ATR and Friedreich ataxia: The role of RuvBL1-RuvBL2 in the FA DNA repair pathway and the fact that depletion of RuvBL1-RuvBL2 leads to hallmark features of FA including MMC sensitivity and chromosomal instability, raises the possibility that its mutation may play a role in chromosomal breakage syndromes, such as Seckel syndrome (characterized by defective ATR signalling (85)) or FA.