Friedreich's ataxia is the most common inherited autosomal recessive ataxia and is characterized by progressive degeneration of the peripheral and central nervous systems and cardiomyopathy. This disease is caused by the silencing of the FXN gene and reduced levels of the encoded protein, frataxin. Frataxin is a mitochondrial protein that functions primarily in iron-sulfur cluster synthesis. Th...

Friedreich's ataxia (FRDA) is the most common hereditary ataxia in the caucasian population and is characterized by a mixed spinocerebellar and sensory ataxia, hypertrophic cardiomyopathy and increased incidence of diabetes. FRDA is caused by impaired expression of the FXN gene coding for the mitochondrial protein frataxin. During the past ten years, the development of mouse models of FRDA has ...

BACKGROUND Friedreich's ataxia is a progressive degenerative disorder caused by deficiency of the frataxin protein. Expanded GAA repeats within intron 1 of the frataxin (FXN) gene lead to its heterochromatinisation and transcriptional silencing. Preclinical studies have shown that the histone deacetylase inhibitor nicotinamide (vitamin B3) can remodel the pathological heterochromatin and upregu...

The genetic defect in Friedreich's ataxia (FRDA) is the hyperexpansion of a GAA•TTC triplet in the first intron of the FXN gene, encoding the essential mitochondrial protein frataxin. Histone post-translational modifications near the expanded repeats are consistent with heterochromatin formation and consequent FXN gene silencing. Using a newly developed human neuronal cell model, derived from p...

Friedreich's ataxia (FA) is a recessive, predominantly neurodegenerative disorder caused in most cases by mutations in the first intron of the frataxin (FXN) gene. This mutation drives the expansion of a homozygous GAA repeat that results in decreased levels of FXN transcription and frataxin protein. Frataxin (Fxn) is a ubiquitous mitochondrial protein involved in iron-sulfur cluster biogenesis...

Friedreich ataxia (FRDA) is caused by hyperexpansion of GAA*TTC repeats located in the first intron of the FXN gene, which inhibits transcription leading to the deficiency of frataxin. The FXN gene is an excellent target for therapeutic intervention since (i) 98% of patients carry the same type of mutation, (ii) the mutation is intronic, thus leaving the FXN coding sequence unaffected and (iii)...

Friedreich’s ataxia (FRDA) is a recessive autosomal ataxia caused by reduced levels of frataxin (FXN), an essential mitochondrial protein that is highly conserved from bacteria to primates. The exact role of frataxin and its primary function remain unclear although this information would be very valuable to design a therapeutic approach for FRDA. A main difficulty encountered so far has been th...

Friedreich's ataxia is an incurable genetic disorder caused by a mutant expansion of the trinucleotide GAA within an intronic FXN RNA. This expansion leads to reduced expression of frataxin (FXN) protein and evidence suggests that transcriptional repression is caused by an R-loop that forms between the expanded repeat RNA and complementary genomic DNA. Synthetic agents that increase levels of F...

Friedreich ataxia is a degenerative disease caused by deficiency of the protein frataxin (FXN). An intronic expansion of GAA triplets in the FXN-encoding gene, FXN, causes gene silencing and thus reduced FXN protein levels. Although it is widely assumed that GAA repeats block transcription via the assembly of an inaccessible chromatin structure marked by methylated H3K9, direct proof for this i...

Abnormally expanded DNA repeats are associated with several neurodegenerative diseases. In Friedreich's ataxia (FRDA), expanded GAA repeats in intron 1 of the frataxin gene (FXN) reduce FXN mRNA levels in averaged cell samples through a poorly understood mechanism. By visualizing FXN expression and nuclear localization in single cells, we show that GAA-expanded repeats decrease the number of FX...