For more than a decade, Allison Brashear, UC Davis School of Medicine dean and world renowned neurologist, has been researching a cure for Rapid Onset Dystonia Parkinsonism (RDP) and Alternating Hemiplegia of Childhood (AHC), both rare neurological disorders, through National Institutes of Health (NIH) grants. She will speak at the 8th annual Symposium on ATP1A3 in Disease on Oct. 3-4 in Reykjavik, Iceland.
Q: What are RDP and AHC?
A: RDP and AHC are caused by a mutation in the protein called ATP1A3. ATP1A3 is the protein responsible for creating energy in the cell. It moves sodium and potassium back and forth. It’s a subunit and it is only localized in neurons in the brain.
All brain cells have this protein and some of the conduction parts of the heart. When this protein doesn’t work, that nerve cell fails to create energy and causes disease. If you get the disease early, you have AHC. The onset is 18 months.
If the onset occurs after age 18, it is called rapid-onset dystonia parkinsonism and the individual may experience movement problems, memory problems and psychiatric disease.
Q: What are the symptoms of AHC?
A: A patient with AHC can have episodes of weakness on one side or both. They can have severe epilepsy and need to be hospitalized with very bad seizures. They can experience developmental delays. It is a complex disease and parents never know what to expect. One day might be a good day and the next they may encounter hundreds of spells. It can be quite disabling.
Q: What causes AHC?
A: It is caused oftentimes by a stressor. Triggers include baths or fevers. I have met many children with AHC and adults with RDP and it’s heartbreaking because you don’t know what will trigger those diseases.
Q: What treatments are available?
A: Mutations of this very critical protein in all brain cells can create terrible disease for which there is absolutely no treatment right now. There is no medicine that affects this particular sodium potassium pump.
Q: What research is being done?
A: Our research has been funded for 11 years by the National Institutes of Health (NIH) to try to understand the basic science of the sodium potassium pump and to understand what pathways in the brain are affected. There is more of this protein in the areas of the brain that control walking -- the cerebellum -- and the areas of the brain that affect other things like Parkinsonism, epilepsy and memory. Understanding this will help us find a treatment and may help us understand the diseases like epilepsy that affect a lot of people.
Q: What are the challenges of treating AHC?
A: One of the challenges is identifying patients who have AHC and RDP because these diseases look like a lot of other diseases. But the more patients we find and the more we understand the diseases, the more likely we can target a treatment and potentially find a cure.
Q: Tell us about the 8th annual Symposium on ATP1A3 in Disease.
A: There are not many groups where patients and families get together with the investigators and the basic scientists from across the world. We have about 150 people attending this meeting from Australia, the Netherlands, Poland, Germany, Iceland, Japan and the U.S. once a year to try to solve the puzzles of this disease. We discuss what we can do, what we have learned; we share. We talk about animal models, patients, imaging and potential treatments and we consider what can still be done to move forward.
ATP1A3-Related Neurologic Disorders – GENEReviews