This publication includes a description and characterization of 18 fibroblast lines derived from FA patients with diverse GAA repeat lengths. This is the largest collection of these cell lines. Researchers can contact the study authors or FARA if they are interested in learning more accessing these cell lines. In addition, this comprehensive analysis revealed that the GAA-induced silencing effect does not influence expression of neighboring genes upstream or downstream of FXN. Furthermore, no long-range silencing effects were detected across a large portion of chromosome 9. Additionally, results of chromatin immunoprecipitation studies confirmed that histone modifications associated with repressed transcription are confined to the FXN locus. Finally, deep sequencing of FXN pre-mRNA molecules revealed a pronounced defect in the transcription elongation rate in FRDA cells when compared to controls. These results indicate that approaches aimed to reactivate frataxin expression should simultaneously address deficits in transcription initiation and elongation at the FXN locus.

Read more: Expanded GAA repeats impede transcription elongation through the FXN gene and induce transcriptional silencing that is restricted to the FXN locus