Friedreich Ataxia
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Overview
Plain-Language Overview
Friedreich Ataxia is a rare inherited disorder that primarily affects the nervous system and causes problems with movement and coordination. It usually begins in childhood or adolescence and leads to difficulty walking, loss of balance, and muscle weakness. The condition also affects the heart, often causing cardiomyopathy, and can lead to diabetes. It results from damage to the spinal cord and peripheral nerves, which are important for sending signals between the brain and muscles. Over time, symptoms worsen, impacting daily activities and overall health. The disease is caused by a genetic mutation that affects a protein important for energy production in cells.
Clinical Definition
Friedreich Ataxia is an autosomal recessive neurodegenerative disorder caused by a GAA trinucleotide repeat expansion in the FXN gene, leading to decreased production of frataxin, a mitochondrial protein essential for iron-sulfur cluster biogenesis. This deficiency results in mitochondrial dysfunction, oxidative stress, and progressive degeneration of the dorsal root ganglia, spinocerebellar tracts, and corticospinal tracts. Clinically, it presents with progressive gait and limb ataxia, loss of deep tendon reflexes, dysarthria, and cardiomyopathy. The disease typically manifests before age 25 and is the most common inherited ataxia. Additional features include scoliosis, pes cavus, and diabetes mellitus. The neurological decline is due to combined sensory and motor pathway involvement, leading to impaired proprioception and muscle weakness.