Researchers have shown preliminary but promising results for a potential cure for Huntington’s disease. Using the genetic therapy known as CRISPR, the team was able to provide a permanent therapeutic treatment for this condition in mice.
Huntington’s disease is a fatal neurodegenerative disorder that causes the breakdown of nerve cells in the brain. It’s an inherited condition that typically begins in adulthood and is caused by a gene that produces proteins that are toxic to cells in the brain.
The research, published in the Journal of Clinical Investigation, focused on mice engineered to develop Huntington’s disease, with symptoms like impaired movement developing when they are nine months old. The team then used CRISPR to change the genes of the mice, and within three weeks, the mice were significantly improved, although not back to the level of a healthy mouse.
The genetic therapy was delivered to the mice's brain cells using a virus. This approach called the adeno-associated virus, or AAV, has been successful in CRISPR. The viral carrier was injected in the brain striatum of the mice, the region that controls movement.
“The findings open up an avenue for treating Huntington's as well as other inherited neurodegenerative diseases, although more testing of safety and long-term effects is needed,” senior author Professor Xiao-Jiang Li, from Emory University School of Medicine, said in a statement.
The potential long-term effects are what makes medical researchers tread carefully when it comes to CRISPR. The potential for CRISPR to be a phenomenal weapon in the medical arsenal is undeniable, but there’s still more that we need to understand.
What if by suppressing a specific gene we know is causing a disease, another gene is affected? Or what if the change leads to other long-term difficulties? The researchers showed that the gene mutations caused by CRISPR in this setup happened only in the Huntington genes and not in off-target genes.
“The long-term effects and safety of injecting AAV in the brain to express CRISPR/Cas9 remain to be rigorously tested before applying this approach to patients,” Li added.
There are no current plans to use CRISPR to fight neurodegenerative disorders in humans, although human trials to make cells able to fight cancer is currently underway in the USA and in China.