Rehabilitation of friedreich ataxia

Friedreich ataxia is the most common of the inherited ataxias affecting approximately one in 30 000 people [1]. The major sites of neuropathology in Friedreich ataxia are the dorsal root ganglia, sensory fibers in the peripheral nerves, the dentate nucleus of the cerebellum, posterior columns of the spinal cord, spinocerebellar tracts, and corticospinal tracts [2–4]. Clinical features include ataxia of gait and upper limbs, atrophy and weakness of the distal extremities, spasticity, absent ankle and knee jerks, up-going plantar responses, loss of joint and vibratory senses, foot deformity, scoliosis, dysarthria, cardiomyopathy, and diabetes mellitus [5, 6]. The combination of the clinical features of ataxia, weakness, and spasticity render Friedreich ataxia an ideal model for developing a rehabilitation program that is applicable to similar movement disorders. Friedreich ataxia is inherited in an autosomal recessive manner and is a consequence of mutations in the FXN gene, impacting the amount and/or function of the protein frataxin, which is involved in mitochondrial iron homeostasis [7]. In 98% of affected individuals, Friedreich ataxia is due to homozygosity for an expansion of a guanasine-adenosine-adenosine (GAA) trinucleotide repeat in intron 1 of the FXN gene. The other 2% are compound heterozygous for a GAA expansion and a point mutation or deletion in FXN [8].