OXCT1 and Friedreich ataxia: To rule out the possibility that OXCT1 reduction simply reflected decreased mitochondrial number in both the cellular and animal model of FRDA (17, 18), we analyzed mitochondrial copy number by measuring the ratio of mitochondrial DNA to nuclear DNA (mtDNA/nDNA) using quantitative PCR (qPCR) in the cerebellar homogenates of 12M KIKO mice.