Friedreich ataxia

**Definition:** Friedreich ataxia is an autosomal recessive ataxia characterised by difficulties to coordinate movements, associated with neurological signs (dysarthria, loss of reflexes, decrease of deep sensation, pes cavus and scoliosis), cardiomyopathy and sometimes diabetes mellitus. It is due to a mutation in the frataxin gene.

**Long definition:** Friedreich ataxia is characterised by difficulties to coordinate movements, associated with neurological signs (dysarthria, loss of reflexes, decrease of deep sensation, pes cavus and scoliosis), cardiomyopathy and sometimes diabetes mellitus. In France prevalence is estimated to 1 in 50,000 and males and females are equally affected. Onset often occurs in childhood or adolescence, but also sometimes in adulthood. It is transmitted as an autosomal recessive trait. The causative gene is the FRDA gene and codes for frataxin. Diagnosis can be made by genetic testing. The disease is due to a frataxin deficiency, which affects the mitochondrial function and the energetic metabolism of the cell. New treatments restoring mitochondrial functions are currently being assessed. Management should address the neurological and cardiological disorders as well as diabetes mellitus. Functional rehabilitation plays a predominant role in the management of the disease. Friedreich ataxia is is progressive, with an inability to walk alone 10 to 20 years after the disease onset.