TDP1 and spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 1: Defects in the latter activity have been associated with human hereditary ataxia and cerebellar degeneration, as illustrated by spinocerebellar ataxia with axonal neuropathy 1 (SCAN1) – mutated in tyrosyl DNA phosphodiesterase 1 (TDP1) [3].