FXN and Friedreich ataxia: While it is known that individuals with FRDA can have decreased tissue-specific mitochondrial function in the setting of frataxin deficiency, to date no studies have investigated the link between mitochondrial function and bone specifically in FRDA (Papiha et al., 1998; Yamasaki and Hagiwara, 2009; Kim et al., 2012; Pandolfo and Hausmann, 2013).