What is gene therapy?

Gene therapy is a method that uses genetic material to treat disease.  This unique treatment addresses the underlying genetic cause, rather than treating the resulting symptoms.  This approach opens up new possibilities to treat or even cure diseases for which few or no other options are available; in particular, it provides hope for rare genetic disorders like 4H Leukodystrophy.

Gene therapy for humans is still an experimental technique; only a few gene therapies are currently approved by the U.S. Food and Drug Administration (FDA) to treat patients. However, a lot of progress has been made over the last decade and there are now many ongoing efforts, both in industry and academia, to develop gene therapies for rare disorders.

Gene therapy for 4H Leukodystrophy

4H Leukodystrophy is caused by mutations in genes that are the recipes for making proteins for an essential cellular machinery (RNA polymerase III). By delivering a functioning copy of the mutated gene directly to cells, we hope to repair the body’s ability to make those proteins. The replacement gene compensates for the nonfunctioning copies and bypasses the underlying cause of the problem.

This study

To deliver the therapeutic genetic material correctly, it needs to be packaged into a vector that can find and attach to the right cells (in our case oligodendrocytes in the brain). Think of wrapping and addressing a parcel for delivery. This delivery method is similar to how a virus enters our cells, but without the infectious part.

Drs. Guangping Gao and Jun Xie are the researchers who work on developing the right vector for our purpose. The vector must then be tested in appropriate disease models to see whether it works as anticipated (known as “Proof of Concept”). Dr. Geneviève Bernard’s laboratory is responsible for generating a mouse model for 4H Leukodystrophy and then performing those tests. The Yaya Foundation’s grant will provide the resources for this important work.

What comes next?

Proof of Concept, mentioned in the previous section, is the very first step on the road to a therapy. If successful, this is followed by the preclinical stage which includes further research and extensive testing to ensure safety. If all goes well, an application is submitted to the FDA to allow testing in humans and to proceed to clinical trials. This is a promising step toward finding a treatment for 4H Leukodystrophy.

Learn more about gene therapy

  • Gene Therapy at a Glance: Quick overview of gene therapy with AAV vectors, the same kind of vector that is used in our study