Question: How many people are affected by episodic ataxia ?
Answer: Episodic ataxia is uncommon, affecting less than 1 in 100,000 people. Only types 1 and 2 have been identified in more than one family, and type 2 is by far the most common form of the condition.
Source: GHR

Question: What are the genetic changes related to episodic ataxia ?
Answer: Episodic ataxia can be caused by mutations in several genes that play important roles in the nervous system. Three of these genes, KCNA1, CACNA1A, and CACNB4, provide instructions for making proteins that are involved in the transport of charged atoms (ions) across cell membranes. The movement of these ions is critical for normal signaling between nerve cells (neurons) in the brain and other parts of the nervous system. Mutations in the KCNA1, CACNA1A, and CACNB4 genes are responsible for episodic ataxia types 1, 2, and 5, respectively. Mutations in the SLC1A3 gene have been found to cause episodic ataxia type 6. This gene provides instructions for making a protein that transports a brain chemical (neurotransmitter) called glutamate. Neurotransmitters, including glutamate, allow neurons to communicate by relaying chemical signals from one neuron to another. Researchers believe that mutations in the KCNA1, CACNA1A, CACNB4, and SLC1A3 genes alter the transport of ions and glutamate in the brain, which causes certain neurons to become overexcited and disrupts normal communication between these cells. Although changes in chemical signaling in the brain underlie the recurrent attacks seen in people with episodic ataxia, it is unclear how mutations in these genes cause the specific features of the disorder. The genetic causes of episodic ataxia types 3, 4, and 7 have not been identified. Researchers are looking for additional genes that can cause episodic ataxia.
Source: GHR

Question: Is episodic ataxia inherited ?
Answer: This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
Source: GHR