Skeletal muscle involvement in friedreich ataxia and potential effects of recombinant human erythropoietin administration on muscle regeneration and neovascularization.

Friedreich ataxia (FRDA) is caused by reduced expression of the mitochondrial protein frataxin. Cardiac muscle involvement has been attributed to mitochondrial dysfunction, but involvement of skeletal muscle has not been fully investigated. Improved motor skills in FRDA patients after administration of recombinant human erythropoietin (rhuEPO) have been reported.

Correlation of frataxin content in blood and skeletal muscle endorses frataxin as a biomarker in Friedreich ataxia.

Background: Friedreich ataxia is an autosomal recessive disorder caused by mutations in the frataxin gene, leading to reduced levels of the mitochondrial protein frataxin. Assays to quantitatively measure frataxin in peripheral blood have been established. To determine the validity of frataxin as a biomarker for clinical trials, we assessed frataxin in clinically affected tissue.