certain blood diseases such as hemophilia.  Gene therapy also looks promising for treating other diseases including cancer, cystic fibrosis, heart disease, diabetes, and AIDS.

Potential risks

Like with any new treatments, gene therapy does come with potential side effects.  Researchers are hopeful in being able to overcome these risks in order to make gene therapy as safe as possible. 

One possible risk is the fact that when introducing the vector containing a virus into the body, the immune system may see this newly introduced virus as an intruder and try to attack it. There is another possibility of the altered viruses infecting additional cells instead of only targeting the cells containing the mutated genes.  Another concern is that the viruses could recover their original ability to cause disease or that a new gene could be introduced into the wrong area of a cell’s DNA which could cause tumor formation.