Friedreich ataxia is the most frequent of inherited ataxias. It is caused by the impaired transcription of the FXN gene, which results in insufficient levels of the protein frataxin. This causes mitochondrial impairment and neuronal degeneration, particularly in the dorsal root ganglia.
The disease progressively leads to severe disability up to premature death often caused by cardiac insufficiency. Symptoms usually appear late in the first decade or early in the second decade of life, and include gait instability and lack of coordination, eventually requiring constant support and wheelchair use.
Dysarthria may occur early in the disease and may progress to complete speech impairment. Congestive heart failure and fatal arrhythmia dominate the cardiac picture. A significant fraction of patients also develops diabetes mellitus.