What Are the Types of Ataxia?

As discussed above, there are two types of ataxia:

• Sporadic ataxias: Ataxias of this type usually begin in adulthood and have no known family history.
• Hereditary ataxias: These ataxias are caused by a defect in a gene that is present from the start of a person's life and can be either dominantly inherited or recessively inherited. Recessive disorders commonly cause symptoms to begin in childhood rather than in adulthood.

Genetic testing is now available. Friedreich's ataxia is recessively inherited and occurs in childhood, but can have an adult onset in up to one third of patients. Dominant ataxia often begins in the twenties or thirties or sometimes even later in life.

Hereditary ataxias are degenerative disorders that may progress over a number of years. How severe the disability depends on the type of ataxia, the age of onset of symptoms, and other factors that are poorly understood.