For example, mutations in the DNA repair enzymes APTX and TDP1 have been shown to contribute to neurodegeneration and the development of ataxia in autosomal recessive disorders such as AOA1 (ataxia with oculomotor apraxia type 1) [44, 45] and SCAN1 (spinocerebellar ataxia with axonal neuropathy) respectively [46]. This evidence concerns the gene TDP1 and axonal neuropathy.