About AHC


Alternating Hemiplegia of Childhood or AHC is one in a million, rare, severe, genetic neurological condition caused by an ion imbalance in the brain.


AHC is most frequently caused by a mutation in the ATP1A3 gene which codes for a protein responsible for maintaining the critical electrochemical gradient in neurons in the brain known as the “sodium potassium pump.” There are only 1,000 diagnosed cases in the world.


Despite its name, AHC does not only occur in childhood and is instead a disease that patients battle throughout their lives and is associated with devastating outcomes like death, brain atrophy, and sudden and permanent degeneration.

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AHC is like having 7 neurological conditions in 1:

Paralysis like stroke

Patients experience debilitating periods of paralysis, which can last for days or weeks.

Seizures and spells of reduced consciousness like epilepsy

These episodes carry a high risk of rapid, severe, and permanent deterioration. Clinical epilepsy occurs in more than 50% of AHC cases.

Low muscle tone like cerebral palsy

Low tone contributes to other serious complications, including the inability to breathe and swallow properly.

Movement problems like Parkinson’s

Patients often experience painful dystonia or involuntary muscle contractions or tremors.

Neurodegeneration like Alzheimer’s

Brain atrophy can cause a decline in motor function, learning capacity, memory, and the ability to breathe, eat and swallow as patients reach adulthood.

Behavioral issues like ADHD

Patients may also have behavioral issues driven in part by pain, frustration, fear and cognitive dysfunction.

Learning challenges like autism

Patients can have cognitive challenges and difficulty with speech, learning, and psychological issues.

Treatments or Cures


There are currently no viable treatments or cures for AHC. The only medications that have been found to mask, rather than treat symptoms of AHC, are drugs like calcium channel blockers, benzodiazepines (anxiety medications), or anti-epiltpetic drugs. There is no identifiable pattern in terms of what drugs work for which patients, and often those who have epilepsy struggle with intractable seizures for the entirety of their lives. 


Practically speaking, patients with AHC will continue to experience any AHC symptom at any time causing the potential for lifelong damage or death until we have a treatment. 

Currently, our three foundations CureAHC, AHCF, and Hope for Annabel, are working on AAV Gene Therapy and Gene Editing projects which would offer viable treatments for our kids. 


However, Henry’s mutation specifically presents a challenge as it is suspected to be dominant negative (rather than loss of function) and thus, AAV gene therapy which provides additional good copies of the needed protein would not be enough of a treatment to halt the progression of this disease. For this reason, an ASO gene therapy is necessary to target or “knockdown” the mutation that is causing dysfunction. Read more about ASOs on our ASO page.

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