To account for involvement of cerebellar cortex, the pathophysiological mechanisms of FRDA could include several components: (1) cell type-specific vulnerability despite the ubiquitous reduction of FXN in all cells, (2) an initial pathology of cellular dysfunction rather than death), and (3) ongoing circuit dysfunction in the cerebellar cortex as a crucial anatomical locus. This evidence concerns the gene FXN and Friedreich ataxia.