REVIEW TDP1-dependent DNA single-strand break repair and neurodegeneration

DNA single-strand breaks (SSBs) are the commonest DNA lesions that arise spontaneously in living cells. Cells employ efficient processes for the rapid repair of these breaks and defects in these processes appear to preferentially impact on the nervous system, causing human ataxia. Spinocere-bellar ataxia with axonal neuropathy (SCAN1) is a human disease that is associated with a defect in repairing certain types of SSBs. Although it is a rare neurodegenerative disease, understanding the molecular basis of SCAN1 will lead to better understanding of the mechanisms that underpin not only neurodegeneration but also cancer. DNA single-strand breaks and human ataxia DNA is under continuous threat and thousands of DNA single-strand breaks (SSBs) arise in each cell per day (1). SSBs can arise either directly (e.g. from attack of deoxyribose by reactiv