Researchers have recently uncovered two new rare diseases caused by the same mutation. This recent discovery is giving more families answers, and should hopefully begin to improve patient outcomes.
The Path to Discovery
The path to this new discovery began with parents of two children with the mutation who were determined to find an answer themselves after doctors couldn’t give them one. The siblings were both experiencing neurodevelopmental deficits as well as seizures, but no doctor was able to provide them with a diagnosis. So, these parents began their own research and reached out to Doctor Carl Ernst, a professor at McGill University.
Ernst was able to uncover that both children had a mutation in the ACTL6B gene. ACTL6B is crucial for neuronal development but not much else is currently understood about its function.
Doctor Philippe Campeau from the CHU Sainte-Justine Research Center, with Julie Lessard, were working on understanding how ACTL6B mutations affect the interactions of proteins. Their research was initiated after the mutations were identified in an epilepsy genome study in two different families.
Dr. Campeau happened to hear a lecture by Dr. Ernst and reached out to him about collaborating. Together, the team found 10 additional patients across the world with a ACTL6B mutation. This is when the true investigation began.
The team found that the patients they had identified actually could be divided into two groups. Some patients had recessive mutations which means that both copies of the ACTL6B gene were mutated. These individuals faced both neurodevelopmental issues and epilepsy. The rest of the patients had only one copy of the ACTL6B gene mutation. These individuals did not have epilepsy however they did have the same neurodevelopmental issues. This group of patients also had characteristics of Rett syndrome, another rare disease.
These differences are what allowed the researchers to conclude that mutations in the ACTL6B gene could actually cause two completely different rare diseases.
Now, the researchers are utilizing technology such as iPSC as well as CRISPR to learn more about this mutation. They know that better understanding this genes role in brain development is essential to learning how to best serve patients affected by ACTL6B mutations.
This research on the ACTL6B discovery was published by Scott Bell in the American Journal of Human Genetics.
You can also read more about this research here.