Hereditary ataxia is a designation for inherited disorders that involve incoordination of voluntary muscle movements as the result of spinocerebellar degeneration. There are several forms of hereditary ataxia, which are delineated according to how they are manifested genetically. Autosomal recessive forms of hereditary ataxia are expressed by means of a mutated recessive gene. For the disease to be expressed, children must inherit two affected genes, one from each parent. There are several identified autosomal recessive ataxias with heterogeneous etiologies and clinical features; however, the most common ataxia is Friedreich ataxia. Friedreich ataxia has a prevalence of 1 in 50,000 persons. Onset of the disorder is usually before 20 years of age, and progression is continuous. Late onset of Freidreich’ ataxia (this includes individuals older than 20 to 25 years) is characterized by a more benign course and lower incidence of skeletal deformities.
One among a cluster of inherited degenerative disorders affecting the spinal cord or cerebellum. These conditions result in muscle tremors, spasms, and muscular atrophy.