R-loops have been described at immunoglobulin class switch sequences, prokaryotic and mitochondrial replication origins, and disease-associated (CAG)n and (GAA)n trinucleotide repeats. The determinants of trinucleotide R-loop formation are unclear. Trinucleotide repeat expansions cause diseases including DM1 (CTG)n, SCA1 (CAG)n, FRAXA (CGG)n, FRAXE (CCG)n and FRDA (GAA)n. Bidirectional converge...

Friedreich ataxia is a neurodegenerative disorder caused by the expansion of a GAA trinucleotide repeat sequence within the first intron of the FXN gene. Interruptions in the GAA repeat may serve to alleviate the inhibitory effects of the GAA expansion on FXN gene expression and to decrease pathogenicity. We have developed a simple and rapid PCR- and restriction enzyme-based assay to assess the...

background: expansion of gaa trinucleotide repeats is the molecular basis of friedreich’s ataxia (frda). precise detection of the gaa expansion repeat in frataxin gene has always been a challenge. different molecular methods have been suggested for detection of gaa expansion, including; short-pcr, long-pcr, triplet repeat primed-pcr (tp-pcr) and southern blotting. the aim of study was to evalua...

how to cite this article: heidari mm , khatami m, pourakrami j. novel point mutations in frataxin gene in iranian patients with friedreich’s ataxia. iran j child neurol. 2014 winter; 8(1):32-36.   objective friedreich’s ataxia is the most common form of hereditary ataxia with autosomal recessive pattern. more than 96% of patients are homozygous for gaa repeat extension on both alleles in the fi...

Using a modified Repeat Expansion Detection (RED) assay, that was optimized for individual oligonucleotides, unrelated individuals were systematically screened for maximal repeat sizes of each of the ten possible trinucleotide repeats. Cloned trinucleotide repeats were generated and used as standards for the detectability of single copy trinucleotide repeat fragments. When the size distribution...

The pMGA genes of the avian respiratory pathogen Mycoplasma gallisepticum encode a family of hemagglutinins that are subject to phase variation. A trinucleotide GAA repeat region is located upstream of the pMGA transcription start site. The length of the repeat region varies at a high frequency due to changes in the number of repeat units. Previous studies have shown that pMGA genes are transcr...

Friedreich's ataxia is an autosomal recessively inherited neurodegenerative disorder caused by expansions of an unstable GAA trinucleotide repeat in the STM7/X25 gene on chromosome 9q. We studied the (GAA)n polymorphism in 178 healthy controls and 102 patients with idiopathic ataxia. The repeat size ranged from 7 to 29 (GAA)n motifs on normal chromosomes and from 66 to 1360 trinucleotide repeti...

Friedreich's ataxia (FA) is an autosomal recessive condition caused by a GAA trinucleotide repeat expansion in the X25 gene on chromosome 9. We describe an unusual form of "pseudodominant" inheritance to illustrate how a diagnosis of FA in a parent does not preclude the diagnosis in the child.

the hereditary ataxias are a group of genetic disorders characterized by slowly progressive incoordination of gait and often associated with poor coordination of hands, speech, and eye movements. frequently, atrophy of the cerebellum occurs. the hereditary ataxias are categorized by mode of inheritance and causative gene or chromosomal locus. genetic forms of ataxia must be distinguished from t...

BACKGROUND Expansion of GAA trinucleotide repeats is the molecular basis of Friedreich's ataxia (FRDA). Precise detection of the GAA expansion repeat in frataxin gene has always been a challenge. Different molecular methods have been suggested for detection of GAA expansion, including; short-PCR, long-PCR, Triplet repeat primed-PCR (TP-PCR) and southern blotting. The aim of study was to evaluat...