Specifically, spinocerebellar ataxia with axonal neuropathy (SCAN1) and mutations in tyrosyl-DNA phosphodiesterase 1 (TDP1) gene; ataxia-telangiectasia-like disorder 1 with mutations in MRE11A gene; Cockayne syndrome carrying mutations in ERCC6 gene, and ten other conditions have been identified as diseases where neuronal function in brain is the primary target. Here, TDP1 is linked to Cockayne syndrome.