APTX and cerebellar ataxia: In addition, the rare genetic neurological disorders, spinocerebellar ataxia with axonal neuropathy 1 (SCAN1)12 and ataxia with oculomotor apraxia 1 (AOA1)13, stem from mutations in genes involved in termini clean-up as part of single-strand break repair (TDP1 and APTX, respectively).