DNMT1 and hereditary sensory neuropathy-deafness-dementia syndrome: To date, multiple studies have demonstrated that DNMT1 mutations could lead to a spectrum of neurodegenerative disorders [16], such as hereditary sensory and autonomic neuropathy type 1E (HSAN1E) and autosomal dominant cerebellar ataxia, deafness, and narcolepsy (ADCA-DN) [17].