Friedreich’s ataxia is an ataxia inherited via an autosomal recessive gene. This is the most common autosomal recessive form of ataxia, accounting for about half of all hereditary ataxia cases.

The incidence of Friedreich’s ataxia is estimated at 1:22,000 to 1:50,000, predominately in populations of Europeans and North Americans of European descent. This disorder is virtually nonexistent among African and Asian populations.

Friedreich’s ataxia is produced by a mutation at the 9q13-21.1 location of chromosome 9, which results in excessive repetitions of the DNA sequence guanine-adenine-adenine (GAA). The onset and length of time until the patient is unable to ambulate is determined by the number of GAA repetitions within the mutation.