and 190 repeats). These mice show symptoms similar to human patients. An overexpression of frataxin in Drosophila has shown an increase in antioxidant capability, resistance to oxidative stress insults and longevity, supporting the theory that the role of frataxin is to protect the mitochondria from oxidative stress and the ensuing cellular damage. Fibroblasts from a mouse model of FRDA and FRDA patient fibroblasts show increased levels of DNA double-strand breaks. A lentivirus gene delivery system was used to deliver the frataxin gene to the FRDA mouse model and human patient cells, and this resulted in long-term restored expression of frataxin mRNA and frataxin protein. This restored expression of the frataxin gene was accompanied by a substantial reduction in the number of DNA double-strand breaks. The impaired frataxin in FRDA cells appears to cause reduced capacity for repair of DNA damage and this may contribute to neurodegeneration. Interactions Frataxin has been shown to biologically interact with the enzyme PMPCB. References Further reading External links GeneReviews/NCBI/NIH/UW entry on Friedreich Ataxia Proteins