It is well known that DNA replication affects the stability of several trinucleotide repeats, but whether replication profiles of human loci carrying an expanded repeat differ from those of normal alleles is poorly understood in the endogenous context. We investigated this issue using cell lines from Friedreich's ataxia patients, homozygous for a GAA-repeat expansion in intron 1 of the Frataxin...

huntingtons disease (hd) is an autosomal dominant inherited disease characterized by involuntary movements, behavioral and personality changes, dementia and cognitive decline. although the mean age of onset is about 40 years, it varies from 5 to 79 years. therefore, at-risk individuals are never sure to have escaped the disease. hd is a member of the growing family of neurodegenerative disorder...

Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by a GAA repeat expansion mutation within intron 1 of the FXN gene, resulting in reduced levels of frataxin protein. We have previously reported the generation of human FXN yeast artificial chromosome (YAC) transgenic FRDA mouse models containing 90-190 GAA repeats, but the presence of multiple GAA repeats wi...

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...

BACKGROUND Compound heterozygosity for a trinucleotide repeat expansion and a point mutation in the FXN gene is a rare cause of Friedreich ataxia (FRDA). METHODS We identified three Swedish FRDA patients with an FXN p.R165P missense mutation and compared their clinical features with six homozygote trinucleotide repeat expansion carriers. Patients were assessed clinically. Trinucleotide expans...

Friedreich ataxia (FRDA) is a neurodegenerative disorder caused by an unstable GAA repeat expansion mutation within intron 1 of the FXN gene. However, the origins of the GAA repeat expansion, its unstable dynamics within different cells and tissues, and its effects on frataxin expression are not yet completely understood. Therefore, we have chosen to generate representative FRDA mouse models by...

The expansion of trinucleotide repeat sequences is associated with several neurodegenerative diseases. The mechanism of this expansion is unknown but may involve slipped-strand structures where adjacent rather than perfect complementary sequences of a trinucleotide repeat become paired. Here, we have studied the interaction of the human mismatch repair protein MSH2 with slipped-strand structure...

OBJECTIVE To evaluate the macular function of Japanese patients with a trinucleotide repeat expansion in the spinocerebellar ataxia type 7 (SCA7) gene. METHODS Ophthalmic findings in patients whose DNA analysis revealed expanded alleles of the trinucleotide repeat in the SCA7 gene were evaluated. RESULTS Trinucleotide repeat was expanded from 40 to 48 in affected patients (control subjects,...

OBJECTIVE Cardiac evaluation (clinical, electrocardiographic and echocardiographic) of 25 Brazilian patients with clinical diagnosis of Friedreich's ataxia (FA) related to the frequency and the size of GAA repeats (unstable expansion of trinucleotide repeats that results in the disease). METHODS Clinical and cardiac study including electrocardiogram and echocardiogram of all patients and mole...

friedreich’s ataxia (frda) is a rare autosomal recessive spinocerebellar ataxia which in the majority of cases is associated with a gaa-trinucleotide repeat expansion in the first intron of frataxin gene located on chromosome 9. the clinical features include progressive gait and limb ataxia, cerebellar dysarthria, neuropathy, optic atrophy, and loss of vibration and proprioception. ataxia with ...