Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder usually characterized by progressive early-onset ataxia. The most common ophthalmic manifestation of FRDA is optic neuropathy, which is usually late in onset, is slowly progressive, and rarely causes severe visual loss. The genetic basis of FRDA in most patients is the homozygous expansion of a GAA trinucleotide repea...

Friedreich’s ataxia (FRDA) is a rare monogenic disease characterized by multisystem, slowly progressive degeneration. Because of the genetic defect in non-coding region FXN gene, FRDA cells exhibit severe deficit frataxin protein levels. Hence, pathophysiology plethora metabolic disruptions related to iron metabolism, mitochondrial homeostasis and oxidative stress. Importantly, an impairment an...

The most common causative mutation of Friedreich ataxia (FRDA) is the unstable hyperexpansion of an intronic GAA triplet repeat that impairs frataxin transcription. Using real time quantitative PCR, we showed that FRDA patients had residual levels of frataxin mRNA ranging between 13% and 30% and that FRDA carriers had about 40% of that of controls. Asymptomatic carriers also showed reduced frat...

The severe reduction in mRNA and protein levels of the mitochondrial protein frataxin, encoded by the X25 gene, causes Friedreich ataxia (FRDA), the most common form of recessive hereditary ataxia. Increasing evidence underlines the pathogenetic role of oxidative stress in this disease. We generated an in vitro cellular model of regulated human frataxin overexpression. We identified, by differe...

Friedreich ataxia (FRDA), the most common hereditary ataxia, is caused by mutations in the frataxin (FXN) gene. The vast majority of FRDA mutations involve expansion of a GAA*TTC-repeat tract in intron 1, which leads to an FXN mRNA deficit. Bisulfite mapping demonstrates that the region adjacent to the repeat was methylated in both unaffected and affected individuals. However, methylation was m...

BACKGROUND Friedreich ataxia (FRDA) is an autosomal recessive disorder caused by guanine-adenine-adenine (GAA) triplet expansions in the FXN gene. Its product, frataxin, which severely reduces in FRDA patients, leads to oxidative damage in mitochondria. The purpose of this study was to evaluate the triple nucleotide repeated expansions in Iranian FRDA patients and to elucidate distinguishable F...

We assessed structural elements of the retina in individuals with Friedreich ataxia (FRDA) and in mouse models of FRDA, as well as functions of the retinal pigment epithelium (RPE) in FRDA using induced pluripotent stem cells (iPSCs). We analyzed the retina of the FRDA mouse models YG22R and YG8R containing a human FRATAXIN (FXN) transgene by histology. We complemented this work with post-morte...

Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder characterized by progressive gait and limb ataxia, cerebellar, pyramidal and dorsal column involvement, visual defects, scoliosis, pes cavus and cardiomyopathy. It is caused by a homozygous guanine-adenine-adenine (GAA) trinucleotide repeat expansion in intron 1 of the frataxin gene (FXN) on chromosome 9q13-q21.1. Ons...

Friedreich's ataxia (FRDA) is caused by the expansion of GAA repeats located in the Frataxin (FXN) gene. The GAA repeats continue to expand in FRDA patients, aggravating symptoms and contributing to disease progression. The mechanism leading to repeat expansion and decreased FXN transcription remains unclear. Using single-molecule analysis of replicated DNA, we detected that expanded GAA repeat...

Friedreich’s ataxia (FRDA) is a form of neuropathy that was fi rst described by Nikolaus Friedreich in a series of 5 papers published from 1863-1877 (1). Freidreich was a third generation physician from Heidelberg, Germany. His grandfather was the fi rst to describe idiopathic facial paralysis, also known as Bell’s palsy. Friedreich trained to be a pathologist under Rudolf Virchow, who proposed...